[ { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/0mmmp-9pz59", "eprint_id": 122545, "eprint_status": "archive", "datestamp": "2023-08-22 21:19:02", "lastmod": "2023-10-23 20:30:02", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Li-Yida", "name": { "family": "Li", "given": "Yida" }, "orcid": "0000-0003-0664-0247" }, { "id": "Villa-Valeria", "name": { "family": "Villa", "given": "Valeria" }, "orcid": "0000-0002-0518-9143" }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" }, { "id": "Persaud-Patricia", "name": { "family": "Persaud", "given": "Patricia" }, "orcid": "0000-0003-3462-7023" } ] }, "title": "Shear Wave Velocities in the San Gabriel and San Bernardino Basins, California", "ispublished": "pub", "full_text_status": "public", "keywords": "Space and Planetary Science; Earth and Planetary Sciences (miscellaneous); Geochemistry and Petrology; Geophysics", "note": "\u00a9 2023. American Geophysical Union. \n\nThe authors thank Zhe Jia for help with the ambient noise correction code and helpful discussions, and Tom Brocher for providing the borehole data. The authors thank all the volunteers who helped with deploying the dense nodal arrays. This research was supported by the National Science Foundation awards 2105358 and 2105320. The BASIN project was partly supported by U.S. Geological Survey awards GS17AP00002 and G19AP00015, and Southern California Earthquake Center awards 18029 and 19033. Nodal instruments were provided by Incorporated Research Institutions for Seismology (IRIS), Portable Array Seismic Studies of the Continental Lithosphere (PASSCAL), University of Utah, Louisiana State University, and the University of Oklahoma. \n\nData Availability Statement: The final Vs model can be downloaded from http://doi.org/10.22002/D1.20248 (Y. Li et al., 2022). All the node and temporary broadband data used in the study are scheduled to be available at the IRIS DMC in 2023. The permanent strong motion and broadband data are available from the Southern California Earthquake Data Center (SCEDC).\n\n
Supplemental Material - 2023jb026488-sup-0001-supporting_information_si-s01.pdf
", "abstract": "We construct a new shear velocity model for the San Gabriel, Chino and San Bernardino basins located in the northern Los Angeles area using ambient noise correlation between dense linear nodal arrays, broadband stations, and accelerometers. We observe Rayleigh and Love waves in the correlation of vertical (Z) and transverse (T) components, respectively. By combining Hilbert and Wavelet transforms, we obtain the separated fundamental and first higher mode of the Rayleigh wave dispersion curves based on their distinct particle motion polarization. Basin depths constrained by receiver functions, gravity, and borehole data are incorporated into the prior model. Our 3D shear wave velocity model covers the upper 3\u20135 km of the crust in the San Gabriel, Chino and San Bernardino basin area. The Vs model is in agreement with the geological and geophysical cross-sections from other studies, but discrepancies exist between our model and a Southern California Earthquake Center community velocity model. Our shear wave velocity model shows good consistency with the CVMS 4.26 in the San Gabriel basin, but predicts a deeper and slower sedimentary basin in the San Bernardino and Chino basins than the community model.", "date": "2023-07", "date_type": "published", "publication": "Journal of Geophysical Research. Solid Earth", "volume": "128", "number": "7", "publisher": "American Geophysical Union", "pagerange": "Art. No. e2023JB026488", "id_number": "CaltechAUTHORS:20230726-216909500.3", "issn": "2169-9313", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230726-216909500.3", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR-2105358" }, { "agency": "NSF", "grant_number": "EAR-2105320" }, { "agency": "USGS", "grant_number": "GS17AP00002" }, { "agency": "USGS", "grant_number": "G19AP00015" }, { "agency": "Southern California Earthquake Center (SCEC)", "grant_number": "18029" }, { "agency": "Southern California Earthquake Center (SCEC)", "grant_number": "19033" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" }, { "id": "Seismological-Laboratory" } ] }, "doi": "10.1029/2023jb026488", "primary_object": { "basename": "2023jb026488-sup-0001-supporting_information_si-s01.pdf", "url": "https://authors.library.caltech.edu/records/0mmmp-9pz59/files/2023jb026488-sup-0001-supporting_information_si-s01.pdf" }, "resource_type": "article", "pub_year": "2023", "author_list": "Li, Yida; Villa, Valeria; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/gzztx-m9x82", "eprint_id": 121595, "eprint_status": "archive", "datestamp": "2023-08-22 20:36:12", "lastmod": "2023-10-23 20:30:34", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Yang-Yan", "name": { "family": "Yang", "given": "Yan" }, "orcid": "0000-0002-6105-2918" }, { "id": "Gao-Angela-F", "name": { "family": "Gao", "given": "Angela F." }, "orcid": "0000-0001-8574-8728" }, { "id": "Azizzadenesheli-Kamyar", "name": { "family": "Azizzadenesheli", "given": "Kamyar" }, "orcid": "0000-0001-8507-1868" }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" }, { "id": "Ross-Z-E", "name": { "family": "Ross", "given": "Zachary E." }, "orcid": "0000-0002-6343-8400" } ] }, "title": "Rapid Seismic Waveform Modeling and Inversion With Neural Operators", "ispublished": "pub", "full_text_status": "public", "keywords": "General Earth and Planetary Sciences; Electrical and Electronic Engineering", "note": "\u00a9 2023 IEEE.\n\nSupplemental Material - supp1-3264210.docx
", "abstract": "Seismic waveform modeling is a powerful tool for determining earth structure models and unraveling earthquake rupture processes, but it is usually computationally expensive. We introduce a scheme to vastly accelerate these calculations with a recently developed machine learning paradigm called the neural operator. Once trained, these models can simulate a full wavefield at negligible cost. We use a U-shaped neural operator to learn a general solution operator to the 2-D elastic wave equation from an ensemble of numerical simulations performed with random velocity models and source locations. We show that full-waveform modeling with neural operators is nearly two orders of magnitude faster than conventional numerical methods, and more importantly, the trained model enables accurate simulation for velocity models, source locations, and mesh discretization distinctly different from the training dataset. The method also enables convenient full-waveform inversion with automatic differentiation.", "date": "2023-04-03", "date_type": "published", "publication": "IEEE Transactions on Geoscience and Remote Sensing", "volume": "61", "publisher": "IEEE", "pagerange": "Art. No. 5906712", "id_number": "CaltechAUTHORS:20230530-441141000.6", "issn": "0196-2892", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230530-441141000.6", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" }, { "id": "Seismological-Laboratory" } ] }, "doi": "10.1109/tgrs.2023.3264210", "primary_object": { "basename": "supp1-3264210.docx", "url": "https://authors.library.caltech.edu/records/gzztx-m9x82/files/supp1-3264210.docx" }, "resource_type": "article", "pub_year": "2023", "author_list": "Yang, Yan; Gao, Angela F.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/jh5g2-fyg97", "eprint_id": 116279, "eprint_status": "archive", "datestamp": "2023-08-20 08:24:37", "lastmod": "2023-10-23 15:28:39", "type": "monograph", "metadata_visibility": "show", "creators": { "items": [ { "id": "Villa-Valeria", "name": { "family": "Villa", "given": "Valeria" }, "orcid": "0000-0002-0518-9143" }, { "id": "Li-Yida", "name": { "family": "Li", "given": "Yida" }, "orcid": "0000-0003-0664-0247" }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" }, { "id": "Persaud-Patricia", "name": { "family": "Persaud", "given": "Patricia" }, "orcid": "0000-0003-3462-7023" } ] }, "title": "Three-Dimensional Basin Depth Map of the Northern Los Angeles Basins from Gravity and Seismic Measurements", "ispublished": "unpub", "full_text_status": "public", "note": "Attribution 4.0 International (CC BY 4.0).\n\nWe are grateful to the hundreds of nodal deployment volunteers, Los Angeles residents, and business owners who hosted our instruments. We thank Liu et al. (2018), Wang et al. (2021), and Ghose et al. (2022)for providing their receiver function results. This research was supported by the National Science Foundation awards 2105358 and 105320. The BASIN project was partly supported by U.S. Geological Survey awards GS17AP00002 and G19AP00015, and Southern California Earthquake Center awards 18029 and 19033. Data collection was supported by Louisiana State University and California Institute of Technology. Nodal instruments were provided by Incorporated Research Institutions for Seismology (IRIS), Portable Array Seismic Studies of the Continental Lithosphere (PASSCAL), University of Utah, Louisiana State 505University, and the University of Oklahoma.\n\nData Availability Statement. The basement time was obtained from Liu et al. (2018), Wang et al. (2021), and Ghose et al. (2022). Li et al. (2022) provided the shear-wave velocity model. The basement depths obtained from well logs are publicly available through the Geologic Energy Management Division's (CalGEM) online mapping application Well Finder https://www.conservation.ca.gov/calgem/Pages/WellFinder.aspxand Buwalda (1940). The Bouguer gravity data was provided by the Pan American CenterEarth and Environmental Science portal. Figures were plotted using the GMT software, PyGMT, and cartopy (Met Office, 2010; Uieda et al., 2022; Wessel et al., 2019). The 3D basin depth model is available at http://doi.org/10.22002/D1.20252.\n\nSubmitted - essoar.10512148.1.pdf
Supplemental Material - agu_suppinfo_vv.pdf
", "abstract": "The San Gabriel, Chino, and San Bernardino sedimentary basins in Southern California amplify earthquake ground motions and prolong the duration of shaking due to the basins' shape and low seismic velocities. In the event of a major earthquake rupture along the southern segment of the San Andreas fault, their connection and physical proximity to Los Angeles can produce a waveguide effect and amplify strong ground motions. Improved estimates of the shape and depth of the sediment-basement interface are needed for more accurate ground-shaking models. \n\nWe obtain a three-dimensional basement map of the basins by integrating gravity and seismic measurements. The travel time of the sediment-basement P-to-s conversion, and the Bouguer gravity along 10 seismic lines, are combined to produce a linear relationship that is used to extend the 2D models to a 3D basin map. Basement depth is calculated using the predicted travel time constrained by gravity with an S-wave velocity model of the area. The model is further constrained by the basement depths from 17 boreholes. \n\nThe basement map shows the south-central part of the San Gabriel basin is the deepest part and a significant gravity signature is associated with our interpretation of the Raymond fault. The Chino basin deepens towards the south and shallows northeastward. The San Bernardino basin, bounded by the San Jacinto fault (SJF) and San Andreas fault zone, deepens along the edge of the SJF. In addition, we demonstrate the benefit of using gravity data to aid in the interpretation of the sediment-basement interface in receiver functions.", "date": "2022-08-16", "date_type": "published", "id_number": "CaltechAUTHORS:20220815-504409000", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20220815-504409000", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR-2105358" }, { "agency": "NSF", "grant_number": "EAR-2105320" }, { "agency": "USGS", "grant_number": "GS17AP00002" }, { "agency": "USGS", "grant_number": "G19AP00015" }, { "agency": "Southern California Earthquake Center (SCEC)", "grant_number": "18029" }, { "agency": "Southern California Earthquake Center (SCEC)", "grant_number": "19033" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1002/essoar.10512148.1", "primary_object": { "basename": "agu_suppinfo_vv.pdf", "url": "https://authors.library.caltech.edu/records/jh5g2-fyg97/files/agu_suppinfo_vv.pdf" }, "related_objects": [ { "basename": "essoar.10512148.1.pdf", "url": "https://authors.library.caltech.edu/records/jh5g2-fyg97/files/essoar.10512148.1.pdf" } ], "resource_type": "monograph", "pub_year": "2022", "author_list": "Villa, Valeria; Li, Yida; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/fgbgn-2rk49", "eprint_id": 116189, "eprint_status": "archive", "datestamp": "2023-08-20 08:22:27", "lastmod": "2023-10-23 15:28:02", "type": "monograph", "metadata_visibility": "show", "creators": { "items": [ { "id": "Li-Yida", "name": { "family": "Li", "given": "Yida" }, "orcid": "0000-0003-0664-0247" }, { "id": "Villa-Valeria", "name": { "family": "Villa", "given": "Valeria" }, "orcid": "0000-0002-0518-9143" }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" }, { "id": "Persaud-Patricia", "name": { "family": "Persaud", "given": "Patricia" }, "orcid": "0000-0003-3462-7023" } ] }, "title": "Shear Wave Velocities in the San Gabriel and San Bernardino Basins, California", "ispublished": "unpub", "full_text_status": "public", "note": "CC_BY_4.0. \n\nThe authors thank Zhe Jia for help with the ambient noise correction code and helpful discussions. The authors thank all the volunteers who helped with deploying the dense nodal arrays. This research was supported by the National Science Foundation awards 2105358 and 210532. The BASIN project was partly supported by U.S. Geological Survey awards GS17AP00002 and G19AP00015, and Southern California Earthquake Center awards 18029 and 19033. Nodal instruments were provided by Incorporated Research Institutions for Seismology (IRIS), Portable Array Seismic Studies of the Continental Lithosphere (PASSCAL), University of Utah, Louisiana State University, and the University of Oklahoma. \n\nData Availability. The final Vs model can be downloaded from http://doi.org/10.22002/D1.20248. All the node and temporary broadband data used in the study are scheduled to be available at the IRIS DMC by the end of 2022. The permanent strong motion and broad data are available from the Southern California Earthquake Data Center (SCEDC).\n\nSubmitted - essoar.10512118.2.pdf
Supplemental Material - supplementary_sgsb.docx
", "abstract": "We construct a new shear velocity model for the San Gabriel, Chino and San Bernardino basins located in the northern Los Angeles area using ambient noise correlation between dense linear nodal arrays, broadband stations, and accelerometers. We observe Rayleigh wave and Love wave in the correlation of vertical (Z) and transverse (T) components, respectively. By combining Hilbert and Wavelet transforms, we obtain the separated fundamental and first higher mode of the Rayleigh wave dispersion curves based on their distinct particle motion polarization. Receiver functions, gravity, and borehole data are incorporated into the prior model to constrain the basin depth. Our 3D shear wave velocity model covers the upper 3 to 5 km of the basin structure in the San Gabriel and San Bernardino basin area. The Vs model is in agreement with the geological and geophysical cross-sections from other studies, but discrepancies exist between our model and a Southern California Earthquake Center (SCEC) community velocity model. Our shear wave velocity model shows good consistency with the CVMS 4.26 in the San Gabriel basin, but predicts a deeper and slower sedimentary basin in the San Bernardino and Chino basins than the community model.", "date": "2022-08-11", "date_type": "published", "id_number": "CaltechAUTHORS:20220809-495535000", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20220809-495535000", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR-2105358" }, { "agency": "NSF", "grant_number": "EAR-2105320" }, { "agency": "USGS", "grant_number": "GS17AP00002" }, { "agency": "USGS", "grant_number": "G19AP00015" }, { "agency": "Southern California Earthquake Center (SCEC)", "grant_number": "18029" }, { "agency": "Southern California Earthquake Center (SCEC)", "grant_number": "19033" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1002/essoar.10512118.2", "primary_object": { "basename": "essoar.10512118.2.pdf", "url": "https://authors.library.caltech.edu/records/fgbgn-2rk49/files/essoar.10512118.2.pdf" }, "related_objects": [ { "basename": "supplementary_sgsb.docx", "url": "https://authors.library.caltech.edu/records/fgbgn-2rk49/files/supplementary_sgsb.docx" } ], "resource_type": "monograph", "pub_year": "2022", "author_list": "Li, Yida; Villa, Valeria; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/9gy4y-y4921", "eprint_id": 114801, "eprint_status": "archive", "datestamp": "2023-08-20 01:45:39", "lastmod": "2023-10-24 15:11:52", "type": "conference_item", "metadata_visibility": "show", "creators": { "items": [ { "id": "Kohler-M-D", "name": { "family": "Kohler", "given": "Monica D." }, "orcid": "0000-0002-4703-190X" }, { "id": "Filippitzis-Filippos", "name": { "family": "Filippitzis", "given": "Filippos" }, "orcid": "0000-0001-8377-4914" }, { "id": "Graves-Robert-W", "name": { "family": "Graves", "given": "Robert" }, "orcid": "0000-0001-9758-453X" }, { "id": "Massari-Anthony", "name": { "family": "Massari", "given": "Anthony" }, "orcid": "0000-0002-6561-4674" }, { "id": "Heaton-T-H", "name": { "family": "Heaton", "given": "Thomas" }, "orcid": "0000-0003-3363-2197" }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert" }, "orcid": "0000-0003-3323-3508" }, { "id": "Bunn-Julian-J", "name": { "family": "Bunn", "given": "Julian" }, "orcid": "0000-0002-3798-298X" }, { "id": "Guy-Richard-G", "name": { "family": "Guy", "given": "Richard" }, "orcid": "0000-0002-8651-5608" }, { "id": "Chandy-K-M", "name": { "family": "Chandy", "given": "K. Mani" }, "orcid": "0000-0001-9190-1290" } ] }, "title": "Variations in Ground Motion Amplification in the Los Angeles Basin due to the 2019 M7.1 Ridgecrest Earthquake: Implications for the Long-Period Response of Infrastructure", "ispublished": "unpub", "full_text_status": "public", "note": "We are grateful to Caltech, the Betty and Gordon Moore Foundation, the Conrad N. Hilton Foundation, and Computers & Structures, Inc., for providing support for the Community Seismic Network and for this study.\n\nAccepted Version - Kohler_etal_ASCE_Lifelines_2021_2022.pdf
", "abstract": "Coherent patterns and large variations in ground shaking amplification were observed in the Los Angeles basin during the 2019 M7.1 Ridgecrest earthquake. In particular, 3 s to 6 s responses showed variations due to shallow basin geological structure that have implications for the response to large earthquakes of mid-rises, high-rises, long-span bridges, and fuel storage tanks, even if epicentral distances are several hundred kilometers. The Ridgecrest strong-motion data were recorded by seismic stations from the spatially dense Community Seismic Network, the Southern California Seismic Network, and the California Strong Motion Instrumentation Program. The mainshock observations are compared at the same locations with ground motion simulations to examine the regions that experienced the largest shaking, and to investigate the geological sources of large-amplitude shaking. The simulations were computed for the two most commonly-used regional community seismic velocity models, CVM-S4.26.M01 ('CVM-S') and CVM-H 15.1.0 ('CVM-H'). Both observations and simulations are used in dynamic analysis with a finite-element model of an existing high-rise with ~6-second fundamental horizontal periods, located in downtown Los Angeles. The geographical variation in maximum story drift, story-level shear force, and story-level moment values suggest that the excitation of a hypothetical high-rise located in an area characterized by the largest 6-s PSA values could be significantly larger than in a downtown Los Angeles location. Ground motion simulations using the CVM-H velocity model more closely predict the long-period site amplifications in greater Los Angeles, particularly in the south-central San Fernando Valley, than simulations using CVM-S.", "date": "2022-05-19", "date_type": "published", "publisher": "Caltech Library", "id_number": "CaltechAUTHORS:20220518-205134775", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20220518-205134775", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Caltech" }, { "agency": "Gordon and Betty Moore Foundation" }, { "agency": "Conrad N. Hilton Foundation" }, { "agency": "Computers & Structures, Inc" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "primary_object": { "basename": "Kohler_etal_ASCE_Lifelines_2021_2022.pdf", "url": "https://authors.library.caltech.edu/records/9gy4y-y4921/files/Kohler_etal_ASCE_Lifelines_2021_2022.pdf" }, "resource_type": "conference_item", "pub_year": "2022", "author_list": "Kohler, Monica D.; Filippitzis, Filippos; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/cdej1-qb156", "eprint_id": 113957, "eprint_status": "archive", "datestamp": "2023-08-22 14:38:20", "lastmod": "2023-10-23 17:58:55", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Park-Sunyoung", "name": { "family": "Park", "given": "Sunyoung" }, "orcid": "0000-0002-6660-0047" }, { "id": "Shin-Changsoo", "name": { "family": "Shin", "given": "Changsoo" } }, { "id": "Kim-Younglib", "name": { "family": "Kim", "given": "Younglib" } }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" } ] }, "title": "Seismic wave simulation using a 3D printed model of the Los Angeles Basin", "ispublished": "pub", "full_text_status": "public", "keywords": "Civil engineering; Design, synthesis and processing; Geophysics; Natural hazards; Seismology; Multidisciplinary", "note": "\u00a9 The Author(s) 2022. This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. \n\nReceived 26 October 2021; Accepted 03 March 2022; Published\n17 March 2022. \n\nThe authors thank the editor, Antonella Amoruson, and the two reviewers, Luca De Siena and Renaud Toussaint, for useful comments that improved our manuscript. The authors thank Daechul Kim, Bruno Pouet, and Andreas Plesch for the helpful discussions. S.P. was partially funded by California Institute of Technology. C.S. thanks the Institute of Engineering Research at Seoul National University. \n\nData availability: Seismic data obtained in this study is available at an online data repository29 (https://doi.org/10.5281/zenodo.6350691). \n\nContributions: S.P. conceptualized the study, analyzed the data, interpreted the results, and wrote the manuscript. C.S. conceived the methodology and obtained the seismic data. Y.K. 3D printed the physical model. R.W.C. supervised the study and edited the manuscript. \n\nThe authors declare no competing interests.\n\nPublished - s41598-022-08732-w.pdf
Supplemental Material - 41598_2022_8732_MOESM1_ESM.docx
", "abstract": "Studying seismic wave propagation through complex media is crucial to numerous aspects of geophysics and engineering including seismic hazard assessment. In particular, small-scale structure such as sedimentary basins and their edges can have significant effects on high-frequency earthquake ground motion, which is the main cause for the damage to buildings and infrastructure. However, such structural effects are poorly understood due to limitations in numerical and analytical methods. To overcome this challenge, for the first time, we utilize the 3D printing technique to build a scaled-down physical representation of geological structure and perform lab-scale seismic experiments on it. Specifically, a physical model based on the Los Angeles Basin is printed and used as synthetic medium to propagate ultrasonic waves, to mimic seismic wave propagation from local earthquakes. Our results show clear body and surface waves recorded at expected time and locations, as well as waves that are scattered from the basin edges. We find that high-frequency energies are significantly reduced at the basin, which is at odds with the conventional view of basins as ground motion amplifiers. This novel waveform modeling approach with 3D printed Earth models is largely automated and provides an effective means to tackle geophysical problems of significance.", "date": "2022-03-17", "date_type": "published", "publication": "Scientific Reports", "volume": "12", "publisher": "Nature Publishing Group", "pagerange": "Art. No. 4613", "id_number": "CaltechAUTHORS:20220317-156665700", "issn": "2045-2322", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20220317-156665700", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Caltech" }, { "agency": "Seoul National University" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1038/s41598-022-08732-w", "pmcid": "PMC8931089", "primary_object": { "basename": "41598_2022_8732_MOESM1_ESM.docx", "url": "https://authors.library.caltech.edu/records/cdej1-qb156/files/41598_2022_8732_MOESM1_ESM.docx" }, "related_objects": [ { "basename": "s41598-022-08732-w.pdf", "url": "https://authors.library.caltech.edu/records/cdej1-qb156/files/s41598-022-08732-w.pdf" } ], "resource_type": "article", "pub_year": "2022", "author_list": "Park, Sunyoung; Shin, Changsoo; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/gqcdm-r9r69", "eprint_id": 113619, "eprint_status": "archive", "datestamp": "2023-08-22 14:09:51", "lastmod": "2023-10-23 17:54:16", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Castellanos-Jorge-C", "name": { "family": "Castellanos", "given": "Jorge C." }, "orcid": "0000-0002-0103-6430" }, { "id": "Humphreys-Eugene-D", "name": { "family": "Humphreys", "given": "Eugene" }, "orcid": "0000-0002-1916-8378" }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" } ] }, "title": "Evidence of Mantle\u2010Based Deformation Across the Western United States", "ispublished": "pub", "full_text_status": "public", "keywords": "mantle dynamics; crustal flow; seismic anisotropy; General Earth and Planetary Sciences; Geophysics", "note": "\u00a9 2022. American Geophysical Union. \n\nIssue Online: 21 February 2022. Version of Record online: 21 February 2022. Accepted manuscript online: 04 February 2022. Manuscript accepted: 26 January 2022. Manuscript revised: 21 January 2022. Manuscript received: 21 June 2021. \n\nThe research was partially supported by NSF/EAR-1546635 and NSF/EAR-1727451. The figures presented in this paper were made using the Generic Mapping Tools version 4.5.9 (https://www.soest.hawaii.edu/gmt/). \n\nData Availability Statement. All the seismic data used in this investigation is available from the IRIS-DMC (http://ds.iris.edu/ds/nodes/dmc/data/).\n\nSupplemental Material - 2021gl094854-sup-0001-supporting_information_si-s01.pdf
Supplemental Material - 2021gl094854-sup-0002-table_si-s01.txt
Supplemental Material - 2021gl094854-sup-0003-table_si-s02.txt
Supplemental Material - 2021gl094854-sup-0004-table_si-s03.txt
Supplemental Material - 2021gl094854-sup-0005-table_si-s04.txt
", "abstract": "We investigate the role that upper mantle buoyancy anomalies play in determining the behavior of the crust. Recently, Castellanos et al. (2020; https://doi.org/10.1126/sciadv.abb0476) observed that the anisotropy of the Pacific Northwest (PNW) crust correlates with the upper-mantle velocity structure and suggested that vertical loads in the upper mantle can displace the Moho and drive crustal flow on a regional scale. To provide further insight into this relation, we resolve the crustal anisotropy in regions where near-surface mantle-based deformation might have occurred or is presently occurring. Specifically, we focus on the crust around the Rocky Mountains and around California since high-resolution tomographic images reveal the presence of mantle structures similar to the ones that are thought to be driving the crust in the PNW. Our results reveal crustal flow driven by mantle vertical loading in both regions and suggest that this mechanism may be key in maintaining crustal isostasy during an orogeny.", "date": "2022-02-28", "date_type": "published", "publication": "Geophysical Research Letters", "volume": "49", "number": "4", "publisher": "American Geophysical Union", "pagerange": "Art. No. e2021GL094854", "id_number": "CaltechAUTHORS:20220225-724794000", "issn": "0094-8276", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20220225-724794000", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR-1546635" }, { "agency": "NSF", "grant_number": "EAR-1727451" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1029/2021gl094854", "primary_object": { "basename": "2021gl094854-sup-0002-table_si-s01.txt", "url": "https://authors.library.caltech.edu/records/gqcdm-r9r69/files/2021gl094854-sup-0002-table_si-s01.txt" }, "related_objects": [ { "basename": "2021gl094854-sup-0003-table_si-s02.txt", "url": "https://authors.library.caltech.edu/records/gqcdm-r9r69/files/2021gl094854-sup-0003-table_si-s02.txt" }, { "basename": "2021gl094854-sup-0004-table_si-s03.txt", "url": "https://authors.library.caltech.edu/records/gqcdm-r9r69/files/2021gl094854-sup-0004-table_si-s03.txt" }, { "basename": "2021gl094854-sup-0005-table_si-s04.txt", "url": "https://authors.library.caltech.edu/records/gqcdm-r9r69/files/2021gl094854-sup-0005-table_si-s04.txt" }, { "basename": "2021gl094854-sup-0001-supporting_information_si-s01.pdf", "url": "https://authors.library.caltech.edu/records/gqcdm-r9r69/files/2021gl094854-sup-0001-supporting_information_si-s01.pdf" } ], "resource_type": "article", "pub_year": "2022", "author_list": "Castellanos, Jorge C.; Humphreys, Eugene; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/y330a-3ym57", "eprint_id": 122577, "eprint_status": "archive", "datestamp": "2023-10-09 15:09:04", "lastmod": "2023-10-24 16:26:11", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Muir-Jack-B", "name": { "family": "Muir", "given": "Jack B." }, "orcid": "0000-0003-2617-3420" }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" }, { "id": "Tsai-V-C", "name": { "family": "Tsai", "given": "Victor C." }, "orcid": "0000-0003-1809-6672" }, { "id": "Brissaud-Quentin", "name": { "family": "Brissaud", "given": "Quentin" }, "orcid": "0000-0001-8189-4699" } ] }, "title": "Parsimonious Velocity Inversion Applied to the Los Angeles Basin, CA", "ispublished": "pub", "full_text_status": "public", "keywords": "Space and Planetary Science; Earth and Planetary Sciences (miscellaneous); Geochemistry and Petrology; Geophysics", "note": "\u00a9 2022 American Geophysical Union. \n\nIssue Online: 28 January 2022; Version of Record online: 28 January 2022; Accepted manuscript online: 22 January 2022; Manuscript accepted: 18 January 2022; Manuscript revised: 10 January 2022; Manuscript received: 24 August 2021. \n\nThe authors would like to thank Rob Graves (USGS) for providing synthetic seismograms for the Ridgecrest events. This study was supported by the United States National Science Foundation awards EAR-1520081, EAR-2105358 and EAR-2011079, and the Southern California Earthquake Center award 20024. JBM acknowledges the support of the General Sir John Monash Foundation and the Origin Energy Foundation for support during his graduate studies. \n\nData Availability Statement: The CSN data used in this paper are freely available from http://csn.caltech.edu/data. The TEKS inversion code may be found at https://doi.org/10.5281/zenodo.5834927 (Muir, 2022). Data analysis codes can be found at https://doi.org/10.5281/zenodo.5823526 (Muir et al., 2022).\n\nPublished - 2021JB023103.pdf
Supplemental Material - 2021jb023103-sup-0001.pdf
Supplemental Material - 2021jb023103-sup-0002-movie_si-s01.mp4
", "abstract": "The proliferation of dense arrays promises to improve our ability to image geological structures at the scales necessary for accurate assessment of seismic hazard. However, combining the resulting local high-resolution tomography with existing regional models presents an ongoing challenge. We developed a framework based on the level-set method that infers where local data provide meaningful constraints beyond those found in regional models - for example the Community Velocity Models (CVMs) of southern California. This technique defines a volume within which updates are made to a reference CVM, with the boundary of the volume being part of the inversion rather than explicitly defined. By penalizing the complexity of the boundary, a minimal update that sufficiently explains the data is achieved. To test this framework, we use data from the Community Seismic Network, a dense permanent urban deployment. We inverted Love wave dispersion and amplification data, from the Mw 6.4 and 7.1 2019 Ridgecrest earthquakes. We invert for an update to CVM-S4.26 using the Tikhonov Ensemble Sampling scheme, a highly efficient derivative-free approximate Bayesian method. We find the data are best explained by a deepening of the Los Angeles Basin with its deepest part south of downtown Los Angeles, along with a steeper northeastern basin wall. This result offers new progress toward the parsimonious incorporation of detailed local basin models within regional reference models utilizing an objective framework and highlights the importance of accurate basin models when accounting for the amplification of surface waves in the high-rise building response band.", "date": "2022-02", "date_type": "published", "publication": "Journal of Geophysical Research. Solid Earth", "volume": "127", "number": "2", "publisher": "American Geophysical Union", "pagerange": "Art. No. e2021JB023103", "id_number": "CaltechAUTHORS:20231006-172908203", "issn": "2169-9313", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20231006-172908203", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR-1520081" }, { "agency": "NSF", "grant_number": "EAR-2105358" }, { "agency": "NSF", "grant_number": "EAR-2011079" }, { "agency": "Southern California Earthquake Center (SCEC)", "grant_number": "20024" }, { "agency": "General Sir John Monash Foundation" }, { "agency": "Origin Energy Foundation" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1029/2021jb023103", "primary_object": { "basename": "2021JB023103.pdf", "url": "https://authors.library.caltech.edu/records/y330a-3ym57/files/2021JB023103.pdf" }, "related_objects": [ { "basename": "2021jb023103-sup-0001.pdf", "url": "https://authors.library.caltech.edu/records/y330a-3ym57/files/2021jb023103-sup-0001.pdf" }, { "basename": "2021jb023103-sup-0002-movie_si-s01.mp4", "url": "https://authors.library.caltech.edu/records/y330a-3ym57/files/2021jb023103-sup-0002-movie_si-s01.mp4" } ], "resource_type": "article", "pub_year": "2022", "author_list": "Muir, Jack B.; Clayton, Robert W.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/wgnkm-pcz52", "eprint_id": 113027, "eprint_status": "archive", "datestamp": "2023-08-22 13:08:35", "lastmod": "2023-10-23 17:49:32", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Yun-Jeena", "name": { "family": "Yun", "given": "Jeena" }, "orcid": "0000-0002-2215-4647" }, { "id": "Kim-YoungHee", "name": { "family": "Kim", "given": "YoungHee" }, "orcid": "0000-0002-1111-632X" }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" } ] }, "title": "Spatial Variation and Frequency Dependence of Lg Wave Attenuation With Site Response Correction Along the CCSE Array in Central California, US", "ispublished": "pub", "full_text_status": "public", "keywords": "Lg wave attenuation; site effect; crustal imaging; Central California; crustal structure; Geochemistry and Petrology; Geophysics", "note": "\u00a9 2022. The Authors.\n\nThis is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.\n\nIssue Online:\n12 January 2022;\nVersion of Record online:\n12 January 2022;\nAccepted manuscript online:\n05 January 2022;\nManuscript accepted:\n27 December 2021;\nManuscript revised:\n07 December 2021;\nManuscript received:\n07 September 2021.\n\nJ. Yun and Y. Kim acknowledge the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT; No. NRF-2019R1G1A1094833), and the funding from Development of unified 3-D seismic velocity model program (KMI2019-00110) through Korea Meteorological Administration. Finally, the authors thank Editor Maureen Long, Dr. Nishath Rajiv Ranasinghe, and an anonymous reviewer for comments which greatly improved this paper.\n\nData Availability Statement:\nSeismic data used in this study are obtained from IRIS Data Management Center, including the CCSE array (https://doi.org/10.7909/C3B56GVW), CI network (https://doi.org/10.7914/SN/CI) and SN network (https://doi.org/10.7914/SN/SN) data. Geologic map is downloaded from the U.S. Geological Survey (USGS) website available at https://mrdata.usgs.gov/geology/state/ (last accessed February 2020). The Pn velocity and the Moho depth data are obtained from the IRIS Earth Model Collaboration website at http://ds.iris.edu/ds/products/emc-earthmodels/ (last accessed September 2020). The VS30 data is available at USGS Earthquake Hazards Program (https://earthquake.usgs.gov/data/vs30/; last accessed April 2021), and the VS model is downloaded from the author's webpage at http://ciei.colorado.edu/Models/ (last accessed February 2020). All figures in this article are generated using the GMT (https://www.generic-mapping-tools.org/) and MATLAB.\n\nSupplemental Material - 2021gc010149-sup-0001-supporting_information_si-s01.pdf
", "abstract": "We estimate lateral Lg wave attenuation (Q) structure at four center frequencies (0.75, 1, 2 and 2.75 Hz) along the Central California Seismic Experiment array in western US crossing the San Andreas Fault and Central Valley. We take two steps in constructing the site-response-corrected Lg Q model: (a) we compute relative site responses at each station using the reverse two-station method, and (b) we estimate Q values based on the two-station method after removing the site term. Removal of the site response in the Q model allows to probe laterally varying Q properties at mid-to-lower crustal depths. Our model follows a power-law frequency dependence as Q(f) = (81 \u00b1 8)f^(0.62\u00b10.11), reflecting the active tectonic setting and the presence of fluids in the region. A change in lithology from softer sediments near Pacific coast to harder basements near Sierra Nevada correlates well with the increasing trend of the Lg Q values towards east. Our laterally varying estimates at lower frequencies generally follow the variation of shear-wave velocities at deeper crustal depth and Moho temperature, whereas those at higher frequencies mostly follow the shear-wave velocity variation at shallow depth. Positive site responses obtained by reverse two-station method are found at 34 stations out of total 46 stations examined, and their responses are mostly correlated with surficial lithology (i.e., sedimentary rocks) along the profile, rather than the thickness of the sediments. The site responses also exhibit a strong negative correlation to the V_(S30) data.", "date": "2022-01", "date_type": "published", "publication": "Geochemistry, Geophysics, Geosystems", "volume": "23", "number": "1", "publisher": "American Geophysical Union", "pagerange": "Art. No. e2021GC010149", "id_number": "CaltechAUTHORS:20220120-890601000", "issn": "1525-2027", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20220120-890601000", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "National Research Foundation of Korea", "grant_number": "NRF\u20102019R1G1A1094833" }, { "agency": "Korea Meteorological Administration", "grant_number": "KMI2019\u201000110" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1029/2021gc010149", "primary_object": { "basename": "2021gc010149-sup-0001-supporting_information_si-s01.pdf", "url": "https://authors.library.caltech.edu/records/wgnkm-pcz52/files/2021gc010149-sup-0001-supporting_information_si-s01.pdf" }, "related_objects": [ { "basename": "Geochem_Geophys_Geosyst_-_2022_-_Yun_-_Spatial_Variation_and_Frequency_Dependence_of_Lg_Wave_Attenuation_With_Site_Response.pdf", "url": "https://authors.library.caltech.edu/records/wgnkm-pcz52/files/Geochem_Geophys_Geosyst_-_2022_-_Yun_-_Spatial_Variation_and_Frequency_Dependence_of_Lg_Wave_Attenuation_With_Site_Response.pdf" } ], "resource_type": "article", "pub_year": "2022", "author_list": "Yun, Jeena; Kim, YoungHee; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/nde62-t1r58", "eprint_id": 111377, "eprint_status": "archive", "datestamp": "2023-10-05 15:53:44", "lastmod": "2023-10-24 16:24:52", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Castellanos-Jorge-C", "name": { "family": "Castellanos", "given": "Jorge C." }, "orcid": "0000-0002-0103-6430" }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" } ] }, "title": "The Fine-Scale Structure of Long Beach, California, and Its Impact on Ground Motion Acceleration", "ispublished": "pub", "full_text_status": "public", "keywords": "ambient seismic noise; ground motion amplification; seismic tomography; surface waves", "note": "\u00a9 2021. American Geophysical Union. \n\nIssue Online: 13 December 2021; Version of Record online: 13 December 2021; Accepted manuscript online: 17 November 2021; Manuscript accepted: 05 November 2021; Manuscript revised: 01 October 2021; Manuscript received: 21 May 2021. \n\nThe authors gratefully acknowledge NodalSeismic and Signal Hill Petroleum for allowing us to use the Long Beach and Extended Long Beach data, and LA seismic for the use of the Seal Beach data. Permission form these organizations is required to access the data. They thank Dan Hollis and Eric Campbell for facilitating the use of the seismic data. They extend our acknowledgement to Dan Gish and Steve Boljen for providing us with the migrated seismic sections of the Seal Beach survey. They also thank Michael Afanasiev and the Mondaic team for their help in setting up the numeric simulations. They are grateful to Zhe Jia for providing us with the ambient noise cross-correlations between the nodal instruments and the SCSN seismic station, and to Bruce Worden for providing us with the Vs30 measurements. They gratefully thank Nori Nakata, Hongjian Fang, and an anonymous reviewer for their careful and constructive suggestions. This project was partially supported by NSF/EAER-1520081. \n\nData Availability Statement: The 3-D shear wave velocity model that is presented in this work can be downloaded from: https://doi.org/10.22002/D1.1970.\n\nPublished - 2021JB022462.pdf
Submitted - essoar10507964.2.pdf
Supplemental Material - 2021jb022462-sup-0001-supporting_information_si-s01.pdf
Supplemental Material - 2021jb022462-sup-0002-movie_si-s01.mp4
Supplemental Material - 2021jb022462-sup-0003-movie_si-s02.mp4
Supplemental Material - 2021jb022462-sup-0004-movie_si-s03.mp4
Supplemental Material - 2021jb022462-sup-0005-movie_si-s04.mp4
", "abstract": "The metropolitan Los Angeles region represents a zone of high-seismic risk due to its proximity to several fault systems, including the San Andreas fault. Adding to this problem is the fact that Los Angeles and its surrounding cities are built on top of soft sediments that tend to trap and amplify seismic waves generated by earthquakes. In this study, we use three dense petroleum industry surveys deployed in a 16 \u00d7 16-km area at Long Beach, California, to produce a high-resolution model of the top kilometer of the crust and investigate the influence of its structural variations on the amplification of seismic waves. Our velocity estimates reveal substantial lateral contrasts and correlate remarkably well with the geological background of the area, illuminating features such as the Newport-Inglewood fault, the Silverado aquifer, and the San Gabriel river. We then use computational modeling to show that the presence of these small-scale structures have a clear impact on the intensity of the expected shaking, and can cause ground-motion motion acceleration to change by several factors over a subkilometer horizontal scale. These results shed light onto the scale of variations that can be expected in this type of tectonic settings and highlight the importance of resolution in modern-day seismic hazard estimates.", "date": "2021-12", "date_type": "published", "publication": "Journal of Geophysical Research. Solid Earth", "volume": "126", "number": "12", "publisher": "American Geophysical Union", "pagerange": "Art. No. e2021JB022462", "id_number": "CaltechAUTHORS:20211012-211827814", "issn": "2169-9313", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20211012-211827814", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR-1520081" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1029/2021JB022462", "primary_object": { "basename": "2021jb022462-sup-0001-supporting_information_si-s01.pdf", "url": "https://authors.library.caltech.edu/records/nde62-t1r58/files/2021jb022462-sup-0001-supporting_information_si-s01.pdf" }, "related_objects": [ { "basename": "2021jb022462-sup-0002-movie_si-s01.mp4", "url": "https://authors.library.caltech.edu/records/nde62-t1r58/files/2021jb022462-sup-0002-movie_si-s01.mp4" }, { "basename": "2021jb022462-sup-0003-movie_si-s02.mp4", "url": "https://authors.library.caltech.edu/records/nde62-t1r58/files/2021jb022462-sup-0003-movie_si-s02.mp4" }, { "basename": "2021jb022462-sup-0004-movie_si-s03.mp4", "url": "https://authors.library.caltech.edu/records/nde62-t1r58/files/2021jb022462-sup-0004-movie_si-s03.mp4" }, { "basename": "2021jb022462-sup-0005-movie_si-s04.mp4", "url": "https://authors.library.caltech.edu/records/nde62-t1r58/files/2021jb022462-sup-0005-movie_si-s04.mp4" }, { "basename": "essoar10507964.2.pdf", "url": "https://authors.library.caltech.edu/records/nde62-t1r58/files/essoar10507964.2.pdf" }, { "basename": "2021JB022462.pdf", "url": "https://authors.library.caltech.edu/records/nde62-t1r58/files/2021JB022462.pdf" } ], "resource_type": "article", "pub_year": "2021", "author_list": "Castellanos, Jorge C. and Clayton, Robert W." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/3g2ne-1f408", "eprint_id": 112353, "eprint_status": "archive", "datestamp": "2023-08-22 11:54:44", "lastmod": "2023-10-23 22:30:37", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Filippitzis-Filippos", "name": { "family": "Filippitzis", "given": "Filippos" }, "orcid": "0000-0001-8377-4914" }, { "id": "Kohler-M-D", "name": { "family": "Kohler", "given": "Monica D." }, "orcid": "0000-0002-4703-190X" }, { "id": "Heaton-T-H", "name": { "family": "Heaton", "given": "Thomas H." }, "orcid": "0000-0003-3363-2197" }, { "id": "Graves-Robert-W", "name": { "family": "Graves", "given": "Robert W." }, "orcid": "0000-0001-9758-453X" }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" }, { "id": "Guy-Richard-G", "name": { "family": "Guy", "given": "Richard G." }, "orcid": "0000-0002-8651-5608" }, { "id": "Bunn-J-J", "name": { "family": "Bunn", "given": "Julian J." }, "orcid": "0000-0002-3798-298X" }, { "id": "Chandy-K-M", "name": { "family": "Chandy", "given": "K. Mani" }, "orcid": "0000-0001-9190-1290" } ] }, "title": "Ground motions in urban Los Angeles from the 2019 Ridgecrest earthquake sequence", "ispublished": "pub", "full_text_status": "public", "keywords": "Earthquake ground motions, ground motion amplification, community seismic network, Ridgecrest earthquake sequence, simulation predictions, GMPE predictions; Geophysics; Geotechnical Engineering and Engineering Geology", "note": "\u00a9 The Author(s) 2021. \n\nArticle first published online: April 28, 2021; Issue published: November 1, 2021. Received: February 09, 2021; Accepted: February 22, 2021. \n\nWe acknowledge the Texas Advanced Computing Center (TACC) at The University of Texas at Austin (http://www.tacc.utexas.edu/) for providing high-performance computing resources through an allocation to the Southern California Earthquake Center (SCEC). We thank John H. Shaw and Andreas Plesch for providing assistance in obtaining the regional basement topography data. The authors appreciate the constructive reviews of the manuscript provided by Morgan Page and Grace Parker. \n\nThe author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: We are grateful to Caltech, the Betty and Gordon Moore Foundation, the Conrad N. Hilton Foundation, and Computers & Structures, Inc., for funding this project and for supporting the continuous operation of the Community Seismic Network. This research was also supported by the Southern California Earthquake Center (Contribution No. 10931). SCEC is funded by NSF Cooperative Agreement EAR-1600087 & USGS Cooperative Agreement G17AC00047. The first author was supported by the Cecil and Sally Drinkward Graduate Fellowship at the California Institute of Technology. \n\nThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.\n\nPublished - 10.1177_87552930211003916.pdf
Supplemental Material - sj-pdf-1-eqs-10.1177_87552930211003916.pdf
", "abstract": "We study ground-motion response in urban Los Angeles during the two largest events (M7.1 and M6.4) of the 2019 Ridgecrest earthquake sequence using recordings from multiple regional seismic networks as well as a subset of 350 stations from the much denser Community Seismic Network. In the first part of our study, we examine the observed response spectral (pseudo) accelerations for a selection of periods of engineering significance (1, 3, 6, and 8\u2009s). Significant ground-motion amplification is present and reproducible between the two events. For the longer periods, coherent spectral acceleration patterns are visible throughout the Los Angeles Basin, while for the shorter periods, the motions are less spatially coherent. However, coherence is still observable at smaller length scales due to the high spatial density of the measurements. Examining possible correlations of the computed response spectral accelerations with basement depth and Vs30, we find the correlations to be stronger for the longer periods. In the second part of the study, we test the performance of two state-of-the-art methods for estimating ground motions for the largest event of the Ridgecrest earthquake sequence, namely three-dimensional (3D) finite-difference simulations and ground motion prediction equations. For the simulations, we are interested in the performance of the two Southern California Earthquake Center 3D community velocity models (CVM-S and CVM-H). For the ground motion prediction equations, we consider four of the 2014 Next Generation Attenuation-West2 Project equations. For some cases, the methods match the observations reasonably well; however, neither approach is able to reproduce the specific locations of the maximum response spectral accelerations or match the details of the observed amplification patterns.", "date": "2021-11-01", "date_type": "published", "publication": "Earthquake Spectra", "volume": "37", "number": "4", "publisher": "Earthquake Engineering Research Institute", "pagerange": "2493-2522", "id_number": "CaltechAUTHORS:20211209-231200000", "issn": "8755-2930", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20211209-231200000", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Caltech" }, { "agency": "Gordon and Betty Moore Foundation" }, { "agency": "Conrad N. Hilton Foundation" }, { "agency": "Computers & Structures, Inc" }, { "agency": "Southern California Earthquake Center (SCEC)", "grant_number": "10931" }, { "agency": "NSF", "grant_number": "EAR-1600087" }, { "agency": "USGS", "grant_number": "G17AC00047" }, { "agency": "Cecil and Sally Drinkward Fellowship" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1177/87552930211003916", "primary_object": { "basename": "10.1177_87552930211003916.pdf", "url": "https://authors.library.caltech.edu/records/3g2ne-1f408/files/10.1177_87552930211003916.pdf" }, "related_objects": [ { "basename": "sj-pdf-1-eqs-10.1177_87552930211003916.pdf", "url": "https://authors.library.caltech.edu/records/3g2ne-1f408/files/sj-pdf-1-eqs-10.1177_87552930211003916.pdf" } ], "resource_type": "article", "pub_year": "2021", "author_list": "Filippitzis, Filippos; Kohler, Monica D.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/xwp00-2fy53", "eprint_id": 111241, "eprint_status": "archive", "datestamp": "2023-08-20 04:41:17", "lastmod": "2023-10-23 20:07:02", "type": "monograph", "metadata_visibility": "show", "creators": { "items": [ { "id": "Yang-Yan", "name": { "family": "Yang", "given": "Yan" } }, { "id": "Gao-Angela-F", "name": { "family": "Gao", "given": "Angela F." } }, { "id": "Castellanos-Jorge-C", "name": { "family": "Castellanos", "given": "Jorge C." }, "orcid": "0000-0002-0103-6430" }, { "id": "Ross-Z-E", "name": { "family": "Ross", "given": "Zachary E." }, "orcid": "0000-0002-6343-8400" }, { "id": "Azizzadenesheli-Kamyar", "name": { "family": "Azizzadenesheli", "given": "Kamyar" }, "orcid": "0000-0001-8507-1868" }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" } ] }, "title": "Seismic wave propagation and inversion with Neural Operators", "ispublished": "unpub", "full_text_status": "public", "keywords": "wave propagation, forward model, inverse tomography, Fourier neural operator", "note": "The authors thank Jack Muir for helpful comments on an early version of the manuscript.\n\nSubmitted - 2108.05421.pdf
", "abstract": "Seismic wave propagation forms the basis for most aspects of seismological research, yet solving the wave equation is a major computational burden that inhibits the progress of research. This is exaspirated by the fact that new simulations must be performed when the velocity structure or source location is perturbed. Here, we explore a prototype framework for learning general solutions using a recently developed machine learning paradigm called Neural Operator. A trained Neural Operator can compute a solution in negligible time for any velocity structure or source location. We develop a scheme to train Neural Operators on an ensemble of simulations performed with random velocity models and source locations. As Neural Operators are grid-free, it is possible to evaluate solutions on higher resolution velocity models than trained on, providing additional computational efficiency. We illustrate the method with the 2D acoustic wave equation and demonstrate the method's applicability to seismic tomography, using reverse mode automatic differentiation to compute gradients of the wavefield with respect to the velocity structure. The developed procedure is nearly an order of magnitude faster than using conventional numerical methods for full waveform inversion.", "date": "2021-10-06", "date_type": "published", "publisher": "arXiv", "id_number": "CaltechAUTHORS:20211006-164248015", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20211006-164248015", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "Center-for-Geomechanics-and-Mitigation-of-Geohazards-(GMG)" }, { "id": "Division-of-Geological-and-Planetary-Sciences" }, { "id": "Seismological-Laboratory" } ] }, "doi": "10.48550/arXiv.2108.05421", "primary_object": { "basename": "2108.05421.pdf", "url": "https://authors.library.caltech.edu/records/xwp00-2fy53/files/2108.05421.pdf" }, "resource_type": "monograph", "pub_year": "2021", "author_list": "Yang, Yan; Gao, Angela F.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/v4ckz-mzh95", "eprint_id": 109750, "eprint_status": "archive", "datestamp": "2023-08-20 04:52:07", "lastmod": "2023-10-23 18:09:07", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Yu-Ellen", "name": { "family": "Yu", "given": "Ellen" } }, { "id": "Bhaskaran-Aparna", "name": { "family": "Bhaskaran", "given": "Aparna" } }, { "id": "Chen-Shang-Lin", "name": { "family": "Chen", "given": "Shang-Lin" } }, { "id": "Ross-Z-E", "name": { "family": "Ross", "given": "Zachary E." }, "orcid": "0000-0002-6343-8400" }, { "id": "Hauksson-E", "name": { "family": "Hauksson", "given": "Egill" }, "orcid": "0000-0002-6834-5051" }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" } ] }, "title": "Southern California Earthquake Data Now Available in the AWS Cloud", "ispublished": "pub", "full_text_status": "restricted", "note": "\u00a9 2021 Seismological Society of America. \n\nManuscript received 5 February 2021; Published online 16 June 2021. \n\nThe Southern California Earthquake Data Center (SCEDC) is partially funded by U.S. Geological Survey (USGS) Cooperative Agreements G19AC00296, G20AP00037, and CalOES Agreement 6012\u20102017 with California Institute of Technology (Caltech) and the Southern California Earthquake Center, which is funded by National Science Foundation (NSF) Cooperative Agreement EAR\u20100529922 and USGS Cooperative Agreement 07HQAG0008. This research was also supported by USGS National Earthquake Hazards Reduction Program (NEHRP) Grant G19AP00035 and the Gordon and Betty Moore Foundation Grant Number 5229 to Caltech. The authors thank Joe Flasher and Peter Schmiedeskamp at Amazon Web Services (AWS) Open Data Program for their guidance with data hosting at the AWS Open Dataset Program. The authors also thank Marine Denolle and Tim Clements for their input and feedback working with the dataset. \n\nThe authors acknowledge that there are no conflicts of interest recorded.", "abstract": "The Southern California Earthquake Data Center is hosting its earthquake catalog and seismic waveform archive in the Amazon Web Services (AWS) Open Dataset Program (s3://scedc\u2010pds; us\u2010west\u20102 region). The cloud dataset's high data availability and scalability facilitate research that uses large volumes of data and computationally intensive processing. We describe the data archive and our rationale for the formats and data organization. We provide two simple examples to show how storing the data in AWS Simple Storage Service can benefit the analysis of large datasets. We share usage statistics of our data during the first year in the AWS Open Dataset Program. We also discuss the challenges and opportunities of a cloud\u2010hosted archive.", "date": "2021-09", "date_type": "published", "publication": "Seismological Research Letters", "volume": "92", "number": "5", "publisher": "Seismological Society of America", "pagerange": "3238-3247", "id_number": "CaltechAUTHORS:20210707-204146758", "issn": "0895-0695", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20210707-204146758", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "USGS", "grant_number": "G19AC00296" }, { "agency": "USGS", "grant_number": "G20AP00037" }, { "agency": "California Office of Emergency Services", "grant_number": "6012\u20102017" }, { "agency": "NSF", "grant_number": "EAR\u20100529922" }, { "agency": "USGS", "grant_number": "07HQAG0008" }, { "agency": "USGS", "grant_number": "G19AP00035" }, { "agency": "Gordon and Betty Moore Foundation", "grant_number": "5229" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1785/0220210039", "resource_type": "article", "pub_year": "2021", "author_list": "Yu, Ellen; Bhaskaran, Aparna; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/aa7cj-kfx93", "eprint_id": 110805, "eprint_status": "archive", "datestamp": "2023-10-04 21:59:00", "lastmod": "2023-10-24 15:33:33", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Wang-Xin", "name": { "family": "Wang", "given": "Xin" }, "orcid": "0000-0002-6180-0058" }, { "id": "Zhan-Zhongwen", "name": { "family": "Zhan", "given": "Zhongwen" }, "orcid": "0000-0002-5586-2607" }, { "id": "Zhong-Minyan", "name": { "family": "Zhong", "given": "Minyan" }, "orcid": "0000-0002-1382-7061" }, { "id": "Persaud-Patricia", "name": { "family": "Persaud", "given": "Patricia" }, "orcid": "0000-0003-3462-7023" }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" } ] }, "title": "Urban Basin Structure Imaging Based on Dense Arrays and Bayesian Array\u2010Based Coherent Receiver Functions", "ispublished": "pub", "full_text_status": "public", "keywords": "Coherent Receiver Function; basin structure; large-N arrays; trans-dimensional inversion; array-processing", "note": "\u00a9 2021. American Geophysical Union. \n\nIssue Online: 29 August 2021; Version of Record online: 29 August 2021; Accepted manuscript online: 16 August 2021; Manuscript accepted: 07 August 2021; Manuscript revised: 26 July 2021; Manuscript received: 21 April 2021. \n\nThe nodal Basin Amplification Seismic INvestigation (BASIN) project is a joint effort between Louisiana State University and California Institute of Technology. We thank IRIS Portable Array Seismic Studies of the Continental Lithosphere (PASSCAL), Louisiana State University, University of Utah, and University of Oklahoma for providing the nodes used to collect the data, and a large number of volunteers for their participation in the seismic surveys. We are also grateful to editor Michael Bostock, the associate editor, and reviewers Karen Lythgoe and Thomas Bodin for their comments. This research is supported by the National Science Foundation (grant 1722879). Dr. Xin Wang is supported by National Natural Science Foundation of China (grants 91958209 and 41774058), and the Young Elite Scientists Sponsorship Program by CAST (grant 2020QNRC001). The BASIN project was partly supported by U.S. Geological Survey awards GS17AP00002 and G19AP00015, Southern California Earthquake Center awards 18029 and 19033, and NSF award 2105320 and 2105358. \n\nData Availability Statement: The BASIN seismic data set is archived in IRIS Data Management Center (https://doi.org/10.7914/SN/XG_2017; https://doi.org/10.7914/SN/4M_2018; https://doi.org/10.7914/SN/6J_2019). The data set will be fully released in December 2021, which is two years after the last data collection. For the codes developed in this study, they are available from Dr. Xin Wang (wangxin@mail.iggcas.ac.cn) upon request.\n\nPublished - 2021JB022279__pub.pdf
Accepted Version - 2021JB022279.pdf
Supplemental Material - 2021jb022279-sup-0001-supporting_information_si-s01.pdf
", "abstract": "Urban basin investigation is crucial for seismic hazard assessment and mitigation. Recent advances in robust nodal-type sensors facilitate the deployment of large-N arrays in urban areas for high-resolution basin imaging. However, arrays typically operate for only one month due to the instruments' battery life, and hence, only record a few teleseismic events. This limits the number of available teleseismic events for traditional receiver function (RF) analysis-the primary method used in sediment-basement interface imaging in passive source seismology. Insufficient stacking of RFs from a limited number of earthquakes could, however, introduce significant biases to the results. In this study, we present a novel Bayesian array-based Coherent Receiver Function (CRF) method that can leverage datasets from short-term dense arrays to constrain basin geometry. We cast the RF deconvolution as a sparsity-promoted inverse problem, in which the deconvolution at a single-station involves the constraints from neighboring stations and multiple events. We solve the inverse problem using a trans-dimensional Markov chain Monte Carlo Bayesian algorithm to find an ensemble of RF solutions, which provides a quantitative way of deciding which features are well resolved and warrant geological interpretation. An application in the northern Los Angeles basin demonstrates the ability of our method to produce reliable and easy-to-interpret RF images. The use of dense seismic networks and the state-of-the-art Bayesian array-based CRF method can provide a robust approach for subsurface structure imaging.", "date": "2021-09", "date_type": "published", "publication": "Journal of Geophysical Research. Solid Earth", "volume": "126", "number": "9", "publisher": "American Geophysical Union", "pagerange": "Art. No. e2021JB022279", "id_number": "CaltechAUTHORS:20210910-174637755", "issn": "2169-9313", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20210910-174637755", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR-1722879" }, { "agency": "National Natural Science Foundation of China", "grant_number": "91958209" }, { "agency": "National Natural Science Foundation of China", "grant_number": "41774058" }, { "agency": "China Association for Science and Technology", "grant_number": "2020QNRC001" }, { "agency": "USGS", "grant_number": "GS17AP00002" }, { "agency": "USGS", "grant_number": "G19AP00015" }, { "agency": "Southern California Earthquake Center (SCEC)", "grant_number": "18029" }, { "agency": "Southern California Earthquake Center (SCEC)", "grant_number": "19033" }, { "agency": "NSF", "grant_number": "2105320" }, { "agency": "NSF", "grant_number": "2105358" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1029/2021jb022279", "primary_object": { "basename": "2021jb022279-sup-0001-supporting_information_si-s01.pdf", "url": "https://authors.library.caltech.edu/records/aa7cj-kfx93/files/2021jb022279-sup-0001-supporting_information_si-s01.pdf" }, "related_objects": [ { "basename": "2021JB022279.pdf", "url": "https://authors.library.caltech.edu/records/aa7cj-kfx93/files/2021JB022279.pdf" }, { "basename": "2021JB022279__pub.pdf", "url": "https://authors.library.caltech.edu/records/aa7cj-kfx93/files/2021JB022279__pub.pdf" } ], "resource_type": "article", "pub_year": "2021", "author_list": "Wang, Xin; Zhan, Zhongwen; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/kv6ta-zgh87", "eprint_id": 111098, "eprint_status": "archive", "datestamp": "2023-08-20 04:18:28", "lastmod": "2023-10-23 20:02:34", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Di-Luccio-Francesca", "name": { "family": "Di Luccio", "given": "Francesca" } }, { "id": "Persaud-Patricia", "name": { "family": "Persaud", "given": "Patricia" }, "orcid": "0000-0003-3462-7023" }, { "id": "Cucci-Luigi", "name": { "family": "Cucci", "given": "Luigi" } }, { "id": "Esposito-Alessandra", "name": { "family": "Esposito", "given": "Alessandra" } }, { "id": "Carniel-Roberto", "name": { "family": "Carniel", "given": "Roberto" } }, { "id": "Cort\u00e9s-Guillermo", "name": { "family": "Cort\u00e9s", "given": "Guillermo" } }, { "id": "Galluzzo-Danilo", "name": { "family": "Galluzzo", "given": "Danilo" } }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" }, { "id": "Ventura-Guido", "name": { "family": "Ventura", "given": "Guido" } } ] }, "title": "Seismicity of Lipari, Aeolian Islands (Italy) From One-Month Recording of the LIPARI Array", "ispublished": "pub", "full_text_status": "public", "keywords": "seismic array, active volcanoes, hydrothermal system, volcano-tectonics, machine learning", "note": "\u00a9 2021 Di Luccio, Persaud, Cucci, Esposito, Carniel, Cort\u00e9s, Galluzzo, Clayton and Ventura. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms. \n\nReceived: 09 March 2021; Accepted: 30 June 2021; Published: 21 July 2021. \n\nWe thank Comune di Lipari for hosting the experiment; INGV\u2013OE of Catania and Lipari Observatory (L. Pruiti) for the logistical support. We are grateful to R. Vilardo and M. Martinelli of the Polo Museale di Lipari, Regione Sicilia, the Hotel Antea, CO.MARK and Tenuta Castellaro, Alessandro (grocery store) di Acquacalda, for hosting some nodes of the experiment. LSU students R. Ajala and E. McCullison assisted with the deployment setup and preparation of the nodes. FD would like to thank: F. Alves Pereira for his invaluable help in ObsPy (Beyreuther et al., 2010) scripting, M. Palano and L. Scognamiglio, for useful discussions about the tectonics of the southern Tyrrhenian region, and A. Ursino for the list of earthquakes of the Aeolian seismic bulletin for the period October 16th to November 15th, 2018. Seismological analyses have been partially done using ObsPy (Beyreuther et al., 2010). Some figures were done using GMT 6.0 (Wessel et al., 2019). We thank the Guest Associate Editor, JG, LD, an anonymous reviewer and the Chief Editor V. Acocella for useful comments. \n\nThis research was supported and funded by the Istituto Nazionale di Geofisica e Vulcanologia, sezione di Roma 1 and partially supported by the Department of Geology and Geophysics of the Louisiana State University. AE was funded by Istituto Nazionale di Geofisica e Vulcanologia, sezione ONT. PP was supported as a 2020-21 fellow of the Radcliffe Institute for Advanced Study at Harvard University. The VSR software development has been funded from EU Horizon 2020 under the Marie Sklodowska-Curie Grant Agreement No. (74249) (VULCAN.ears). \n\nData Availability Statement: The raw data supporting the conclusions of this article will be made available by the authors, without undue reservation. \n\nAuthor Contributions: FD and PP conceived the study. FD, LC, AE and GV deployed the Lipari array. RWC and PP downloaded the full dataset and generated the 1-h SAC files for the analysis. FD, LC and AE carried out the seismological analysis. RC computed the SOM and cluster analysis. GC computed the automatic evolution of seismic data. DG applied the array techniques to seismic data. FD wrote a preliminary draft of the manuscript, with contributions and suggestions from all authors. All authors contributed to the interpretation and discussion of the results and to the final version of the manuscript. \n\nThe authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.\n\nPublished - feart-09-678581.pdf
Supplemental Material - Table1_The_Seismicity_of_Lipari,_Aeolian_Islands__Italy__From_One-Month_Recording_of_the_LIPARI_Array.docx
", "abstract": "Seismic activity in volcanic settings could be the signature of processes that include magma dynamics, hydrothermal activity and geodynamics. The main goal of this study is to analyze the seismicity of Lipari Island (Southern Tyrrhenian Sea) to characterize the dynamic processes such as the interaction between pre-existing structures and hydrothermal processes affecting the Aeolian Islands. We deployed a dense seismic array of 48 autonomous 3-component nodes. For the first time, Lipari and its hydrothermal field are investigated by a seismic array recording continuously for about a month in late 2018 with a 0.1\u20131.5 km station spacing. We investigate the distribution and evolution of the seismicity over the full time of the experiment using self-organized maps and automatic algorithms. We show that the sea wave motion strongly influences the background seismic noise. Using an automatic template matching approach, we detect and locate a seismic swarm offshore the western coast of Lipari. This swarm, made of transient-like signals also recognized by array and polarization analyses in the time and frequency domains, is possibly associated with the activation of a NE-SW fault. We also found the occurrence of hybrid events close to the onshore Lipari hydrothermal system. These events suggest the involvement of hot hydrothermal fluids moving along pre-existing fractures. Seismological analyses of one month of data detect signals related to the regional tectonics, hydrothermal system and sea dynamics in Lipari Island.", "date": "2021-07-21", "date_type": "published", "publication": "Frontiers in Earth Science", "volume": "9", "publisher": "Frontiers Media SA", "pagerange": "Art. No. 678581", "id_number": "CaltechAUTHORS:20210929-193934993", "issn": "2296-6463", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20210929-193934993", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Istituto Nazionale di Geofisica e Vulcanologia" }, { "agency": "Louisiana State University" }, { "agency": "Harvard University" }, { "agency": "Marie Curie Fellowship", "grant_number": "74249" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.3389/feart.2021.678581", "primary_object": { "basename": "Table1_The_Seismicity_of_Lipari,_Aeolian_Islands__Italy__From_One-Month_Recording_of_the_LIPARI_Array.docx", "url": "https://authors.library.caltech.edu/records/kv6ta-zgh87/files/Table1_The_Seismicity_of_Lipari,_Aeolian_Islands__Italy__From_One-Month_Recording_of_the_LIPARI_Array.docx" }, "related_objects": [ { "basename": "feart-09-678581.pdf", "url": "https://authors.library.caltech.edu/records/kv6ta-zgh87/files/feart-09-678581.pdf" } ], "resource_type": "article", "pub_year": "2021", "author_list": "Di Luccio, Francesca; Persaud, Patricia; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/rdqe2-hsq97", "eprint_id": 108849, "eprint_status": "archive", "datestamp": "2023-08-22 09:43:34", "lastmod": "2023-10-23 17:22:22", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Jia-Zhe", "name": { "family": "Jia", "given": "Zhe" }, "orcid": "0000-0003-0652-2646" }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" } ] }, "title": "Determination of Near Surface Shear-Wave Velocities in the Central Los Angeles Basin With Dense Arrays", "ispublished": "pub", "full_text_status": "public", "keywords": "Dense array; ground motion amplification; Los Angeles Basin; seismic tomography; structural heterogeneity", "note": "\u00a9 2021 American Geophysical Union. \n\nIssue Online: 03 May 2021; Version of Record online: 03 May 2021; Accepted manuscript online: 20 April 2021; Manuscript accepted: 14 April 2021; Manuscript revised: 09 April 2021; Manuscript received: 14 November 2020. \n\nThe authors gratefully thank reviewer Yixiao Sheng, an anonymous reviewer, associate editor Nori Nakata and editor Yehuda Ben\u2010Zion for their constructive comments and suggestions. The authors gratefully thank Signal Hill Petroleum for providing permission to use the ambient noise data for the Long Beach (LB3D), Extended Long Beach (ELB) arrays, Breitburn Energy for the use of the Santa Fe Springs and Rosecrans arrays, and LA Seismic for providing the Seal Beach array. Access to the raw data requires permission from these owners. The authors thank Jorge C. Castellanos for helpful discussions. This project is supported by NSF/EAR\u201015200081. \n\nData Availability Statement: The Rayleigh wave group velocity dispersion data used to generate the final velocity model can be downloaded from: http://doi.org/10.22002/D1.1670. The final LAS1 wave velocity model can also be downloaded from that site. The authors thank the Southern California Earthquake Data Center for providing public access to the broadband seismic ambient noise data (https://scedc.caltech.edu).\n\nPublished - 2020JB021369.pdf
Supplemental Material - downloadSupplement_doi=10.1029_2F2020JB021369_file=2020JB021369-sup-0001-Supporting+Information+SI-S01.docx
", "abstract": "In this study, we investigate the shallow shear wave velocity structure of the Los Angeles Basin in southern California, using ambient noise correlations between 5 dense arrays and 21 broadband stations from the Southern California Seismic Network (SCSN). We observe clear fundamental mode and first overtone Rayleigh waves in the frequency band 0.25\u20132.0 Hz, and obtain group velocity maps through tomography. We further derive a 3D shear wave velocity model, covering a large portion of the central LA Basin for the depths shallower than 3 km. We found that the small scale shallow velocity structure heterogeneities are better resolved compared with the SCEC Community velocity models. Our model captures the presence of the Newport\u2010Inglewood fault by a NW\u2013SE trending high velocity belt. Our model provides more accurate constraints on local ground motion predictions with detailed mapping of structural heterogeneities.", "date": "2021-05", "date_type": "published", "publication": "Journal of Geophysical Research. Solid Earth", "volume": "126", "number": "5", "publisher": "American Geophysical Union", "pagerange": "Art. No. e2020JB021369", "id_number": "CaltechAUTHORS:20210423-164905232", "issn": "2169-9313", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20210423-164905232", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR-15200081" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1029/2020jb021369", "primary_object": { "basename": "2020JB021369.pdf", "url": "https://authors.library.caltech.edu/records/rdqe2-hsq97/files/2020JB021369.pdf" }, "resource_type": "article", "pub_year": "2021", "author_list": "Jia, Zhe and Clayton, Robert W." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/dz98n-pfq25", "eprint_id": 108218, "eprint_status": "archive", "datestamp": "2023-08-22 08:46:45", "lastmod": "2023-10-23 16:21:31", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Dougherty-Sara-L", "name": { "family": "Dougherty", "given": "Sara L." }, "orcid": "0000-0002-5327-3286" }, { "id": "Jiang-Chengxin", "name": { "family": "Jiang", "given": "Chengxin" }, "orcid": "0000-0002-8768-2782" }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" }, { "id": "Schmandt-Brandon", "name": { "family": "Schmandt", "given": "Brandon" }, "orcid": "0000-0003-1049-9020" }, { "id": "Hansen-Steven-M", "name": { "family": "Hansen", "given": "Steven M." } } ] }, "title": "Seismic evidence for a fossil slab origin for the Isabella anomaly", "ispublished": "pub", "full_text_status": "public", "keywords": "Body waves; Interface waves; Seismic tomography; Crustal structure; Subduction zone processes", "note": "\u00a9 The Author(s) 2020. Published by Oxford University Press on behalf of The Royal Astronomical Society. This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model (https://academic.oup.com/journals/pages/open_access/funder_policies/chorus/standard_publication_model). \n\nAccepted 2020 September 29. Received 2020 September 27; in original form 2020 March 7. Published: 05 October 2020. \n\nSeismic waveform data from the CCSE array (CCSE, doi: 10.7909/C3B56GVW) and other broad-band networks used in this study are available from the Incorporated Research Institutions for Seismology Data Management Center. Earthquake catalogue data were obtained from the Advanced National Seismic System Comprehensive Earthquake Catalog and the International Seismological Centre Bulletin event catalogue and are provided in the Supporting Information. We are grateful to Richard Guy and Charles Hoots for their work installing the CCSE array. We thank the Gordon and Betty Moore Foundation through the Tectonics Observatory at Caltech for the use of the instruments. We also thank Editor Ana Ferreira, Robert Porritt and an anonymous reviewer for helpful comments which improved the manuscript. This research was supported by NSF EAR-1314910 and EAR-1315856.\n\nPublished - ggaa472.pdf
Supplemental Material - ggaa472_supplemental_files.zip
", "abstract": "A teleseismic receiver function image of a slab-like feature that extends from the Pacific coast to the foothills of the Sierra Nevada beneath central California connects the expected location of the subducted remnant of the Monterey microplate to the high-velocity Isabella anomaly in the upper mantle. The observed structure indicates that this anomaly is a relic of the subduction zone that preceded capture of the Monterey microplate by the Pacific plate and is not due to the delamination of the lithosphere beneath the Sierra Nevada Mountains, as had been previously proposed. The fossil slab connection is also supported by surface wave tomographic images. The images are derived in part from a new linear broad-band array across the western part of central California.", "date": "2021-02", "date_type": "published", "publication": "Geophysical Journal International", "volume": "224", "number": "2", "publisher": "Royal Astronomical Society", "pagerange": "1188-1196", "id_number": "CaltechAUTHORS:20210225-144902662", "issn": "0956-540X", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20210225-144902662", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Gordon and Betty Moore Foundation" }, { "agency": "Caltech Tectonics Observatory" }, { "agency": "NSF", "grant_number": "EAR-1314910" }, { "agency": "NSF", "grant_number": "EAR-1315856" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1093/gji/ggaa472", "primary_object": { "basename": "ggaa472.pdf", "url": "https://authors.library.caltech.edu/records/dz98n-pfq25/files/ggaa472.pdf" }, "related_objects": [ { "basename": "ggaa472_supplemental_files.zip", "url": "https://authors.library.caltech.edu/records/dz98n-pfq25/files/ggaa472_supplemental_files.zip" } ], "resource_type": "article", "pub_year": "2021", "author_list": "Dougherty, Sara L.; Jiang, Chengxin; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/8tfkv-sm396", "eprint_id": 103525, "eprint_status": "archive", "datestamp": "2023-08-20 00:31:49", "lastmod": "2023-10-20 16:27:41", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Zhang-Xiaotian", "name": { "family": "Zhang", "given": "Xiaotian" } }, { "id": "Jia-Zhe", "name": { "family": "Jia", "given": "Zhe" }, "orcid": "0000-0003-0652-2646" }, { "id": "Ross-Z-E", "name": { "family": "Ross", "given": "Zachary E." }, "orcid": "0000-0002-6343-8400" }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" } ] }, "title": "Extracting Dispersion Curves From Ambient Noise Correlations Using Deep Learning", "ispublished": "pub", "full_text_status": "public", "keywords": "Convolutional networks, deep learning, dispersion curves, surface waves", "note": "\u00a9 2020 IEEE. \n\nManuscript received February 5, 2020; revised April 29, 2020; accepted April 29, 2020. Date of publication May 25, 2020; date of current version November 24, 2020. \n\nThis work was supported in part by NSF/EAR under Grant 1520081. \n\nThe authors would like to thank M. Mousavi and an Anonymous Reviewer for their constructive reviews of this article. They would like to thank Signal Hill Petroleum for permission to use the Long Beach Array and the Southern California Seismic Network for providing data from the broadband stations. They would also like to thank Y. Yue for helpful discussions.\n\nSubmitted - 2002.02040.pdf
", "abstract": "We present a machine learning approach to classify the phases of surface wave dispersion curves. Standard frequency-time analysis (FTAN) analysis of seismograms observed on an array of receivers is converted into an image, of which each pixel is classified as fundamental mode, first overtone, or noise. We use a convolutional neural network (U-Net) architecture with a supervised learning objective and incorporate transfer learning. The training is initially performed with synthetic data to learn coarse structure, followed by fine-tuning of the network using approximately 10% of the real data based on human classification. The results show that the machine classification is nearly identical to the human picked phases. Expanding the method to process multiple images at once did not improve the performance. The developed technique will facilitate the automated processing of large dispersion curve data sets.", "date": "2020-12", "date_type": "published", "publication": "IEEE Transactions on Geoscience and Remote Sensing", "volume": "58", "number": "12", "publisher": "IEEE", "pagerange": "8932-8939", "id_number": "CaltechAUTHORS:20200528-140757334", "issn": "0196-2892", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200528-140757334", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR-1520081" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1109/tgrs.2020.2992043", "primary_object": { "basename": "2002.02040.pdf", "url": "https://authors.library.caltech.edu/records/8tfkv-sm396/files/2002.02040.pdf" }, "resource_type": "article", "pub_year": "2020", "author_list": "Zhang, Xiaotian; Jia, Zhe; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/m4qpg-a5r57", "eprint_id": 107360, "eprint_status": "archive", "datestamp": "2023-08-20 00:10:20", "lastmod": "2023-10-23 15:48:48", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Kohler-M-D", "name": { "family": "Kohler", "given": "Monica D." }, "orcid": "0000-0002-4703-190X" }, { "id": "Filippitzis-Filippos", "name": { "family": "Filippitzis", "given": "Filippos" }, "orcid": "0000-0001-8377-4914" }, { "id": "Heaton-T-H", "name": { "family": "Heaton", "given": "Thomas" }, "orcid": "0000-0003-3363-2197" }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" }, { "id": "Guy-Richard-G", "name": { "family": "Guy", "given": "Richard" }, "orcid": "0000-0002-8651-5608" }, { "id": "Bunn-Julian", "name": { "family": "Bunn", "given": "Julian" }, "orcid": "0000-0002-3798-298X" }, { "id": "Chandy-K-M", "name": { "family": "Chandy", "given": "K. Mani" }, "orcid": "0000-0001-9190-1290" } ] }, "title": "2019 Ridgecrest Earthquake Reveals Areas of Los Angeles That Amplify Shaking of High-Rises", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 2020 Seismological Society of America. \n\nManuscript received 4 May 2020; Published online 30 September 2020. \n\nThis article greatly benefitted from thoughtful reviews provided by Art Frankel and an anonymous reviewer. The authors are grateful to Caltech, the Betty and Gordon Moore Foundation, the Conrad N. Hilton Foundation, and Computers & Structures, Inc. for providing support for the Community Seismic Network and for this study. \n\nData and Resources: Community Seismic Network (CSN) strong\u2010motion data for the Ridgecrest earthquake are available from csn.caltech.edu/data. Southern California Seismic Network (SCSN) data are available from the Southern California Earthquake Data Center (scedc.caltech.edu). The authors acknowledge accessing strong\u2010motion data through the Center for Engineering Strong Motion Data (CESMD; strongmotioncenter.org. All websites were last accessed August 2020. The networks or agencies providing the data used in this article are the California Strong Motion Instrumentation Program (CSMIP) and the U.S. Geological Survey (USGS) National Strong Motion Project (NSMP). The unpublished manuscript by F. Filippitzis, M. D. Kohler, T. H. Heaton, R. W. Graves, R. W. Clayton, R. G. Guy, J. J. Bunn, and K. M. Chandy (2020), \"Ground motion response in urban Los Angeles from the 2019 Ridgecrest earthquake sequence,\" submitted to Earthq. Spectra. The supplemental material contains seven figures (Figs. S1\u2013S7) cited in the main article.\n\nSupplemental Material - srl-2020170_supplement.pdf
", "abstract": "The populace of Los Angeles, California, was startled by shaking from the M 7.1 earthquake that struck the city of Ridgecrest located 200 km to the north on 6 July 2019. Although the earthquake did not cause damage in Los Angeles, the experience in high\u2010rise buildings was frightening in contrast to the shaking felt in short buildings. Observations from 560 ground\u2010level accelerometers reveal large variations in shaking in the Los Angeles basin that occurred for more than 2 min. The observations come from the spatially dense Community Seismic Network (CSN), combined with the sparser Southern California Seismic Network and California Strong Motion Instrumentation Program networks. Site amplification factors for periods of 1, 3, 6, and 8 s are computed as the ratio of each station's response spectral values combined for the two horizontal directions, relative to the average of three bedrock sites. Spatially coherent behavior in site amplification emerges for periods \u22653\u2009\u2009s\u2060, and the maximum calculated site amplifications are the largest, by factors of 7, 10, and 8, respectively, for 3, 6, and 8 s periods. The dense CSN observations show that the long\u2010period amplification is clearly, but only partially, correlated with the depth to basement. Sites with the largest amplifications for the long periods (\u2060\u22653\u2009\u2009s\u2060) are not close to the deepest portion of the basin. At 6 and 8 s periods, the maximum amplifications occur in the western part of the Los Angeles basin and in the south\u2010central San Fernando Valley sedimentary basin. The observations suggest that the excitation of a hypothetical high\u2010rise located in an area characterized by the largest site amplifications could be four times larger than in a downtown Los Angeles location.", "date": "2020-11", "date_type": "published", "publication": "Seismological Research Letters", "volume": "91", "number": "6", "publisher": "Seismological Society of America", "pagerange": "3370-3380", "id_number": "CaltechAUTHORS:20210107-103141484", "issn": "0895-0695", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20210107-103141484", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Caltech" }, { "agency": "Gordon and Betty Moore Foundation" }, { "agency": "Conrad N. Hilton Foundation" }, { "agency": "Computers and Structures, Inc." } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1785/0220200170", "primary_object": { "basename": "srl-2020170_supplement.pdf", "url": "https://authors.library.caltech.edu/records/m4qpg-a5r57/files/srl-2020170_supplement.pdf" }, "resource_type": "article", "pub_year": "2020", "author_list": "Kohler, Monica D.; Filippitzis, Filippos; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/7heky-10m77", "eprint_id": 104433, "eprint_status": "archive", "datestamp": "2023-08-22 06:13:53", "lastmod": "2023-10-20 20:27:53", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" } ] }, "title": "A detailed image of the continent-borderland transition beneath Long Beach, California", "ispublished": "pub", "full_text_status": "public", "keywords": "Crustal imaging; Seismic interferometry; Seismic noise", "note": "\u00a9 The Author(s) 2020. Published by Oxford University Press on behalf of The Royal Astronomical Society. This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model (https://academic.oup.com/journals/pages/open_access/funder_policies/chorus/standard_publication_model). \n\nAccepted 2020 June 8. Received 2020 June 8; in original form 2020 March 6. Published: 12 June 2020. \n\nThe work was support under the NSF award EAR-1520081 and a THOR (Caltech internal research fund) award. We thank Signal Hill Petroleum for permission to use the Long Beach array data and Dan Hollis and Nodal Seismic for facilitating the interaction. This study benefitted from discussions with Mark Legg and Jason Saleeby. We also thank John Shaw and an anonymous reviewer for constructive comments that improved this paper. Data used in this study is the property of Signal Hill Petroleum and a 'non-distribution' agreement with them is required from them to use data.\n\nPublished - ggaa286.pdf
Supplemental Material - ggaa286_supplemental_files.zip
", "abstract": "New crustal images beneath Long Beach, California show the region of the Inner Borderland to continent transition. The cross-sections are obtained from stacked autocorrelations of virtual sources generated from oil-industry data recorded in the city of Long Beach, CA. They show that the Moho is dipping at 65\u00b0 and obliquely truncates an \u223c10 km thick flat-lying lower crustal fabric. The Moho appears to be fault controlled and an integral part of the extrusion of the Catalina Schist that underlays the Inner Borderland. The basement interface has significant offsets of up to 2 km, none of which correspond to the mapped trace of the Newport\u2013Inglewood Fault.", "date": "2020-09", "date_type": "published", "publication": "Geophysical Journal International", "volume": "222", "number": "3", "publisher": "Royal Astronomical Society", "pagerange": "2102-2107", "id_number": "CaltechAUTHORS:20200717-155018558", "issn": "0956-540X", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200717-155018558", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR-1520081" }, { "agency": "Caltech Terrestrial Hazard Observation and Reporting (THOR) Center" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1093/gji/ggaa286", "primary_object": { "basename": "ggaa286.pdf", "url": "https://authors.library.caltech.edu/records/7heky-10m77/files/ggaa286.pdf" }, "related_objects": [ { "basename": "ggaa286_supplemental_files.zip", "url": "https://authors.library.caltech.edu/records/7heky-10m77/files/ggaa286_supplemental_files.zip" } ], "resource_type": "article", "pub_year": "2020", "author_list": "Clayton, Robert W." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/s0t1d-xy587", "eprint_id": 104309, "eprint_status": "archive", "datestamp": "2023-08-19 22:20:52", "lastmod": "2023-10-20 19:17:21", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Castellanos-J-C", "name": { "family": "Castellanos", "given": "Jorge C." }, "orcid": "0000-0002-0103-6430" }, { "id": "Perry-Houts-J", "name": { "family": "Perry-Houts", "given": "Jonathan" }, "orcid": "0000-0002-3652-6202" }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" }, { "id": "Kim-YoungHee", "name": { "family": "Kim", "given": "YoungHee" }, "orcid": "0000-0002-1111-632X" }, { "id": "Stanciu-A-C", "name": { "family": "Stanciu", "given": "A. Christian" }, "orcid": "0000-0002-8768-2432" }, { "id": "Niday-B", "name": { "family": "Niday", "given": "Bart" }, "orcid": "0000-0003-3743-1392" }, { "id": "Humphreys-E", "name": { "family": "Humphreys", "given": "Eugene" }, "orcid": "0000-0002-1916-8378" } ] }, "title": "Seismic anisotropy reveals crustal flow driven by mantle vertical loading in the Pacific NW", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 2020 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works. Distributed under a Creative Commons Attribution NonCommercial License 4.0 (CC BY-NC). \n\nSubmitted 25 January 2020; Accepted 26 May 2020; Published 8 July 2020. \n\nWe thank P. Ryan and R. Guy for help in deploying the Wallowa2 array. We thank S. King and an anonymous reviewer for the careful and constructive suggestions. We also thank F.-C. Lin for providing us with the crustal anisotropy measurements for California. Y.K. acknowledges support from the Creative Pioneering Researchers Program of Seoul National University (SNU SRnD 3345-20160014). The figures presented in this paper were made using the Generic Mapping Tools version 4.5.9 (https://www.soest.hawaii.edu/gmt/). We used HC 1.0.5 (50, 57\u201359) published under the GPL2 license. \n\nThis project was supported by NSF/EAR 1546635 and 1547594. \n\nAuthor contributions: J.C.C. produced the anisotropy results and cowrote the paper. J.P.-H. modeled the coupling between mantle and crust and cowrote the paper. Y.K., A.C.S., and B.N. synthesized the receiver functions, seismic tomography, and SKS results. R.W.C. and E.H. conceptualized the project and edited the paper. All authors contributed to the interpretation of the results and the preparation of the manuscript for publication. \n\nThe authors declare that they have no competing interests. \n\nData and materials availability: The project used data from High Lava Plains, IDOR, Wallowa, and Wallowa2 surveys, along with data from the T.A. (Transportable Array) from EarthScope. All data are available from the IRIS-DMC (https://iris.edu/hq/). All data needed to evaluate the conclusions in the paper are present in the paper and/or the Supplementary Materials. Additional data related to this paper may be requested from the authors.\n\nPublished - eabb0476.full.pdf
Supplemental Material - abb0476_Data_file_S1.tfml.zip
Supplemental Material - abb0476_SM.pdf
Supplemental Material - abb0476_Table_S1.txt
Supplemental Material - abb0476_Table_S2.txt
", "abstract": "Buoyancy anomalies within Earth's mantle create large convective currents that are thought to control the evolution of the lithosphere. While tectonic plate motions provide evidence for this relation, the mechanism by which mantle processes influence near-surface tectonics remains elusive. Here, we present an azimuthal anisotropy model for the Pacific Northwest crust that strongly correlates with high-velocity structures in the underlying mantle but shows no association with the regional mantle flow field. We suggest that the crustal anisotropy is decoupled from horizontal basal tractions and, instead, created by upper mantle vertical loading, which generates pressure gradients that drive channelized flow in the mid-lower crust. We then demonstrate the interplay between mantle heterogeneities and lithosphere dynamics by predicting the viscous crustal flow that is driven by local buoyancy sources within the upper mantle. Our findings reveal how mantle vertical load distribution can actively control crustal deformation on a scale of several hundred kilometers.", "date": "2020-07-08", "date_type": "published", "publication": "Science Advances", "volume": "6", "number": "28", "publisher": "American Association for the Advancement of Science", "pagerange": "Art. No. eabb0476", "id_number": "CaltechAUTHORS:20200709-101235393", "issn": "2375-2548", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200709-101235393", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR-1546635" }, { "agency": "NSF", "grant_number": "EAR-1547594" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1126/sciadv.abb0476", "pmcid": "PMC7439309", "primary_object": { "basename": "abb0476_Data_file_S1.tfml.zip", "url": "https://authors.library.caltech.edu/records/s0t1d-xy587/files/abb0476_Data_file_S1.tfml.zip" }, "related_objects": [ { "basename": "abb0476_SM.pdf", "url": "https://authors.library.caltech.edu/records/s0t1d-xy587/files/abb0476_SM.pdf" }, { "basename": "abb0476_Table_S1.txt", "url": "https://authors.library.caltech.edu/records/s0t1d-xy587/files/abb0476_Table_S1.txt" }, { "basename": "abb0476_Table_S2.txt", "url": "https://authors.library.caltech.edu/records/s0t1d-xy587/files/abb0476_Table_S2.txt" }, { "basename": "eabb0476.full.pdf", "url": "https://authors.library.caltech.edu/records/s0t1d-xy587/files/eabb0476.full.pdf" } ], "resource_type": "article", "pub_year": "2020", "author_list": "Castellanos, Jorge C.; Perry-Houts, Jonathan; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/se7bz-k9a90", "eprint_id": 102368, "eprint_status": "archive", "datestamp": "2023-08-22 04:52:21", "lastmod": "2023-10-23 16:19:41", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Castellanos-J-C", "name": { "family": "Castellanos", "given": "Jorge C." }, "orcid": "0000-0002-0103-6430" }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" }, { "id": "Juarez-A", "name": { "family": "Juarez", "given": "Alan" }, "orcid": "0000-0001-7565-5333" } ] }, "title": "Using a Time-based Subarray Method to Extract and Invert Noise-derived Body Waves at Long Beach, California", "ispublished": "pub", "full_text_status": "public", "keywords": "Ambient noise; Body waves; Double\u2010beamforming; Seismic tomography; Long Beach", "note": "\u00a9 2020 The Authors. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. \n\nReceived 8 OCT 2019; Accepted 25 MAR 2020; Accepted article online 6 APR 2020. \n\nThe data used in this study is the property of Signal Hill Petroleum Inc., and permission from them is required to access it. We gratefully acknowledge Signal Hill Petroleum, Inc., for permitting us to use the Long Beach data. This work was supported by NSF/EAR\u201015200081. We thank Dunzhu Li for providing the ambient noise cross\u2010correlations. We gratefully thank Nori Nakata and an anonymous reviewer for their careful and constructive suggestions. The figures presented in this paper were made using the Generic Mapping Tools v.4.5.9 (https:/soest.hawaii.edu/gmt). The final P wave velocity model can be downloaded from: https://doi.org/10.22002/D1.1293. The traveltime measurements used to generate the velocity model can also be downloaded from that site.\n\nPublished - 2019JB018855.pdf
Supplemental Material - jgrb54121-sup-0001-2019jb018855-text_si-s01.pdf
Supplemental Material - jgrb54121-sup-0002-2019jb018855-movie_si-s01.mp4
Supplemental Material - jgrb54121-sup-0003-2019jb018855-movie_si-s02.mp4
Supplemental Material - jgrb54121-sup-0004-2019jb018855-movie_si-s03.mp4
Supplemental Material - jgrb54121-sup-0005-2019jb018855-movie_si-s04.mp4
", "abstract": "The reconstruction of body waves from the cross\u2010correlation of random wavefields has recently emerged as a promising approach to probe the fine\u2010scale structure of the Earth. However, because of the nature of the ambient noise field, the retrieval of body waves from seismic noise recordings is highly challenging and has only been successful in a few cases. Here, we use seismic noise data from a 5,200\u2010node oil\u2010company survey to reconstruct body waves and determine the velocity structure beneath Long Beach, California. To isolate the body wave energy from the ambient noise field, we divide the entire survey into small\u2010aperture subarrays and apply a modified double\u2010beamforming scheme to enhance coherent arrivals within the cross\u2010correlated waveforms. The resulting beamed traces allow us to identify clear refracted P waves traveling between different subarray pairs, which we then use to construct a high\u2010resolution 3D velocity model of the region. The inverted velocity model reveals velocity variations of the order of 3% and strong lateral discontinuities caused by the presence of sharp geologic structures such as the Newport\u2010Inglewood fault (NIF). Additionally, we show that the resolution that is achieved through the use of high\u2010frequency body waves allows us to illuminate small geometric variations of the NIF that were previously unresolved with traditional passive imaging methods.", "date": "2020-05", "date_type": "published", "publication": "Journal of Geophysical Research. Solid Earth", "volume": "125", "number": "5", "publisher": "American Geophysical Union", "pagerange": "Art. No. e2019JB018855", "id_number": "CaltechAUTHORS:20200407-074554849", "issn": "2169-9313", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200407-074554849", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR-15200081" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1029/2019jb018855", "primary_object": { "basename": "jgrb54121-sup-0001-2019jb018855-text_si-s01.pdf", "url": "https://authors.library.caltech.edu/records/se7bz-k9a90/files/jgrb54121-sup-0001-2019jb018855-text_si-s01.pdf" }, "related_objects": [ { "basename": "jgrb54121-sup-0002-2019jb018855-movie_si-s01.mp4", "url": "https://authors.library.caltech.edu/records/se7bz-k9a90/files/jgrb54121-sup-0002-2019jb018855-movie_si-s01.mp4" }, { "basename": "jgrb54121-sup-0003-2019jb018855-movie_si-s02.mp4", "url": "https://authors.library.caltech.edu/records/se7bz-k9a90/files/jgrb54121-sup-0003-2019jb018855-movie_si-s02.mp4" }, { "basename": "jgrb54121-sup-0004-2019jb018855-movie_si-s03.mp4", "url": "https://authors.library.caltech.edu/records/se7bz-k9a90/files/jgrb54121-sup-0004-2019jb018855-movie_si-s03.mp4" }, { "basename": "jgrb54121-sup-0005-2019jb018855-movie_si-s04.mp4", "url": "https://authors.library.caltech.edu/records/se7bz-k9a90/files/jgrb54121-sup-0005-2019jb018855-movie_si-s04.mp4" }, { "basename": "2019JB018855.pdf", "url": "https://authors.library.caltech.edu/records/se7bz-k9a90/files/2019JB018855.pdf" } ], "resource_type": "article", "pub_year": "2020", "author_list": "Castellanos, Jorge C.; Clayton, Robert W.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/r8k57-m8t03", "eprint_id": 99876, "eprint_status": "archive", "datestamp": "2023-08-19 20:25:29", "lastmod": "2023-10-18 18:53:37", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" }, { "id": "Kohler-M-D", "name": { "family": "Kohler", "given": "Monica" } }, { "id": "Guy-Richard", "name": { "family": "Guy", "given": "Richard" } }, { "id": "Bunn-J", "name": { "family": "Bunn", "given": "Julian" }, "orcid": "0000-0002-3798-298X" }, { "id": "Heaton-T-H", "name": { "family": "Heaton", "given": "Thomas" }, "orcid": "0000-0003-3363-2197" }, { "id": "Chandy-K-M", "name": { "family": "Chandy", "given": "Mani" } } ] }, "title": "CSN-LAUSD Network: A Dense Accelerometer Network in Los Angeles Schools", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 2019 Seismological Society of America. \n\nPublished Online 13 November 2019. \n\nData and Resources: Data from felt and interesting events are available at http://csn.caltech.edu/data/ along with the recordings of other Community Seismic Network (CSN) stations. In particular the data of the Ridgecrest earthquake shown in Figures 3, 5, 6, 7 and S1 are archived there. The continuous data from the CSN network are not generally released due to privacy concerns, but we are attempting to obtain permission for the Los Angeles Unified School District (LAUSD) stations. The VS30 measures in the region of LAUSD are available from https://earthquake.usgs.gov/data/vs30. The client software is available at https://github.com/jjbunn/PyCSN. More information on the CSN and CSN\u2010LAUSD networks is available at http://csn.caltech.edu (last accessed July 27, 2019). The Raspberry Shake network can be accessed at https://raspberryshake.org. Details on the Phidget sensor are available at https://www.phidgets.com/?&prodid=31. All websites were last accessed on July 2019. The supplemental material includes movies of ground accelerations due to the 6 July 2019 M7.1 Ridgecrest earthquake are shown in Figure S1. The time slices shown in Figure 6 are one panel from each of the videos. The data have been bandpass filtered from 100\u20101 s and 100\u20105 s. The movie starts at 60 s after the origin time and runs until 92 s. \n\nThe authors thank the Betty and Gordon Moore Foundation, Caltech, the Conrad N. Hilton Foundation, and Computers and Structures, Inc., for funding for this project. The authors thank Los Angeles Unified School District (LAUSD), and in particular Jill Barnes, for facilitating this project, and the many volunteers who have helped build the Community Seismic Network (CSN) sensors. Charles Dorn and Filippos Filippitzis from Caltech created Figures 4 and 7, respectively.\n\nAccepted Version - SRL-2019200_Galley_Final.pdf
Supplemental Material - srl-2019200_supplement.docx
Supplemental Material - srl-2019200_supplement_movie-1sec.mpg
Supplemental Material - srl-2019200_supplement_movie-5sec.mpg
", "abstract": "The Community Seismic Network\u2010Los Angeles Unified School District is a network of 300 low\u2010cost microelectromechanical systems accelerometers located in schools in the Los Angeles, California, region. They are capable of accurately recording strong motion up to \u00b12g and are sufficiently spatially dense that they provide unaliased measurements of strong motions up to 1 Hz following a major earthquake. They are used to provide state\u2010of\u2010health monitoring for the schools and surrounding communities to guide the emergency response. As a research tool, they can be used to provide estimates of the site response at the schools and, therefore, provide a much denser set of site responses for ground\u2010motion prediction than is currently available.", "date": "2020-03-01", "date_type": "published", "publication": "Seismological Research Letters", "volume": "91", "number": "2A", "publisher": "Seismological Society of America", "pagerange": "622-630", "id_number": "CaltechAUTHORS:20191115-160214215", "issn": "0895-0695", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20191115-160214215", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Gordon and Betty Moore Foundation" }, { "agency": "Caltech" }, { "agency": "Conrad N. Hilton Foundation" }, { "agency": "Computers and Structures, Inc." } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1785/0220190200", "primary_object": { "basename": "srl-2019200_supplement_movie-1sec.mpg", "url": "https://authors.library.caltech.edu/records/r8k57-m8t03/files/srl-2019200_supplement_movie-1sec.mpg" }, "related_objects": [ { "basename": "srl-2019200_supplement_movie-5sec.mpg", "url": "https://authors.library.caltech.edu/records/r8k57-m8t03/files/srl-2019200_supplement_movie-5sec.mpg" }, { "basename": "SRL-2019200_Galley_Final.pdf", "url": "https://authors.library.caltech.edu/records/r8k57-m8t03/files/SRL-2019200_Galley_Final.pdf" }, { "basename": "srl-2019200_supplement.docx", "url": "https://authors.library.caltech.edu/records/r8k57-m8t03/files/srl-2019200_supplement.docx" } ], "resource_type": "article", "pub_year": "2020", "author_list": "Clayton, Robert W.; Kohler, Monica; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/ndh0k-gx591", "eprint_id": 103040, "eprint_status": "archive", "datestamp": "2023-08-19 20:27:17", "lastmod": "2023-10-20 00:43:38", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" } ] }, "title": "Imaging the Subsurface with Ambient Noise Autocorrelations", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 2020 Seismological Society of America. \n\nManuscript received 24 September 2019; Published online 29 January 2020. \n\nThe author thanks Signal Hill Petroleum for permission to use the Long Beach and Extended Long Beach surveys in this study. The author also thanks Dan Hollis for facilitating the use of these data. Reviewers Charles Langston and Nori Nakata improved this study with their comments. This work was supported by National Science Foundation and U.S. Geological Survey Grant Numbers NSF/EAR\u20101520081 and USGS/G17AP0000, respectively. \n\nData and Resources: The data associated with the Long Beach example are owned by Signal Hill Petroleum and requires permission from them to use. The data associated with the San Bernardino example will be placed in the public domain in 2021 and will be available from the Incorporated Research Institutions for Seismology Data Management Center (IRIS\u2010DMC). The supplemental material has images with different choices of the stacking parameters. The unpublished manuscript by R. Clayton (2020), \"A detailed image of the continent\u2010borderland transition beneath Long Beach,\" submitted to Geophys. Res. Lett.\n\nSupplemental Material - srl-2019272_supplement.pdf
", "abstract": "Autocorrelations created by stacks of near\u2010offset traces from virtual source gathers are used to form an image of the deeper subsurface. We minimize the masking effects of the effective source time function by subtracting the survey\u2010wide average autocorrelation from each trace. The result is a zero\u2010offset reflection image of the subsurface generated by ambient noise correlation. The technique can be particularly useful for imaging the mid and lower crust, in which traditional seismic methods have penetration problems. We show examples from a one\u2010component 3D survey and a three\u2010component 2D profile. The 3D example shows the crust in the transition zone between the continent and the Inner Borderland in the Los Angeles, California, area, and for the first time, shows an image of the lower crust. The 2D profile provides both a P image and an S image of the basement interface in the San Bernardino basin in southern California.", "date": "2020-03-01", "date_type": "published", "publication": "Seismological Research Letters", "volume": "91", "number": "2A", "publisher": "Seismological Society of America", "pagerange": "930-935", "id_number": "CaltechAUTHORS:20200506-132126128", "issn": "0895-0695", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200506-132126128", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR\u20101520081" }, { "agency": "USGS", "grant_number": "G17AP0000" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1785/0220190272", "primary_object": { "basename": "srl-2019272_supplement.pdf", "url": "https://authors.library.caltech.edu/records/ndh0k-gx591/files/srl-2019272_supplement.pdf" }, "resource_type": "article", "pub_year": "2020", "author_list": "Clayton, Robert W." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/4vags-f6n72", "eprint_id": 101016, "eprint_status": "archive", "datestamp": "2023-08-22 03:29:44", "lastmod": "2023-10-19 22:20:43", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Perton-M", "name": { "family": "Perton", "given": "Mathieu" }, "orcid": "0000-0001-5141-5255" }, { "id": "Spica-Z-J", "name": { "family": "Spica", "given": "Zack J." }, "orcid": "0000-0002-9259-1973" }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" }, { "id": "Beroza-G-C", "name": { "family": "Beroza", "given": "Gregory C." }, "orcid": "0000-0002-8667-1838" } ] }, "title": "Shear wave structure of a transect of the Los Angeles basin from multimode surface waves and H/V spectral ratio analysis", "ispublished": "pub", "full_text_status": "public", "keywords": "Tomography; Seismic noise; Site effect; Surface waves and free oscillations", "note": "\u00a9 2019 The Author(s). Published by Oxford University Press on behalf of The Royal Astronomical Society. This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model (https://academic.oup.com/journals/pages/open_access/funder_policies/chorus/standard_publication_model). \n\nAccepted 2019 October 8. Received 2019 September 23; in original form 2019 May 16. Published: 10 October 2019. \n\nWe thank Jorj\u00f3n Castillo Castellanos for providing us the Green's functions computed by Yiran Ma. This research was supported by the Southern California Earthquake Center (Contribution No. 9096). SCEC is funded by NSF Cooperative Agreement EAR-1600087 & USGS Cooperative Agreement G17AC00047. Zack Spica thanks the long-term visiting program of the Earthquake Research Institute. We thank the partners of the LASSIE survey: Nodalseismic (Dan Hollis and Mitchell Barklage), USGS (Elizabeth Cochran), UCLA (Paul Davis) and CalPoly Pomona (J. Polet). The authors are grateful for the editorial work of Andrea Morelli and thorough reviews from Michael Asten and another anonymous referee.\n\nPublished - ggz458.pdf
Supplemental Material - ggz458_supplemental_figure.docx
", "abstract": "We use broad-band stations of the 'Los Angeles Syncline Seismic Interferometry Experiment' (LASSIE) to perform a joint inversion of the Horizontal to Vertical spectral ratios (H/V) and multimode dispersion curves (phase and group velocity) for both Rayleigh and Love waves at each station of a dense line of sensors. The H/V of the autocorrelated signal at a seismic station is proportional to the ratio of the imaginary parts of the Green's function. The presence of low-frequency peaks (\u223c0.2 Hz) in H/V allows us to constrain the structure of the basin with high confidence to a depth of 6 km. The velocity models we obtain are broadly consistent with the SCEC CVM-H community model and agree well with known geological features. Because our approach differs substantially from previous modelling of crustal velocities in southern California, this research validates both the utility of the diffuse field H/V measurements for deep structural characterization and the predictive value of the CVM-H community velocity model in the Los Angeles region. We also analyse a lower frequency peak (\u223c0.03 Hz) in H/V and suggest it could be the signature of the Moho. Finally, we show that the independent comparison of the H and V components with their corresponding theoretical counterparts gives information about the degree of diffusivity of the ambient seismic field.", "date": "2020-01", "date_type": "published", "publication": "Geophysical Journal International", "volume": "220", "number": "1", "publisher": "Royal Astronomical Society", "pagerange": "415-427", "id_number": "CaltechAUTHORS:20200130-154313815", "issn": "0956-540X", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200130-154313815", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Southern California Earthquake Center (SCEC)" }, { "agency": "NSF", "grant_number": "EAR-1600087" }, { "agency": "USGS", "grant_number": "G17AC00047" } ] }, "other_numbering_system": { "items": [ { "id": "9096", "name": "Southern California Earthquake Center" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1093/gji/ggz458", "primary_object": { "basename": "ggz458_supplemental_figure.docx", "url": "https://authors.library.caltech.edu/records/4vags-f6n72/files/ggz458_supplemental_figure.docx" }, "related_objects": [ { "basename": "ggz458.pdf", "url": "https://authors.library.caltech.edu/records/4vags-f6n72/files/ggz458.pdf" } ], "resource_type": "article", "pub_year": "2020", "author_list": "Perton, Mathieu; Spica, Zack J.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/vpx5k-a9t75", "eprint_id": 100257, "eprint_status": "archive", "datestamp": "2023-08-22 03:10:20", "lastmod": "2023-10-18 19:47:10", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Rodr\u00edguez-Dom\u00ednguez-M", "name": { "family": "Rodr\u00edguez-Dom\u00ednguez", "given": "Miguel" }, "orcid": "0000-0002-8862-375X" }, { "id": "P\u00e9rez-Campos-Xyoli", "name": { "family": "P\u00e9rez-Campos", "given": "Xyoli" }, "orcid": "0000-0001-8970-7966" }, { "id": "Montealegre-C\u00e1zares-C", "name": { "family": "Montealegre-C\u00e1zares", "given": "Conrado" }, "orcid": "0000-0001-8609-5204" }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" }, { "id": "Cabral-Cano-E", "name": { "family": "Cabral-Cano", "given": "Enrique" }, "orcid": "0000-0002-9143-2401" } ] }, "title": "Crustal structure variations in south-central Mexico from receiver functions", "ispublished": "pub", "full_text_status": "public", "keywords": "Structure of the Earth; Crustal imaging; Crustal structure", "note": "\u00a9 2019 The Author(s). Published by Oxford University Press on behalf of The Royal Astronomical Society. This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model (https://academic.oup.com/journals/pages/open_access/funder_policies/chorus/standard_publication_model). \n\nAccepted 2019 September 30. Received 2019 September 23; in original form 2019 April 11. Published: 03 October 2019. \n\nData and Resources: Broad-band data from the permanent SSN and UV networks is available by request http://www.ssn.unam.mx/doi/networks/mx/). Data from station POCC of CENAPRED should be requested to Ing. Gilberto Pescina (gilberto@cenapred.unam.mx). Data from OxNet is available since mid-2006 to early 2012 at http://tlalocnet.udg.mx/. Data from MASE and VEOX experiments are available from the IRIS Data Management Center, http://service.iris.edu/fdsnws/dataselect/1/. Data from Los Humeros network should be requested to Instituto de Ingenier\u00eda, UNAM (www.iingen.unam.mx/, JLermoS@iingen.unam.mx); data from GECO network can be requested to PI X. P\u00e9rez-Campos (xyoli@igeofisica.unam.mx) and will be open on 2021. Topography grids were provided by Amante & Eakins (2009). \n\nThis work was supported by Universidad Nacional Aut\u00f3noma de Mexico through project UNAM-PAPIIT IN105816, and Consejo Nacional de Ciencia y Tecnolog\u00eda (Conacyt) through project 177676. SSN data was obtained by the Servicio Sismol\u00f3gico Nacional (M\u00e9xico), station maintenance, data acquisition and distribution are possible thanks to its personnel. This work is also partly based on seismic data generated from OxNet through an NSF +++Grant EAR-1246944 to M. Brudzinzki. We thank the personnel involved in operation and maintenance of all the stations used in this work. We especially thank Antonio de Jes\u00fas Mendoza Carvajal (SSN), and Jorge Real P\u00e9rez (Instituto de Geof\u00edsica, UNAM) for installing and maintaining the GECO stations and Oscar D\u00edaz-Molina and Luis Salazar-Tlaczani (Instituto de Geof\u00edsica, UNAM) for the OxNet operations. We also thank Francisco C\u00f3rdoba-Montiel (UV), Javier Lermo-Samaniego (Los Humeros) and Gilberto Castel\u00e1n-Pescina (CENAPRED) for providing data used on this project. We thank the Academic Writing UNAM-Canada program for their assistance in the elaboration of this paper. M. Rodr\u00edguez-Dom\u00ednguez had a Conacyt graduate scholarship. Figs 1, 2 and 6 were made using the Generic Mapping Tools version 4.5.9 (www.soest.hawaii.edu/gmt; Wessel & Smith 1998). Finally, we thank the editor Prof Frederik Simons, Dr Luca Ferrari and an anonymous reviewer for their valuable comments that improved this paper.\n\nPublished - ggz434.pdf
Supplemental Material - ggz434_supplemental_file.docx
", "abstract": "Mexico has a complex geological history that is typified by the distinctive terranes that are found in the south-central region. Crustal thickness variations often correlate with geological terranes that have been altered by several processes in the past, for example aerial or subduction erosion, underplating volcanic material or rifting but few geophysical studies have locally imaged the entire continental crust in Mexico. In this paper, the thickness of three layers of the crust in south-central Mexico is determined. To do this, we use P- and S-wave receiver functions (RF) from 159 seismological broad-band stations. Thanks to its adaptive nature, we use an empirical mode decomposition (EMD) algorithm to reconstruct the RFs into intrinsic mode functions (IMF) in order to enhance the pulses related to internal discontinuities within the crust. To inspect possible lateral variations, the RFs are grouped into quadrants of 90\u00b0, and their amplitudes are mapped into the thickness assuming a three-layer model. Using this approach, we identify a shallow sedimentary layer with a thickness in the range of 1\u20134 km. The upper-crust was estimated to be of a few kilometers (<10 km) thick near the Pacific coast, and thicker, approximately 15 km in central Oaxaca and under the Trans-Mexican Volcanic Belt (TMVB). Close to the Pacific coast, we infer a thin crust of approximately 16 \u00b1 0.9 km, while in central Oaxaca and beneath the TMVB, we observe a thicker crust ranging between 30 and 50 km \u00b1 2.0 km. We observe a crustal thinning, of approximately 6 km, from central Oaxaca (37 \u00b1 1.9 km) towards the Gulf of Mexico, under the Veracruz Basin, where we estimate a crustal thickness of 31.6 \u00b1 1.9 km. The boundary between the upper and lower crust in comparison with the surface of the Moho do not show significant variations other than the depth difference. We observe small crustal variations across the different terranes on the study area, with the thinnest crust located at the Pacific coast and Gulf of Mexico coast. The thickest crust is estimated to be in central Oaxaca and beneath the TMVB.", "date": "2019-12", "date_type": "published", "publication": "Geophysical Journal International", "volume": "219", "number": "3", "publisher": "Royal Astronomical Society", "pagerange": "2174-2186", "id_number": "CaltechAUTHORS:20191210-085856635", "issn": "0956-540X", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20191210-085856635", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Universidad Nacional Aut\u00f3noma de M\u00e9xico", "grant_number": "IN105816" }, { "agency": "Consejo Nacional de Ciencia y Tecnolog\u00eda (CONACYT)", "grant_number": "177676" }, { "agency": "NSF", "grant_number": "EAR-1246944" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1093/gji/ggz434", "primary_object": { "basename": "ggz434.pdf", "url": "https://authors.library.caltech.edu/records/vpx5k-a9t75/files/ggz434.pdf" }, "related_objects": [ { "basename": "ggz434_supplemental_file.docx", "url": "https://authors.library.caltech.edu/records/vpx5k-a9t75/files/ggz434_supplemental_file.docx" } ], "resource_type": "article", "pub_year": "2019", "author_list": "Rodr\u00edguez-Dom\u00ednguez, Miguel; P\u00e9rez-Campos, Xyoli; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/vx0ef-bkq45", "eprint_id": 99762, "eprint_status": "archive", "datestamp": "2023-08-22 03:01:33", "lastmod": "2023-10-18 18:45:36", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Jang-Hyoihn", "name": { "family": "Jang", "given": "Hyoihn" } }, { "id": "Kim-YoungHee", "name": { "family": "Kim", "given": "YoungHee" }, "orcid": "0000-0002-1111-632X" }, { "id": "Lim-Hobin", "name": { "family": "Lim", "given": "Hobin" }, "orcid": "0000-0001-7510-4507" }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" } ] }, "title": "Seismic attenuation structure of southern Peruvian subduction system", "ispublished": "pub", "full_text_status": "public", "keywords": "Seismic attenuation; Quality factor (Q); t*; Seismicity; Subduction zone system; Nazca Ridge", "note": "\u00a9 2019 Elsevier B.V. \n\nReceived 1 August 2019, Revised 14 September 2019, Accepted 14 September 2019, Available online 8 November 2019. \n\nH. Jang, Y. Kim, and H. Lim acknowledge Creative-Pioneering Researchers Program through Seoul National University (SNU SRnD 3345-20160014), and the Nuclear Safety Research Program through the Korea Foundation of Nuclear Safety (KoFONS), granted financial resource from the Nuclear Safety and Security Commission (NSSC), Republic of Korea (No. 1705010). The authors are grateful to the many institutions that deployed and maintained temporary networks in southern Peru and northwestern Bolivia. In particular, the authors thank the Peru Subduction Experiment (PeruSE) for providing the seismic waveform data used in this study. Seismic instruments for the Central Andean Uplift and Geodynamics of High Topography (CAUGHT) and the Peru Lithosphere and Slab Experiment (PULSE) experiments were provided by the Incorporated Research Institutions for Seismology (IRIS) through the Program for the Array Seismic Studies of the Continental Lithosphere (PASSCAL) Instrument Center at the New Mexico Institute of Mining and Technology. Finally, the authors thank Editor Kelin Wang and the two reviewers for their comments, which greatly improved this article.\n\nSupplemental Material - 1-s2.0-S004019511930318X-mmc1.docx
", "abstract": "Seismic attenuation provides key constraints on understanding the structure and dynamics of subduction-zone system. In this study, we provide the first three-dimensional P and S-wave attenuation models beneath the Nazca-South America subduction zone by inverting t* data from 397 local shallow and intermediate-depth earthquakes. The study area covers the southern part of the Peruvian flat-slab region (11\u00b0\u201315 \u00b0S) (where the subducting Nazca Ridge is migrating), and the Central Andean Plateau (\u223c13\u00b0\u201318 \u00b0S) (associated with the subducting Nazca Plate) and the Brazilian mantle lithosphere. We obtain five major features in our attenuation model with seismicity including (1) well-defined along-strike and along-dip Nazca slab structure in terms of low attenuation, (2) high attenuation associated with the passage of Nazca Ridge and present location of the oceanic ridges, (3) high attenuation in the backarc mantle wedge and continental crust, (4) clear image of Brazilian Shield in terms of low attenuation, underthrusting to the west, and (5) high attenuation related to the slab dehydration beneath the volcanic arc at 100 and 200 km depths. In particular, prominent low-Q zones in the continental crust and mantle wedge beneath the active volcanic arc reflect source zones of arc magmatism caused by fluids from the slab dehydration. The observed along-arc differences in slab Q estimates can be attributed to different hydration states between the flat and normal-dip slabs due to the subduction of the Nazca Ridge.", "date": "2019-11-20", "date_type": "published", "publication": "Tectonophysics", "volume": "771", "publisher": "Elsevier", "pagerange": "Art. No. 228203", "id_number": "CaltechAUTHORS:20191111-073558672", "issn": "0040-1951", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20191111-073558672", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Seoul National University", "grant_number": "SNU SRnD 3345-20160014" }, { "agency": "Korea Foundation of Nuclear Safety" }, { "agency": "Nuclear Safety and Security Commission (Korea)", "grant_number": "1705010" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/j.tecto.2019.228203", "primary_object": { "basename": "1-s2.0-S004019511930318X-mmc1.docx", "url": "https://authors.library.caltech.edu/records/vx0ef-bkq45/files/1-s2.0-S004019511930318X-mmc1.docx" }, "resource_type": "article", "pub_year": "2019", "author_list": "Jang, Hyoihn; Kim, YoungHee; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/shqr2-qz694", "eprint_id": 89362, "eprint_status": "archive", "datestamp": "2023-08-19 11:40:46", "lastmod": "2023-10-18 22:41:49", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Massari-A", "name": { "family": "Massari", "given": "Anthony" }, "orcid": "0000-0002-6561-4674" }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" }, { "id": "Kohler-M-D", "name": { "family": "Kohler", "given": "Monica" } } ] }, "title": "Damage Detection by Template Matching of Scattered Waves", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 2018 Seismological Society of America. \n\nManuscript received 20 October 2017; Published Online 4 September 2018. \n\nThe authors thank the Community Seismic Network (CSN) project at Caltech for supplying data for the buildings used in this study and the building owners and engineers for supplying detailed plans that allowed us to build the computational models. A.M. was supported by the Caltech Housner Fellowship during this study. \n\nData and Resources: The data used in this study were synthetically created. The modeling was done with ETABS available from Structural and Earthquake Engineering Software, Computers and Structures, Inc. (1995), Berkeley, California, https://www.csiamerica.com/products/etabs and http://docs.csiamerica.com/manuals/etabs/Analysis%20Reference.pdf (last accessed August 2018).\n\nAccepted Version - BSSA-2017319_FINALED_2.pdf
", "abstract": "A method based on template matching is presented to detect and locate damage in buildings following severe shaking by an earthquake. The templates are constructed by finite\u2010element simulations of a suite of damage scenarios, with the solutions evaluated at the location (and orientation) of each sensor in the structure. The damage detection is carried out by cross\u2010correlating the templates with recordings acquired from earthquakes. A dense distributed network of sensors is important for detecting anomalies in the presence of ambient noise. The cross correlation of the templates with themselves provides a measure of the resolution of the damage location.", "date": "2018-10", "date_type": "published", "publication": "Bulletin of the Seismological Society of America", "volume": "108", "number": "5A", "publisher": "Seismological Society of America", "pagerange": "2556-2564", "id_number": "CaltechAUTHORS:20180904-140804322", "issn": "0037-1106", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180904-140804322", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "George Housner Fellowship, Caltech" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1785/0120170319", "primary_object": { "basename": "BSSA-2017319_FINALED_2.pdf", "url": "https://authors.library.caltech.edu/records/shqr2-qz694/files/BSSA-2017319_FINALED_2.pdf" }, "resource_type": "article", "pub_year": "2018", "author_list": "Massari, Anthony; Clayton, Robert W.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/sjk25-br738", "eprint_id": 88052, "eprint_status": "archive", "datestamp": "2023-08-22 00:01:42", "lastmod": "2023-10-18 21:40:09", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Lim-Hobin", "name": { "family": "Lim", "given": "Hobin" }, "orcid": "0000-0001-7510-4507" }, { "id": "Kim-YoungHee", "name": { "family": "Kim", "given": "YoungHee" }, "orcid": "0000-0002-1111-632X" }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" }, { "id": "Thurber-C-H", "name": { "family": "Thurber", "given": "Clifford H." } } ] }, "title": "Seismicity and structure of Nazca Plate subduction zone in southern Peru", "ispublished": "pub", "full_text_status": "public", "keywords": "seismicity; subduction zone system; Nazca Plate; relocation; double-difference tomography; southern Peru", "note": "\u00a9 2018 Elsevier. \n\nReceived 31 January 2018, Revised 5 July 2018, Accepted 10 July 2018, Available online 20 July 2018. \n\nEditor: M. Ishii \n\nWe acknowledge Creative-Pioneering Researchers Program through Seoul National University (SNU SRnD 3345-20160014), and the Nuclear Safety Research Program through the Korea Foundation of Nuclear Safety (KoFONS), granted financial resource from the Nuclear Safety and Security Commission (NSSC), Republic of Korea (No. 1705010). We thank Editor Miaki Ishii and reviewers for comments that greatly improved this paper.\n\nSupplemental Material - 1-s2.0-S0012821X18304205-mmc1.docx
Supplemental Material - 1-s2.0-S0012821X18304205-mmc2.txt
", "abstract": "We define subducting plate geometries in the Nazca subduction zone by (re)locating intra-slab earthquakes in southern Peru (14\u201318\u00b0S) and using previously published converted phase analysis results to clarify the slab geometry and inferred relationships to the seismicity. We also provide both P- and S-wave velocity models of the subducting Nazca Plate and mantle layer above the slab using double-difference tomography to understand upper-plate volcanism and subduction zone process. The double-difference constraints for determining the hypocenters and velocity model ensure high accuracy of the relative location of earthquakes with respect to velocity structure. The relocated seismicity shows a smooth contortion in the slab-dip transition zone for \u223c400 km between the shallow (30\u00b0)-to-flat dipping interface to the northwest and the 30\u00b0-dipping interface to the southeast. We find a significant slab-dip difference (up to 10\u00b0) between our results and previous slab models along the profile region sampling the horizontal slab at a depth of \u223c85\u201395 km. Robust features in both P- and S-wave tomography inversions are both arc-normal and along-arc velocity variations. In the arc-normal direction, all profile results show that the slab velocities beneath the forearc (down to a depth of \u223c100 km) transition to higher velocities beneath the backarc (at \u223c100\u2013140 km depth). In the along-arc direction, velocities of the subducting flat slab are shown to be depressed compared to those of the normal-dip slab. In addition, high shear-wave velocities and low Vp/Vs are detected in the mantle layer above the flat slab, indicating its cold and dry environment. Such differences in the velocity structures for the slab and mantle wedge between the two regions may indicate different hydration states, which greatly affects the upper-plate structure of southern Peru.", "date": "2018-09-15", "date_type": "published", "publication": "Earth and Planetary Science Letters", "volume": "498", "publisher": "Elsevier", "pagerange": "334-347", "id_number": "CaltechAUTHORS:20180720-100400953", "issn": "0012-821X", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180720-100400953", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Seoul National University", "grant_number": "SRnD 3345-20160014" }, { "agency": "Nuclear Safety and Security Commission (Korea)", "grant_number": "1705010" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/j.epsl.2018.07.014", "primary_object": { "basename": "1-s2.0-S0012821X18304205-mmc1.docx", "url": "https://authors.library.caltech.edu/records/sjk25-br738/files/1-s2.0-S0012821X18304205-mmc1.docx" }, "related_objects": [ { "basename": "1-s2.0-S0012821X18304205-mmc2.txt", "url": "https://authors.library.caltech.edu/records/sjk25-br738/files/1-s2.0-S0012821X18304205-mmc2.txt" } ], "resource_type": "article", "pub_year": "2018", "author_list": "Lim, Hobin; Kim, YoungHee; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/y87zg-bva23", "eprint_id": 89082, "eprint_status": "archive", "datestamp": "2023-08-21 23:54:26", "lastmod": "2023-10-18 22:30:18", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Castellanos-J-C", "name": { "family": "Castellanos", "given": "Jorge C." }, "orcid": "0000-0002-0103-6430" }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" }, { "id": "P\u00e9rez-Campos-Xyoli", "name": { "family": "P\u00e9rez\u2010Campos", "given": "Xyoli" }, "orcid": "0000-0001-8970-7966" } ] }, "title": "Imaging the eastern Trans\u2010Mexican Volcanic Belt with ambient seismic noise: evidence for a slab tear", "ispublished": "pub", "full_text_status": "public", "keywords": "ambient noise; subduction; seismic anisotropy; surface waves; Trans\u2010Mexican Volcanic Belt; Middle America Trench", "note": "\u00a9 2018 The Authors. This is an open access article under the\nterms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the\nuse is non-commercial and no modifications or adaptations are made. \n\nReceived 16 MAR 2018; Accepted 18 AUG 2018; Accepted article online 22 AUG 2018; Published online 13 SEP 2018. \n\nThis research was supported by NSF, EAR\u20101645063 award. Our recognition is extended to the DGAPA\u2010PAPIIT IN105816 and CONACYT 177676 projects for maintaining the GECO Network. Our recognition is extended to the DGAPA\u2010PAPIIT IN105816, CONACYT 270544, and CONACYT 177676 projects for financing and maintaining the GECO Network. SSN data were obtained by the Servicio Sismol\u00f3gico Nacional (M\u00e9xico), and we thank its personnel for station maintenance, data acquisition, and distribution (SSN, 2017). We also thank the Centro de Ciencias de la Tierra de la Universidad Veracruzana (CCTUV) and the Civil Protection authorities of Veracruz (SPC\u2010VER) for maintaining the UV network. We are grateful to Michael Brudzinski, Enrique Cabral\u2010Cano, and Alejandra Arciniega\u2010Ceballos for providing access to OXNET data. We also thank the IRIS\u2010PASSCAL Instrumentation Center for making the data available. Figures were made using the Generic Mapping Tools v.4.5.9 (www.soest.hawaii.edu/gmt, last accessed November 2017; Wessel and Smith, 1998). We gratefully thank Zack Spica and Sara Dougherty for providing their insight and expertise throughout the development of this work. We are also very grateful to Martha Savage and two anonymous reviewers for their careful and constructive suggestions. The final shear wave velocity and radial anisotropy models can be downloaded from https://github.com/JorgeCastillo90/Paper-2018JB015783R.git.\n\nPublished - Castellanos_et_al-2018-Journal_of_Geophysical_Research_3A_Solid_Earth.pdf
Supplemental Material - jgrb53003-sup-0001-supplementary.pdf
Supplemental Material - jgrb53003-sup-0002-supplementary.xlsx
Supplemental Material - jgrb53003-sup-0003-supplementary.xlsx
", "abstract": "The eastern sector of the Trans\u2010Mexican Volcanic Belt (TMVB) is an enigmatic narrow zone that lies just above where the Cocos plate displays a sharp transition in dipping angle in central Mexico. Current plate models indicate that the transition from flat to steeper subduction is continuous through this region, but the abrupt end of the TMVB suggests that the difference in subduction styles is more likely to be accommodated by a slab tear. Based on a high\u2010resolution shear wave velocity and radial anisotropy model of the region, we argue that a slab tear within South Cocos can explain the abrupt end of the TMVB. We also quantify the azimuthal anisotropy beneath each seismic station and present a well\u2010defined flow pattern that shows how mantle material is being displaced from beneath the slab to the mantle wedge through the tear in the subducted Cocos plate. We suggest that the toroidal mantle flow formed around the slab edges is responsible for the existence of the volcanic gap in central Mexico. Moreover, we propose that the temperature increase caused by the influx of hot, less\u2010dense mantle material flowing through the tear to the Veracruz area may have significant implications for the thermomechanical state of the subducted slab, and explain why the intermediate\u2010depth seismicity ends suddenly at the southern boundary of the Veracruz basin. The composite mantle flow formed by the movement of mantle material through the slab tears in western and southern Mexico may be allowing the Cocos plate to rollback in segments.", "date": "2018-09", "date_type": "published", "publication": "Journal of Geophysical Research. Solid Earth", "volume": "123", "number": "9", "publisher": "American Geophysical Union", "pagerange": "7741-7759", "id_number": "CaltechAUTHORS:20180823-085003488", "issn": "2169-9313", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180823-085003488", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR-1645063" }, { "agency": "Universidad Nacional Aut\u00f3noma de M\u00e9xico (UNAM)", "grant_number": "IN105816" }, { "agency": "Consejo Nacional de Ciencia y Tecnolog\u00eda (CONACYT)", "grant_number": "177676" }, { "agency": "Consejo Nacional de Ciencia y Tecnolog\u00eda (CONACYT)", "grant_number": "270544" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1029/2018JB015783", "primary_object": { "basename": "jgrb53003-sup-0003-supplementary.xlsx", "url": "https://authors.library.caltech.edu/records/y87zg-bva23/files/jgrb53003-sup-0003-supplementary.xlsx" }, "related_objects": [ { "basename": "Castellanos_et_al-2018-Journal_of_Geophysical_Research_3A_Solid_Earth.pdf", "url": "https://authors.library.caltech.edu/records/y87zg-bva23/files/Castellanos_et_al-2018-Journal_of_Geophysical_Research_3A_Solid_Earth.pdf" }, { "basename": "jgrb53003-sup-0001-supplementary.pdf", "url": "https://authors.library.caltech.edu/records/y87zg-bva23/files/jgrb53003-sup-0001-supplementary.pdf" }, { "basename": "jgrb53003-sup-0002-supplementary.xlsx", "url": "https://authors.library.caltech.edu/records/y87zg-bva23/files/jgrb53003-sup-0002-supplementary.xlsx" } ], "resource_type": "article", "pub_year": "2018", "author_list": "Castellanos, Jorge C.; Clayton, Robert W.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/j9nzx-pbh47", "eprint_id": 88490, "eprint_status": "archive", "datestamp": "2023-08-19 11:15:28", "lastmod": "2023-10-18 22:06:03", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Liu-Guibao", "name": { "family": "Liu", "given": "Guibao" } }, { "id": "Persaud-P", "name": { "family": "Persaud", "given": "Patricia" }, "orcid": "0000-0003-3462-7023" }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" } ] }, "title": "Structure of the Northern Los Angeles Basins Revealed in Teleseismic Receiver Functions from Short\u2010Term Nodal Seismic Arrays", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 2018 Seismological Society of America. \n\nPublished Online 1 August 2018. \n\nData and Resources: The broadband seismograms used in this study were downloaded from the Incorporated Research Institutions for Seismology (IRIS) Data Management Center (DMC) at www.iris.edu (last accessed October 2017) or from the Southern California Earthquake Data Center using the Seismogram Transfer Program (STP) at http://scedc.caltech.edu/research-tools/stp/STPdocumentation.html (last accessed February 2018). Nodal data were collected by the three deployments operated by Louisiana State University, the California Institute of Technology, and the University of Utah. Seismic data from the SG1 line are archived at the IRIS DMC (Persaud, 2017; doi: 10.7914/SN/XG_2017); the presented data from SG2 and SB4 can be obtained from the authors. Event origin times and locations were obtained from the IRIS Data Service at https://ds.iris.edu/wilber3/find_event (last accessed October 2017). Active faults were compiled from the 2010 Fault Activity Map of California (Jennings and Bryant, 2010). \n\nThe broadband and nodal waveforms were all preprocessed using the Seismic Analysis Code (SAC) software (Goldstein et al., 2003), and the figures were all prepared with the Generic Mapping Tool (GMT) software (Wessel et al., 2013) and SAC. The authors thank Massimo Di Bona for providing the codes for calculating the receiver functions and Nicola Piana Agostinetti for his advice on the use of the codes. The authors are grateful to the deployment and pickup crews from the California State Polytechnic University, Pomona, local California high schools, the Jet Propulsion Laboratory, California Institute of Technology, and Louisiana State University who helped with the fieldwork; the Los Angeles area homeowners for their willingness to host the nodes, and Bridget O'Neill and Noel Barstow for their help coordinating the Incorporated Research Institutions for Seismology (IRIS) Portable Array Seismic Studies of the Continental Lithosphere (PASSCAL) nodes that were deployed along SG1. The authors thank Carl Tape, an anonymous reviewer, Editor\u2010in\u2010Chief Zhigang Peng, and Guest Editors Marianne Karplus and Brandon Schmandt for their thoughtful and constructive comments that helped improve the article. G. L. and P. P. thank the Geology and Geophysics Department at Louisiana State University for supporting this project. This research was partially supported by the U.S. Geological Survey (USGS) Award GS17AP00002.\n\nSupplemental Material - srl-2018071_esupp.zip
", "abstract": "We use teleseismic receiver functions computed from an \u223c35\u2010day nodal dataset recorded along three profiles in the northern basins of Los Angeles, California, to map the depth and shape of the sediment\u2013basement interface and to identify possible deep fault offsets. The results show the Moho discontinuity, the bottom of the basement, and intermediary sedimentary layers. There are also indications of midcrustal offsets along strike of the Red Hill and Raymond faults. The results are compared with receiver functions from nearby permanent broadband stations and the 1993 Los Angeles Region Seismic Experiment (LARSE) profile. The images show that dense deployments of node\u2010type sensors can be used to characterize basin structure in a noisy urban environment.", "date": "2018-09", "date_type": "published", "publication": "Seismological Research Letters", "volume": "89", "number": "5", "publisher": "Seismological Society of America", "pagerange": "1680-1689", "id_number": "CaltechAUTHORS:20180802-082417478", "issn": "0895-0695", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180802-082417478", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Louisiana State University" }, { "agency": "USGS", "grant_number": "GS17AP00002" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1785/0220180071", "primary_object": { "basename": "srl-2018071_esupp.zip", "url": "https://authors.library.caltech.edu/records/j9nzx-pbh47/files/srl-2018071_esupp.zip" }, "resource_type": "article", "pub_year": "2018", "author_list": "Liu, Guibao; Persaud, Patricia; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/eyaa6-hf002", "eprint_id": 87838, "eprint_status": "archive", "datestamp": "2023-08-19 09:32:22", "lastmod": "2023-10-18 21:28:44", "type": "conference_item", "metadata_visibility": "show", "creators": { "items": [ { "id": "Kohler-M-D", "name": { "family": "Kohler", "given": "M. D." } }, { "id": "Guy-R", "name": { "family": "Guy", "given": "R." } }, { "id": "Bunn-J", "name": { "family": "Bunn", "given": "J." }, "orcid": "0000-0002-3798-298X" }, { "id": "Massari-A", "name": { "family": "Massari", "given": "A." }, "orcid": "0000-0002-6561-4674" }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "R." }, "orcid": "0000-0003-3323-3508" }, { "id": "Heaton-T-H", "name": { "family": "Heaton", "given": "T." }, "orcid": "0000-0003-3363-2197" }, { "id": "Chandy-K-M", "name": { "family": "Chandy", "given": "K. M." } }, { "id": "Ebrahimian-H", "name": { "family": "Ebrahimian", "given": "H." } }, { "id": "Dorn-C", "name": { "family": "Dorn", "given": "C." }, "orcid": "0000-0001-6516-2586" } ] }, "title": "Community seismic network and localized earthquake situational awareness", "ispublished": "unpub", "full_text_status": "public", "note": "This study was partially funded by a Caltech-JPL Research and Technology Development Fund grant. We also thank the Betty and Gordon Moore Foundation, the Terrestrial Hazard Observation and Reporting Center at Caltech, and the Divisions of Geological and Planetary Science, and Engineering and Applied Science at Caltech for funding the development of the Community Seismic Network.\n\nPublished - Kohler_etal_11ncee_1675.pdf
", "abstract": "Community-hosted seismic networks are a solution to the need for large numbers of sensors to operate over a seismically active region in order to accurately measure the size and location of an earthquake, assess resulting damage, and provide alerts. The Community Seismic Network is one such strong-motion network, currently comprising hundreds of elements located in California. It consists of low-cost, three-component, MEMS accelerometers capable of recording accelerations up to twice the level of gravity. The primary product of the network is to produce measurements of shaking of the ground and multiple locations of every upper floor in buildings, in the seconds during and following a major earthquake. Each sensor uses a small, dedicated ARM processor computer running Linux, and analyzes time series data in real time at hundreds of samples per second. The network reports on shaking parameters that indicate intensity of the structural response levels such as maximum floor acceleration and velocity, displacement of a floor in a building, as well as data products that depend on the response time histories. To do this, Cloud computing has been expanded through the use of statically defined subsets of sensors called cloudlets. These are smaller subsets of similar sensors that carry out customized calculations for those locations. The measurements are reported as rapidly as possible following an earthquake so that they may be incorporated into structural diagnosis and prognosis applications that can be used by first responders to prioritize their initial disaster management efforts. The cloudlet displays are customized for specific buildings and they show in real time: instantaneous displacement, inter-story drift, and resonant frequency and mode shapes using system identification software tools. The real-time display products are useful for decision-making about whether the potential for damage exists, what level of damage may have occurred and where, and whether total business disruption is necessary. City-wide dense monitoring makes it possible for emergency response managers to prioritize the target locations requiring first response on a block-by-block scale based on reports of shaking intensity.", "date": "2018-06", "date_type": "published", "publisher": "Caltech Library", "id_number": "CaltechAUTHORS:20180713-133233514", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180713-133233514", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Caltech-JPL Research and Technology Development Fund" }, { "agency": "Gordon and Betty Moore Foundation" }, { "agency": "Terrestrial Hazard Observation and Reporting Center" }, { "agency": "Caltech Division of Geological and Planetary Science" }, { "agency": "Caltech Division of Engineering and Applied Science" } ] }, "other_numbering_system": { "items": [ { "id": "2018-04", "name": "EERL Report" } ] }, "local_group": { "items": [ { "id": "Earthquake-Engineering-Research-Laboratory" }, { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "primary_object": { "basename": "Kohler_etal_11ncee_1675.pdf", "url": "https://authors.library.caltech.edu/records/eyaa6-hf002/files/Kohler_etal_11ncee_1675.pdf" }, "resource_type": "conference_item", "pub_year": "2018", "author_list": "Kohler, M. D.; Guy, R.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/ffmbm-2r198", "eprint_id": 86154, "eprint_status": "archive", "datestamp": "2023-08-21 23:21:36", "lastmod": "2023-10-18 19:18:06", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Jiang-Chengxin", "name": { "family": "Jiang", "given": "Chengxin" }, "orcid": "0000-0002-8768-2782" }, { "id": "Schmandt-B", "name": { "family": "Schmandt", "given": "Brandon" }, "orcid": "0000-0003-1049-9020" }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" } ] }, "title": "An anisotropic contrast in the lithosphere across the central San Andreas fault", "ispublished": "pub", "full_text_status": "public", "keywords": "central California; SKS splitting; fault\u2010parallel anisotropy; Isabella anomaly", "note": "\u00a9 2018 American Geophysical Union. \n\nReceived 5 FEB 2018; Accepted 20 APR 2018; Accepted article online 30 APR 2018; Published online 9 MAY 2018. \n\nCCSE seismic data are publicly available via the IRIS DMC (http://ds.iris.edu/ds/nodes/dmc/), network code TO 2013\u20102015 (CCSE, 2013). This research was supported by NSF\u2010EAR 1315856 and 1554908, and the seismic instruments used were acquired with support from the Gordon and Betty Moore Foundation. Two anonymous reviewers and the Editor Gavin Hayes are thanked for their constructive feedback.\n\nPublished - Jiang_et_al-2018-Geophysical_Research_Letters.pdf
Supplemental Material - grl57387-sup-0001-figure_s01.pdf
", "abstract": "Seismic anisotropy of the lithosphere and asthenosphere was investigated with a dense broadband seismic transect nearly orthogonal to the central San Andreas fault (SAF). A contrast in SK(K)S splitting was found across the SAF, with a clockwise rotation of the fast orientation ~26\u00b0 closer to the strike of the SAF and greater delay times for stations located within 35 km to the east. Dense seismograph spacing requires heterogeneous anisotropy east of the SAF in the uppermost mantle or crust. Based on existing station coverage, such a contrast in splitting orientations across the SAF may be unusual along strike and its location coincides with the high\u2010velocity Isabella anomaly in the upper mantle. If the Isabella anomaly is a fossil slab fragment translating with the Pacific plate, the anomalous splitting east of the SAF could indicate a zone of margin\u2010parallel shear beneath the western edge of North America.", "date": "2018-05-16", "date_type": "published", "publication": "Geophysical Research Letters", "volume": "45", "number": "9", "publisher": "American Geophysical Union", "pagerange": "3967-3975", "id_number": "CaltechAUTHORS:20180501-112233586", "issn": "0094-8276", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180501-112233586", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR-1315856" }, { "agency": "NSF", "grant_number": "EAR-1554908" }, { "agency": "Gordon and Betty Moore Foundation" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1029/2018GL077476", "primary_object": { "basename": "Jiang_et_al-2018-Geophysical_Research_Letters.pdf", "url": "https://authors.library.caltech.edu/records/ffmbm-2r198/files/Jiang_et_al-2018-Geophysical_Research_Letters.pdf" }, "related_objects": [ { "basename": "grl57387-sup-0001-figure_s01.pdf", "url": "https://authors.library.caltech.edu/records/ffmbm-2r198/files/grl57387-sup-0001-figure_s01.pdf" } ], "resource_type": "article", "pub_year": "2018", "author_list": "Jiang, Chengxin; Schmandt, Brandon; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/k4x30-dcj47", "eprint_id": 84898, "eprint_status": "archive", "datestamp": "2023-08-21 23:11:05", "lastmod": "2023-10-18 16:57:12", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Jiang-Chengxin", "name": { "family": "Jiang", "given": "Chengxin" }, "orcid": "0000-0002-8768-2782" }, { "id": "Schmandt-B", "name": { "family": "Schmandt", "given": "Brandon" }, "orcid": "0000-0003-1049-9020" }, { "id": "Hansen-S-M", "name": { "family": "Hansen", "given": "Steven M." } }, { "id": "Dougherty-S-L", "name": { "family": "Dougherty", "given": "Sara L." }, "orcid": "0000-0002-5327-3286" }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" }, { "id": "Farrell-J", "name": { "family": "Farrell", "given": "Jamie" } }, { "id": "Lin-Fan-Chi", "name": { "family": "Lin", "given": "Fan-Chi" }, "orcid": "0000-0003-0394-6830" } ] }, "title": "Rayleigh and S wave tomography constraints on subduction termination and lithospheric foundering in central California", "ispublished": "pub", "full_text_status": "public", "keywords": "Isabella Anomaly; San Andreas Fault; Sierra Nevada; Monterey microplate; lithospheric foundering", "note": "\u00a9 2018 Elsevier B.V. \n\nReceived 3 November 2017, Revised 2 February 2018, Accepted 6 February 2018, Available online 19 February 2018. \n\nAny use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government. \n\nSeismic data from the CCSE array will be openly available through the IRIS Data Management Center starting in November 2017. Deployment of the CCSE array would not have been possible without the support of private landowners and the Kern and Tulare County Fire Departments who hosted seismographs. Richard Guy is thanked for coordinating much of the fieldwork effort. Most of the seismographs used in the project were provided by the Tectonics Observatory at Caltech, which was funded by the Gordon and Betty Moore Foundation. Emily Brodsky and Elizabeth Cochran are thanked for loaning additional instruments. Emily Wolin, Will Levandowski, and Carl Tape are thanked for constructive reviews. Data collection and analysis were supported by NSF EAR1315856 (BS), 1314910 (RWC), and CyberSEES-1442665 (FCL).\n\nSupplemental Material - mmc1.pdf
Supplemental Material - mmc2.pdf
Supplemental Material - mmc3.pdf
Supplemental Material - mmc4.pdf
Supplemental Material - mmc5.pdf
Supplemental Material - mmc6.pdf
", "abstract": "The crust and upper mantle structure of central California have been modified by subduction termination, growth of the San Andreas plate boundary fault system, and small-scale upper mantle convection since the early Miocene. Here we investigate the contributions of these processes to the creation of the Isabella Anomaly, which is a high seismic velocity volume in the upper mantle. There are two types of hypotheses for its origin. One is that it is the foundered mafic lower crust and mantle lithosphere of the southern Sierra Nevada batholith. The alternative suggests that it is a fossil slab connected to the Monterey microplate. A dense broadband seismic transect was deployed from the coast to the western Sierra Nevada to fill in the least sampled areas above the Isabella Anomaly, and regional-scale Rayleigh and S wave tomography are used to evaluate the two hypotheses. New shear velocity (Vs) tomography images a high-velocity anomaly beneath coastal California that is sub-horizontal at depths of \u223c40\u201380 km. East of the San Andreas Fault a continuous extension of the high-velocity anomaly dips east and is located beneath the Sierra Nevada at \u223c150\u2013200 km depth. The western position of the Isabella Anomaly in the uppermost mantle is inconsistent with earlier interpretations that the Isabella Anomaly is connected to actively foundering foothills lower crust. Based on the new Vs images, we interpret that the Isabella Anomaly is not the dense destabilized root of the Sierra Nevada, but rather a remnant of Miocene subduction termination that is translating north beneath the central San Andreas Fault. Our results support the occurrence of localized lithospheric foundering beneath the high elevation eastern Sierra Nevada, where we find a lower crustal low Vs layer consistent with a small amount of partial melt. The high elevations relative to crust thickness and lower crustal low Vs zone are consistent with geological inferences that lithospheric foundering drove uplift and a \u223c3\u20134 Ma pulse of basaltic magmatism.", "date": "2018-04-15", "date_type": "published", "publication": "Earth and Planetary Science Letters", "volume": "488", "publisher": "Elsevier", "pagerange": "14-26", "id_number": "CaltechAUTHORS:20180221-090936349", "issn": "0012-821X", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180221-090936349", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Gordon and Betty Moore Foundation" }, { "agency": "NSF", "grant_number": "EAR-1315856" }, { "agency": "NSF", "grant_number": "EAR-1314910" }, { "agency": "NSF", "grant_number": "CCE-1442665" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/j.epsl.2018.02.009", "primary_object": { "basename": "mmc1.pdf", "url": "https://authors.library.caltech.edu/records/k4x30-dcj47/files/mmc1.pdf" }, "related_objects": [ { "basename": "mmc2.pdf", "url": "https://authors.library.caltech.edu/records/k4x30-dcj47/files/mmc2.pdf" }, { "basename": "mmc3.pdf", "url": "https://authors.library.caltech.edu/records/k4x30-dcj47/files/mmc3.pdf" }, { "basename": "mmc4.pdf", "url": "https://authors.library.caltech.edu/records/k4x30-dcj47/files/mmc4.pdf" }, { "basename": "mmc5.pdf", "url": "https://authors.library.caltech.edu/records/k4x30-dcj47/files/mmc5.pdf" }, { "basename": "mmc6.pdf", "url": "https://authors.library.caltech.edu/records/k4x30-dcj47/files/mmc6.pdf" } ], "resource_type": "article", "pub_year": "2018", "author_list": "Jiang, Chengxin; Schmandt, Brandon; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/wq0s5-e4j30", "eprint_id": 83973, "eprint_status": "archive", "datestamp": "2023-08-21 22:25:47", "lastmod": "2024-01-14 19:15:29", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Castro-R-R", "name": { "family": "Castro", "given": "Ra\u00fal R." } }, { "id": "Stock-J-M", "name": { "family": "Stock", "given": "Joann M." }, "orcid": "0000-0003-4816-7865" }, { "id": "Hauksson-E", "name": { "family": "Hauksson", "given": "Egill" }, "orcid": "0000-0002-6834-5051" }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" } ] }, "title": "Source Functions and Path Effects from Earthquakes in the Farallon Transform Fault Region, Gulf of California, Mexico that Occurred on October 2013", "ispublished": "unpub", "full_text_status": "restricted", "keywords": "Earthquakes in the Gulf of California; source and path effects; Farallon transform fault", "note": "\u00a9 2018 Springer International Publishing AG. \n\nFirst Online: 21 December 2017. \n\nReprinted from: Pure Appl. Geophys. 174 (2017), 2239\u20132256, 2016 Springer International Publishing. DOI 10.1007/s00024-016-1346-4. \n\nThe operation of the RESBAN network has been possible thanks to the financial support of the Mexican National Council for Science and Technology (CONACYT) (projects CB-2011-01-165401(C0C059), G33102-T and 59216). This paper was prepared while the first author (RRC) was on sabbatical year in Caltech. We thank Prof. Gurnis for the support provided. Dr. Lenin Avila-Barrientos facilitated part of the spectral records used to calculate the site functions. Antonio Mendoza Camberos pre-process the data from the RESBAN network and Arturo Perez Vertti maintains and operates the stations. We thank Dr. Edwards and the anonymous reviewer for their careful revisions, comments and suggestions which help us to improve the manuscript. We also acknowledge the Editor, Dr. Thomas H.W. Goebel.", "abstract": "We determined source spectral functions, Q and site effects using regional records of body waves from the October 19, 2013 (M_w = 6.6) earthquake and eight aftershocks located 90 km east of Loreto, Baja California Sur, Mexico. We also analyzed records from a foreshock with magnitude 3.3 that occurred 47 days before the mainshock. The epicenters of this sequence are located in the south-central region of the Gulf of California (GoC) near and on the Farallon transform fault. This is one of the most active regions of the GoC, where most of the large earthquakes have strike\u2013slip mechanisms. Based on the distribution of the aftershocks, the rupture propagated northwest with a rupture length of approximately 27 km. We calculated 3-component P- and S-wave spectra from ten events recorded by eleven stations of the Broadband Seismological Network of the GoC (RESBAN). These stations are located around the GoC and provide good azimuthal coverage (the average station gap is 39\u25e6). The spectral records were corrected for site effects, which were estimated calculating average spectral ratios between horizontal and vertical components (HVSR method). The site-corrected spectra were then inverted to determine the source functions and to estimate the attenuation quality factor Q. The values of Q resulting from the spectral inversion can be approximated by the relations Q_P = 48.1 1\u00b11^(f0:880:04) and QS = 135:4 1:1f \u00b1^(0:580:03) and are consistent with previous estimates reported by Vidales-Basurto et al. (Bull Seism Soc Am 104:2027\u20132042, 2014) for the south-central GoC. The stress drop estimates, obtained using the \u03c9^2 model, are below 1.7 MPa, with the highest stress drops determined for the mainshock and the aftershocks located in the ridge zone. We used the values of Q obtained to recalculate source and site effects with a different spectral inversion scheme. We found that sites with low S-wave amplification also tend to have low P-wave amplification, except for stations BAHB, GUYB and SFQB, located on igneous rocks, where the P-wave site amplification is higher.", "date": "2017-12-21", "date_type": "published", "publisher": "Birkh\u00e4user", "place_of_pub": "Cham, Switzerland", "pagerange": "45-62", "id_number": "CaltechAUTHORS:20171220-093808988", "isbn": "978-3-319-71564-3", "book_title": "Earthquakes and Multi-hazards Around the Pacific Rim", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20171220-093808988", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Comisi\u00f3n Nacional de Investigaci\u00f3n Cient\u00edfica y Tecnol\u00f3gica (CONICYT)", "grant_number": "CB-2011-01-165401(C0C059)" }, { "agency": "Comisi\u00f3n Nacional de Investigaci\u00f3n Cient\u00edfica y Tecnol\u00f3gica (CONICYT)", "grant_number": "G33102-T" }, { "agency": "Comisi\u00f3n Nacional de Investigaci\u00f3n Cient\u00edfica y Tecnol\u00f3gica (CONICYT)", "grant_number": "59216" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "contributors": { "items": [ { "id": "Zhang-Yongxian", "name": { "family": "Zhang", "given": "Yongxian" } }, { "id": "Goebel-T", "name": { "family": "Goebel", "given": "Thomas" } }, { "id": "Peng-Zhigang", "name": { "family": "Peng", "given": "Zhigang" } }, { "id": "Williams-C-A", "name": { "family": "Williams", "given": "Charles A." } }, { "id": "Yode-M", "name": { "family": "Yode", "given": "Mark" } }, { "id": "Rundle-J-B", "name": { "family": "Rundle", "given": "John B." } } ] }, "doi": "10.1007/978-3-319-71565-0_4", "resource_type": "book_section", "pub_year": "2017", "author_list": "Castro, Ra\u00fal R.; Stock, Joann M.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/wb5pg-ear41", "eprint_id": 74473, "eprint_status": "archive", "datestamp": "2023-08-21 22:11:18", "lastmod": "2023-10-24 22:40:49", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Castro-R-R", "name": { "family": "Castro", "given": "R. R." } }, { "id": "Stock-J-M", "name": { "family": "Stock", "given": "J. M." }, "orcid": "0000-0003-4816-7865" }, { "id": "Hauksson-E", "name": { "family": "Hauksson", "given": "E." }, "orcid": "0000-0002-6834-5051" }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "R. W." }, "orcid": "0000-0003-3323-3508" } ] }, "title": "Active tectonics in the Gulf of California and seismicity (M > 3.0) for the period 2002\u20132014", "ispublished": "pub", "full_text_status": "restricted", "keywords": "Seismotectonics; Gulf of California, Mexico; Seismicity catalog", "note": "\u00a9 2017 Elsevier B.V. \n\nReceived 29 July 2016, Revised 14 February 2017, Accepted 20 February 2017, Available online 22 February 2017. \n\nThis paper was prepared while the first author (RRC) was on sabbatical year in Caltech. We thank CONACYT and Prof. Michael Gurnis for the support provided. The operation of the RESBAN network has been possible thanks to the financial support of the National Council of Science and Technology, Mexico (CONACYT) (projects CB-2011-01-165401(C0C059), G33102-T and 59216). Antonio Mendoza Camberos pre-process the data from the RESBAN network and Arturo Perez Vertti maintains and operates the stations. The authors thank the editors and the comments and suggestions of two anonymous reviewers.", "abstract": "We present a catalog of accurate epicenter coordinates of earthquakes located in the Gulf of California (GoC) in the period 2002\u20132014 that permits us to analyze the seismotectonics and to estimate the depth of the seismogenic zone of this region. For the period April 2002 to December 2014 we use body-wave arrival times from regional stations of the Broadband Seismological Network of the GoC (RESBAN) operated by CICESE to improve hypocenter locations reported by global catalogs. For the northern region of the GoC (30\u00b0N\u201332\u00b0N) we added relocated events from the 2011-Hauksson-Yang-Shearer, Waveform Relocated Earthquake Catalog for Southern California (Hauksson et al., 2012; Lin et al., 2007). From October 2005 to October 2006 we incorporated hypcenters located by Sumy et al. (2013) in the southern GoC combining an array of ocean-bottom seismographs, of the SCOOBA experiment, with onshore stations of the NARS-Baja array. This well constrained catalog of seismicity highlights zones of active tectonics and seismic deformation within the North America-Pacific plate boundary. We estimate that the minimum magnitude of completeness of this catalog is Mc = 3.3 \u00b1 0.1 and the b = 0.92 \u00b1 0.04 value of the Gutenberg-Richter relation. We find that most earthquakes in the southern GoC are generated by transform faults and this region is more active than the central GoC region. However, the northern region, where most deformation is generated by oblique faults is as active as the southern region. We used the ISC catalog to evaluate the size distribution of seismicity of these regions, and the b value of the Gutenberg-Richter relation and found that b is slightly lower in the central GoC (b = 0.86 \u00b1 0.02) compared to the northern (b = 1.14 \u00b1 0.04) and the southern (b = 1.11 \u00b1 0.04) regions. We observed seismicity that occurs in the Stable Central Peninsular Province, despite the fact that significant active deformation has not been identified in this region.", "date": "2017-11-13", "date_type": "published", "publication": "Tectonophysics", "volume": "719-720", "publisher": "Elsevier", "pagerange": "4-16", "id_number": "CaltechAUTHORS:20170222-145907573", "issn": "0040-1951", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170222-145907573", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Consejo Nacional de Ciencia y Tecnolog\u00eda (CONACYT)", "grant_number": "CB-2011-01-165401" }, { "agency": "Consejo Nacional de Ciencia y Tecnolog\u00eda (CONACYT)", "grant_number": "G33102-T" }, { "agency": "Consejo Nacional de Ciencia y Tecnolog\u00eda (CONACYT)", "grant_number": "59216" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/j.tecto.2017.02.015", "resource_type": "article", "pub_year": "2017", "author_list": "Castro, R. R.; Stock, J. M.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/3ptje-xec95", "eprint_id": 79231, "eprint_status": "archive", "datestamp": "2023-08-19 03:55:26", "lastmod": "2023-10-26 14:43:18", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Castro-R-R", "name": { "family": "Castro", "given": "Ra\u00fal R." } }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert" }, "orcid": "0000-0003-3323-3508" }, { "id": "Hauksson-E", "name": { "family": "Hauksson", "given": "Egill" }, "orcid": "0000-0002-6834-5051" }, { "id": "Stock-J-M", "name": { "family": "Stock", "given": "Joann" }, "orcid": "0000-0003-4816-7865" } ] }, "title": "Observations of remotely triggered seismicity in Salton Sea and Coso geothermal regions, Southern California, USA, after big (M_W>7.8) teleseismic earthquakes", "ispublished": "pub", "full_text_status": "public", "keywords": "remote triggering, seismicity southern California, USA, Coso geothermal field, Salton Sea geothermal field", "note": "\u00a9 2017 Instituto de Geof\u00edsica is licensed under a Creative Commons Reconocimiento-NoComercial-SinObraDerivada 3.0 Unported License. \n\nReceived: September 27, 2016; accepted: January 08, 2017; published on line: July 01, 2017. \n\nThis paper was prepared while the first author (RRC) was on sabbatical year in Caltech. We thank CONACYT and Prof. Gurnis for the support provided. Antonio Mendoza helped us to prepare some maps. We used parametric data from the Caltech/USGS Southern California Seismic Network (SCSN); DOI: 10.7914/SN/CI; stored at the Southern California Earthquake Center. doi:10.7909/C3WD3xH1. We thank the two anonymous reviewers and the Editor Dr. Xyoli P\u00e9rez-Campos for their comments and suggestions.\n\nPublished - 4castro.pdf
", "abstract": "A relocated catalog was used to search for changes in seismicity rate in the Salton Sea and the Coso geothermal regions, southern California, USA, during and after large (M_W>7.8) teleseismic earthquakes. Seismicity in these two regions was analyzed within 30- day windows before and after the occurrence of five major earthquakes: the 2002 Denali fault, Alaska (M_W 7.9); the 2004 Sumatra-Andaman (M_W 9.2); the 2010 Central Chile (M_W 8.8); the 2011 Tohoku-Oki, Japan (M_W 9.1); and the 2012 Offshore Northern Sumatra (M_W 8.6) earthquakes. \n\nThe Denali (M_W 7.9) earthquake coincided with an increase in seismicity in the Salton Sea region the day when this remote event occurred, indicating that instantaneous triggered seismicity was likely related with the passage of its surface waves. However, in the Coso region the seismicity rate remained approximately constant during the 30-day observation period. The seismicity after the 2004 Sumatra-Andaman (M_W 9.2) earthquake increased in both regions 9 days after the mega-earthquake. The seismicity after the 2010 Chile (M_W 8.8) earthquake increased in both regions approximately 14 days after the remote event. The seismicity in Salton Sea and Coso regions increased 17 and 14 days, respectively, after the 2011 Japan (M_W 9.1) earthquake, suggesting that delayed triggered seismicity was induced after the passage of the surface waves in both regions. Similarly, 6 and 16 days after the 2012 northern Sumatra (M_W 8.6) earthquake the seismicity also increased in Salton Sea and Coso regions, respectively. These observations can be interpreted as evidence of instantaneous and delayed dynamic triggering induced by large remote earthquakes. The maximum magnitude of the delayed triggered swarm increased with the strength (M_0/D) of the mega-earthquake and, the stronger the remote earthquake, the longer the delay time.", "date": "2017-07", "date_type": "published", "publication": "Geofisica Internacional", "volume": "56", "number": "3", "publisher": "Union Fisica Mexicana", "pagerange": "269-286", "id_number": "CaltechAUTHORS:20170720-074723751", "issn": "0016-7169", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170720-074723751", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Consejo Nacional de Ciencia y Tecnolog\u00eda (CONACYT)" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "primary_object": { "basename": "4castro.pdf", "url": "https://authors.library.caltech.edu/records/3ptje-xec95/files/4castro.pdf" }, "resource_type": "article", "pub_year": "2017", "author_list": "Castro, Ra\u00fal R.; Clayton, Robert; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/y62qc-5ch85", "eprint_id": 71851, "eprint_status": "archive", "datestamp": "2023-08-21 21:07:22", "lastmod": "2023-10-23 15:49:49", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Castro-R-R", "name": { "family": "Castro", "given": "Ra\u00fal R." } }, { "id": "Stock-J-M", "name": { "family": "Stock", "given": "Joann M." }, "orcid": "0000-0003-4816-7865" }, { "id": "Hauksson-E", "name": { "family": "Hauksson", "given": "Egill" }, "orcid": "0000-0002-6834-5051" }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" } ] }, "title": "Source Functions and Path Effects from Earthquakes in the Farallon Transform Fault Region, Gulf of California, Mexico that Occurred on October 2013", "ispublished": "pub", "full_text_status": "restricted", "keywords": "Earthquakes in the Gulf of California; source and path effects; Farallon transform fault", "note": "\u00a9 2016 Springer International Publishing. \n\nReceived: 25 January 2016; Revised: 27 June 2016; Accepted: 29 June 2016; First Online: 09 July 2016. \n\nThe operation of the RESBAN network has been possible thanks to the financial support of the Mexican National Council for Science and Technology (CONACYT) (projects CB-2011-01-165401(C0C059), G33102-T and 59216). This paper was prepared while the first author (RRC) was on sabbatical year in Caltech. We thank Prof. Gurnis for the support provided. Dr. Lenin Avila-Barrientos facilitated part of the spectral records used to calculate the site functions. Antonio Mendoza Camberos pre-process the data from the RESBAN network and Arturo Perez Vertti maintains and operates the stations. We thank Dr. Edwards and the anonymous reviewer for their careful revisions, comments and suggestions which help us to improve the manuscript. We also acknowledge the Editor, Dr. Thomas H.W. Goebel.", "abstract": "We determined source spectral functions, Q and site effects using regional records of body waves from the October 19, 2013 (M_w = 6.6) earthquake and eight aftershocks located 90 km east of Loreto, Baja California Sur, Mexico. We also analyzed records from a foreshock with magnitude 3.3 that occurred 47 days before the mainshock. The epicenters of this sequence are located in the south-central region of the Gulf of California (GoC) near and on the Farallon transform fault. This is one of the most active regions of the GoC, where most of the large earthquakes have strike\u2013slip mechanisms. Based on the distribution of the aftershocks, the rupture propagated northwest with a rupture length of approximately 27 km. We calculated 3-component P- and S-wave spectra from ten events recorded by eleven stations of the Broadband Seismological Network of the GoC (RESBAN). These stations are located around the GoC and provide good azimuthal coverage (the average station gap is 39\u00b0). The spectral records were corrected for site effects, which were estimated calculating average spectral ratios between horizontal and vertical components (HVSR method). The site-corrected spectra were then inverted to determine the source functions and to estimate the attenuation quality factor Q. The values of Q resulting from the spectral inversion can be approximated by the relations Q_P =48.1\u00b11.1f^(0.88\u00b10.04) and Q_S =135.4\u00b11.1f^(0.58\u00b10.03) and are consistent with previous estimates reported by Vidales-Basurto et al. (Bull Seism Soc Am 104:2027\u20132042, 2014) for the south-central GoC. The stress drop estimates, obtained using the \u03c92 model, are below 1.7 MPa, with the highest stress drops determined for the mainshock and the aftershocks located in the ridge zone. We used the values of Q obtained to recalculate source and site effects with a different spectral inversion scheme. We found that sites with low S-wave amplification also tend to have low P-wave amplification, except for stations BAHB, GUYB and SFQB, located on igneous rocks, where the P-wave site amplification is higher.", "date": "2017-06", "date_type": "published", "publication": "Pure and Applied Geophysics", "volume": "174", "number": "6", "publisher": "Springer", "pagerange": "2239-2256", "id_number": "CaltechAUTHORS:20161109-071414936", "issn": "0033-4553", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161109-071414936", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Consejo Nacional de Ciencia y Tecnolog\u00eda (CONACYT)", "grant_number": "CB-2011-01-165401" }, { "agency": "Consejo Nacional de Ciencia y Tecnolog\u00eda (CONACYT)", "grant_number": "C0C059" }, { "agency": "Consejo Nacional de Ciencia y Tecnolog\u00eda (CONACYT)", "grant_number": "G33102-T" }, { "agency": "Consejo Nacional de Ciencia y Tecnolog\u00eda (CONACYT)", "grant_number": "59216" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1007/s00024-016-1346-4", "resource_type": "article", "pub_year": "2017", "author_list": "Castro, Ra\u00fal R.; Stock, Joann M.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/kmdpr-3pb02", "eprint_id": 73802, "eprint_status": "archive", "datestamp": "2023-08-19 01:01:50", "lastmod": "2023-10-24 16:28:01", "type": "conference_item", "metadata_visibility": "show", "creators": { "items": [ { "id": "Massari-A", "name": { "family": "Massari", "given": "A." }, "orcid": "0000-0002-6561-4674" }, { "id": "Kohler-M-D", "name": { "family": "Kohler", "given": "M." } }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "R." }, "orcid": "0000-0003-3323-3508" }, { "id": "Guy-R", "name": { "family": "Guy", "given": "R." } }, { "id": "Heaton-T-H", "name": { "family": "Heaton", "given": "T." }, "orcid": "0000-0003-3363-2197" }, { "id": "Bunn-J", "name": { "family": "Bunn", "given": "J." }, "orcid": "0000-0002-3798-298X" }, { "id": "Chandy-K-M", "name": { "family": "Chandy", "given": "K. M." } }, { "id": "Demetri-D", "name": { "family": "Demetri", "given": "D." } } ] }, "title": "Dense Building Instrumentation Application for City-Wide Structural Health Monitoring", "ispublished": "unpub", "full_text_status": "public", "keywords": "damage detection, structural health monitoring, seismic instrumentation, earthquake engineering, resilient cities", "note": "We thank Christopher Janover for his work developing the automation tools used in our study. This study was partially funded by a Caltech-JPL Research and Technology Development Fund grant. We also thank the Betty and Gordon Moore Foundation, the Terrestrial Hazard Observation and Reporting Center at Caltech, and the Divisions of Geological and Planetary Science, and Engineering and Applied Science at Caltech for funding the development of the Community Seismic Network.\n\nAccepted Version - Massari_etal_Paper_N\u00b0_3735.pdf
", "abstract": "The Community Seismic Network (CSN) has partnered with the NASA Jet Propulsion Laboratory (JPL) to initiate a campus-wide structural monitoring program of all buildings on the premises. The JPL campus serves as a proxy for a densely instrumented urban city with localized vibration measurements collected throughout the free-field and built environment. Instrumenting the entire campus provides dense measurements in a horizontal geospatial sense for soil response; in addition five buildings have been instrumented on every floor of the structure. Each building has a unique structural system as well as varied amounts of structural information via structural drawings, making several levels of assessment and evaluation possible. Computational studies with focus on damage detection applied to the campus structural network are demonstrated for a collection of buildings. For campus-wide real-time and post-event evaluation, ground and building response products using CSN data are illustrating the usefulness of higher spatial resolution compared to what was previously typical with sparser instrumentation.", "date": "2017-01-28", "date_type": "published", "publisher": "Caltech Library", "id_number": "CaltechAUTHORS:20170127-163202195", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170127-163202195", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "JPL Research and Technology Development Fund" }, { "agency": "Gordon and Betty Moore Foundation" }, { "agency": "Caltech Terrestrial Hazards Observations and Reporting center (THOR)" }, { "agency": "Caltech Division of Geological and Planetary Sciences" }, { "agency": "Caltech Division of Engineering and Applied Science" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "primary_object": { "basename": "Massari_etal_Paper_N\u00b0_3735.pdf", "url": "https://authors.library.caltech.edu/records/kmdpr-3pb02/files/Massari_etal_Paper_N\u00b0_3735.pdf" }, "resource_type": "conference_item", "pub_year": "2017", "author_list": "Massari, A.; Kohler, M.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/qgy3n-byt61", "eprint_id": 70995, "eprint_status": "archive", "datestamp": "2023-08-20 14:10:24", "lastmod": "2023-10-23 15:15:13", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Inbal-Asaf", "name": { "family": "Inbal", "given": "A." }, "orcid": "0000-0001-8848-7279" }, { "id": "Ampuero-J-P", "name": { "family": "Ampuero", "given": "J. P." }, "orcid": "0000-0002-4827-7987" }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "R. W." }, "orcid": "0000-0003-3323-3508" } ] }, "title": "Localized seismic deformation in the upper mantle revealed by dense seismic arrays", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 2016 American Association for the Advancement of Science. \n\n23 December 2015; accepted 31 August 2016. \n\nWe thank Signal Hill Petroleum and NodalSeismic for granting us permission to use the Long Beach Array data, and we thank Breitburn Energy and LA Seismic for permission to use the Rosecrans Array data. We acknowledge J. P. Avouac, R. B\u00fcrgmann, Y. Ma, and W. Frank for helpful discussions. This research was supported by NSF awards EAR-1214912 and EAR-1520081 and by the Terrestrial Hazard Observation and Reporting Center at Caltech. The seismic data are property of Signal Hill Petroleum and Breitburn Energy. Data are available for noncommercial use through a license agreement with the data owners that includes but is not limited to a nondistribution agreement. Please contact the authors for additional information.\n\nSupplemental Material - Inbal.SM.pdf
", "abstract": "Seismicity along continental transform faults is usually confined to the upper half of the crust, but the Newport-Inglewood fault (NIF), a major fault traversing the Los Angeles basin, is seismically active down to the upper mantle. We use seismic array analysis to illuminate the seismogenic root of the NIF beneath Long Beach, California, and identify seismicity in an actively deforming localized zone penetrating the lithospheric mantle. Deep earthquakes, which are spatially correlated with geochemical evidence of a fluid pathway from the mantle, as well as with a sharp vertical offset in the lithosphere-asthenosphere boundary, exhibit narrow size distribution and weak temporal clustering. We attribute these characteristics to a transition from strong to weak interaction regimes in a system of seismic asperities embedded in a ductile fault zone matrix.", "date": "2016-10-07", "date_type": "published", "publication": "Science", "volume": "354", "number": "6308", "publisher": "American Association for the Advancement of Science", "pagerange": "88-92", "id_number": "CaltechAUTHORS:20161011-114625632", "issn": "0036-8075", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161011-114625632", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR-1214912" }, { "agency": "NSF", "grant_number": "EAR-1520081" }, { "agency": "Terrestrial Hazard Observation and Reporting Center, Caltech" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1126/science.aaf1370", "primary_object": { "basename": "Inbal.SM.pdf", "url": "https://authors.library.caltech.edu/records/qgy3n-byt61/files/Inbal.SM.pdf" }, "resource_type": "article", "pub_year": "2016", "author_list": "Inbal, A.; Ampuero, J. P.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/06k9t-0ba65", "eprint_id": 69768, "eprint_status": "archive", "datestamp": "2023-08-22 18:34:50", "lastmod": "2023-10-20 20:35:38", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Ma-Yiran", "name": { "family": "Ma", "given": "Yiran" }, "orcid": "0000-0002-8369-3310" }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" }, { "id": "Li-Dunzhu", "name": { "family": "Li", "given": "Dunzhu" }, "orcid": "0000-0003-3149-0236" } ] }, "title": "Higher-mode ambient-noise Rayleigh waves in sedimentary basins", "ispublished": "pub", "full_text_status": "public", "keywords": "Interferometry; Surface waves and free oscillations; Wave propagation", "note": "\u00a9 2016 The Authors. Published by Oxford University Press on behalf of The Royal Astronomical Society. \n\nAccepted 2016 June 20. Received 2016 June 18; in original form 2016 January 21. First published online: June 24, 2016. \n\nWe thank Mich Barklage and Dan Hollis from NodalSeismic, Paul Davis and Igor Stubailo from UCLA, Elizabeth Cochran from USGS, Jacha Polet from Cal Poly Pomona, and several grad students for their participation in the LASSIE experiment. We thank Victor Tsai at Caltech for useful discussions. We also thank two anonymous reviewers for their helpful comments. This work was partially supported by the USGS Earthquake Science Center/Caltech Cooperative Agreement G14AC00109 and by SCEC award #15018.\n\nPublished - Geophys._J._Int.-2016-Ma-1634-44.pdf
Supplemental Material - Supp.pdf
", "abstract": "We show that higher modes are an important component of high-frequency Rayleigh waves in the cross-correlations over sedimentary basins. The particle motions provide a good test for distinguishing and separating the fundamental from the first higher mode, with the fundamental mode having retrograde and the first higher mode having prograde motion in the 1\u201310 s period of interest. The basement depth controls the cut-off period of the first higher mode, which coincides with a rapid increase (over period) in the particle-motion ellipticity or H/V ratio of the fundamental mode. The strong higher mode we observed is not only due to the low-velocity sedimentary layer but also due to the noise sources with significant radial component such as the basin edge scattering. It is important to correctly identify the mode order when inverting the dispersion curves because misidentifying the higher mode as fundamental will lead to an anomalous high V_(SV) velocity.", "date": "2016-09", "date_type": "published", "publication": "Geophysical Journal International", "volume": "206", "number": "3", "publisher": "Royal Astronomical Society", "pagerange": "1634-1644", "id_number": "CaltechAUTHORS:20160819-084824753", "issn": "0956-540X", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160819-084824753", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "USGS", "grant_number": "G14AC00109" }, { "agency": "Southern California Earthquake Center (SCEC)", "grant_number": "15018" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1093/gji/ggw235", "primary_object": { "basename": "Geophys._J._Int.-2016-Ma-1634-44.pdf", "url": "https://authors.library.caltech.edu/records/06k9t-0ba65/files/Geophys._J._Int.-2016-Ma-1634-44.pdf" }, "related_objects": [ { "basename": "Supp.pdf", "url": "https://authors.library.caltech.edu/records/06k9t-0ba65/files/Supp.pdf" } ], "resource_type": "article", "pub_year": "2016", "author_list": "Ma, Yiran; Clayton, Robert W.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/661hw-pg955", "eprint_id": 69770, "eprint_status": "archive", "datestamp": "2023-08-22 18:34:57", "lastmod": "2023-10-20 20:35:43", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Ma-Yiran", "name": { "family": "Ma", "given": "Yiran" }, "orcid": "0000-0002-8369-3310" }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" } ] }, "title": "Structure of the Los Angeles Basin from ambient noise and receiver functions", "ispublished": "pub", "full_text_status": "public", "keywords": "Interferometry; Interface waves; Seismic tomography", "note": "\u00a9 2016 The Authors. Published by Oxford University Press on behalf of The Royal Astronomical Society. \n\nAccepted 2016 June 20. Received 2016 June 18; in original form 2016 March 29. First published online: June 29, 2016.\n\nWe thank our partners in the LASSIE survey: Nodalseismic (Dan Hollis and Mitchell Barklage), USGS (Elizabeth Cochran), UCLA (Paul Davis) and CalPoly Pomona (J. Polet). This project was partially supported by the USGS/Caltech Cooperative Agreement G14AC00109 and SCEC Project 15018.\n\nPublished - Geophys._J._Int.-2016-Ma-1645-51.pdf
Supplemental Material - supp.pdf
", "abstract": "A velocity (V_s) and structure model is derived for the Los Angeles Basin, California based on ambient-noise surface wave and receiver-function analysis, using data from a low-cost, short-duration, dense broad-band survey (LASSIE) deployed across the basin. The shear wave velocities show lateral variations at the Compton-Los Alamitos and the Whittier Faults. The basement beneath the Puente Hills\u2013San Gabriel Valley shows an unusually high velocity (\u223c4.0 km s^(\u22121)) and indicates the presence of schist. The structure of the model shows that the basin is a maximum of 8 km deep along the profile and that the Moho rises to a depth of 17 km under the basin. The basin has a stretch factor of 2.6 in the centre grading to 1.3 at the edges and is in approximate isostatic equilibrium.", "date": "2016-09", "date_type": "published", "publication": "Geophysical Journal International", "volume": "206", "number": "3", "publisher": "Royal Astronomical Society", "pagerange": "1645-1651", "id_number": "CaltechAUTHORS:20160819-085614479", "issn": "0956-540X", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160819-085614479", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "USGS", "grant_number": "G14AC00109" }, { "agency": "Southern California Earthquake Center (SCEC)", "grant_number": "15018" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1093/gji/ggw236", "primary_object": { "basename": "Geophys._J._Int.-2016-Ma-1645-51.pdf", "url": "https://authors.library.caltech.edu/records/661hw-pg955/files/Geophys._J._Int.-2016-Ma-1645-51.pdf" }, "related_objects": [ { "basename": "supp.pdf", "url": "https://authors.library.caltech.edu/records/661hw-pg955/files/supp.pdf" } ], "resource_type": "article", "pub_year": "2016", "author_list": "Ma, Yiran and Clayton, Robert W." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/ch58y-08r59", "eprint_id": 68832, "eprint_status": "archive", "datestamp": "2023-08-20 13:32:01", "lastmod": "2023-10-20 15:46:35", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Kohler-M-D", "name": { "family": "Kohler", "given": "Monica D." } }, { "id": "Massari-A", "name": { "family": "Massari", "given": "Anthony" }, "orcid": "0000-0002-6561-4674" }, { "id": "Heaton-T-H", "name": { "family": "Heaton", "given": "Thomas H." }, "orcid": "0000-0003-3363-2197" }, { "id": "Kanamori-H", "name": { "family": "Kanamori", "given": "Hiroo" }, "orcid": "0000-0001-8219-9428" }, { "id": "Hauksson-E", "name": { "family": "Hauksson", "given": "Egill" }, "orcid": "0000-0002-6834-5051" }, { "id": "Guy-R", "name": { "family": "Guy", "given": "Richard" } }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" }, { "id": "Bunn-J", "name": { "family": "Bunn", "given": "Julian" }, "orcid": "0000-0002-3798-298X" }, { "id": "Chandy-K-M", "name": { "family": "Chandy", "given": "K. M." } } ] }, "title": "Downtown Los Angeles 52-Story High-Rise and Free-Field Response to an Oil Refinery Explosion", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 2016 Earthquake Engineering Research Institute. \n\nWe appreciate discussions with Caltech Professor of Aeronautics and Mechanical Engineering Joseph Shepherd, and Caltech Professor of Planetary Science Andrew Ingersol who provided useful feedback on this study. We thank three anonymous reviewers whose comments improved this paper. We also thank the Betty and Gordon Moore Foundation, the Terrestrial Hazard Observation and Reporting Center at Caltech, and the Divisions of Geological and Planetary Science, and Engineering and Applied Science at Caltech for funding the development of the Community Seismic Network. The USGS Advanced National Seismic System and California Office of Emergency Services provided funding for SCSN operations. The Los Angeles/Long Beach Urban Area Security Initiative (UASI) funded a recent upgrade of the SCSN.\n\nPublished - 062315eqs101m.pdf
", "abstract": "The ExxonMobil Corp. oil refinery in Torrance, California experienced an explosion on February 18, 2015 causing ground shaking equivalent to a magnitude 2.0 earthquake. The impulse response for the source was computed from Southern California Seismic Network data for a single force system with a value of 2\u00d710^5 kN vertically downward. The refinery explosion produced an air pressure wave that was recorded 22.8 km away in a 52-story high-rise building in downtown Los Angeles by a dense accelerometer array that is a component of the Community Seismic Network. The array recorded anomalous waveforms on each floor displaying coherent arrivals that are consistent with the building's elastic response to a pressure wave caused by the refinery explosion. Using a finite-element model of the building, the force on the building on a floor-by-floor scale was found to range up to 1.42 kN, corresponding to a pressure perturbation of 7.7 Pa.", "date": "2016-08-30", "date_type": "published", "publication": "Earthquake Spectra", "volume": "32", "number": "3", "publisher": "Earthquake Engineering Research Institute", "pagerange": "1793-1820", "id_number": "CaltechAUTHORS:20160705-133353269", "issn": "8755-2930", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160705-133353269", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Gordon and Betty Moore Foundation" }, { "agency": "Terrestrial Hazard Observation and Reporting Center" }, { "agency": "Caltech" }, { "agency": "USGS" }, { "agency": "California Office of Emergency Services" }, { "agency": "Los Angeles/Long Beach Urban Area Security Initiative (UASI)" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1193/062315EQS101M", "primary_object": { "basename": "062315eqs101m.pdf", "url": "https://authors.library.caltech.edu/records/ch58y-08r59/files/062315eqs101m.pdf" }, "resource_type": "article", "pub_year": "2016", "author_list": "Kohler, Monica D.; Massari, Anthony; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/mp3hf-4tx42", "eprint_id": 61454, "eprint_status": "archive", "datestamp": "2023-08-22 16:47:50", "lastmod": "2023-10-25 14:54:21", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Kim-YoungHee", "name": { "family": "Kim", "given": "YoungHee" }, "orcid": "0000-0002-1111-632X" }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" } ] }, "title": "Seismic properties of the Nazca oceanic crust in southern Peruvian subduction system", "ispublished": "pub", "full_text_status": "public", "keywords": "subduction geometry; southern Peruvian subduction dynamics; Nazca Ridge; receiver function; mineralogy; slab hydration", "note": "\u00a9 2015 Elsevier B.V. \n\nReceived 22 April 2015; Received in revised form 16 July 2015; Accepted 24 July 2015; Available online 14 August 2015. \n\nThis work was supported by the National Research Foundation of Korea Grant funded by the Korean Government(NRF-2014S1A2A2027609), and by the Korea Meteorological Ad-ministration Research and Development Program under Grant KMIPA2015-7020. We thank H. Lim from Seoul National University for extracting plate interface depths from the four published slab geometry models (in Fig.2a). We thank Y. Ma from Cal-tech for discussion on the data, and M. Chlieh from Universit\u00e9 de Nice Sophia-Antipolis for providing the data for slip distribu-tion of four large megathrust events in southern Peru from his paper (Chliehetal.,2011). We thank the PeruSE project for supplying the seismic data used. Finally, we thank Editor P. Shearer, N. Piana Agostinetti, and one anonymous reviewer for thoughtful comments, which helped improve the manuscript.\n\nSupplemental Material - mmc1.docx
", "abstract": "The horizontal Nazca slab, extending over a distance of \u223c800 km along the trench is one of enigmatic features in Peruvian subduction zone. Increased buoyancy of the oceanic lithosphere alone due to the subduction of Nazca Ridge is insufficient to fully explain such a lengthy segment. We use data from the recent seismic experiment in southern Peru to find that the subduction-related hydration plays a major role in controlling shear wave velocities within the upper part of the oceanic crust and overlying materials. We observe substantial velocity reductions of \u223c20\u201340% near the top plate interface along- and perpendicular-to the trench from \u223c40\u2013120 km depths. In particular, significant shear wave velocity reductions and subsequently higher P-to-S velocity ratio (exceeding 2.0) at the flat slab region suggest that the seismically probed layer is fluid-rich and mechanically weak. The dominant source of fluid comes from metasediments and subducted crust (Nazca Ridge). Long-term supply of fluid from the southward migrating Nazca Ridge provides additional buoyancy of the subducting oceanic lithosphere and also lowers the viscosity of the overlying mantle wedge to drive and sustain the flat plate segment of \u223c800 km along the trench. Also, by comparing calculated seismic velocities with experimentally derived mineral physics data, we additionally provide mechanical constraints on the possible changes in frictional behavior across the subduction zone plate interface. Observed low seismic velocities in the seismogenic zone suggest a presence of low strength materials that may be explained by overpressured pore fluids (i.e., accreted sediment included in the subduction channel).", "date": "2015-11-01", "date_type": "published", "publication": "Earth and Planetary Science Letters", "volume": "429", "publisher": "Elsevier", "pagerange": "110-121", "id_number": "CaltechAUTHORS:20151022-152559100", "issn": "0012-821X", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20151022-152559100", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "National Research Foundation of Korea", "grant_number": "NRF-2014S1A2A2027609" }, { "agency": "Korea Meteorological Administration", "grant_number": "KMIPA2015-7020" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/j.epsl.2015.07.055", "primary_object": { "basename": "mmc1.docx", "url": "https://authors.library.caltech.edu/records/mp3hf-4tx42/files/mmc1.docx" }, "resource_type": "article", "pub_year": "2015", "author_list": "Kim, YoungHee and Clayton, Robert W." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/b3tan-cab83", "eprint_id": 62614, "eprint_status": "archive", "datestamp": "2023-08-20 08:24:57", "lastmod": "2023-10-25 17:16:47", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Vriend-N-M", "name": { "family": "Vriend", "given": "N. M." } }, { "id": "Hunt-M-L", "name": { "family": "Hunt", "given": "M. L." }, "orcid": "0000-0001-5592-2334" }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "R. W." }, "orcid": "0000-0003-3323-3508" } ] }, "title": "Linear and nonlinear wave propagation in booming sand dunes", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 2015 AIP Publishing LLC. \n\nReceived 20 March 2015; accepted 14 September 2015; published online 27 October 2015. \n\nThe authors would like to thank Dr. Chiara Daraio for the stimulating and fruitful discussions on wave propagation in a granular material. The help of Dr. Christopher Earls Brennen, Natalie Becerra, Dr. Angel Ruiz-Angulo, Dr. Erin Koos, and many others was essential during the field experiments at Dumont and Eureka Dunes. Travel and equipment support for N.M.V. was provided through funding from the Pieter Langerhuizen Lambertuszoon Fonds. Raw data supporting Figures 1, 3\u20138, and 10 are available in the supplementary material.\n\nPublished - 1.4931971.pdf
Supplemental Material - 652491_0_data_set_7757931_nlcw9j.csv
Supplemental Material - 652491_0_data_set_7757932_nlcw9k.csv
Supplemental Material - 652491_0_data_set_7757933_nlcw9k.csv
Supplemental Material - 652491_0_data_set_7757934_nlcw9k.csv
Supplemental Material - 652491_0_data_set_7757935_nlcw9k.csv
Supplemental Material - 652491_0_data_set_7757936_nlcw9k.csv
Supplemental Material - 652491_0_data_set_7757937_nlcw9k.csv
Supplemental Material - 652491_0_data_set_7757938_nlcw9k.csv
Supplemental Material - 652491_0_data_set_7757939_nlcw9k.csv
Supplemental Material - 652491_0_data_set_7757940_nlcw9k.csv
Supplemental Material - 652491_0_data_set_7757941_nlcw9k.csv
Supplemental Material - 652491_0_data_set_7757942_nlcw9l.csv
Supplemental Material - 652491_0_data_set_7757943_nlcw9l.csv
Supplemental Material - readme.txt
", "abstract": "The current field study examines linear and non-linear acoustic waves found in large desert sand dunes using field measurements of wave speed, frequency content, dispersion, and polarization. At the dune fields visited, an avalanching of sand can trigger a loud booming or rumbling sound with narrow peak frequencies centered between 70 and 105\u2009Hz with higher harmonics. Prior to the onset of the nearly monotone booming, the emission consists of short bursts or burps of sound of smaller amplitude and over a significantly broader range of frequencies. These burps created at dune sites have similar frequency content to sounds generated by small-scale shearing in laboratory-scale experiments. By investigating the wave characteristics of both burping and booming emissions, this manuscript demonstrates that booming and burping correspond with the transmission of different waves within the dune. The burping sounds correspond to a surface Rayleigh wave with nonlinear and dispersive properties. The booming emission results from a linear, non-dispersive P-wave, which supports an earlier analysis where booming is modeled as the trapping of the body waves in the dune's surficial layer. Besides characterizing the booming and burping emissions, this manuscript illustrates the effect of scale in the wave propagation of granular materials, when non-linear, dispersive waves across small scales transition to linear, non-dispersive waves across larger scales.", "date": "2015-10", "date_type": "published", "publication": "Physics of Fluids", "volume": "27", "number": "10", "publisher": "American Institute of Physics", "pagerange": "Art. No. 103305", "id_number": "CaltechAUTHORS:20151204-103416664", "issn": "1070-6631", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20151204-103416664", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Pieter Langerhuizen Lambertuszoon Fonds" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1063/1.4931971", "primary_object": { "basename": "652491_0_data_set_7757935_nlcw9k.csv", "url": "https://authors.library.caltech.edu/records/b3tan-cab83/files/652491_0_data_set_7757935_nlcw9k.csv" }, "related_objects": [ { "basename": "652491_0_data_set_7757938_nlcw9k.csv", "url": "https://authors.library.caltech.edu/records/b3tan-cab83/files/652491_0_data_set_7757938_nlcw9k.csv" }, { "basename": "652491_0_data_set_7757940_nlcw9k.csv", "url": "https://authors.library.caltech.edu/records/b3tan-cab83/files/652491_0_data_set_7757940_nlcw9k.csv" }, { "basename": "readme.txt", "url": "https://authors.library.caltech.edu/records/b3tan-cab83/files/readme.txt" }, { "basename": "652491_0_data_set_7757937_nlcw9k.csv", "url": "https://authors.library.caltech.edu/records/b3tan-cab83/files/652491_0_data_set_7757937_nlcw9k.csv" }, { "basename": "652491_0_data_set_7757939_nlcw9k.csv", "url": "https://authors.library.caltech.edu/records/b3tan-cab83/files/652491_0_data_set_7757939_nlcw9k.csv" }, { "basename": "652491_0_data_set_7757942_nlcw9l.csv", "url": "https://authors.library.caltech.edu/records/b3tan-cab83/files/652491_0_data_set_7757942_nlcw9l.csv" }, { "basename": "652491_0_data_set_7757931_nlcw9j.csv", "url": "https://authors.library.caltech.edu/records/b3tan-cab83/files/652491_0_data_set_7757931_nlcw9j.csv" }, { "basename": "652491_0_data_set_7757932_nlcw9k.csv", "url": "https://authors.library.caltech.edu/records/b3tan-cab83/files/652491_0_data_set_7757932_nlcw9k.csv" }, { "basename": "652491_0_data_set_7757936_nlcw9k.csv", "url": "https://authors.library.caltech.edu/records/b3tan-cab83/files/652491_0_data_set_7757936_nlcw9k.csv" }, { "basename": "652491_0_data_set_7757941_nlcw9k.csv", "url": "https://authors.library.caltech.edu/records/b3tan-cab83/files/652491_0_data_set_7757941_nlcw9k.csv" }, { "basename": "652491_0_data_set_7757943_nlcw9l.csv", "url": "https://authors.library.caltech.edu/records/b3tan-cab83/files/652491_0_data_set_7757943_nlcw9l.csv" }, { "basename": "1.4931971.pdf", "url": "https://authors.library.caltech.edu/records/b3tan-cab83/files/1.4931971.pdf" }, { "basename": "652491_0_data_set_7757933_nlcw9k.csv", "url": "https://authors.library.caltech.edu/records/b3tan-cab83/files/652491_0_data_set_7757933_nlcw9k.csv" }, { "basename": "652491_0_data_set_7757934_nlcw9k.csv", "url": "https://authors.library.caltech.edu/records/b3tan-cab83/files/652491_0_data_set_7757934_nlcw9k.csv" } ], "resource_type": "article", "pub_year": "2015", "author_list": "Vriend, N. M.; Hunt, M. L.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/ey8ff-5dp31", "eprint_id": 62079, "eprint_status": "archive", "datestamp": "2023-08-20 08:13:16", "lastmod": "2023-10-25 16:50:27", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Ma-Yiran", "name": { "family": "Ma", "given": "Yiran" }, "orcid": "0000-0002-8369-3310" }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" } ] }, "title": "Flat slab deformation caused by interplate suction force", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 2015 American Geophysical Union. \n\nReceived 1 JUL 2015; Accepted 17 AUG 2015; Accepted article online 20 AUG 2015; Published online 12 SEP 2015. \n\nThe PeruSE experiment was supported by the Gordon and Betty Moore Foundation and NSF (EAR-1045683), and the data used are available through IRIS. We thank Lara Wagner and other members of the PULSE experiment for providing data from six stations. We also thank the Editor and reviewers for constructive comments. The script files necessary to reproduce the results are available from the authors upon request.\n\nPublished - Ma_et_al-2015-Geophysical_Research_Letters.pdf
Supplemental Material - grl53366-sup-0001-SsuppInfo.doc
", "abstract": "We image the structure at the southern end of the Peruvian flat subduction zone, using receiver function and surface wave methods. The Nazca slab subducts to ~100\u2009km depth and then remains flat for ~300\u2009km distance before it resumes the dipping subduction. The flat slab closely follows the topography of the continental Moho above, indicating a strong suction force between the slab and the overriding plate. A high-velocity mantle wedge exists above the initial half of the flat slab, and the velocity resumes to normal values before the slab steepens again, indicating the resumption of dehydration and ecologitization. Two prominent midcrust structures are revealed in the 70\u2009km thick crust under the Central Andes: molten rocks beneath the Western Cordillera and the underthrusting Brazilian Shield beneath the Eastern Cordillera.", "date": "2015-09-16", "date_type": "published", "publication": "Geophysical Research Letters", "volume": "42", "number": "17", "publisher": "American Geophysical Union", "pagerange": "7064-7072", "id_number": "CaltechAUTHORS:20151112-141913068", "issn": "0094-8276", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20151112-141913068", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Gordon and Betty Moore Foundation" }, { "agency": "NSF", "grant_number": "EAR-1045683" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1002/2015GL065195", "primary_object": { "basename": "grl53366-sup-0001-SsuppInfo.doc", "url": "https://authors.library.caltech.edu/records/ey8ff-5dp31/files/grl53366-sup-0001-SsuppInfo.doc" }, "related_objects": [ { "basename": "Ma_et_al-2015-Geophysical_Research_Letters.pdf", "url": "https://authors.library.caltech.edu/records/ey8ff-5dp31/files/Ma_et_al-2015-Geophysical_Research_Letters.pdf" } ], "resource_type": "article", "pub_year": "2015", "author_list": "Ma, Yiran and Clayton, Robert W." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/c96wg-85x76", "eprint_id": 61021, "eprint_status": "archive", "datestamp": "2023-08-20 07:59:22", "lastmod": "2023-10-24 23:18:56", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" }, { "id": "Heaton-T-H", "name": { "family": "Heaton", "given": "Thomas" }, "orcid": "0000-0003-3363-2197" }, { "id": "Kohler-M-D", "name": { "family": "Kohler", "given": "Monica" } }, { "id": "Chandy-K-M", "name": { "family": "Chandy", "given": "Mani" } }, { "id": "Guy-Richard", "name": { "family": "Guy", "given": "Richard" } }, { "id": "Bunn-J", "name": { "family": "Bunn", "given": "Julian" }, "orcid": "0000-0002-3798-298X" } ] }, "title": "Community Seismic Network: A Dense Array to Sense Earthquake Strong Motion", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 2015 Seismological Society of America. \n\nPublished Online 5 August 2015. \n\nWe thank the Betty and Gordon Moore Foundation and the California Institute of Technology for funding the development of the Community Seismic Network.\n\nPublished - 1354.full.pdf
", "abstract": "The Community Seismic Network (CSN) is currently a 500\u2010element strong\u2010motion network located in the Los Angeles area of California (see Fig. 1). The sensors in the network are low\u2010cost microelectromechanical (MEM) accelerometers that are capable of recording on scale up to accelerations of \u00b12g. The primary product of the network is a set of measurements of ground shaking in the seconds following a major earthquake. An example of this is shown in Figure 2. The shaking information will be contributed to U.S. Geological Survey products such as ShakeMap (Wald et al., 1999) and ShakeCast (Wald et al., 2006), with the goal of providing first responders a proxy for damage that can guide efforts immediately following the event. The basic premise is the strong ground\u2010motion shaking varies on a subkilometer scale, which will require a dense network to meaningfully measure the shaking. Evidence for this comes from earthquakes recorded by dense oil company surveys in the Los Angeles area (Clayton et al., 2011).", "date": "2015-09", "date_type": "published", "publication": "Seismological Research Letters", "volume": "86", "number": "5", "publisher": "Seismological Society of America", "pagerange": "1354-1363", "id_number": "CaltechAUTHORS:20151012-154950185", "issn": "0895-0695", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20151012-154950185", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Gordon and Betty Moore Foundation" }, { "agency": "Caltech" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1785/0220150094", "primary_object": { "basename": "1354.full.pdf", "url": "https://authors.library.caltech.edu/records/c96wg-85x76/files/1354.full.pdf" }, "resource_type": "article", "pub_year": "2015", "author_list": "Clayton, Robert W.; Heaton, Thomas; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/cr0fc-dpd59", "eprint_id": 60294, "eprint_status": "archive", "datestamp": "2023-08-20 07:46:36", "lastmod": "2023-10-24 16:24:08", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Inbal-Asaf", "name": { "family": "Inbal", "given": "Asaf" }, "orcid": "0000-0001-8848-7279" }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" }, { "id": "Ampuero-J-P", "name": { "family": "Ampuero", "given": "Jean-Paul" }, "orcid": "0000-0002-4827-7987" } ] }, "title": "Imaging widespread seismicity at midlower crustal depths beneath Long Beach, CA, with a dense seismic array: Evidence for a depth-dependent earthquake size distribution", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 2015 American Geophysical Union.\n\nReceived 13 JUN 2015; Accepted 24 JUL 2015; Accepted article online 29 JUL 2015; Published online 13 AUG 2015. \n\nWe thank Dan Hollis of Nodalseismic Inc for supplying the data used in this\nstudy and Signal Hill Petroleum for giving permission to use it. Comments from two anonymous reviewers have helped improve this manuscript. This\nwork was supported by the NSF award EAR-1214912 and a THOR award that\nfunded the mass-storage system for data archiving. \n\nThe Editor thanks two anonymous reviewers for their assistance in\nevaluating this paper.\n\nPublished - grl53271.pdf
Supplemental Material - grl53271-sup-0001-supinfo.pdf
", "abstract": "We use a dense seismic array composed of 5200 vertical geophones to monitor microseismicity in Long Beach, California. Poor signal-to-noise ratio due to anthropogenic activity is mitigated via downward-continuation of the recorded wavefield. The downward-continued data are continuously back projected to search for coherent arrivals from sources beneath the array, which reveals numerous, previously undetected events. The spatial distribution of seismicity is uncorrelated with the mapped fault traces, or with activity in the nearby oil-fields. Many events are located at depths larger than 20 km, well below the commonly accepted seismogenic depth for that area. The seismicity exhibits temporal clustering consistent with Omori's law, and its size distribution obeys the Gutenberg-Richter relation above 20 km but falls off exponentially at larger depths. The dense array allows detection of earthquakes two magnitude units smaller than the permanent seismic network in the area. Because the event size distribution above 20 km depth obeys a power law whose exponent is near one, this improvement yields a hundred-fold decrease in the time needed for effective characterization of seismicity in Long Beach.", "date": "2015-08-16", "date_type": "published", "publication": "Geophysical Research Letters", "volume": "42", "number": "15", "publisher": "American Geophysical Union", "pagerange": "6314-6323", "id_number": "CaltechAUTHORS:20150917-080641646", "issn": "0094-8276", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150917-080641646", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR-1214912" }, { "agency": "Terrestrial Hazards Observation and Reporting Center" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1002/2015GL064942", "primary_object": { "basename": "grl53271-sup-0001-supinfo.pdf", "url": "https://authors.library.caltech.edu/records/cr0fc-dpd59/files/grl53271-sup-0001-supinfo.pdf" }, "related_objects": [ { "basename": "grl53271.pdf", "url": "https://authors.library.caltech.edu/records/cr0fc-dpd59/files/grl53271.pdf" } ], "resource_type": "article", "pub_year": "2015", "author_list": "Inbal, Asaf; Clayton, Robert W.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/tb67n-bb110", "eprint_id": 57573, "eprint_status": "archive", "datestamp": "2023-08-22 15:13:51", "lastmod": "2023-10-23 17:32:38", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Persaud-P", "name": { "family": "Persaud", "given": "Patricia" }, "orcid": "0000-0003-3462-7023" }, { "id": "Di-Luccio-F", "name": { "family": "Di Luccio", "given": "Francesca" } }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" } ] }, "title": "Rayleigh wave dispersion measurements reveal low-velocity zones beneath the new crust in the Gulf of California", "ispublished": "pub", "full_text_status": "public", "keywords": "off-axis partial melt; lower crustal flow; oblique rifting; surface wave tomography", "note": "\u00a9 2015 American Geophysical Union.\n\nReceived 9 FEB 2015; Accepted 2 MAR 2015; Accepted article online 5 MAR 2015; Published online 30 MAR 2015. \n\nWe thank L. Ferrari and S. Bryan for their review and useful discussions on the tectonics and volcanism in the southern Gulf of California, J. Contreras-P\u00e9rez for his thoughtful review of the manuscript, and V. Langenheim for providing the magnetic potential data for the study region. We also thank an anonymous reviewer and the Editor for their help in improving the final manuscript. Some figures were generated using the GMT software [Wessel and Smith, 1998]. \n\nThe Editor thanks Peter Clift for his assistance evaluating this paper.\n\nPublished - grl52721.pdf
Supplemental Material - grl52721-sup-0001-Supp.doc
", "abstract": "Rayleigh wave tomography provides images of the shallow mantle shear wave velocity structure beneath the Gulf of California. Low-velocity zones (LVZs) are found on axis between 26 and 50\u2009km depth beneath the Guaymas Basin but mostly off axis under the other rift basins, with the largest feature underlying the Ballenas Transform Fault. We interpret the broadly distributed LVZs as regions of partial melting in a solid mantle matrix. The pathway for melt migration and focusing is more complex than an axis-centered source aligned above a deeper region of mantle melt and likely reflects the magmatic evolution of rift segments. We also consider the existence of solid lower continental crust in the Gulf north of the Guaymas Basin, where the association of the LVZs with asthenospheric upwelling suggests lateral flow assisted by a heat source. These results provide key constraints for numerical models of mantle upwelling and melt focusing in this young oblique rift.", "date": "2015-03-28", "date_type": "published", "publication": "Geophysical Research Letters", "volume": "42", "number": "6", "publisher": "American Geophysical Union", "pagerange": "1766-1774", "id_number": "CaltechAUTHORS:20150515-152216867", "issn": "0094-8276", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150515-152216867", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1002/2015GL063420", "primary_object": { "basename": "grl52721-sup-0001-Supp.doc", "url": "https://authors.library.caltech.edu/records/tb67n-bb110/files/grl52721-sup-0001-Supp.doc" }, "related_objects": [ { "basename": "grl52721.pdf", "url": "https://authors.library.caltech.edu/records/tb67n-bb110/files/grl52721.pdf" } ], "resource_type": "article", "pub_year": "2015", "author_list": "Persaud, Patricia; Di Luccio, Francesca; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/7dats-7kg82", "eprint_id": 56306, "eprint_status": "archive", "datestamp": "2023-08-22 14:39:02", "lastmod": "2023-10-23 15:18:05", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Dougherty-S-L", "name": { "family": "Dougherty", "given": "Sara L." }, "orcid": "0000-0002-5327-3286" }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" } ] }, "title": "Seismic structure in southern Peru: evidence for a smooth contortion between flat and normal subduction of the Nazca Plate", "ispublished": "pub", "full_text_status": "public", "keywords": "Seismicity and tectonics; Body waves; Computational seismology; Subduction zone processes", "note": "\u00a9 2014 The Authors. Published by Oxford University Press on behalf of The Royal Astronomical Society\n\nAccepted 2014 October 21. Received 2014 October 17; in original form 2014 June 17.\n\nThis study was supported by the Gordon and Betty Moore Foundation through the Tectonics Observatory at California Institute of Technology and NSF award EAR-1045683. We are grateful to the CAUGHT project team for providing waveform data. We thank Joann Stock for enlightening discussions. We also thank Editor Saskia Goes, Megan Anderson and an anonymous reviewer for helpful comments which improved the manuscript.\n\nPublished - Geophys._J._Int.-2015-Dougherty-534-55.pdf
Supplemental Material - Supplemental_References.pdf
Supplemental Material - Supporting_Information.pdf
", "abstract": "Rapid changes in slab geometry are typically associated with fragmentation of the subducted plate; however, continuous curvature of the slab is also possible. The transition from flat to normal subduction in southern Peru is one such geometrical change. The morphology of the subducted Nazca Plate along this transition is explored using intraslab earthquakes recorded by temporary regional seismic arrays. Observations of a gradual increase in slab dip coupled with a lack of any gaps or vertical offsets in the intraslab seismicity suggest warping of the slab. Concentrations of focal mechanisms at orientations which are indicative of slab bending are also observed along the change in slab geometry. The presence of a thin ultra-slow velocity layer (USL) atop the horizontal Nazca slab is identified and located. The lateral extent of this USL is coincident with the margin of the projected linear continuation of the subducting Nazca Ridge, implying a causal relationship wherein increased hydration of the ridge results in the formation of the USL downdip. Waveform modelling of the 2-D structure in southern Peru using a finite-difference algorithm provides constraints on the velocity and geometry of the slab's seismic structure and confirms the absence of any tears in the slab. The seismicity and structural evidence suggests smooth contortion of the Nazca Plate along the transition from flat to normal subduction. The slab is estimated to have experienced 10\u2009per\u2009cent strain in the along-strike direction across this transition.", "date": "2015-01", "date_type": "published", "publication": "Geophysical Journal International", "volume": "200", "number": "1", "publisher": "Royal Astronomical Society", "pagerange": "534-555", "id_number": "CaltechAUTHORS:20150402-103259901", "issn": "0956-540X", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150402-103259901", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Gordon and Betty Moore Foundation" }, { "agency": "NSF", "grant_number": "EAR-1045683" } ] }, "local_group": { "items": [ { "id": "Caltech-Tectonics-Observatory" }, { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1093/gji/ggu415", "primary_object": { "basename": "Geophys._J._Int.-2015-Dougherty-534-55.pdf", "url": "https://authors.library.caltech.edu/records/7dats-7kg82/files/Geophys._J._Int.-2015-Dougherty-534-55.pdf" }, "related_objects": [ { "basename": "Supplemental_References.pdf", "url": "https://authors.library.caltech.edu/records/7dats-7kg82/files/Supplemental_References.pdf" }, { "basename": "Supporting_Information.pdf", "url": "https://authors.library.caltech.edu/records/7dats-7kg82/files/Supporting_Information.pdf" } ], "resource_type": "article", "pub_year": "2015", "author_list": "Dougherty, Sara L. and Clayton, Robert W." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/0xvam-0r059", "eprint_id": 53193, "eprint_status": "archive", "datestamp": "2023-08-22 14:19:57", "lastmod": "2023-10-19 14:38:12", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Di-Luccio-F", "name": { "family": "Di Luccio", "given": "F." } }, { "id": "Persaud-P", "name": { "family": "Persaud", "given": "P." }, "orcid": "0000-0003-3462-7023" }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "R. W." }, "orcid": "0000-0003-3323-3508" } ] }, "title": "Seismic structure beneath the Gulf of California: a contribution from group velocity measurements", "ispublished": "pub", "full_text_status": "public", "keywords": "Surface waves and free oscillations; Seismic tomography; Dynamics of lithosphere and mantle; Crustal structure", "note": "\u00a9 2014 The Authors. Published by Oxford University Press on behalf of The Royal Astronomical Society.\n\nAccepted 2014 September 2. Received 2014 August 27; in original form 2013 June 21.\n\nWe would like to thank J. Contreras, J. Gaherty, R. Negrete-Aranda,\nM. Pasyanos, J. O. Campos-Enr\u00edquez and F. Lin for the very constructive\ncomments on different aspects of the manuscript. We also\nthank F. Pereira for his help in developing the tomographic code. We\nare grateful to B. Savage supplying his velocity model. Comments\nfrom two anonymous reviewers and the Editor W. Friederich contributed\nto improve the final version of the manuscript. Some figures\nwere generated using GMT software (Wessel & Smith 1998).\n\nPublished - Geophys._J._Int.-2014-Di_Luccio-1861-77.pdf
Supplemental Material - SupplementaryMaterial.pdf
", "abstract": "Rayleigh wave group velocity dispersion measurements from local and regional earthquakes are used to interpret the lithospheric structure in the Gulf of California region. We compute group velocity maps for Rayleigh waves from 10 to 150 s using earthquakes recorded by broad-band stations of the Network of Autonomously Recording Seismographs in Baja California and Mexico mainland, UNM in Mexico, BOR, DPP and GOR in southern California and TUC in Arizona. The study area is gridded in 120 longitude cells by 180 latitude cells, with an equal spacing of 10 \u00d7 10 km. Assuming that each gridpoint is laterally homogeneous, for each period the tomographic maps are inverted to produce a 3-D lithospheric shear wave velocity model for the region. \n\nNear the Gulf of California rift axis, we found three prominent low shear wave velocity regions, which are associated with mantle upwelling near the Cerro Prieto volcanic field, the Ballenas Transform Fault and the East Pacific Rise. Upwelling of the mantle at lithospheric and asthenospheric depths characterizes most of the Gulf. This more detailed finding is new when compared to previous surface wave studies in the region. A low-velocity zone in northcentral Baja at \u223c28\u00baN which extends east\u2013south\u2013eastwards is interpreted as an asthenospheric window. In addition, we also identify a well-defined high-velocity zone in the upper mantle beneath central-western Baja California, which correlates with the previously interpreted location of the stalled Guadalupe and Magdalena microplates. We interpret locations of the fossil slab and slab window in light of the distribution of unique post-subduction volcanic rocks in the Gulf of California and Baja California. We also observe a high-velocity anomaly at 50-km depth extending down to \u223c130 km near the southwestern Baja coastline and beneath Baja, which may represent another remnant of the Farallon slab.", "date": "2014-12", "date_type": "published", "publication": "Geophysical Journal International", "volume": "199", "number": "3", "publisher": "Royal Astronomical Society", "pagerange": "1861-1877", "id_number": "CaltechAUTHORS:20150105-142549856", "issn": "0956-540X", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150105-142549856", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1093/gji/ggu338", "primary_object": { "basename": "Geophys._J._Int.-2014-Di_Luccio-1861-77.pdf", "url": "https://authors.library.caltech.edu/records/0xvam-0r059/files/Geophys._J._Int.-2014-Di_Luccio-1861-77.pdf" }, "related_objects": [ { "basename": "SupplementaryMaterial.pdf", "url": "https://authors.library.caltech.edu/records/0xvam-0r059/files/SupplementaryMaterial.pdf" } ], "resource_type": "article", "pub_year": "2014", "author_list": "Di Luccio, F.; Persaud, P.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/qmzxx-d2n74", "eprint_id": 50049, "eprint_status": "archive", "datestamp": "2023-08-22 14:07:55", "lastmod": "2023-10-17 22:28:11", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Selvans-M-M", "name": { "family": "Selvans", "given": "M. M." } }, { "id": "Stock-J-M", "name": { "family": "Stock", "given": "J. M." }, "orcid": "0000-0003-4816-7865" }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "R. W." }, "orcid": "0000-0003-3323-3508" }, { "id": "Cande-S", "name": { "family": "Cande", "given": "S." } }, { "id": "Granot-R", "name": { "family": "Granot", "given": "R." } } ] }, "title": "Deep crustal structure of the Adare and Northern Basins, Ross Sea, Antarctica, from sonobuoy data", "ispublished": "pub", "full_text_status": "public", "keywords": "West Antarctic Rift System; marine seismic data; crustal structure; sonobuoy; Adare Basin; Northern Basin", "note": "\u00a9 2014 Elsevier B.V. \n\nReceived 8 March 2014;\nReceived in revised form 21 August 2014;\nAccepted 25 August 2014.\n\nWe thank F. Davey for helpful discussions of sonobuoy data analysis and interpretation, and K.S. Panter and an anonymous re-viewer for suggestions that improved the figures in this manuscript. We also thank Captain Mike Watson, the crew, and the Raytheon Polar Services Corporation technical staff on board the Nathaniel B. Palmer. This study was supported by National Science Foun-dation grants OPP04-40959 (S. Cande) and OPP-0440923 and OPP-0944711 (J. Stock and R. Clayton).\n\nSupplemental Material - mmc1.docx
", "abstract": "Extension associated with ultraslow seafloor spreading within the Adare Basin, in oceanic crust just north of the continental shelf in the Ross Sea, Antarctica, extended south into the Northern Basin. Magnetic and gravity anomaly data suggest continuity of crustal structure across the continental shelf break that separates the Adare and Northern Basins. We use sonobuoy refraction data and multi-channel seismic (MCS) reflection data collected during research cruise NBP0701, including 71 new sonobuoy records, to provide constraints on crustal structure in the Adare and Northern Basins. Adjacent 1D sonobuoy profiles along several MCS lines reveal deep crustal structure in the vicinity of the continental shelf break, and agree with additional sonobuoy data that document fast crustal velocities (6000\u20138000 m/s) at shallow depths (1\u20136 km below sea level) from the Adare Basin to the continental shelf, a structure consistent with that of other ultraslow-spread crust. Our determination of crustal structure in the Northern Basin only extends through sedimentary rock to the basement rock, and so cannot help to distinguish between different hypotheses for formation of the basin.", "date": "2014-11-01", "date_type": "published", "publication": "Earth and Planetary Science Letters", "volume": "405", "publisher": "Elsevier", "pagerange": "220-230", "id_number": "CaltechAUTHORS:20140926-090020854", "issn": "0012-821X", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140926-090020854", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "OPP04-40959" }, { "agency": "NSF", "grant_number": "OPP-0440923" }, { "agency": "NSF", "grant_number": "OPP-0944711" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/j.epsl.2014.08.029", "primary_object": { "basename": "mmc1.docx", "url": "https://authors.library.caltech.edu/records/qmzxx-d2n74/files/mmc1.docx" }, "resource_type": "article", "pub_year": "2014", "author_list": "Selvans, M. M.; Stock, J. M.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/cnzr3-x6138", "eprint_id": 48315, "eprint_status": "archive", "datestamp": "2023-08-20 01:45:13", "lastmod": "2023-10-17 18:42:04", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Faulkner-M", "name": { "family": "Faulkner", "given": "Matthew" } }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert" }, "orcid": "0000-0003-3323-3508" }, { "id": "Heaton-T-H", "name": { "family": "Heaton", "given": "Thomas H." }, "orcid": "0000-0003-3363-2197" }, { "id": "Chandy-K-M", "name": { "family": "Chandy", "given": "K. Mani" } }, { "id": "Kohler-M-D", "name": { "family": "Kohler", "given": "Monica" } }, { "id": "Bunn-J", "name": { "family": "Bunn", "given": "Julian" }, "orcid": "0000-0002-3798-298X" }, { "id": "Guy-R", "name": { "family": "Guy", "given": "Richard" } }, { "id": "Liu-Annie-H", "name": { "family": "Liu", "given": "Annie" } }, { "id": "Olson-M", "name": { "family": "Olson", "given": "Michael" } }, { "id": "Cheng-Ming-Hei", "name": { "family": "Cheng", "given": "MingHei" } }, { "id": "Krause-A", "name": { "family": "Krause", "given": "Andreas" }, "orcid": "0000-0001-7260-9673" } ] }, "title": "The Caltech CSN project collects sensor data from thousands of personal devices for realtime response to dangerous earthquakes", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 2014 ACM, Inc. \n\nWe would like to thank the Gordon and Betty Moore Foundation, the National Science Foundation (awards CNS0932392, IIS0953413), and European Research Council Starting Grant 307036. Andreas Krause was supported in part by a Microsoft Research Faculty Fellowship. We also thank Signal Hill Petroleum and Nodal Seismic for data from the Long\nBeach Network, and the Southern California Seismic Network for data from the permanent earthquake network in Southern California.\n\nSubmitted - Faulkner2013-CACM.pdf
", "abstract": "The proliferation of smartphones and other powerful sensor-equipped consumer devices enables a new class of Web application: community sense and response (CSR) systems, distinguished from standard Web applications by their use of community-owned commercial sensor hardware. Just as social networks connect and share human-generated content, CSR systems gather, share, and act on sensory data from users' Internet-enabled devices. Here, we discuss the Caltech Community Seismic Network (CSN) as a prototypical CSR system harnessing accelerometers in smartphones and consumer electronics, including the systems and algorithmic challenges of designing, building, and evaluating a scalable network for real-time awareness of dangerous earthquakes.", "date": "2014-07-01", "date_type": "published", "publication": "Communications of the ACM", "volume": "57", "number": "7", "publisher": "Association for Computing Machinery", "pagerange": "66-75", "id_number": "CaltechAUTHORS:20140811-131704662", "issn": "0001-0782", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140811-131704662", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Gordon and Betty Moore Foundation" }, { "agency": "NSF", "grant_number": "CNS-0932392" }, { "agency": "NSF", "grant_number": "IIS-0953413" }, { "agency": "European Research Council (ERC)", "grant_number": "307036" }, { "agency": "Microsoft Research" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1145/2622633", "primary_object": { "basename": "Faulkner2013-CACM.pdf", "url": "https://authors.library.caltech.edu/records/cnzr3-x6138/files/Faulkner2013-CACM.pdf" }, "resource_type": "article", "pub_year": "2014", "author_list": "Faulkner, Matthew; Clayton, Robert; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/06xvj-bp732", "eprint_id": 48687, "eprint_status": "archive", "datestamp": "2023-08-20 01:38:28", "lastmod": "2023-10-17 19:32:46", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Faulkner-M", "name": { "family": "Faulkner", "given": "Matthew" } }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" }, { "id": "Heaton-T-H", "name": { "family": "Heaton", "given": "Thomas" }, "orcid": "0000-0003-3363-2197" }, { "id": "Chandy-K-M", "name": { "family": "Chandy", "given": "K. Mani" } }, { "id": "Kohler-M-D", "name": { "family": "Kohler", "given": "Monica D." } }, { "id": "Bunn-J", "name": { "family": "Bunn", "given": "Julian" }, "orcid": "0000-0002-3798-298X" }, { "id": "Guy-R", "name": { "family": "Guy", "given": "Richard" } }, { "id": "Liu-Annie-H", "name": { "family": "Liu", "given": "Annie" } }, { "id": "Olson-M", "name": { "family": "Olson", "given": "Michael" } }, { "id": "Cheng-Ming-Hei", "name": { "family": "Cheng", "given": "Ming-Hei" } }, { "id": "Krause-A", "name": { "family": "Krause", "given": "Andreas" }, "orcid": "0000-0001-7260-9673" } ] }, "title": "Community Sense and Response Systems: Your Phone as Quake Detector", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 2014 ACM.\n\nWe would like to thank the Gordon and Betty Moore Foundation, the National Science Foundation (awards\nCNS0932392, IIS0953413), and European Research Council Starting Grant 307036. Andreas Krause was supported in part by a Microsoft Research Faculty Fellowship. We also\nthank Signal Hill Petroleum and Nodal Seismic for data from the Long Beach Network, and the Southern California Seismic Network for data from the permanent earthquake network in Southern California.\n\nAccepted Version - Faulkner2013-CACM.pdf
", "abstract": "The proliferation of smartphones and other powerful sensor-equipped consumer devices enables a new class of Web application: community sense and response (CSR) systems, distinguished from standard Web applications by their use of community-owned commercial sensor hardware. Just as social networks connect and share human-generated content, CSR systems gather, share, and act on sensory data from users' Internet-enabled devices. Here, we discuss the Caltech Community Seismic Network (CSN) as a prototypical CSR system harnessing accelerometers in smartphones and consumer electronics, including the systems and algorithmic challenges of designing, building, and evaluating a scalable network for real-time awareness of dangerous earthquakes.", "date": "2014-07", "date_type": "published", "publication": "Communications of the ACM", "volume": "57", "number": "7", "publisher": "Association for Computing Machinery", "pagerange": "66-75", "id_number": "CaltechAUTHORS:20140819-131736568", "issn": "0001-0782", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140819-131736568", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Gordon and Betty Moore Foundation" }, { "agency": "NSF", "grant_number": "CNS-0932392" }, { "agency": "NSF", "grant_number": "IIS-0953413" }, { "agency": "European Research Council (ERC)", "grant_number": "307036" }, { "agency": "Microsoft Research" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1145/2622633", "primary_object": { "basename": "Faulkner2013-CACM.pdf", "url": "https://authors.library.caltech.edu/records/06xvj-bp732/files/Faulkner2013-CACM.pdf" }, "resource_type": "article", "pub_year": "2014", "author_list": "Faulkner, Matthew; Clayton, Robert W.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/4p20a-9h073", "eprint_id": 49805, "eprint_status": "archive", "datestamp": "2023-08-20 01:39:52", "lastmod": "2023-10-17 22:13:05", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Kim-YoungHee", "name": { "family": "Kim", "given": "YoungHee" }, "orcid": "0000-0002-1111-632X" }, { "id": "Lim-Hobin", "name": { "family": "Lim", "given": "Hobin" }, "orcid": "0000-0001-7510-4507" }, { "id": "Miller-M-S", "name": { "family": "Miller", "given": "Meghan S." }, "orcid": "0000-0001-5494-2296" }, { "id": "Pearce-F", "name": { "family": "Pearce", "given": "Fred" } }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" } ] }, "title": "Evidence of an upper mantle seismic anomaly opposing the Cocos slab beneath the Isthmus of Tehuantepec, Mexico", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 2014 American Geophysical Union.\n\nReceived 27 FEB 2014;\nAccepted 5 JUL 2014;\nAccepted article online 10 JUL 2014;\nPublished online 25 JUL 2014.\n\nY.K. and H.L. were funded by the Korea\nMeteorological Administration\nResearch and Development Program\nunder Grant CATER-2013-8010. M.S.M.\nwas funded by NSF EAR-1054638.\nAuthors thank entire VEOX team for\nmaking the data available. Finally,\nauthors thank the editor and\nanonymous reviewers for helpful\ncomments, which greatly improved\nthe paper.\n\nPublished - ggge20522.pdf
", "abstract": "Subduction of the Cocos plate beneath southern Mexico is characterized by several unusual features, such as a discontinuous volcanic arc, unusual arc chemistry, and anomalously low topography of Tehuantepec Isthmus. Recent seismic images from both receiver functions and seismic tomography suggest that there may be an additional, opposing structure dipping to the southwest from the Gulf of Mexico, and these images have been previously explained by a southwest-dipping slab. However, standard models of the Caribbean tectonic history do not support this interpretation. To better define the Cocos slab's structure and the possible existence of a structure dipping in the opposite direction, dense seismic data across southern Mexico are used to form high-resolution seismic images, based on the 2-D generalized radon transform method, and to relocate regional earthquakes. Our images show the Cocos plate dipping at 30\u00b0 to the northeast encounters the anomaly that is dipping in the opposite sense at \u223c150 km depth. Relocated seismicity clearly delineates a Wadati-Benioff zone that marks the subducting Cocos plate. A cluster of seismicity also appears at \u223c150 km depth which may be related to the subduction of the Tehuantepec ridge and/or to the imaged seismic structure with opposite polarity.", "date": "2014-07", "date_type": "published", "publication": "Geochemistry, Geophysics, Geosystems", "volume": "15", "number": "7", "publisher": "American Geophysical Union", "pagerange": "3021-3034", "id_number": "CaltechAUTHORS:20140918-083707405", "issn": "1525-2027", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140918-083707405", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Korea Meteorological Administration Research and Development Program", "grant_number": "CATER-2013-8010" }, { "agency": "NSF", "grant_number": "EAR-1054638" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1002/2014GC005320", "primary_object": { "basename": "ggge20522.pdf", "url": "https://authors.library.caltech.edu/records/4p20a-9h073/files/ggge20522.pdf" }, "resource_type": "article", "pub_year": "2014", "author_list": "Kim, YoungHee; Lim, Hobin; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/6gzff-cc513", "eprint_id": 46350, "eprint_status": "archive", "datestamp": "2023-08-22 12:53:18", "lastmod": "2023-10-26 19:41:14", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Ma-Yiran", "name": { "family": "Ma", "given": "Yiran" }, "orcid": "0000-0002-8369-3310" }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" } ] }, "title": "The crust and uppermost mantle structure of Southern Peru from ambient noise and earthquake surface wave analysis", "ispublished": "pub", "full_text_status": "public", "keywords": "Central Andes; flat subduction; surface wave tomography", "note": "\u00a9 2014 Elsevier B.V. Received 17 December 2013, Revised 7 March 2014, Accepted 8 March 2014, Available online 4 April 2014. Editor: P. Shearer. We thank Prof. Huajian Yao for providing the ambient noise dispersion measurement code, Prof. Don Forsyth for providing the two-plane-wave tomography code, and Dunzhu Li for useful discussions. We also thank the editor and two anonymous reviewers for their helpful comments. This work is supported by NSF (EAR-1045683) and the Gordon and Betty Moore Foundation through the Tectonics Observatory at Caltech (contribution number 257).\n\nSupplemental Material - mmc1.docx
", "abstract": "Southern Peru is located in the northern Central Andes, which is the highest plateau along an active subduction zone. In this region, the Nazca slab changes from normal to flat subduction, with the associated Holocene volcanism ceasing above the flat subduction regime. We use 6 s to 67 s period surface wave signals from ambient noise cross-correlations and earthquake data, to image the shear wave velocity (V_(SV) structure to a depth of 140 km. A mid-crust low-velocity zone is revealed, and is interpreted as partially molten rocks that are part of the Andean low-velocity zone. It is oblique to the present trench, and possibly indicates the location of the volcanic arcs formed during the steepening of the Oligocene flat slab beneath the Altiplano plateau. The recently subducted slab beneath the forearc shows a decrease in velocity from the normal to flat subduction regime that might be related to hydration during the formation of the Nazca ridge, which in turn may contribute to the buoyancy of the flat slab. The mantle above the flat slab has a comparatively high velocity, which indicates the lack of melting and thus explains the cessation of the volcanism above. A velocity contrast from crust to uppermost mantle is imaged across the Cusco\u2013Vilcanota Fault System, and is interpreted as the boundary between two lithospheric blocks.", "date": "2014-06-01", "date_type": "published", "publication": "Earth and Planetary Science Letters", "volume": "395", "publisher": "Elsevier", "pagerange": "61-70", "id_number": "CaltechAUTHORS:20140619-084953376", "issn": "0012-821X", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140619-084953376", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR-1045683" }, { "agency": "Gordon and Betty Moore Foundation" } ] }, "other_numbering_system": { "items": [ { "id": "257", "name": "Caltech Tectonics Observatory" } ] }, "local_group": { "items": [ { "id": "Caltech-Tectonics-Observatory" }, { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/j.epsl.2014.03.013", "primary_object": { "basename": "mmc1.docx", "url": "https://authors.library.caltech.edu/records/6gzff-cc513/files/mmc1.docx" }, "resource_type": "article", "pub_year": "2014", "author_list": "Ma, Yiran and Clayton, Robert W." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/14m8h-tkd83", "eprint_id": 46809, "eprint_status": "archive", "datestamp": "2023-08-22 12:48:30", "lastmod": "2023-10-26 19:54:51", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "P\u00e9rez-Campos-X", "name": { "family": "P\u00e9rez-Campos", "given": "Xyoli" } }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" } ] }, "title": "Interaction of Cocos and Rivera plates with the upper-mantle transition zone underneath central Mexico", "ispublished": "pub", "full_text_status": "public", "keywords": "Mantle processes; Phase transitions; North America", "note": "\u00a9 2014 The Authors.\n\nAccepted 2014 March 7. Received 2014 February 28; in original form 2013 July 25.\n\nFigures were done using Generic Mapping Tools (GMT; Wessel &\nSmith 1991). We thank C. C\u00e1rdenas and E.A. Solano for providing noise curves for the SSN. We thank all the volunteers that made possible the operation of MASE, VEOX, MARS, GGAP and CONA, and the SSN personnel for installation and maintenance of the stations and making possible data availability. CONA stations were funded by Conacyt project J51566-F. GGAP stations were funded through the Agence Nationale de la Recherche (France) under the contract RA0000CO69 (ANR G-GAP). Fund for this work was provided by DGAPA-UNAM project IN105910 and the Tectonics Observatory at Caltech, which is funded by the Betty and Gordon\nMoore Foundation. This is contribution #233 from the Tectonics Observatory. XP-C had a sabbatical fellowship from DGAPA-UNAM and thanks the Tectonics Observatory at Caltech for partial funding for her sabbatical. We further thank B. Tauzin and an anonymous reviewer whose comments helped improve this paper.\n\nPublished - Geophys._J._Int.-2014-P\u00e9rez-Campos-1763-9.pdf
Supplemental Material - PerezCamposAndClayton_CSmex_suppMat_28feb2014.pdf
", "abstract": "Receiver functions (RFs) from 224 permanent and temporary stations in central and southern Mexico were used to characterize the upper-mantle transition zone in that region. Discontinuities at 410 and 660 km depth are both deeper compared to iasp91, which reflects a slow velocity anomaly in the upper mantle. They show topography on the interfaces that is consistent with the interaction of the subducted slab or its broken off extension. A low-velocity layer on top of the 410 is identified mainly on the continental side of where the slab pierces it (i.e. in the lee of the slab roll-back). In general the RFs show a complex behaviour where the mantle has been disturbed by the lateral motion of the subducted slab, and are simple where it has not. Complexity on the 660 coincides with the place where the broken off portion of the Farallon Plate would have penetrated this interface or is possibly lying on top of it.", "date": "2014-06", "date_type": "published", "publication": "Geophysical Journal International", "volume": "197", "number": "3", "publisher": "Royal Astronomical Society", "pagerange": "1763-1769", "id_number": "CaltechAUTHORS:20140703-103933633", "issn": "0956-540X", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140703-103933633", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "CONACyT (Mexico)", "grant_number": "J51566-F" }, { "agency": "Agence Nationale pour la Recherche (ANR) (France)", "grant_number": "RA0000CO69" }, { "agency": "DGAPA-UNAM", "grant_number": "IN105910" }, { "agency": "Caltech Tectonics Observatory" }, { "agency": "Gordon and Betty Moore Foundation" } ] }, "other_numbering_system": { "items": [ { "id": "233", "name": "Caltech Tectonics Observatory" } ] }, "local_group": { "items": [ { "id": "Caltech-Tectonics-Observatory" }, { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1093/gji/ggu087", "primary_object": { "basename": "PerezCamposAndClayton_CSmex_suppMat_28feb2014.pdf", "url": "https://authors.library.caltech.edu/records/14m8h-tkd83/files/PerezCamposAndClayton_CSmex_suppMat_28feb2014.pdf" }, "related_objects": [ { "basename": "Geophys._J._Int.-2014-P\u00e9rez-Campos-1763-9.pdf", "url": "https://authors.library.caltech.edu/records/14m8h-tkd83/files/Geophys._J._Int.-2014-P\u00e9rez-Campos-1763-9.pdf" } ], "resource_type": "article", "pub_year": "2014", "author_list": "P\u00e9rez-Campos, Xyoli and Clayton, Robert W." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/cbxpn-p2d14", "eprint_id": 46028, "eprint_status": "archive", "datestamp": "2023-08-22 12:34:35", "lastmod": "2023-10-26 18:37:31", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Li-Dunzhu", "name": { "family": "Li", "given": "Dunzhu" }, "orcid": "0000-0003-3149-0236" }, { "id": "Helmberger-D-V", "name": { "family": "Helmberger", "given": "Don" } }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" }, { "id": "Sun-Daoyuan", "name": { "family": "Sun", "given": "Daoyuan" }, "orcid": "0000-0003-4461-4664" } ] }, "title": "Global synthetic seismograms using a 2-D finite-difference method", "ispublished": "pub", "full_text_status": "public", "keywords": "Body waves; Computational seismology; Wave propagation", "note": "\u00a9 2014 The Authors. Published by Oxford University Press on behalf of The Royal Astronomical Society\n\nAccepted 2014 February 6. Received 2014 February 5; in original form 2013 September 20.\nFirst published online: March 1, 2014.\n\nWe thank the Editor and two anonymous reviewers for their comments\nwhich greatly improved the manuscript. Data were provided\nby the IRIS data center and EarthScope USArray. This work was\nsupported by NSF EAR-1053064 and CSEDI EAR-1161046 at Caltech,\nwith partial support of D. Sun at USC under EAR-0809023.\n\nPublished - Geophys._J._Int.-2014-Li-1166-83.pdf
", "abstract": "Two-dimensional (2-D) finite-difference (FD) synthetics, which fill the gap between fast 1-D analytic synthetics and time-consuming full 3-D synthetics in our ability to model seismograms, have been used in many studies. We address several issues involving 2-D FD methods in generating global synthetic seismograms. These include: (1) interfacing point source excitation for earthquakes with 2-D FD methods; (2) out-of-plane spreading corrections and (3) reducing the spherical Earth to the flattened models. The first issue is tackled using two methods, a 'transparent source box' approach and a moment tensor excitation approach, where each has its own advantages. Moreover, our 'source box' excitation does not have the late-time drift problem that occurred in previous studies. The out-of-plane geometric spreading correction is accounted for by estimating the ray parameter and applying a post-simulation filter to 2-D synthetics. Finally, parameters of the Earth-flattening transformation are discussed and validated. The effectiveness of this method is demonstrated by comparing our synthetics with frequency\u2013wavenumber summation, normal-mode and 3-D spectral-element synthetics.", "date": "2014-05", "date_type": "published", "publication": "Geophysical Journal International", "volume": "197", "number": "2", "publisher": "Royal Astronomical Society", "pagerange": "1166-1183", "id_number": "CaltechAUTHORS:20140602-124952161", "issn": "0956-540X", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140602-124952161", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR-1053064" }, { "agency": "NSF", "grant_number": "EAR-1161046" }, { "agency": "NSF", "grant_number": "EAR-0809023" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1093/gji/ggu050", "primary_object": { "basename": "Geophys._J._Int.-2014-Li-1166-83.pdf", "url": "https://authors.library.caltech.edu/records/cbxpn-p2d14/files/Geophys._J._Int.-2014-Li-1166-83.pdf" }, "resource_type": "article", "pub_year": "2014", "author_list": "Li, Dunzhu; Helmberger, Don; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/bqe0p-der08", "eprint_id": 47476, "eprint_status": "archive", "datestamp": "2023-08-20 00:12:33", "lastmod": "2023-10-26 20:38:17", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Dougherty-S-L", "name": { "family": "Dougherty", "given": "Sara L." }, "orcid": "0000-0002-5327-3286" }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" } ] }, "title": "Seismicity and structure in central Mexico: Evidence for a possible slab tear in the South Cocos plate", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 2014 American Geophysical Union.\n\nReceived 2 DEC 2013;\nAccepted 6 APR 2014;\nAccepted article online 9 APR 2014;\nPublished online 29 APR 2014;\nCorrected 2 JUL 2014.\n\nMASE and VEOX data are available\nat the IRIS DMC under the network\ncode TO. Researchers should contact\nMichael Brudzinski for OXNET data\nand Carlos M. Valdes Gonzalez for SSN\nwaveform data. The SSN event catalog\nis accessible from the Servicio\nSismol\u00f3gico Nacional website (http://\nwww.ssn.unam.mx/). The SSN CMT catalog\nis available on the Mexican CMT\nProject website (http://laxdoru.igeofcu.\nunam.mx/cmt). The ISC Bulletin\nevent catalog is accessible from the\nInternational Seismological Centre\nwebsite (http://www.isc.ac.uk). This\nstudy was supported in part by the\nGordon and Betty Moore Foundation\nthrough the Tectonics Observatory\nat California Institute of Technology.\nThis is contribution 256 from the\nCaltech Tectonics Observatory. We\nare grateful to Michael Brudzinski,\nEnrique Cabral-Cano, and Alejandra\nArciniega-Ceballos for making the\nOXNET waveform data available. We\nthank Arturo Iglesias for providing\nthe Servicio Sismol\u00f3gico Nacional\nevent catalog and Ting Chen for the\nslab isodepth contour lines. We also\nthank Editor Robert Nowack, the\nAssociate Editor, Sebastiano D'Amico,\nand an anonymous reviewer for\nhelpful comments, which improved\nthe manuscript.\n\nErratum:\nIn the originally published version of this article two citations were missing. The error has since been\ncorrected and this version may be considered the authoritative version of record.\n\nPublished - jgrb50646.pdf
Supplemental Material - 2013JB010883fS01.ps
Supplemental Material - 2013JB010883fS02.ps
Supplemental Material - 2013JB010883fS03.ps
Supplemental Material - 2013JB010883fS04.ps
Supplemental Material - 2013JB010883fS05.ps
Supplemental Material - 2013JB010883fS06.ps
Supplemental Material - 2013JB010883readme.docx
", "abstract": "The morphology of the transition from flat to normal subduction in eastern central Mexico is explored using intraslab earthquakes recorded by temporary and permanent regional seismic arrays. Observations of a sharp transition in slab dip near the abrupt end of the Trans-Mexican Volcanic Belt (TMVB) suggest a possible slab tear located within the subducted South Cocos plate. The eastern lateral extent of a thin ultra-slow velocity layer (USL) imaged atop the Cocos slab in recent studies along the Meso America Subduction Experiment array is examined here using additional data. We find an end to this USL which is coincident with the western boundary of a zone of decreased seismicity and the end of the TMVB near the sharp transition in slab dip. Waveform modeling of the 2-D structure in this region using a finite difference algorithm provides constraints on the velocity and geometry of the slab's seismic structure and confirms the location of the USL. Analysis of intraslab seismicity patterns reveals clustering, sudden increase in depth, variable focal mechanism orientations and faulting types, and alignment of source mechanisms along the sharp transition in slab dip. The seismicity and structural evidence suggests a possible tear in the South Cocos slab. This potential tear, together with the tear along the Orozco Fracture Zone to the northwest, indicates a slab rollback mechanism in which separate slab segments move independently, allowing for mantle flow between the segments.", "date": "2014-04", "date_type": "published", "publication": "Journal of Geophysical Research. Solid Earth", "volume": "119", "number": "4", "publisher": "American Geophysical Union", "pagerange": "3424-3447", "id_number": "CaltechAUTHORS:20140724-143520914", "issn": "2169-9313", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140724-143520914", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Gordon and Betty Moore Foundation" } ] }, "other_numbering_system": { "items": [ { "id": "256", "name": "Caltech Tectonics Observatory" } ] }, "local_group": { "items": [ { "id": "Caltech-Tectonics-Observatory" }, { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1002/2013JB010883", "primary_object": { "basename": "2013JB010883fS01.ps", "url": "https://authors.library.caltech.edu/records/bqe0p-der08/files/2013JB010883fS01.ps" }, "related_objects": [ { "basename": "2013JB010883fS02.ps", "url": "https://authors.library.caltech.edu/records/bqe0p-der08/files/2013JB010883fS02.ps" }, { "basename": "2013JB010883fS03.ps", "url": "https://authors.library.caltech.edu/records/bqe0p-der08/files/2013JB010883fS03.ps" }, { "basename": "2013JB010883fS04.ps", "url": "https://authors.library.caltech.edu/records/bqe0p-der08/files/2013JB010883fS04.ps" }, { "basename": "2013JB010883fS05.ps", "url": "https://authors.library.caltech.edu/records/bqe0p-der08/files/2013JB010883fS05.ps" }, { "basename": "2013JB010883fS06.ps", "url": "https://authors.library.caltech.edu/records/bqe0p-der08/files/2013JB010883fS06.ps" }, { "basename": "2013JB010883readme.docx", "url": "https://authors.library.caltech.edu/records/bqe0p-der08/files/2013JB010883readme.docx" }, { "basename": "jgrb50646.pdf", "url": "https://authors.library.caltech.edu/records/bqe0p-der08/files/jgrb50646.pdf" } ], "resource_type": "article", "pub_year": "2014", "author_list": "Dougherty, Sara L. and Clayton, Robert W." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/jnh18-tz089", "eprint_id": 44630, "eprint_status": "archive", "datestamp": "2023-08-22 11:49:45", "lastmod": "2023-10-26 14:49:59", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Phillips-K", "name": { "family": "Phillips", "given": "Kristin" } }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" } ] }, "title": "Structure of the subduction transition region from seismic array data in southern Peru", "ispublished": "pub", "full_text_status": "public", "keywords": "Seismicity and tectonics; Continental margins: convergent; Crustal structure.", "note": "\u00a9 2014 The Authors. Published by Oxford University Press on behalf of The Royal Astronomical Society. Accepted 2013 December 11. Received 2013 December 7. In original form 2013 August 28. First published online: January 10, 2014. We thank the Betty and Gordon Moore Foundation for their support through the Tectonics Observatory at Caltech. This research was partially support by NSF award EAR-1045683. Also thanks to Richard Guy, Paul Davis and Igor Stubailo of the UCLA Center for Embedded Networked Systems, Steven Skinner of the Caltech Seismological Laboratory, Hernando Tavera and Victor Aguilar of the Instituto Geofisico del Peru and Laurence Audin of Institute of Research for Development. We also thank the PULSE and CAUGHT projects for contributing data to this study. Contribution #238 from\nthe Tectonics Observatory.\n\nPublished - Geophys._J._Int.-2014-Phillips-1889-905.pdf
", "abstract": "Data from three seismic arrays installed in southern Peru were analysed using receiver functions from P, PP and PKP wave phases, in order to image the subducted Nazca slab. The arrays cover the transition region from flat slab subduction in central Peru to normal subduction with an angle of about 30\u00b0 further south. A previous study used data from the first array in the normal subduction region to image the Moho depth and slab, and showed the existence of a mid-crustal structure at 40 km depth that is suggested to be a possible underthrusting of the Brazilian shield. Here, we discuss new observations from the other two arrays that span the transition between the two subduction regimes and the flat subduction region. The results provide an image of the flattened slab from the coast to approximately 300 km inland and also across the transition region from flat to 30\u00b0 subduction, which appears to be a bend rather than a tear in the slab. In the flat slab region, the slab is well defined near the coast and flattens out at 100 km depth beneath the Altiplano. The slab appears to start flattening some 400 km in advance of the subduction of the Nazca Ridge and the flattening is maintained for 1300 km after its passage. The Moho begins at a depth of around 30 km near the coast and has a maximum depth of 75 km beneath the Altiplano, consistent with the results of the other arrays. Both arrays also show a positive impedance mid-crustal structure at 40 km depth, which if explainable by underthrusting of the Brazilian shield, would add further support to the observations from the normal subduction region and show the northward and westward extent of the signal. The underthrusting hypothesis would explain the missing crust from the shortening budget needed to support the Altiplano. The Vp/Vs ratios for both arrays exhibit average values between 1.73 and 1.75 indicating a lesser likelihood that there is a high degree of partial melting or magma bodies at depth in this region. The receiver function results provide new imaging of the flat slab and transition from normal to flat slab subduction which allows for comparison of different subduction regimes.", "date": "2014-03", "date_type": "published", "publication": "Geophysical Journal International", "volume": "196", "number": "3", "publisher": "Royal Astronomical Society", "pagerange": "1889-1905", "id_number": "CaltechAUTHORS:20140403-100641102", "issn": "0956-540X", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140403-100641102", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Betty and Gordon Moore Foundation" }, { "agency": "Caltech Tectonics Observatory" }, { "agency": "NSF", "grant_number": "EAR-1045683" } ] }, "other_numbering_system": { "items": [ { "id": "238", "name": "Caltech Tectonics Observatory" } ] }, "local_group": { "items": [ { "id": "Caltech-Tectonics-Observatory" }, { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1093/gji/ggt504", "primary_object": { "basename": "Geophys._J._Int.-2014-Phillips-1889-905.pdf", "url": "https://authors.library.caltech.edu/records/jnh18-tz089/files/Geophys._J._Int.-2014-Phillips-1889-905.pdf" }, "resource_type": "article", "pub_year": "2014", "author_list": "Phillips, Kristin and Clayton, Robert W." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/3jbte-41t81", "eprint_id": 43400, "eprint_status": "archive", "datestamp": "2023-08-22 11:07:25", "lastmod": "2023-10-25 23:31:05", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Kim-YoungHee", "name": { "family": "Kim", "given": "YoungHee" }, "orcid": "0000-0002-1111-632X" }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" }, { "id": "Asimow-P-D", "name": { "family": "Asimow", "given": "Paul D." }, "orcid": "0000-0001-6025-8925" }, { "id": "Jackson-J-M", "name": { "family": "Jackson", "given": "Jennifer M." }, "orcid": "0000-0002-8256-6336" } ] }, "title": "Generation of talc in the mantle wedge and its role in subduction dynamics in central Mexico", "ispublished": "pub", "full_text_status": "restricted", "keywords": "subduction; talc; serpentine; receiver function; mantle wedge; P-to-S velocity ratio", "note": "\u00a9 2013 Elsevier B.V.\nReceived 13 August 2013;\nReceived in revised form 3 October 2013;\nAccepted 4 October 2013;\nAvailable online 27 October 2013.\nEditor: P. Shearer\n\nThis work was funded by the Korea Meteorological Administration Research and Development Program under Grant CATER-2013-8010. This study was also supported by the Gordon and Betty Moore Foundation through the Tectonics Observatory at California Institute of Technology (Contribution number 223) and NSF award EAR 0609707. We used Excel Worksheets and Macros from Hacker and Abers (2004) for calculating seismic speeds. We thank Xyoli Perez-Campos, Arturo Iglesias, and others at the Universidad Nacional Autonoma de Mexico for deploying and maintaining the MASE line. We also thank Joann Stock and Michael Gurnis from California Institute of Technology for discussions. Finally, we thank Editor Peter Shearer, Pascal Audet, and one anonymous reviewer for helpful comments which improved the manuscript.", "abstract": "Geophysical evidence shows the presence of low-seismic velocity material at the surface of slabs in subduction zones. In the central Mexican subduction zone this appears as a thin (\u223c4 km) low-velocity zone that absorbs nearly all of the strain. The P-to-S velocity ratio as a function of S wave velocity distinguishes among the various candidate hydrous (low-strength) minerals; the thin layer in the flat-slab region is most consistent with a layer showing enrichment in talc overlying normal MORB-like gabbro. Based on available thermodynamic data for equilibria for talc, its generation at the trench is nearly impossible, and hence we propose it originates from the mantle wedge during the slab flattening process coupled with trench rollback. The evolution of this low-strength zone has important implications for the dynamics of the slab-flattening process as well as the geochemistry of the mantle wedge and arc in central Mexico.", "date": "2013-12-15", "date_type": "published", "publication": "Earth and Planetary Science Letters", "volume": "384", "publisher": "Elsevier", "pagerange": "81-87", "id_number": "CaltechAUTHORS:20140116-090617911", "issn": "0012-821X", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140116-090617911", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Korea Meteorological Administration Research and Development Program", "grant_number": "CATER-2013-8010" }, { "agency": "Gordon and Betty Moore Foundation" }, { "agency": "Caltech Tectonics Observatory" }, { "agency": "NSF", "grant_number": "EAR 0609707" } ] }, "other_numbering_system": { "items": [ { "id": "223", "name": "Caltech Tectonics Observatory" } ] }, "local_group": { "items": [ { "id": "Caltech-Tectonics-Observatory" }, { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/j.epsl.2013.10.006", "resource_type": "article", "pub_year": "2013", "author_list": "Kim, YoungHee; Clayton, Robert W.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/qf3d2-j4717", "eprint_id": 43704, "eprint_status": "archive", "datestamp": "2023-08-22 10:30:49", "lastmod": "2023-10-25 23:47:42", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Schmandt-B", "name": { "family": "Schmandt", "given": "Brandon" }, "orcid": "0000-0003-1049-9020" }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" } ] }, "title": "Analysis of teleseismic P waves with a 5200-station array in Long Beach, California: Evidence for an abrupt boundary to Inner Borderland rifting", "ispublished": "pub", "full_text_status": "public", "keywords": "teleseismic imaging; Inner Borderland; seismic arrays; rifting", "note": "\u00a9 2013 American Geophysical Union.\n\nReceived 14 April 2013; revised 23 August 2013; accepted 9 September 2013; published 3 October 2013.\n\nNodalSeismic LLC and Signal Hill Petroleum Inc. are thanked for providing data access, and we specifically thank Dan\nHollis for his efforts in making the data available. We thank Craig Jones and Vadim Levin for constructive reviews. This research was supported in part by the Gordon and Betty Moore Foundation through the Tectonics Observatory at Caltech and by NSF grant EAR1214912. This is contribution\n#237 from the Tectonics Observatory. B.S. was also partially supported by the University of New Mexico.\n\nPublished - jgrb50370.pdf
", "abstract": "We analyze teleseismic P waves from four Mw\u2009\u2265\u20096.5 earthquakes recorded by a petroleum industry survey in Long Beach, California. The survey used a 2-D array with up to 5200 seismometers, 120\u2009m mean spacing, and 7 \u2013 10\u2009km aperture. At frequencies near 1\u2009Hz, P wave travel times and amplitudes exhibit coherent lateral variations over scales as short as ~400\u2009m, including locally delayed travel times and increased amplitudes at the crest of the Long Beach anticline. Deeper heterogeneity is indicated by P wave phase velocities that deviate from reference model predictions for events from southwestern azimuths. We postulate that a sharp northeastward increase in Moho depth from the Inner Borderland (IB) to mainland southern California causes the anomalous phase velocities. Elastic forward modeling finds the travel times are fit well by a Moho that dips 65\u00b0 to the northeast and flattens ~10\u2009km southwest of the Newport-Inglewood fault zone. Constraining the felsic thickness of mainland crust to 28\u2009km requires an 8\u2009km thick layer with a P-velocity of 7\u2009km/s beneath it, which could result from basal accretion of former Farallon ocean crust or magmatic underplating during Miocene volcanism. Forward models with a 65\u00b0 Moho dip predict a P-to-s conversion with a phase velocity of ~5\u2009km/s. Deconvolution of the array's mean P wave signal isolates a similar later arriving phase. The steep crust thickness transition supports a locally abrupt boundary to IB rifting. Our results highlight the utility of dense short-period arrays for passive imaging at near surface to uppermost mantle depths.", "date": "2013-10", "date_type": "published", "publication": "Journal of Geophysical Research. Solid Earth", "volume": "118", "number": "10", "publisher": "American Geophysical Union", "pagerange": "5320-5338", "id_number": "CaltechAUTHORS:20140206-114352976", "issn": "2169-9313", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140206-114352976", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Gordon and Betty Moore Foundation" }, { "agency": "NSF", "grant_number": "EAR-1214912" }, { "agency": "Caltech Tectonics Observatory" }, { "agency": "University of New Mexico" } ] }, "other_numbering_system": { "items": [ { "id": "237", "name": "Caltech Tectonics Observatory" } ] }, "local_group": { "items": [ { "id": "Caltech-Tectonics-Observatory" }, { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1002/jgrb.50370", "primary_object": { "basename": "jgrb50370.pdf", "url": "https://authors.library.caltech.edu/records/qf3d2-j4717/files/jgrb50370.pdf" }, "resource_type": "article", "pub_year": "2013", "author_list": "Schmandt, Brandon and Clayton, Robert W." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/qp6zx-ytp61", "eprint_id": 41411, "eprint_status": "archive", "datestamp": "2023-08-22 10:10:58", "lastmod": "2023-10-24 23:42:47", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Zhan-Zhongwen", "name": { "family": "Zhan", "given": "Zhongwen" }, "orcid": "0000-0002-5586-2607" }, { "id": "Tsai-V-C", "name": { "family": "Tsai", "given": "Victor C." }, "orcid": "0000-0003-1809-6672" }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" } ] }, "title": "Spurious velocity changes caused by temporal variations in ambient noise frequency content", "ispublished": "pub", "full_text_status": "public", "keywords": "Time-series analysis; Interferometry; Surface waves and free oscillations; Coda waves", "note": "\u00a9 The Authors 2013. Published by Oxford University Press on behalf of The Royal Astronomical Society.\n\nAccepted 2013 April 23; Received 2013 April 22; In original form 2013 February 18.\n\nWe thank Fan-Chi Lin and Dongzhou Zhang for helpful discussions. We thank the editorMichael Ritzwoller and two anonymous reviewers for their comments that improved the manuscript. The facilities of the Southern California Earthquake Data Center (SCEDC), and the Southern California Seismic Network (SCSN), were used for access to waveforms data required in this study. This work is partially\nsupported by the NSF/EAR-0838247 and Southern California\nEarthquake Center (12064).\n\nPublished - Geophys._J._Int.-2013-Zhan-1574-81.pdf
", "abstract": "Ambient seismic noise cross-correlations are now being used to detect temporal variations of seismic velocity, which are typically on the order of 0.1 per cent. At this small level, temporal variations in the properties of noise sources can cause apparent velocity changes. For example, the spatial distribution and frequency content of ambient noise have seasonal variations due to the seasonal hemispherical shift of storms. Here, we show that if the stretching method is used to measure time-shifts, then the temporal variability of noise frequency content causes apparent velocity changes due to the changes in both amplitude and phase spectra caused by waveform stretching. With realistic seasonal variations of frequency content in the Los Angeles Basin, our numerical tests produce about 0.05 per cent apparent velocity change, comparable to what Meier et al. observed in the Los Angeles Basin. We find that the apparent velocity change from waveform stretching depends on time windows and station-pair distances, and hence it is important to test a range of these parameters to diagnose the stretching bias. Better understanding of spatiotemporal noise source properties is critical for more accurate and reliable passive monitoring.", "date": "2013-09", "date_type": "published", "publication": "Geophysical Journal International", "volume": "194", "number": "3", "publisher": "Royal Astronomical Society", "pagerange": "1574-1581", "id_number": "CaltechAUTHORS:20130919-113717281", "issn": "0956-540X", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130919-113717281", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR-0838247" }, { "agency": "Southern California Earthquake Center (SCEC)", "grant_number": "12064" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1093/gji/ggt170", "primary_object": { "basename": "Geophys._J._Int.-2013-Zhan-1574-81.pdf", "url": "https://authors.library.caltech.edu/records/qp6zx-ytp61/files/Geophys._J._Int.-2013-Zhan-1574-81.pdf" }, "resource_type": "article", "pub_year": "2013", "author_list": "Zhan, Zhongwen; Tsai, Victor C.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/rh8an-awb39", "eprint_id": 39942, "eprint_status": "archive", "datestamp": "2023-08-22 09:57:25", "lastmod": "2023-10-24 17:19:36", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "P\u00e9rez-Campos-Xyoli", "name": { "family": "P\u00e9rez-Campos", "given": "Xyoli" }, "orcid": "0000-0001-8970-7966" }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" } ] }, "title": "Evidence of upper-mantle processes related to continental rifting versus oceanic crust in the Gulf of California", "ispublished": "pub", "full_text_status": "public", "keywords": "Mantle processes; Phase transitions; North America", "note": "\u00a9 2013 The Authors. Published by Oxford University Press on behalf of The Royal Astronomical Society.\n\nAccepted 2013 April 4. Received 2013 April 3; in original form 2012 June 27.\n\nFirst published online: April 30, 2013.\n\nFigures were done using Generic Mapping Tools (Wessel & Smith\n1991). We thank three anonymous reviewers whose comments improved\nthis paper.We thank Cicese for data and maintenance of the\nRESBAN and NARS-Baja stations and the SSN and the SCSN for\ntheir data and station maintenance. The operation of the RESBAN\narray (Red Sismol\u00f3gica de Banda Ancha del Golfo de California)\nhas been possible thanks to the financial support of the Mexican\nNational Council for Science and Technology (Conacyt) by means\nof the projects 48852, 62116. Partial funding for this work was provided\nby project DGAPA-IN105910, and by the Tectonics Observatory\nat Caltech, which is funded by the Betty and Gordon Moore\nFoundation. This is contribution #203 from the Tectonics Observatory. X.P.-C. had a sabbatical fellowship from DGAPA-UNAM and\nthanks the Tectonics Observatory at Caltech for partial funding.\n\nPublished - ggt133.pdf
Supplemental Material - PerezCamposAndClayton_SupplementaryInformation.doc
", "abstract": "Receiver functions from teleseismic events, recorded by stations around the Gulf of California,\nare used to map the upper-mantle seismic discontinuities. We observe a mean transition zone\nthickness comparable to the global average for most of the region. A low-velocity layer is\ndetected above the 410 discontinuity that varies in thickness along the Gulf of California. The\n660 discontinuity shows complex waveforms south of latitude 30\u25e6N as a result of the phase\nchange of garnet to perovskite. Within the transition zone, a complex behaviour of the receiver\nfunctions is observed mainly at the southern end of the Gulf. The north\u2013south variations of\nthis zone are likely associated with a slab window at the northern Gulf, resulting from the\ncessation of subduction of the Farallon plate 12 Ma, and the subduction of the Guadalupe and\nMagdalena microplates at the southern end, resulting in a hydrated upper mantle. Our results\nsuggest that change in rifting styles occurring along the Gulf of California mirrors deeper\nprocesses in the upper mantle.", "date": "2013-08", "date_type": "published", "publication": "Geophysical Journal International", "volume": "194", "number": "2", "publisher": "Royal Astronomical Society", "pagerange": "952-960", "id_number": "CaltechAUTHORS:20130815-095035975", "issn": "0956-540X", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130815-095035975", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "National Council for Science and Technology (CONACYT) (Mexico)", "grant_number": "48852" }, { "agency": "National Council for Science and Technology (CONACYT) (Mexico)", "grant_number": "62116" }, { "agency": "Universidad Nacional Autonoma de Mexico (UNAM)", "grant_number": "DGAPA-IN105910" }, { "agency": "Caltech Tectonics Observatory" }, { "agency": "Betty and Gordon Moore Foundation" }, { "agency": "Universidad Nacional Autonoma de Mexico (UNAM) Direcci\u00f3n General Asuntos del Personal Acad\u00e9mico (DGAPA)" } ] }, "other_numbering_system": { "items": [ { "id": "203", "name": "Caltech Tectonics Observatory" } ] }, "local_group": { "items": [ { "id": "Caltech-Tectonics-Observatory" }, { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1093/gji/ggt133", "primary_object": { "basename": "PerezCamposAndClayton_SupplementaryInformation.doc", "url": "https://authors.library.caltech.edu/records/rh8an-awb39/files/PerezCamposAndClayton_SupplementaryInformation.doc" }, "related_objects": [ { "basename": "ggt133.pdf", "url": "https://authors.library.caltech.edu/records/rh8an-awb39/files/ggt133.pdf" } ], "resource_type": "article", "pub_year": "2013", "author_list": "P\u00e9rez-Campos, Xyoli and Clayton, Robert W." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/t88rn-36q74", "eprint_id": 41159, "eprint_status": "archive", "datestamp": "2023-08-19 20:33:40", "lastmod": "2023-10-24 23:29:59", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Lin-Fan-Chi", "name": { "family": "Lin", "given": "Fan-Chi" }, "orcid": "0000-0003-0394-6830" }, { "id": "Li-Dunzhu", "name": { "family": "Li", "given": "Dunzhu" }, "orcid": "0000-0003-3149-0236" }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" }, { "id": "Hollis-D", "name": { "family": "Hollis", "given": "Dan" } } ] }, "title": "High-resolution 3D shallow crustal structure in Long Beach, California: Application of ambient noise tomography on a dense seismic array", "ispublished": "pub", "full_text_status": "public", "keywords": "surface wave, shear wave (S-wave), tomography, 3D, noise", "note": "\u00a9 2013 Society of Exploration Geophysicists.\n\nManuscript received by the Editor 26 October 2012; revised manuscript received 4 March 2013; published online 1 August 2013.\n\nThe authors gratefully acknowledge NodalSeismic LLC and\nSignal Hill Petroleum, Inc., for permitting us to use the Long Beach\ndata. We also thank K. Wapenaar, the associate editor, A. Verdel,\nand two anonymous reviewers for constructive comments and V.\nTsai and C. Stork for helpful discussions.\n\nPublished - geo2012-0453.1.pdf
", "abstract": "Ambient noise tomography has proven to be effective in resolving shallow earth structure. We applied ambient noise tomography on a dense seismic array in Long Beach, California. The array was composed of more than 5200 stations with an average spacing close to 100 m. Three weeks of passive ambient noise were crosscorrelated between each station pair, which resulted in more than 13.5 million crosscorrelations within the area. Clear fundamental-mode Rayleigh waves were observed between 0.5 and 4 Hz, which were most sensitive to structure above 1-km depth. For each station pair, we applied frequency-time analysis to determine the phase traveltime dispersion, and, for each frequency, we applied eikonal tomography to determine the Rayleigh wave phase velocity map. The eikonal tomography accounted for ray bending by tracking the wavefront and allowed uncertainties to be estimated through statistical analysis. The compilation of phase velocity maps was then used to invert for 3D shear velocity structure. The inverted model showed clear correlation with the known geologic features such as the shallow south\u2013north velocity dichotomy and a deeper fast anomaly associated with the Newport-Inglewood fault zone. Our results can potentially be used to complement traditional active source studies.", "date": "2013-07", "date_type": "published", "publication": "Geophysics", "volume": "78", "number": "4", "publisher": "Society of Exploration Geophysicists", "pagerange": "Q45-Q56", "id_number": "CaltechAUTHORS:20130909-085627813", "issn": "0016-8033", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130909-085627813", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1190/GEO2012-0453.1", "primary_object": { "basename": "geo2012-0453.1.pdf", "url": "https://authors.library.caltech.edu/records/t88rn-36q74/files/geo2012-0453.1.pdf" }, "resource_type": "article", "pub_year": "2013", "author_list": "Lin, Fan-Chi; Li, Dunzhu; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/hxb41-nee32", "eprint_id": 39709, "eprint_status": "archive", "datestamp": "2023-08-22 09:30:01", "lastmod": "2023-10-24 17:06:36", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Skinner-S-M", "name": { "family": "Skinner", "given": "Steven M." } }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" } ] }, "title": "The lack of correlation between flat slabs and bathymetric\n impactors in South America", "ispublished": "pub", "full_text_status": "public", "keywords": "flat slab; subduction; South America", "note": "\u00a9 2013 Elsevier B.V. Received 6 August 2012. Received in revised form 8 April 2013. Accepted 10 April 2013. Editor: Y. Ricard. Available online 11 May 2013. We thank J.P. Avouac and J. Stock for discussion and comments on the manuscript. We thank the editor, M.A. Gutscher, and V. Ramos for helpful reviews. This study was supported by the Gordon and Betty Moore Foundation through the Tectonics Observatory at Caltech. This is contribution number 201 from the\nCaltech Tectonics Observatory.\n\nSupplemental Material - mmc1.pdf
", "abstract": "Flat slab subduction has been attributed to various causes including mantle wedge dynamics, overriding by the upper plate, age of the subducting plate, and subduction of anomalously thick oceanic crust. One often favored explanation for flat slabs is the subduction of buoyant features on the oceanic plate in the form of an aseismic-ridge or oceanic plateau. We show through plate tectonic reconstructions of the Marquesas, Tuamotu, and Austral plateau, assuming that features on the conjugate plate can be used as proxies for subducted bathymetric anomalies, that there is very little correlation between the subduction of such anomalies and historic zones of flat subduction in South America. It is apparent that subduction of a bathymetric anomaly need not lead to a flat slab and not all flat slabs are associated with the subduction of a bathymetric anomaly.", "date": "2013-06", "date_type": "published", "publication": "Earth and Planetary Science Letters", "volume": "371", "publisher": "Elsevier", "pagerange": "1-5", "id_number": "CaltechAUTHORS:20130801-130008317", "issn": "0012-821X", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130801-130008317", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Gordon and Betty Moore Foundation" }, { "agency": "Caltech Tectonics Observatory" } ] }, "other_numbering_system": { "items": [ { "id": "201", "name": "Caltech Tectonics Observatory" } ] }, "local_group": { "items": [ { "id": "Caltech-Tectonics-Observatory" }, { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/j.epsl.2013.04.013", "primary_object": { "basename": "mmc1.pdf", "url": "https://authors.library.caltech.edu/records/hxb41-nee32/files/mmc1.pdf" }, "resource_type": "article", "pub_year": "2013", "author_list": "Skinner, Steven M. and Clayton, Robert W." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/mcwyz-6vy31", "eprint_id": 37614, "eprint_status": "archive", "datestamp": "2023-08-22 08:46:19", "lastmod": "2023-10-23 17:51:19", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Ma-Yiran", "name": { "family": "Ma", "given": "Yiran" }, "orcid": "0000-0002-8369-3310" }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" }, { "id": "Tsai-V-C", "name": { "family": "Tsai", "given": "Victor C." }, "orcid": "0000-0003-1809-6672" }, { "id": "Zhan-Zhongwen", "name": { "family": "Zhan", "given": "Zhongwen" }, "orcid": "0000-0002-5586-2607" } ] }, "title": "Locating a scatterer in the active volcanic area of Southern Peru from ambient noise cross-correlation", "ispublished": "pub", "full_text_status": "public", "keywords": "Interferometry; Wave scattering and diffraction; Volcanic arc processes", "note": "\u00a9 2013 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society. \n\nAccepted 2012 December 5. Received 2012 November 3; in original form 2012 July 17. First published online: January 10, 2013. \n\nWe thank Fan-Chi Lin at Caltech for providing many useful suggestions and thank Dunzhu Li at Caltech for providing the finite difference code. We also thank two anonymous reviewers for their helpful comments. Contribution number 212 from the Tectonics Observatory at Caltech. This work is supported by NSF (EAR-1045683) and the Gordon and Betty Moore Foundation.\n\nPublished - Geophys._J._Int.-2013-Ma-1332-41.pdf
", "abstract": "We report on a strong scatterer of seismic energy in the 5\u201310 s period range located in the volcanic arc of Southern Peru. It is superficially like an active noise source in that it produces a continuous signal that arrives earlier than the inter-station surface wave in the noise cross-correlations. However, it is clearly determined to be a scatterer based on the coda arrivals observed in the cross-correlations, and the fact that it scatters waves from earthquake sources. We model the scatterer as a cylinder approximately 5 km in diameter with a shear wave velocity 30\u2009per\u2009cent lower than the background velocity. It is likely to exist at the depth of 5\u201310 km, and is located at 71.6\u00b0W/16.1\u00b0S with an error of 10 km, which is near the inactive volcano Nevado Chachani and the active volcano El Misti which recently erupted in 1985.", "date": "2013-03", "date_type": "published", "publication": "Geophysical Journal International", "volume": "192", "number": "3", "publisher": "Royal Astronomical Society", "pagerange": "1332-1341", "id_number": "CaltechAUTHORS:20130325-143244581", "issn": "0956-540X", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130325-143244581", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR-1045683" }, { "agency": "Gordon and Betty Moore Foundation" } ] }, "other_numbering_system": { "items": [ { "id": "212", "name": "Caltech Tectonics Observatory" } ] }, "local_group": { "items": [ { "id": "Caltech-Tectonics-Observatory" }, { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1093/gji/ggs103", "primary_object": { "basename": "Geophys._J._Int.-2013-Ma-1332-41.pdf", "url": "https://authors.library.caltech.edu/records/mcwyz-6vy31/files/Geophys._J._Int.-2013-Ma-1332-41.pdf" }, "resource_type": "article", "pub_year": "2013", "author_list": "Ma, Yiran; Clayton, Robert W.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/adtvy-fze27", "eprint_id": 37538, "eprint_status": "archive", "datestamp": "2023-08-22 08:10:21", "lastmod": "2023-10-23 17:44:10", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Sun-Daoyuan", "name": { "family": "Sun", "given": "Daoyuan" }, "orcid": "0000-0003-4461-4664" }, { "id": "Helmberger-D-V", "name": { "family": "Helmberger", "given": "Don V." } }, { "id": "Jackson-J-M", "name": { "family": "Jackson", "given": "Jennifer M." }, "orcid": "0000-0002-8256-6336" }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" }, { "id": "Bower-D-J", "name": { "family": "Bower", "given": "Dan J." }, "orcid": "0000-0002-0673-4860" } ] }, "title": "Rolling hills on the core\u2013mantle boundary", "ispublished": "pub", "full_text_status": "public", "keywords": "core\u2013mantle boundary (CMB); iron-rich (Mg,Fe)O; USArray; low velocity zone", "note": "\u00a9 2012 Elsevier B.V. Received 14 June 2012. Received in revised form 6 October 2012. Accepted 30 October 2012. Editor: P.Shearer Available online 11 December 2012. The authors would like to thank the Editor Peter Shearer and\ntwo anonymous reviewers for their constructive comments. We\nthank J. K. Wicks and M. Gurnis for stimulating conversations and a constructive review by Alex Song. Data were provided by IRIS data center sand Earth scope US Array. This work was supported by NSF CSEDI EAR-0855815. D. Sunis supported by a Carnegie fellowship at the Department of Terrestrial Magnetism, Carnegie Institution of Washington.\n\nSupplemental Material - mmc1.pdf
", "abstract": "Recent results suggest that an iron-rich oxide may have fractionally crystallized from a primordial magma ocean and settled on the core\u2013mantle boundary (CMB). Based on experimental results, the presence of only a few percent of Fe-rich oxide could slow seismic waves down by several percent. This heavy layer can become highly undulating as predicted from dynamic modeling but can remain as a distinct structure with uniform velocity reductions. Here, we use the large USArray seismic network to search for such structures. Strong constraints on D\u2033 are provided by the core-phase SKS where it bifurcates, containing a short segment of P-wave diffractions (P_d) when crossing the CMB, called SKS_d. Synthetics from models with moderate velocity drops (less than 10%) involving a layer with variable thickness, perhaps a composite of sharp small structures, with strong variation in thickness can explain both the observed SKS_d waveforms and large scatter in differential times between SKKS and SKS. A smooth 3D image is obtained from inverting SKS_d waveforms displaying rolling-hills with elongated dome-like structures sitting on the CMB. The most prominent one has an 80-km height, \u223c8\u00b0 length, and \u223c4\u00b0 width, thus adding still more structural complexity to the lower mantle. We suggest that these results can be explained by a dynamically-stabilized material containing small amounts (\u223c5%) iron-rich (Mg,Fe)O providing a self-consistent physical interpretation.", "date": "2013-01-01", "date_type": "published", "publication": "Earth and Planetary Science Letters", "volume": "361", "publisher": "Elsevier", "pagerange": "333-342", "id_number": "CaltechAUTHORS:20130318-110208034", "issn": "0012-821X", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130318-110208034", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF CSEDI", "grant_number": "EAR-0855815" }, { "agency": "Carnegie Institution of Washington Department of Terrestrial Magnetism" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/j.epsl.2012.10.027", "primary_object": { "basename": "mmc1.pdf", "url": "https://authors.library.caltech.edu/records/adtvy-fze27/files/mmc1.pdf" }, "resource_type": "article", "pub_year": "2013", "author_list": "Sun, Daoyuan; Helmberger, Don V.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/sqd9h-dk594", "eprint_id": 36403, "eprint_status": "archive", "datestamp": "2023-08-19 13:35:03", "lastmod": "2023-10-20 23:07:09", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Phillips-K", "name": { "family": "Phillips", "given": "Kristin" } }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" }, { "id": "Davis-P", "name": { "family": "Davis", "given": "Paul" } }, { "id": "Tavera-H", "name": { "family": "Tavera", "given": "Hernando" } }, { "id": "Guy-R", "name": { "family": "Guy", "given": "Richard" } }, { "id": "Skinner-S", "name": { "family": "Skinner", "given": "Steven" } }, { "id": "Stubailo-I", "name": { "family": "Stubailo", "given": "Igor" } }, { "id": "Audin-L", "name": { "family": "Audin", "given": "Laurence" } }, { "id": "Aguilar-V", "name": { "family": "Aguilar", "given": "Victor" } } ] }, "title": "Structure of the subduction system in southern Peru from seismic array data", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 2012 American Geophysical Union. Received 18 June 2012; revised 3 October 2012; accepted 14 October 2012; published 28 November 2012. We thank the Betty and Gordon Moore\nFoundation for their support through the Tectonics Observatory at Caltech. This research was partially support by NSF award EAR-1045683. This is contribution number 199 from the Tectonics Observatory at Caltech.\n\nPublished - 2012JB009540.pdf
Supplemental Material - jgrb17358-sup-0001-readme.txt
Supplemental Material - jgrb17358-sup-0002-fs01.tif
Supplemental Material - jgrb17358-sup-0003-fs02.tif
Supplemental Material - jgrb17358-sup-0004-fs03.tif
Supplemental Material - jgrb17358-sup-0005-fs04.tif
", "abstract": "The subduction zone in southern Peru is imaged using converted phases from teleseismic P, PP, and PKP waves and Pwave tomography using local and teleseismic events with a linear array of 50 broadband seismic stations spanning 300 km from the coast to near Lake Titicaca. The slab dips at 30\u00b0 and can be observed to a depth of over 200 km. The Moho is seen as a continuous interface along the profile, and the crustal thickness in the back-arc region (the Altiplano) is 75 km thick, which is sufficient to isostatically support the Andes, as evidenced by the gravity. The shallow crust has zones of negative impedance at a depth of 20 km, which is likely the result of volcanism. At the midcrustal level of 40 km, there is a continuous structure with a positive impedance contrast, which we interpret as the western extent of the Brazilian Craton as it underthrusts to the west. V_p/V_s ratios estimated from receiver function stacks show average values for this region with a few areas of elevated V_p/V_s near the volcanic arc and at a few points in the Altiplano. The results support a model of crustal thickening in which the margin crust is underthrust by the Brazilian Shield.", "date": "2012-11-28", "date_type": "published", "publication": "Journal of Geophysical Research B", "volume": "117", "number": "B11", "publisher": "American Geophysical Union", "pagerange": "Art. No. B11306", "id_number": "CaltechAUTHORS:20130115-145644857", "issn": "0148-0227", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130115-145644857", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Betty and Gordon Moore Foundation" }, { "agency": "NSF", "grant_number": "EAR-1045683" } ] }, "other_numbering_system": { "items": [ { "id": "199", "name": "Caltech Tectonics Observatory" } ] }, "local_group": { "items": [ { "id": "Caltech-Tectonics-Observatory" }, { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1029/2012JB009540", "primary_object": { "basename": "jgrb17358-sup-0005-fs04.tif", "url": "https://authors.library.caltech.edu/records/sqd9h-dk594/files/jgrb17358-sup-0005-fs04.tif" }, "related_objects": [ { "basename": "2012JB009540.pdf", "url": "https://authors.library.caltech.edu/records/sqd9h-dk594/files/2012JB009540.pdf" }, { "basename": "jgrb17358-sup-0001-readme.txt", "url": "https://authors.library.caltech.edu/records/sqd9h-dk594/files/jgrb17358-sup-0001-readme.txt" }, { "basename": "jgrb17358-sup-0002-fs01.tif", "url": "https://authors.library.caltech.edu/records/sqd9h-dk594/files/jgrb17358-sup-0002-fs01.tif" }, { "basename": "jgrb17358-sup-0003-fs02.tif", "url": "https://authors.library.caltech.edu/records/sqd9h-dk594/files/jgrb17358-sup-0003-fs02.tif" }, { "basename": "jgrb17358-sup-0004-fs03.tif", "url": "https://authors.library.caltech.edu/records/sqd9h-dk594/files/jgrb17358-sup-0004-fs03.tif" } ], "resource_type": "article", "pub_year": "2012", "author_list": "Phillips, Kristin; Clayton, Robert W.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/9cteg-twn93", "eprint_id": 34666, "eprint_status": "archive", "datestamp": "2023-08-19 10:31:46", "lastmod": "2023-10-19 21:21:58", "type": "conference_item", "metadata_visibility": "show", "creators": { "items": [ { "id": "Lin-Fan-Chi", "name": { "family": "Lin", "given": "Fan-Chi" }, "orcid": "0000-0003-0394-6830" }, { "id": "Li-Dunzhu", "name": { "family": "Li", "given": "Dunzhu" }, "orcid": "0000-0003-3149-0236" }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" } ] }, "title": "Interferometry with a dense 3D dataset", "ispublished": "unpub", "full_text_status": "public", "note": "The authors gratefully acknowledge NodalSeismic LLC\nand Signal Hill Petroleum Inc for permitting us to use the\nLong Beach data. We also thank Victor Tsai and Christof\nStork for helpful discussions.\n\nPublished - Lin-SEG2012.pdf
", "abstract": "In this paper we report on progress using ambient noise\ncorrelation with a dense 3D survey conducted in Long\nBeach, California, to estimate subsurface velocity. We\nshow that both Rayleigh wave and body wave signals can\nbe clearly observed between 0.2-10 Hz frequency range in\nthe noise cross-correlations. The observed signals also\ncompare well with an active source gather. We apply\neikonal tomography to invert for the Rayleigh wave phase\nvelocity maps at several different frequencies. The phase\nvelocity maps, which are most sensitive to structure in the\ntop 600 meters, show clear correlation with known surface\nfeatures such as the slow anomaly adjacent to the coast in\nthe south and a fast anomaly associated with the Newport-\nInglewood fault zone. The results presented in this study\nshow the potential of using ambient noise interferometry\nmethod to complement active source techniques in studying\nhigh-resolution shallow crustal structure.", "date": "2012-10-03", "date_type": "published", "publisher": "Caltech Library", "id_number": "CaltechAUTHORS:20121003-112803929", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121003-112803929", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "primary_object": { "basename": "Lin-SEG2012.pdf", "url": "https://authors.library.caltech.edu/records/9cteg-twn93/files/Lin-SEG2012.pdf" }, "resource_type": "conference_item", "pub_year": "2012", "author_list": "Lin, Fan-Chi; Li, Dunzhu; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/4kgad-m4z03", "eprint_id": 34724, "eprint_status": "archive", "datestamp": "2023-08-22 06:58:20", "lastmod": "2023-10-19 21:24:22", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Dougherty-S-L", "name": { "family": "Dougherty", "given": "Sara L." }, "orcid": "0000-0002-5327-3286" }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" }, { "id": "Helmberger-D-V", "name": { "family": "Helmberger", "given": "Don V." } } ] }, "title": "Seismic structure in central Mexico: Implications for fragmentation of the subducted Cocos plate", "ispublished": "pub", "full_text_status": "public", "keywords": "modeling; structure; subduction", "note": "\u00a9 2012 American Geophysical Union.\nReceived 14 June 2012; revised 21 August 2012; accepted 22 August 2012; published 29 September 2012.\n\nThis study was supported in part by the\nGordon and Betty Moore Foundation through the Tectonics Observatory\nat California Institute of Technology. This is contribution number 207 from\nthe Caltech Tectonics Observatory. We are grateful to the Incorporated\nResearch Institutions for Seismology Data Management Center (IRISDMC)\nfor making the waveform data available. We thank Arturo Iglesias\nfor providing the Servicio Sismol\u00f3gico Nacional event catalog. We also\nthank Editor Robert Nowack and two anonymous reviewers for helpful\ncomments which greatly improved the manuscript.\n\nPublished - 2012JB009528.pdf
Supplemental Material - 2012JB009528-fs01.ps
Supplemental Material - 2012JB009528-fs02.ps
Supplemental Material - 2012JB009528-fs03.ps
Supplemental Material - 2012JB009528-fs04.ps
", "abstract": "The fine-scale seismic structure of the central Mexico subduction zone is studied using moderate-sized (M4-6) intraslab earthquakes. Regional waveforms from the Mapping the Rivera Subduction Zone (MARS) seismic array are complicated and contain detailed information about the subduction zone structure, including evidence of lateral heterogeneity. This waveform information is used to model the structure of the subducted plates, particularly along the transition from flat to normal subduction, where recent studies have shown evidence for possible slab tearing along the eastern projection of the Orozco Fracture Zone (OFZ). The lateral extent of a thin ultra-slow velocity layer (USL) imaged atop the Cocos slab in recent studies along the Meso America Subduction Experiment array is examined here using MARS waveforms. We find an edge to this USL which is coincident with the western boundary of the projected OFZ region. Forward modeling of the 2D structure of the subducted Rivera and Cocos plates using a finite difference algorithm provides constraints on the velocity and geometry of each slab's seismic structure in this region and confirms the location of the USL edge. We propose that the Cocos slab is currently fragmenting into a North Cocos plate and a South Cocos plate along the projection of the OFZ, in agreement with observations of variable Cocos plate motion on either side of the OFZ. This tearing event may be a young analogy to the 10 Ma Rivera-Cocos plate boundary, and may be related to the slab rollback in central Mexico.", "date": "2012-09-29", "date_type": "published", "publication": "Journal of Geophysical Research B", "volume": "117", "publisher": "American Geophysical Union", "pagerange": "Art. No. B09316", "id_number": "CaltechAUTHORS:20121005-155032242", "issn": "0148-0227", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121005-155032242", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Gordon and Betty Moore Foundation" }, { "agency": "Caltech Tectonics Observatory" } ] }, "other_numbering_system": { "items": [ { "id": "207", "name": "Caltech Tectonics Observatory" } ] }, "local_group": { "items": [ { "id": "Caltech-Tectonics-Observatory" }, { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1029/2012JB009528", "primary_object": { "basename": "2012JB009528-fs03.ps", "url": "https://authors.library.caltech.edu/records/4kgad-m4z03/files/2012JB009528-fs03.ps" }, "related_objects": [ { "basename": "2012JB009528-fs04.ps", "url": "https://authors.library.caltech.edu/records/4kgad-m4z03/files/2012JB009528-fs04.ps" }, { "basename": "2012JB009528.pdf", "url": "https://authors.library.caltech.edu/records/4kgad-m4z03/files/2012JB009528.pdf" }, { "basename": "2012JB009528-fs01.ps", "url": "https://authors.library.caltech.edu/records/4kgad-m4z03/files/2012JB009528-fs01.ps" }, { "basename": "2012JB009528-fs02.ps", "url": "https://authors.library.caltech.edu/records/4kgad-m4z03/files/2012JB009528-fs02.ps" } ], "resource_type": "article", "pub_year": "2012", "author_list": "Dougherty, Sara L.; Clayton, Robert W.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/6j8rq-97637", "eprint_id": 34633, "eprint_status": "archive", "datestamp": "2023-08-19 12:39:08", "lastmod": "2023-10-19 21:20:44", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Chen-Ting", "name": { "family": "Chen", "given": "Ting" }, "orcid": "0000-0002-9599-871X" }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" } ] }, "title": "Structure of central and southern Mexico from velocity and attenuation tomography", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 2012 American Geophysical Union. Received 13 February 2012; accepted 20 July 2012; published 5 September 2012. This study was supported by the Gordon and Betty Moore Foundation through the Tectonics Observatory at Caltech\nand NSF grant EAR0609707. Contribution 91 from the Caltech Tectonics Observatory. We would like to acknowledge Victor Hugo Espindola Castro for providing the SSN catalog. We thank Donna Eberhart-Phillips and Egill Hauksson for the help with the simul2000 package. We also thank Brandon\nSchmandt and Andreas Rietbrock for helpful discussions. Finally, we thank Editor Robert Nowack and two anonymous reviewers for helpful comments which improved the manuscript.\n\nPublished - 2012JB009233.pdf
", "abstract": "The 3D V_p, V_p/_Vs, P- and S-wave attenuation structure of the Cocos subduction zone in Mexico is imaged using earthquakes recorded by two temporary seismic arrays and local stations. Direct P wave arrivals on vertical components and direct S wave arrivals on transverse components from local earthquakes are used for velocity imaging. Relative delay times for P and PKP phases from teleseismic events are also used to obtain a deeper velocity structure beneath the southern seismic array. Using a spectral-decay method, we calculate a path attenuation operator t^* for each P and S waveform from local events, and then invert for 3D spatial variations in attenuation (Q_p^(\u22121) and Q_s^(\u22121)). Inversion results reveal a low-attenuation and high-velocity Cocos slab. The slab dip angle increases from almost flat in central Mexico near Mexico City to about 30\u00b0 in southern Mexico near the Isthmus of Tehuantepec. High attenuation and low velocity in the crust beneath the Trans-Mexico Volcanic Belt correlate with low resistivity, and are probably related to dehydration of the slab and melting processes. The most pronounced high-attenuation, low-V_p and high-V_p/V_s anomaly is found in the crust beneath the Veracruz Basin. A high-velocity structure dipping into the mantle from the side of Gulf of Mexico coincides with a discontinuity from a receiver functions study, and provides an evidence for the collision between the Yucat\u00e1n Block and Mexico in the Miocene.", "date": "2012-09-05", "date_type": "published", "publication": "Journal of Geophysical Research B", "volume": "117", "number": "9", "publisher": "American Geophysical Union", "pagerange": "B09302", "id_number": "CaltechAUTHORS:20121002-130315621", "issn": "0148-0227", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121002-130315621", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Gordon and Betty Moore Foundation" }, { "agency": "Caltech Tectonic Observatory" }, { "agency": "NSF", "grant_number": "EAR0609707" } ] }, "other_numbering_system": { "items": [ { "id": "91", "name": "Caltech Tectonics Observatory" } ] }, "local_group": { "items": [ { "id": "Caltech-Tectonics-Observatory" }, { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1029/2012JB009233", "primary_object": { "basename": "2012JB009233.pdf", "url": "https://authors.library.caltech.edu/records/6j8rq-97637/files/2012JB009233.pdf" }, "resource_type": "article", "pub_year": "2012", "author_list": "Chen, Ting and Clayton, Robert W." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/4edhx-bhf21", "eprint_id": 34559, "eprint_status": "archive", "datestamp": "2023-08-22 06:18:28", "lastmod": "2023-10-19 20:44:31", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Kim-YoungHee", "name": { "family": "Kim", "given": "YoungHee" }, "orcid": "0000-0002-1111-632X" }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" }, { "id": "Jackson-J-M", "name": { "family": "Jackson", "given": "Jennifer M." }, "orcid": "0000-0002-8256-6336" } ] }, "title": "Distribution of hydrous minerals in the subduction system beneath Mexico", "ispublished": "pub", "full_text_status": "public", "keywords": "subduction; Mexico; receiver function; hydrous minerals; Bayesian inversion", "note": "\u00a9 2012 Elsevier B.V. Received 3 January 2012. Received in revised form 26 May 2012. Accepted 1 June 2012. Editor: P.Shearer. Available online 6 July 2012. This study was supported by the Gordon and Betty Moore\nFoundation through the Tectonics Observatory at California Institute of Technology (Contribution number 176) and NSF award EAR 0609707. We thank Xyoli P\u00e9rez-Campos, Arturo Iglesias, and others at the Universidad Nacional Aut\u03ccnoma de M\u00e9xico for\ndeploying and maintaining the MASE and VEOX lines. We thank\nJoann Stock, Michael Gurnis, and Victor Tsai from California\nInstitute of Technology for suggestions,and Ting Chen for providing slab contour lines for Mexican subduction zone. Finally, we thank Editor Peter Shearer and two anonymous reviewers for helpful comments which improved the manuscript.\n\nSupplemental Material - mmc1.docx
", "abstract": "Teleseismic converted phases are used to probe the composition of the downgoing oceanic crust as a function of depth along the Cocos slab in central and southern Mexico. Previously, modeling of the receiver function (RF) conversion amplitude of the flat Cocos slab beneath central Mexico at 45 km depth revealed a thin low-velocity upper oceanic crust of a thickness of 4 \u00b1 1 km, which has much lower seismic velocities (\u223c20\u201330% reduction in shear wave velocities) than (normal) lower crust. High Vp/Vs ratio (\u223c2.0) also suggested a large concentration of hydrous minerals such as talc in combination of high pore-fluid pressure in the horizontal segment. We extend this previous effort to examine seismic properties of both the steeply subducting Cocos oceanic crust beneath the Trans-Mexican Volcanic Belt (TMVB) in central Mexico and the shallowly dipping crust beneath southern Mexico. Inverted seismic velocities using the converted amplitudes at the top and bottom of the dipping oceanic crust are compared with experimentally constrained seismic velocities of candidate mineral phases in a range of likely pressures and temperatures. The composition of the oceanic crust downdip in the steep part of slab beneath the TMVB includes the minerals such as lawsonite and zoisite at 60\u2013100 km depth, and the eclogitization occurs around 100 km depth. This is related to arc volcanism in the TMVB directly above the slab as well as the slab rollback. In contrast, the dominant mineral phase in the upper oceanic crust of southern Mexico beneath the Isthmus of Tehauntepec is amphibole on top of unaltered gabbroic oceanic crust. The difference in mineral assemblages of the subducted oceanic crust may help explain the difference in slab geometries between central and southern Mexico.", "date": "2012-08", "date_type": "published", "publication": "Earth and Planetary Science Letters", "volume": "341-344", "publisher": "Elsevier", "pagerange": "58-67", "id_number": "CaltechAUTHORS:20120928-155511390", "issn": "0012-821X", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20120928-155511390", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Gordon and Betty Moore Foundation" }, { "agency": "NSF", "grant_number": "EAR-0609707" } ] }, "other_numbering_system": { "items": [ { "id": "176", "name": "Caltech Tectonics Observatory" } ] }, "local_group": { "items": [ { "id": "Caltech-Tectonics-Observatory" }, { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/j.epsl.2012.06.001", "primary_object": { "basename": "mmc1.docx", "url": "https://authors.library.caltech.edu/records/4edhx-bhf21/files/mmc1.docx" }, "resource_type": "article", "pub_year": "2012", "author_list": "Kim, YoungHee; Clayton, Robert W.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/5ba9q-eq494", "eprint_id": 33123, "eprint_status": "archive", "datestamp": "2023-08-22 06:14:58", "lastmod": "2023-10-18 18:49:16", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Vriend-N-M", "name": { "family": "Vriend", "given": "N. M." } }, { "id": "Hunt-M-L", "name": { "family": "Hunt", "given": "M. L." }, "orcid": "0000-0001-5592-2334" }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "R. W." }, "orcid": "0000-0003-3323-3508" } ] }, "title": "Sedimentary structure of large sand dunes: examples from Dumont and Eureka dunes, California", "ispublished": "pub", "full_text_status": "public", "keywords": "Ground penetrating radar; Geomorphology; Wave propagation", "note": "\u00a9 2012 The Authors. Geophysical Journal International \u00a9 2012 RAS.\n\nAccepted 2012 April 17; Received 2012 April 17; in original form 2011 June 5.\n\nThe authors would like to thank Dr. Richard Hereford (USGS\nFlagstaff, Arizona) for his willingness to share long term environmental data, collected from averaging precipitation records from 52 Mojave desert weather stations. The help of Dr. Christopher Earls Brennen, Natalie Becerra, Angel Ruiz-Angulo, Erin Koos and many others, was essential during the field experiments at Dumont and Eureka dunes. Travel and equipment support for N. M. V. was provided through funding from the Pieter Langerhuizen Lambertuszoon Fonds.\n\nPublished - Vriend2012p19105Geophys_J_Int.pdf
Supplemental Material - GJI_5514_sm_supplement.zip
", "abstract": "The current research presents ground penetrating radar images up to 30 m in depth of two large desert dunes in California, USA\u2014 a barchanoid ridge in the Dumont field and a linear dune in the Eureka expanse. The radar images show a complicated structure of internal layering with ascending cross-strata, cross-bedding and bounding surfaces cutting through layers. Additional research using seismic refraction surveys and sand sampling refine the image of the subsurface (<5 m) structure. The sedimentary structure of the dune shows a strong internal layering with a cemented structure that may immobilize and influence migration of dune expanses. The subsurface features of the sand dune fields in the Mojave Desert provide evidence of dune building, wind regime and precipitation history.", "date": "2012-08", "date_type": "published", "publication": "Geophysical Journal International", "volume": "190", "number": "2", "publisher": "Royal Astronomical Society", "pagerange": "981-992", "id_number": "CaltechAUTHORS:20120813-104703591", "issn": "0956-540X", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20120813-104703591", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Pieter Langerhuizen Lambertuszoon Fonds" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1111/j.1365-246X.2012.05514.x", "primary_object": { "basename": "Vriend2012p19105Geophys_J_Int.pdf", "url": "https://authors.library.caltech.edu/records/5ba9q-eq494/files/Vriend2012p19105Geophys_J_Int.pdf" }, "related_objects": [ { "basename": "GJI_5514_sm_supplement.zip", "url": "https://authors.library.caltech.edu/records/5ba9q-eq494/files/GJI_5514_sm_supplement.zip" } ], "resource_type": "article", "pub_year": "2012", "author_list": "Vriend, N. M.; Hunt, M. L.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/fhtv6-1jx31", "eprint_id": 32976, "eprint_status": "archive", "datestamp": "2023-08-22 06:10:44", "lastmod": "2023-10-18 17:58:42", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Kim-YoungHee", "name": { "family": "Kim", "given": "YoungHee" }, "orcid": "0000-0002-1111-632X" }, { "id": "Miller-M-S", "name": { "family": "Miller", "given": "Meghan S." }, "orcid": "0000-0001-5494-2296" }, { "id": "Pearce-F", "name": { "family": "Pearce", "given": "Frederick" } }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" } ] }, "title": "Seismic imaging of the Cocos plate subduction zone system\n in central Mexico", "ispublished": "pub", "full_text_status": "public", "keywords": "Mexico; inversion; mantle wedge; oceanic crust; subduction zone; volcanic arc", "note": "\u00a9 2012 American Geophysical Union. \n\nReceived 9 January 2012; accepted 4 June 2012; published 7 July 2012. \n\nWe thank entire MASE team for making the data available\n(http://www.tectonics.caltech.edu/mase/). Y. Kim is supported by the Gordon and Betty Moore Foundation through the Tectonics Observatory at California Institute of Technology (contribution number 190) and NSF award EAR 0609707. We thank G. Abers, M. Bostock, L. MacKenzie, and S. Rondenay for discussion on imaging the steeply dipping slab. We also thank X. P\u00e9rez-Campos for providing the local seismicity data, T. Chen for providing slab contour lines for Mexico subduction zone, and T. Song and S. Straub for comments on the melt feature underneath the arc in central Mexico. Finally, we thank the Editor J. Tyburczy, Associate Editor, J. Gu, and an anonymous reviewer for helpful comments, which greatly improved the paper.\n\nPublished - Kim2012p19051Geochem_Geophy_Geosy.pdf
", "abstract": "Broadband data from the Meso-America Subduction Experiment (MASE) line in central Mexico were used to image the subducted Cocos plate and the overriding continental lithosphere beneath central Mexico using a generalized radon transform based migration. Our images provide insight into the process of subducting relatively young oceanic lithosphere and its complex geometry beneath continental North America. The converted and reverberated phase image shows complete horizontal tectonic underplating of the Cocos oceanic lithosphere beneath the North American continental lithosphere, with a clear image of a very thin low-velocity oceanic crust (7\u20138 km) which dips at 15\u201320 degrees at Acapulco then flattens approximately 300 km from the Middle America Trench. Farther inland the slab then appears to abruptly change from nearly horizontal to a steeply dipping geometry of approximately 75 degrees underneath the Trans-Mexican Volcanic Belt (TMVB). Where the slab bends underneath the TMVB, the migrated image depicts the transition from subducted oceanic Moho to continental Moho at \u223c230 km from the coast, neither of which were clearly resolved in previous seismic images. The deeper seismic structure beneath the TMVB shows a prominent negative discontinuity (fast-to-slow) at \u223c65\u201375 km within the upper mantle. This feature, which spans horizontally beneath the arc (\u223c100 km), may delineate the top of a layer of ponded partial melt.", "date": "2012-07-07", "date_type": "published", "publication": "Geochemistry, Geophysics, Geosystems", "volume": "13", "number": "7", "publisher": "American Geophysical Union", "pagerange": "Art. No. Q07001", "id_number": "CaltechAUTHORS:20120807-103715823", "issn": "1525-2027", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20120807-103715823", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Gordon and Betty Moore Foundation" }, { "agency": "NSF", "grant_number": "EAR 0609707" } ] }, "other_numbering_system": { "items": [ { "id": "190", "name": "Caltech Tectonics Observatory" } ] }, "local_group": { "items": [ { "id": "Caltech-Tectonics-Observatory" }, { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1029/2012GC004033", "primary_object": { "basename": "Kim2012p19051Geochem_Geophy_Geosy.pdf", "url": "https://authors.library.caltech.edu/records/fhtv6-1jx31/files/Kim2012p19051Geochem_Geophy_Geosy.pdf" }, "resource_type": "article", "pub_year": "2012", "author_list": "Kim, YoungHee; Miller, Meghan S.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/3chsf-kfk37", "eprint_id": 30067, "eprint_status": "archive", "datestamp": "2023-08-22 05:02:22", "lastmod": "2023-10-17 15:16:37", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Selvans-M-M", "name": { "family": "Selvans", "given": "M. M." } }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "R. W." }, "orcid": "0000-0003-3323-3508" }, { "id": "Stock-J-M", "name": { "family": "Stock", "given": "J. M." }, "orcid": "0000-0003-4816-7865" }, { "id": "Granot-R", "name": { "family": "Granot", "given": "R." } } ] }, "title": "Using overlapping sonobuoy data from the Ross Sea to construct a 2D deep crustal velocity model", "ispublished": "pub", "full_text_status": "restricted", "keywords": "Sonobuoy; Multi-channel seismic; Ross Sea; Finite-difference; 2D velocity model; Crustal structure", "note": "\u00a9 2011 Springer Science+Business Media B.V.\nReceived: 13 June 2011; Accepted: 1 December 2011; Published online: 20 December 2011.\nWe would like to thank Captain Mike Watson,\nthe crew, and the Raytheon Polar Services Corporation technical staff\non board the Nathaniel B. Palmer. This study was supported by\nNational Science Foundation grants OPP04-40959 (S. Cande) and\nOPP-0440923 and OPP-0944711 (J. Stock and R. Clayton).", "abstract": "Sonobuoys provide an alternative to using long streamers while conducting multi-channel seismic (MCS) studies, in order to provide deeper velocity control. We present analysis and modeling techniques for interpreting the sonobuoy data and illustrate the method with ten overlapping sonobuoys collected in the Ross Sea, offshore from Antarctica. We demonstrate the importance of using the MCS data to correct for ocean currents and changes in ship navigation, which is required before using standard methods for obtaining a 1D velocity profile from each sonobuoy. We verify our 1D velocity models using acoustic finite-difference (FD) modeling and by performing depth migration on the data, and demonstrate the usefulness of FD modeling for tying interval velocities to the shallow crust imaged using MCS data. Finally, we show how overlapping sonobuoys along an MCS line can be used to construct a 2D velocity model of the crust. The velocity model reveals a thin crust (5.5 \u00b1 0.4 km) at the boundary between the Adare and Northern Basins, and implies that the crustal structure of the Northern Basin may be more similar to that of the oceanic crust in the Adare Basin than to the stretched continental crust further south in the Ross Sea.", "date": "2012-03", "date_type": "published", "publication": "Marine Geophysical Research", "volume": "33", "number": "1", "publisher": "Springer Verlag", "pagerange": "17-32", "id_number": "CaltechAUTHORS:20120412-132057738", "issn": "0025-3235", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20120412-132057738", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "OPP04-40959" }, { "agency": "NSF", "grant_number": "OPP-0440923" }, { "agency": "NSF", "grant_number": "OPP-0944711" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1007/s11001-011-9143-z", "resource_type": "article", "pub_year": "2012", "author_list": "Selvans, M. M.; Clayton, R. W.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/ywzke-a8n54", "eprint_id": 28512, "eprint_status": "archive", "datestamp": "2023-08-22 04:04:00", "lastmod": "2023-10-24 17:57:00", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Kim-YoungHee", "name": { "family": "Kim", "given": "YoungHee" }, "orcid": "0000-0002-1111-632X" }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" }, { "id": "Keppie-F", "name": { "family": "Keppie", "given": "Fraser" } } ] }, "title": "Evidence of a collision between the Yucat\u00e1n Block and Mexico in the Miocene", "ispublished": "pub", "full_text_status": "public", "keywords": "Seismicity and tectonics; Body waves; Seismic tomography; Subduction zone processes; Dynamics of lithosphere and mantle; Dynamics: seismotectonics", "note": "\u00a9 2011 The Authors.\nGeophysical Journal International \u00a9 2011 RAS.\nAccepted 2011 August 10. Received 2011 July 29; in original form 2011 June 1.\nArticle first published online: 15 Sep. 2011.\n\nThis study was supported by the Gordon and Betty Moore Foundation\nthrough the Tectonics Observatory at California Institute\nof Technology (Contribution number 131) and NSF award EAR\n0609707. We thank Xyoli P\u00e9rez-Campos, Arturo Iglesias and others\nat the Universidad Nacional Aut\u00f3noma de M\u00e9xico for deploying\nand maintaining the VEOX line. We also thank Servicio\nSismol\u00f3gico Nacional (SSN) of Mexico for data and Oscar Alberto\nCastro Artola for the relocated seismicity from the VEOX line. We\nalso thank Joann Stock from California Institute of Technology for\ndiscussions. Finally, we thank Editor Christine Thomas and two\nanonymous reviewers for helpful comments which improved the\nmanuscript.\n\nPublished - Kim2011p16521Geophys_J_Int.pdf
", "abstract": "We present the evidence for an anomalous southwest-dipping slab in southern Mexico. The main evidence comes from a clear receiver function image along a seismic line across the Isthmus of Tehuantepec and is also supported by a previous global tomographic model. The slab dips at 35\u00b0, is approximately 250 km in length and appears to truncate the Cocos slab at about 120 km depth. We hypothesize that the slab was created by subduction of oceanic lithosphere prior to the collision of the Yucat\u00e1n Block with Mexico at approximately 12 Ma. This scenario would explain the Chiapas Fold and Thrust Belt as the product of this collision, and its age constrains the date of the event to be in the Miocene.", "date": "2011-11", "date_type": "published", "publication": "Geophysical Journal International", "volume": "187", "number": "2", "publisher": "Royal Astronomical Society", "pagerange": "989-1000", "id_number": "CaltechAUTHORS:20111219-095119813", "issn": "0956-540X", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20111219-095119813", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Gordon and Betty Moore Foundation" }, { "agency": "NSF", "grant_number": "EAR-0609707" } ] }, "other_numbering_system": { "items": [ { "id": "131", "name": "Caltech Tectonics Observatory" } ] }, "local_group": { "items": [ { "id": "Caltech-Tectonics-Observatory" }, { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1111/j.1365-246X.2011.05191.x", "primary_object": { "basename": "Kim2011p16521Geophys_J_Int.pdf", "url": "https://authors.library.caltech.edu/records/ywzke-a8n54/files/Kim2011p16521Geophys_J_Int.pdf" }, "resource_type": "article", "pub_year": "2011", "author_list": "Kim, YoungHee; Clayton, Robert W.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/t0yqk-0pn58", "eprint_id": 25269, "eprint_status": "archive", "datestamp": "2023-08-22 03:27:16", "lastmod": "2023-10-24 15:45:01", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Kosarian-M", "name": { "family": "Kosarian", "given": "Minoo" } }, { "id": "Davis-P-M", "name": { "family": "Davis", "given": "Paul M." } }, { "id": "Tanimoto-Toshiro", "name": { "family": "Tanimoto", "given": "Toshiro" } }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" } ] }, "title": "The relationship between upper mantle anisotropic structures beneath California, transpression, and absolute plate motions", "ispublished": "pub", "full_text_status": "public", "keywords": "California; anisotropy; motions; plate; seismic; transpression", "note": "\u00a9 2011 American Geophysical Union.\n\nReceived 3 June 2010; accepted 19 May 2011; published 20 August 2011. \n\n\n\nThis research was supported by the Southern\nCalifornia Earthquake Center. SCEC is funded by NSF cooperative\nagreement EAR-8920136 and USGS cooperative agreements 14-08-0001-A0899 and 1434-HQ-97AG01718. SCEC contribution 1482. Data\nwere obtained from the Southern and Northern California Data Centers.\nDave Okaya is thanked for anisotropy calculations used to test the stripping\nmethod. Karen Fischer is thanked for providing the propagator matrix\ncoded for anisotropic layers. Two reviewers provided comments that substantially\nimproved the paper.\n\nPublished - Kosarian2011p15715J_Geophys_Res-Sol_Ea.pdf
", "abstract": "We calculated SKS splitting parameters for the California Integrated Seismic Network. In southern California, we also estimated splitting in the upper 100 km using azimuthal anisotropy determined from surface waves. The inferred splitting from surface waves in the mantle lithosphere is small (on average < 0.2 s) compared with SKS splitting (1.5 s) and obtains a maximum value (0.5 s) in the transpressive region of the Big Bend, south of, and aligned with, the San Andreas Fault (SAF). In contrast, the SKS splitting is approximately E-W and is relatively uniform spatially either side of the Big Bend of the SAF. These differences suggest that most of the SKS splitting is generated much deeper (down to 300\u2013400 km) than previously thought, probably in the asthenosphere. Fast directions align with absolute plate motions (APM) in northern and southeastern California but not in southwestern California. We interpret the parallelism with APM as indicating the SKS anisotropy is caused by cumulative drag of the asthenosphere by the overlying plates. The discrepancy in southwestern California arises from the diffuse boundary there compared to the north, where relative plate motion has concentrated near the SAF system. In southern California the relative motion originated offshore in the Borderlands and gradually transitioned onshore to the SAF system. This has given rise to smaller displacement across the SAF (160\u2013180 km) compared with central and northern California (400\u2013500 km). Thus, in southwestern California the inherited anisotropy, from prior North American APM, has not yet been overprinted by Pacific APM.", "date": "2011-08-20", "date_type": "published", "publication": "Journal of Geophysical Research B", "volume": "116", "publisher": "American Geophysical Union", "pagerange": "Art. No. B08307", "id_number": "CaltechAUTHORS:20110909-102813331", "issn": "0148-0227", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20110909-102813331", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Southern California Earthquake Center (SCEC)" }, { "agency": "NSF", "grant_number": "EAR-8920136" }, { "agency": "USGS", "grant_number": "14-08-0001-A0899" }, { "agency": "USGS", "grant_number": "1434-HQ-97AG01718" } ] }, "other_numbering_system": { "items": [ { "id": "1482", "name": "Southern California Earthquake Center (SCEC)" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1029/2010JB007742", "primary_object": { "basename": "Kosarian2011p15715J_Geophys_Res-Sol_Ea.pdf", "url": "https://authors.library.caltech.edu/records/t0yqk-0pn58/files/Kosarian2011p15715J_Geophys_Res-Sol_Ea.pdf" }, "resource_type": "article", "pub_year": "2011", "author_list": "Kosarian, Minoo; Davis, Paul M.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/e2s9m-6xb66", "eprint_id": 24630, "eprint_status": "archive", "datestamp": "2023-08-22 03:17:02", "lastmod": "2023-10-23 23:31:35", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Skinner-S-M", "name": { "family": "Skinner", "given": "Steven M." } }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" } ] }, "title": "An Evaluation of Proposed Mechanisms of Slab Flattening in Central Mexico", "ispublished": "pub", "full_text_status": "public", "keywords": "Mexico; flat slab; subduction", "note": "\u00a9 2011 The Author(s).\nThis article is distributed under the terms of the\nCreative Commons Attribution Noncommercial License which\npermits any noncommercial use, distribution, and reproduction in\nany medium, provided the original author(s) and source are\ncredited.\nReceived February 5, 2010; revised June 28, 2010; accepted August 18, 2010; Published online November 16, 2010.\n\nThis study was supported by the Gordon and Betty Moore Foundation through the Tectonics Observatory at Caltech. This is contribution number 136 from the Caltech Tectonics Observatory.\n\nPublished - Skinner2011p15339Pure_Appl_Geophys.pdf
", "abstract": "Central Mexico is the site of an enigmatic zone of flat subduction. The general geometry of the subducting slab has\nbeen known for some time and is characterized by a horizontal zone bounded on either side by two moderately dipping sections. We systematically evaluate proposed hypotheses for shallow subduction in Mexico based on the spatial and temporal evidence, and we find no simple or obvious explanation for the shallow subduction in Mexico. We are unable to locate an oceanic lithosphere impactor, or the conjugate of an impactor, that is most often called upon to explain shallow subduction zones as in South America, Japan, and Laramide deformation in the US. The only bathymetric feature that is of the right age and in the correct position on the conjugate plate is a set of unnamed seamounts that are too small to have a significant effect on the buoyancy of the slab. The only candidate that we cannot dismiss is a change in the dynamics of\nsubduction through a change in wedge viscosity, possibly caused by water brought in by the slab.", "date": "2011-08", "date_type": "published", "publication": "Pure and Applied Geophysics", "volume": "168", "number": "8-9", "publisher": "Springer", "pagerange": "1461-1474", "id_number": "CaltechAUTHORS:20110802-135440314", "issn": "0033-4553", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20110802-135440314", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Gordon and Betty Moore Foundation" } ] }, "other_numbering_system": { "items": [ { "id": "136", "name": "Caltech Tectonics Observatory" } ] }, "local_group": { "items": [ { "id": "Caltech-Tectonics-Observatory" }, { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1007/s00024-010-0200-3", "primary_object": { "basename": "Skinner2011p15339Pure_Appl_Geophys.pdf", "url": "https://authors.library.caltech.edu/records/e2s9m-6xb66/files/Skinner2011p15339Pure_Appl_Geophys.pdf" }, "resource_type": "article", "pub_year": "2011", "author_list": "Skinner, Steven M. and Clayton, Robert W." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/rnqrr-5y876", "eprint_id": 29260, "eprint_status": "archive", "datestamp": "2023-08-19 04:56:08", "lastmod": "2023-10-24 22:02:47", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" }, { "id": "Heaton-T-H", "name": { "family": "Heaton", "given": "Thomas" }, "orcid": "0000-0003-3363-2197" }, { "id": "Chandy-K-M", "name": { "family": "Chandy", "given": "Mani" } }, { "id": "Krause-A", "name": { "family": "Krause", "given": "Andreas" }, "orcid": "0000-0001-7260-9673" }, { "id": "Kohler-M-D", "name": { "family": "Kohler", "given": "Monica" } }, { "id": "Bunn-J", "name": { "family": "Bunn", "given": "Julian" }, "orcid": "0000-0002-3798-298X" }, { "id": "Guy-R", "name": { "family": "Guy", "given": "Richard" } }, { "id": "Olson-M", "name": { "family": "Olson", "given": "Michael" } }, { "id": "Faulkner-M", "name": { "family": "Faulkner", "given": "Matthew" } }, { "id": "Cheng-Ming-Hei", "name": { "family": "Cheng", "given": "MingHei" } }, { "id": "Strand-L", "name": { "family": "Strand", "given": "Leif" } }, { "id": "Chandy-R", "name": { "family": "Chandy", "given": "Rishi" } }, { "id": "Obenshain-D", "name": { "family": "Obenshain", "given": "Daniel" } }, { "id": "Liu-Annie-H", "name": { "family": "Liu", "given": "Anne" } }, { "id": "Aivazis-M", "name": { "family": "Aivazis", "given": "Michael" } } ] }, "title": "Community Seismic Network", "ispublished": "pub", "full_text_status": "public", "keywords": "Seismology/Ground motion, Instruments and techniques, Seismic risk, Computational geophysics/Algorithms and implementation, Data dissemination/Seismological data", "note": "\u00a9 2011 Istituto Nazionale di Geofisica e Vulcanologia.\nThis work is licensed under a Creative Commons Attribution 3.0 License. \n\nReceived June 30, 2011; accepted October 26, 2011.\n\nThe development of the Community Seismic Network is supported by the Betty and Gordon Moore Foundation. This\nresearch is also supported by NSF Award CNS0932392. We \nthank NodalSeismic Inc. for the samples of data used in Figure 3. The manuscript was significantly improved by suggestions from the associate editor, Paul Earle, and a reviewer, Jesse Lawrence.\n\nPublished - Clayton2011p17102Ann_Geophys-Italy.pdf
", "abstract": "The article describes the design of the Community Seismic Network, which is a dense open seismic network based on low cost sensors. The inputs are from sensors hosted by volunteers from the community by direct connection to their personal computers, or through sensors built into mobile devices. The server is cloud-based for robustness and to dynamically handle the load of impulsive earthquake events. The main product of the network is a map of peak acceleration, delivered within seconds of the ground shaking. The lateral variations in the level of shaking will be valuable to first responders, and the waveform information from a dense network will allow detailed mapping of the rupture process. Sensors in buildings may be useful for monitoring the state-of-health of the structure after major shaking.", "date": "2011", "date_type": "published", "publication": "Annals of Geophysics", "volume": "54", "number": "6", "publisher": "Istituto Nazionale di Geofisica e Vulcanologia", "pagerange": "738-747", "id_number": "CaltechAUTHORS:20120213-121753118", "issn": "1593-5213", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20120213-121753118", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Gordon and Betty Moore Foundation" }, { "agency": "NSF", "grant_number": "CNS-0932392" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.4401/ag-5269", "primary_object": { "basename": "Clayton2011p17102Ann_Geophys-Italy.pdf", "url": "https://authors.library.caltech.edu/records/rnqrr-5y876/files/Clayton2011p17102Ann_Geophys-Italy.pdf" }, "resource_type": "article", "pub_year": "2011", "author_list": "Clayton, Robert W.; Heaton, Thomas; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/v98g5-1wm31", "eprint_id": 21867, "eprint_status": "archive", "datestamp": "2023-08-22 01:35:25", "lastmod": "2023-10-23 15:27:17", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Kostoglodov-V", "name": { "family": "Kostoglodov", "given": "Vladimir" }, "orcid": "0000-0001-7169-3121" }, { "id": "Husker-Allen-L", "name": { "family": "Husker", "given": "Allen" }, "orcid": "0000-0003-1139-0502" }, { "id": "Shapiro-N-M", "name": { "family": "Shapiro", "given": "Nikolai M." } }, { "id": "Payero-J-S", "name": { "family": "Payero", "given": "Juan S." } }, { "id": "Campillo-M", "name": { "family": "Campillo", "given": "Michel" } }, { "id": "Cotte-N", "name": { "family": "Cotte", "given": "Nathalie" }, "orcid": "0000-0002-1596-0755" }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert" }, "orcid": "0000-0003-3323-3508" } ] }, "title": "The 2006 slow slip event and nonvolcanic tremor in the Mexican subduction zone", "ispublished": "pub", "full_text_status": "public", "keywords": "nonvolcanic tremor; slow slip events; subduction zone", "note": "\u00a9 2010 American Geophysical Union.\n\nReceived 8 September 2010; revised 13 October 2010; accepted 18 October 2010; published 16 December 2010.\n\nThis study was supported by PAPIIT\nIN103808, CONACYT 84544, SEP\u2010CONACYT\u2010ANUIES\u2010ECOS M06\u2010\nU02, I832 (G\u2010GAP) ANR, ANR\u201006\u2010CEXC\u2010005 (COHERSIS), and ERC\nadvanced 227507 \"WHISPER\" grants. The MASE experiment of the\nCaltech Tectonics Observatory was funded by the Gordon and Betty Moore\nFoundation. Contribution 82 from the Caltech Tectonics Observatory.\n\nPublished - Kostoglodov2010p12418Geophys_Res_Lett.pdf
Supplemental Material - 2010gl045424-fs01a.ps
Supplemental Material - 2010gl045424-fs01b.ps
Supplemental Material - 2010gl045424-fs02a.ps
Supplemental Material - 2010gl045424-fs02b.ps
Supplemental Material - 2010gl045424-fs03.ps
Supplemental Material - 2010gl045424-txts01.txt
", "abstract": "The last decade featured an explosive sequence of discoveries of slow slip events (SSE) and nonvolcanic tremor (NVT) in different subduction zones and continental faults. Many observations show that SSE is usually associated with an increased NVT activity but it is not clear yet if those events are the result of the same process or are independent expressions of a common underlying seismotectonic source. A large SSE in Central Mexico occurred in 2006 during the Meso-American Subduction Experiment (MASE) which provided continuous observations of the NVT for the years 2005\u20132007. GPS and abundant seismic data show that although the NVT energy increased notably during the 2006 SSE, the two phenomena were separated spatially and not completely synchronized in time. Significant NVT episodes occur during the period between SSEs, suggesting again that large slow slip events and NVT observed in the Mexican subduction zone are of different origins. The results presented here contribute to uncovering the nature of these two separate phenomena that have been indistinguishable in some other regions.", "date": "2010-12-16", "date_type": "published", "publication": "Geophysical Research Letters", "volume": "37", "publisher": "American Geophysical Union", "pagerange": "Art. No. L24301", "id_number": "CaltechAUTHORS:20110124-144408477", "issn": "0094-8276", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20110124-144408477", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Programa de Apoyo a Proyectos de Investigaci\u00f3n e Innovaci\u00f3n Tecnol\u00f3gica (PAPIIT)", "grant_number": "IN103808" }, { "agency": "Consejo Nacional de Ciencia y Tecnolog\u00eda (CONACYT)", "grant_number": "84544" }, { "agency": "SEP-CONACYT-ANUIES-ECOS", "grant_number": "M06-U02" }, { "agency": "(G-GAP) ANR", "grant_number": "I832" }, { "agency": "ANR-06-CEXC-005 (COHERSIS)" }, { "agency": "European Research Council (ERC)", "grant_number": "227507" }, { "agency": "Gordon and Betty Moore Foundation" } ] }, "other_numbering_system": { "items": [ { "id": "82", "name": "Caltech Tectonics Observatory" } ] }, "local_group": { "items": [ { "id": "Caltech-Tectonics-Observatory" }, { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1029/2010GL045424", "primary_object": { "basename": "2010gl045424-txts01.txt", "url": "https://authors.library.caltech.edu/records/v98g5-1wm31/files/2010gl045424-txts01.txt" }, "related_objects": [ { "basename": "Kostoglodov2010p12418Geophys_Res_Lett.pdf", "url": "https://authors.library.caltech.edu/records/v98g5-1wm31/files/Kostoglodov2010p12418Geophys_Res_Lett.pdf" }, { "basename": "2010gl045424-fs01a.ps", "url": "https://authors.library.caltech.edu/records/v98g5-1wm31/files/2010gl045424-fs01a.ps" }, { "basename": "2010gl045424-fs01b.ps", "url": "https://authors.library.caltech.edu/records/v98g5-1wm31/files/2010gl045424-fs01b.ps" }, { "basename": "2010gl045424-fs02a.ps", "url": "https://authors.library.caltech.edu/records/v98g5-1wm31/files/2010gl045424-fs02a.ps" }, { "basename": "2010gl045424-fs02b.ps", "url": "https://authors.library.caltech.edu/records/v98g5-1wm31/files/2010gl045424-fs02b.ps" }, { "basename": "2010gl045424-fs03.ps", "url": "https://authors.library.caltech.edu/records/v98g5-1wm31/files/2010gl045424-fs03.ps" } ], "resource_type": "article", "pub_year": "2010", "author_list": "Kostoglodov, Vladimir; Husker, Allen; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/6w7nz-f0409", "eprint_id": 19709, "eprint_status": "archive", "datestamp": "2023-08-22 00:32:22", "lastmod": "2023-10-20 21:17:20", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Granot-R", "name": { "family": "Granot", "given": "R." } }, { "id": "Cande-S-C", "name": { "family": "Cande", "given": "S. C." } }, { "id": "Stock-J-M", "name": { "family": "Stock", "given": "J. M." }, "orcid": "0000-0003-4816-7865" }, { "id": "Davey-F-J", "name": { "family": "Davey", "given": "F. J." } }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "R. W." }, "orcid": "0000-0003-3323-3508" } ] }, "title": "Postspreading rifting in the Adare Basin, Antarctica: Regional tectonic consequences", "ispublished": "pub", "full_text_status": "public", "keywords": "West Antarctic rift system; rift; Adare Basin; multichannel seismic reflection; magnetic anomalies; tectonics", "note": "\u00a9 2010 American Geophysical Union.\n\nReceived 26 February 2010; accepted 6 May 2010; published 4 August 2010. \nWe would like to thank Captain M. Watson, the crew,\nand the Raytheon staff of the R/VIB Nathaniel B. Palmer for\ntheir dedicated work during cruise NBP0701. Also, we thank\nDietmar M\u00fcller and Sean Gulick for their helpful reviews;\nNeal Driscoll, Donna Blackman, and Jeff Gee for helpful discussions;\nPaul Henkart for the continuous help with SIOSEIS;\nand Chris Sorlein for introducing us to SPW software. Detlef\nDamaske is thanked for making the aeromagnetic data available\nfor us. Interpretation of the seismic profiles was done with\nKingdom Suite, a contribution of Seismic Micro\u2010Technology.\nThis project was funded by NSF grant OPP04\u201040959 (SIO)\nand OPP04\u201040923 (Caltech).\n\nPublished - Granot2010p11186Geochem_Geophy_Geosy.pdf
", "abstract": "Extension during the middle Cenozoic (43\u201326 Ma) in the north end of the West Antarctic rift system (WARS) is well constrained by seafloor magnetic anomalies formed at the extinct Adare spreading axis. Kinematic solutions for this time interval suggest a southward decrease in relative motion between East and West Antarctica. Here we present multichannel seismic reflection and seafloor mapping data acquired within and near the Adare Basin on a recent geophysical cruise. We have traced the ANTOSTRAT seismic stratigraphic framework from the northwest Ross Sea into the Adare Basin, verified and tied to DSDP drill sites 273 and 274. Our results reveal three distinct periods of tectonic activity. An early localized deformational event took place close to the cessation of seafloor spreading in the Adare Basin (~24 Ma). It reactivated a few normal faults and initiated the formation of the Adare Trough. A prominent pulse of rifting in the early Miocene (~17 Ma) resulted in normal faulting that initiated tilted blocks. The overall trend of structures was NE\u2013SW, linking the event with the activity outside the basin. It resulted in major uplift of the Adare Trough and marks the last extensional phase of the Adare Basin. Recent volcanic vents (Pliocene to present day) tend to align with the early Miocene structures and the on-land Hallett volcanic province. This latest phase of tectonic activity also involves near-vertical normal faulting (still active in places) with negligible horizontal consequences. The early Miocene extensional event found within the Adare Basin does not require a change in the relative motion between East and West Antarctica. However, the lack of subsequent rifting within the Adare Basin coupled with the formation of the Terror Rift and an on-land and subice extension within the WARS require a pronounced change in the kinematics of the rift. These observations indicate that extension increased southward, therefore suggesting that a major change in relative plate motion took place in the middle Miocene. The late Miocene pole of rotation might have been located north of the Adare Basin, with opposite opening sign compared to the Eocene-Oligocene pole.", "date": "2010-08-04", "date_type": "published", "publication": "Geochemistry, Geophysics, Geosystems", "volume": "11", "publisher": "American Geophysical Union", "pagerange": "Art. No. Q08005", "id_number": "CaltechAUTHORS:20100830-113018904", "issn": "1525-2027", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20100830-113018904", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "OPP04-40959" }, { "agency": "NSF", "grant_number": "OPP04-40923" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1029/2010GC003105", "primary_object": { "basename": "Granot2010p11186Geochem_Geophy_Geosy.pdf", "url": "https://authors.library.caltech.edu/records/6w7nz-f0409/files/Granot2010p11186Geochem_Geophy_Geosy.pdf" }, "resource_type": "article", "pub_year": "2010", "author_list": "Granot, R.; Cande, S. C.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/q2zry-vzf70", "eprint_id": 18864, "eprint_status": "archive", "datestamp": "2023-08-22 00:09:57", "lastmod": "2023-10-20 19:08:20", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Zhan-Zhongwen", "name": { "family": "Zhan", "given": "Zhongwen" }, "orcid": "0000-0002-5586-2607" }, { "id": "Ni-Sidao", "name": { "family": "Ni", "given": "Sidao" }, "orcid": "0000-0003-2988-4850" }, { "id": "Helmberger-D-V", "name": { "family": "Helmberger", "given": "Don V." } }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" } ] }, "title": "Retrieval of Moho-reflected shear wave arrivals from ambient seismic noise", "ispublished": "pub", "full_text_status": "public", "keywords": "Interferometry; Body waves; Crustal structure", "note": "\u00a9 2010 The Authors. Journal compilation \u00a9 2010 RAS.\nAccepted 2010 April 13. Received 2010 April 6; in original form 2009 December 2.\n\nThe authors thank the operators of the Southern Africa Seismic\nExperiment and CANOE array, IRIS, Earthquakes Canada for providing\ndata used in this study. We acknowledge Ronald M. Clowes\nand Gabriela Fernandez Viejo for providing the velocity model of\nGreat Slave region. The suggestions from two reviewers were very\nhelpful to improving the paper. This work was supported by NSFC\n40674027 and CAS fund kzcx2-yw-116-01 and by USGS Award\n#G09AP0082 at California Institute of Technology. This is contribution 10038 of the Tectonics Observatory at Caltech.\n\nPublished - Zhan2010p10538Geophys_J_Int.pdf
", "abstract": "Theoretical studies on ambient seismic noise (ASN) predict that complete Green's function between seismic stations can be retrieved from cross correlation. However, only fundamental mode surface waves emerge in most studies involving real data. Here we show that Moho-reflected body wave (SmS) and its multiples can be identified with ASN for station pairs near their critical distances in the short period band (1\u20135 s). We also show that an uneven distribution of noise sources, such as mining activity and wind\u2013topography interaction, can cause surface wave precursors, which mask weaker body wave phases.", "date": "2010-07", "date_type": "published", "publication": "Geophysical Journal International", "volume": "182", "number": "1", "publisher": "Royal Astronomical Society", "pagerange": "408-420", "id_number": "CaltechAUTHORS:20100629-165425794", "issn": "0956-540X", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20100629-165425794", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "National Natural Science Foundation of China", "grant_number": "40674027" }, { "agency": "Chinese Academy of Sciences", "grant_number": "kzcx2-yw-116-01" }, { "agency": "USGS", "grant_number": "G09AP0082" } ] }, "other_numbering_system": { "items": [ { "id": "10038", "name": "Caltech Division of Geological and Planetary Sciences" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1111/j.1365-246X.2010.04625.x", "primary_object": { "basename": "Zhan2010p10538Geophys_J_Int.pdf", "url": "https://authors.library.caltech.edu/records/q2zry-vzf70/files/Zhan2010p10538Geophys_J_Int.pdf" }, "resource_type": "article", "pub_year": "2010", "author_list": "Zhan, Zhongwen; Ni, Sidao; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/yvy6g-d2060", "eprint_id": 19026, "eprint_status": "archive", "datestamp": "2023-08-22 00:08:02", "lastmod": "2023-10-20 19:18:08", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Kim-YoungHee", "name": { "family": "Kim", "given": "Y." }, "orcid": "0000-0002-1111-632X" }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "R. W." }, "orcid": "0000-0003-3323-3508" }, { "id": "Jackson-J-M", "name": { "family": "Jackson", "given": "J. M." }, "orcid": "0000-0002-8256-6336" } ] }, "title": "Geometry and seismic properties of the subducting Cocos plate in central Mexico", "ispublished": "pub", "full_text_status": "public", "keywords": "subduction; receiver function; inversion", "note": "\u00a9 2010 American Geophysical Union.\nReceived 31 August 2009; accepted 25 January 2010; published 17 June 2010.\nThis study was supported by the Gordon\nand Betty Moore Foundation through the Tectonics Observatory at Caltech\nand NSF award EAR 0609707. We thank Juan S. Payero for providing the\nNVT locations and the many volunteers who worked on the MASE experiment.\nThis is contribution 108 from the Caltech Tectonics Observatory.\n\nPublished - Kim2010p10642J_Geophys_Res-Sol_Ea.pdf
", "abstract": "The geometry and properties of the interface of the Cocos plate beneath central Mexico are determined from the receiver functions (RFs) utilizing data from the Meso America Subduction Experiment (MASE). The RF image shows that the subducting oceanic crust is shallowly dipping to the north at 15\u00b0 for 80 km from Acapulco and then horizontally underplates the continental crust for approximately 200 km to the Trans-Mexican Volcanic Belt (TMVB). The crustal image also shows that there is no continental root associated with the TMVB. The migrated image of the RFs shows that the slab is steeply dipping into the mantle at about 75\u00b0 beneath the TMVB. Both the continental and oceanic Moho are clearly seen in both images, and modeling of the RF conversion amplitudes and timings of the underplated features reveals a thin low-velocity zone between the plate and the continental crust that appears to absorb nearly all of the strain between the upper plate and the slab. By inverting RF amplitudes of the converted phases and their time separations, we produce detailed maps of the seismic properties of the upper and lower oceanic crust of the subducting Cocos plate and its thickness. High Poisson's and Vp/Vs ratios due to anomalously low S wave velocity at the upper oceanic crust in the flat slab region may indicate the presence of water and hydrous minerals or high pore pressure. The evidence of high water content within the oceanic crust explains the flat subduction geometry without strong coupling of two plates. This may also explain the nonvolcanic tremor activity and slow slip events occurring in the subducting plate and the overlying crust.", "date": "2010-06-17", "date_type": "published", "publication": "Journal of Geophysical Research B", "volume": "115", "publisher": "American Geophysical Union", "pagerange": "Art. No. B06310", "id_number": "CaltechAUTHORS:20100713-105555426", "issn": "0148-0227", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20100713-105555426", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Gordon and Betty Moore Foundation" }, { "agency": "NSF", "grant_number": "EAR 0609707" } ] }, "other_numbering_system": { "items": [ { "id": "108", "name": "Caltech Tectonics Observatory" } ] }, "local_group": { "items": [ { "id": "Caltech-Tectonics-Observatory" }, { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1029/2009JB006942", "primary_object": { "basename": "Kim2010p10642J_Geophys_Res-Sol_Ea.pdf", "url": "https://authors.library.caltech.edu/records/yvy6g-d2060/files/Kim2010p10642J_Geophys_Res-Sol_Ea.pdf" }, "resource_type": "article", "pub_year": "2010", "author_list": "Kim, Y.; Clayton, R. W.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/esy7a-6q834", "eprint_id": 18971, "eprint_status": "archive", "datestamp": "2023-08-22 00:07:49", "lastmod": "2023-10-20 19:14:56", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Iglesias-Arturo", "name": { "family": "Iglesias", "given": "A." } }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "R. W." }, "orcid": "0000-0003-3323-3508" }, { "id": "P\u00e9rez\u2010Campos-Xyoli", "name": { "family": "P\u00e9rez\u2010Campos", "given": "X." }, "orcid": "0000-0001-8970-7966" }, { "id": "Singh-Shri-Krishna", "name": { "family": "Singh", "given": "S. K." } }, { "id": "Pacheco-Javier-F", "name": { "family": "Pacheco", "given": "J. F." } }, { "id": "Garc\u00eda-D", "name": { "family": "Garc\u00eda", "given": "D." } }, { "id": "Vald\u00e9s\u2010Gonz\u00e1lez-Carlos", "name": { "family": "Vald\u00e9s\u2010Gonz\u00e1lez", "given": "C." } } ] }, "title": "S wave velocity structure below central Mexico using high-resolution surface wave tomography", "ispublished": "pub", "full_text_status": "public", "keywords": "surface wave tomography; structure below central Mexico; MASE", "note": "\u00a9 2010 American Geophysical Union.\nReceived 26 January 2009; accepted 11 January 2010; published 15 June 2010. \nThis study was supported by the Tectonics\nObservatory of Caltech and by the PAPIIT\u2010UNAM project IN104308.\nMASE was funded by the Gordon and Betty Moore Foundation. We thank\nE. Debayle and M. Sambridge for providing their tomographic and resolution\ncodes. O. A. Castro kindly assisted us in relocating some of the events\nused in this study. We thank S. I. Franco\u2010S\u00e1nchez for the help in preparing\nthe last versions of Figures 6 and 7. SSN and C.I.S., I.I., UNAM staff\ngenerously provided us seismic data from their networks. We thank all\nMASE volunteers, most of them undergraduate students. Finally, we thank\nthe JGR Editor and two anonymous reviewers for their comments and\nsuggestions that led to a much improved manuscript. Contribution 91 of the\nTectonics Observatory.\n\nPublished - Iglesias2010p10588J_Geophys_Res-Sol_Ea.pdf
", "abstract": "Shear wave velocity of the crust below central Mexico is estimated using surface wave dispersion measurements from regional earthquakes recorded on a dense, 500 km long linear seismic network. Vertical components of regional records from 90 well-located earthquakes were used to compute Rayleigh-wave group-velocity dispersion curves. A tomographic inversion, with high resolution in a zone close to the array, obtained for periods between 5 and 50 s reveals significant differences relative to a reference model, especially at larger periods (>30 s). A 2-D S wave velocity model is obtained from the inversion of local dispersion curves that were reconstructed from the tomographic solutions. The results show large differences, especially in the lower crust, among back-arc, volcanic arc, and fore-arc regions; they also show a well-resolved low-velocity zone just below the active part of the Trans Mexican Volcanic Belt (TMVB) suggesting the presence of a mantle wedge. Low densities in the back arc, inferred from the low shear wave velocities, can provide isostatic support for the TMVB.", "date": "2010-06-15", "date_type": "published", "publication": "Journal of Geophysical Research B", "volume": "115", "publisher": "American Geophysical Union", "pagerange": "Art. No. B06307", "id_number": "CaltechAUTHORS:20100709-135147262", "issn": "0148-0227", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20100709-135147262", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Caltech Tectonics Observatory" }, { "agency": "Programa de Apoyo a Proyectos de Investigaci\u00f3n e Innovaci\u00f3n Tecnol\u00f3gica - Universidad Nacional Aut\u00f3noma de M\u00e9xico (PAPIIT-UNAM)", "grant_number": "IN104308" }, { "agency": "Gordon and Betty Moore Foundation" } ] }, "other_numbering_system": { "items": [ { "id": "91", "name": "Caltech Tectonics Observatory" } ] }, "local_group": { "items": [ { "id": "Caltech-Tectonics-Observatory" }, { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1029/2009JB006332", "primary_object": { "basename": "Iglesias2010p10588J_Geophys_Res-Sol_Ea.pdf", "url": "https://authors.library.caltech.edu/records/esy7a-6q834/files/Iglesias2010p10588J_Geophys_Res-Sol_Ea.pdf" }, "resource_type": "article", "pub_year": "2010", "author_list": "Iglesias, A.; Clayton, R. W.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/dqsnj-ywa49", "eprint_id": 16645, "eprint_status": "archive", "datestamp": "2023-08-20 02:17:46", "lastmod": "2023-10-19 22:27:03", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Chen-Ting", "name": { "family": "Chen", "given": "Ting" }, "orcid": "0000-0002-9599-871X" }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" } ] }, "title": "Seismic attenuation structure in central Mexico: Image of a focused high-attenuation zone in the mantle wedge", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 2009 American Geophysical Union.\nReceived 29 July 2008; revised 19 February 2009; accepted 21 April 2009; published 14 July 2009.\n\nThis study was supported by the Gordon\nand Betty Moore Foundation through the Tectonics Observatory at Caltech\nand NSF grant EAR0609707. Contribution 91 from the Caltech Tectonics\nObservatory. The ray tracing was done using the package developed by\nWilliam Menke. We thank Donna Eberhart-Phillips for the t* code. We\nthank two anonymous reviewers for their constructive comments that\nhelped to improve the manuscript.\n\nPublished - Chen2009p6273J_Geophys_Res-Sol_Ea.pdf
", "abstract": "Velocity spectra from moderate-sized earthquakes were used to investigate the P wave attenuation structure in central Mexico. In particular, we included regional events with magnitudes in the range of 4.5 to 6.1 recorded from 2005 to 2007 on the Middle American Subduction Experiment (MASE) array, which consists of 100 broadband sensors across central Mexico from Acapulco to Tempoal, near the Gulf of Mexico. By assuming a Brune-type source, a frequency-independent t* value was obtained for each seismogram in the frequency band 1 to 30 Hz. These measurements were then inverted for two-dimensional spatial variations in Q_p in the cross section along the MASE array, perpendicular to the trench. The model has uniform 20 km vertical grid spacing down to a depth of 200 km and 50 km or 100 km horizontal grid spacing depending on ray coverage. The inversion results show low attenuation in the subducting slab and high attenuation in the mantle wedge and the crust below and to the north of the volcanic belt. The focused high-attenuation zone (Q_p < 200) in the mantle wedge lies away from the top of the slab, between depths of 80 km and 120 km beneath the volcanic belt, and is likely to be related to relatively high temperature, fluids, and partial melts produced in subduction process. The high-attenuation region in the lower crust correlates with the low-resistivity and low-velocity region and could be caused by partial melts and fluids from dehydration and magmatic processes.", "date": "2009-07-14", "date_type": "published", "publication": "Journal of Geophysical Research B", "volume": "114", "publisher": "American Geophysical Union", "pagerange": "Art. No. B07304", "id_number": "CaltechAUTHORS:20091110-133506410", "issn": "0148-0227", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20091110-133506410", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Gordon and Betty Moore Foundation" }, { "agency": "NSF", "grant_number": "EAR-0609707" } ] }, "other_numbering_system": { "items": [ { "id": "129", "name": "Caltech Tectonics Observatory" } ] }, "local_group": { "items": [ { "id": "Caltech-Tectonics-Observatory" }, { "id": "Caltech-Tectonics-Observatory.-MesoAmerican-Subduction-Experiment-(MASE)" }, { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1029/2008JB005964", "primary_object": { "basename": "Chen2009p6273J_Geophys_Res-Sol_Ea.pdf", "url": "https://authors.library.caltech.edu/records/dqsnj-ywa49/files/Chen2009p6273J_Geophys_Res-Sol_Ea.pdf" }, "resource_type": "article", "pub_year": "2009", "author_list": "Chen, Ting and Clayton, Robert W." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/0vj8b-6zt68", "eprint_id": 14176, "eprint_status": "archive", "datestamp": "2023-08-20 01:31:59", "lastmod": "2023-10-18 16:18:48", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Song-Teh-Ru-Alex", "name": { "family": "Song", "given": "Teh-Ru Alex" }, "orcid": "0000-0003-3697-5881" }, { "id": "Helmberger-D-V", "name": { "family": "Helmberger", "given": "Donald V." } }, { "id": "Brudzinski-M-R", "name": { "family": "Brudzinski", "given": "Michael R." } }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" }, { "id": "Davis-P", "name": { "family": "Davis", "given": "Paul" } }, { "id": "P\u00e9rez-Campos-Xyoli", "name": { "family": "P\u00e9rez-Campos", "given": "Xyoli" }, "orcid": "0000-0001-8970-7966" }, { "id": "Singh-Shri-K", "name": { "family": "Singh", "given": "Shri K." } } ] }, "title": "Subducting slab ultra-slow velocity layer coincident with silent earthquakes in southern Mexico", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 2009 American Association for the Advancement of Science.\n23 October 2008; accepted 20 February 2009.\nWe thank S. Sacks, P. Silver, S. Shirey, M. Bostock,\nJ.-P. Avouav, and V. Manea for helpful discussions;\nR. Engdahl provided the global relocated seismic catalog\nused in fig. S10. We thank CENS at UCLA for support and the\nentire MASE team for making the MASE data available. We\nthank H. Hinojosa-Prieto, E. Cabral-Cano, A. Arciniega,\nO. Diaz-Molina, and C. DeMets for sharing their work on\nepisodic tremor and slip in Oaxaca. Incorporated Research\nInstitutions for Seismology Data Management Center and\nCanadian National Data Centre provided the GEOSCOPE data\nand Yellowknife short-period data used in this analysis,\nrespectively. Station UNM is operated and maintained by\nServicio Sismol\u00f3gical Nacional. This work is partially\nsupported by NSF grant EAR-0636012. This is Tectonic\nObservatory contribution 10015. T.-R.A.S. is supported by a\nCarnegie fellowship at the Department of Terrestrial\nMagnetism.\n\nPublished - Song2009p2048Science.pdf
Supplemental Material - SUPPSong2009p2048Science.pdf
", "abstract": "Great earthquakes have repeatedly occurred on the plate interface in a few shallow-dipping subduction zones where the subducting and overriding plates are strongly locked. Silent earthquakes (or slow slip events) were recently discovered at the down-dip extension of the locked zone and interact with the earthquake cycle. Here, we show that locally observed converted SP arrivals and teleseismic underside reflections that sample the top of the subducting plate in southern Mexico reveal that the ultra-slow velocity layer (USL) varies spatially (3 to 5 kilometers, with an S-wave velocity of ~2.0 to 2.7 kilometers per second). Most slow slip patches coincide with the presence of the USL, and they are bounded by the absence of the USL. The extent of the USL delineates the zone of transitional frictional behavior.", "date": "2009-04-24", "date_type": "published", "publication": "Science", "volume": "324", "number": "5926", "publisher": "American Association for the Advancement of Science", "pagerange": "502-506", "id_number": "CaltechAUTHORS:20090507-090314466", "issn": "0036-8075", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20090507-090314466", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR-0636012" }, { "agency": "Carnegie Trust" } ] }, "other_numbering_system": { "items": [ { "id": "10015", "name": "Caltech Tectonics Observatory" } ] }, "local_group": { "items": [ { "id": "Caltech-Tectonics-Observatory" }, { "id": "Caltech-Tectonics-Observatory.-MesoAmerican-Subduction-Experiment-(MASE)" }, { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1126/science.1167595", "primary_object": { "basename": "SUPPSong2009p2048Science.pdf", "url": "https://authors.library.caltech.edu/records/0vj8b-6zt68/files/SUPPSong2009p2048Science.pdf" }, "related_objects": [ { "basename": "Song2009p2048Science.pdf", "url": "https://authors.library.caltech.edu/records/0vj8b-6zt68/files/Song2009p2048Science.pdf" } ], "resource_type": "article", "pub_year": "2009", "author_list": "Song, Teh-Ru Alex; Helmberger, Donald V.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/v6fm4-qvh83", "eprint_id": 34551, "eprint_status": "archive", "datestamp": "2023-08-20 01:22:22", "lastmod": "2023-10-19 20:44:09", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Lukac-M", "name": { "family": "Lukac", "given": "Martin" } }, { "id": "Stubailo-I", "name": { "family": "Stubailo", "given": "Igor" } }, { "id": "Guy-R", "name": { "family": "Guy", "given": "Richard" } }, { "id": "Davis-P", "name": { "family": "Davis", "given": "Paul" } }, { "id": "Puruhuaya-V-A", "name": { "family": "Puruhuaya", "given": "Victor Aguilar" } }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert" }, "orcid": "0000-0003-3323-3508" }, { "id": "Estrin-D", "name": { "family": "Estrin", "given": "Deborah" } } ] }, "title": "First-class meta-data: a step towards a highly reliable wireless seismic network in Peru", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2009 ACM.\n\nThe Peru array and this work were partially supported under NSF Cooperative Agreement #CCR-0120778 and by the\nGordon and Betty Moore Foundation through the Caltech\nTectonics Observatory contribution number 118.", "abstract": "A 200-mile long temporary sensor network is inherently\nfragile, yet domain scientists legitimately demand reli-\nable sensor data capture and transport. We report here\non a currently deployed and operational sensor network\nsystem that considers sensor and general system health\nmeta-data to be equally important as sensor data. We\nargue that this is both essential to, and effective for,\nreliable system operation. The meta-data constitutes a\n0.1% storage space and transport system overhead in a\nfielded seismic sensing network.", "date": "2009-04", "date_type": "published", "publisher": "Association for Computing Machinery", "id_number": "CaltechAUTHORS:20120928-142859688", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20120928-142859688", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "CCR-0120778" }, { "agency": "Gordon and Betty Moore Foundation" }, { "agency": "Caltech Tectonics Observatory" } ] }, "other_numbering_system": { "items": [ { "id": "118", "name": "Caltech Tectonics Observatory" } ] }, "local_group": { "items": [ { "id": "Caltech-Tectonics-Observatory" }, { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "resource_type": "book_section", "pub_year": "2009", "author_list": "Lukac, Martin; Stubailo, Igor; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/4z0ss-mcy78", "eprint_id": 20775, "eprint_status": "archive", "datestamp": "2023-08-22 14:01:26", "lastmod": "2023-10-20 23:26:13", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Lukac-M", "name": { "family": "Lukac", "given": "Martin" } }, { "id": "Davis-P", "name": { "family": "Davis", "given": "Paul" } }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert" }, "orcid": "0000-0003-3323-3508" }, { "id": "Estrin-D", "name": { "family": "Estrin", "given": "Deborah" } } ] }, "title": "Recovering Temporal Integrity with Data Driven Time Synchronization", "ispublished": "unpub", "full_text_status": "public", "keywords": "Time Synchronization; Microseisms; Background Noise Correlation", "note": "\u00a9 2009 ACM.\nIssue Date: 13-16 April 2009.\nDate of Current Version: 21 August 2009.\n\nWe would like to thank Akos Ledeczi and the reviewers\nfor their feedback and suggestions. The MASE array\nand this work were partially supported under NSF Cooperative\nAgreement #CCR-0120778. The MASE array\nwas partially supported by the Gordon and Betty\nMoore Foundation through the Tectonics Observatory\nat Caltech. Contribution number 110 from the Tectonics\nObservatory.\n\nPublished - 2009Martin_IPSN.pdf
", "abstract": "Data Driven Time Synchronization (DDTS) provides\nsynchronization across sensors by using underlying characteristics of data collected by an embedded sensing sys-\ntem. We apply the concept of Data Driven Time Synchronization through a seismic deployment consisting\nof 100 seismic sensors to repair data that was not time\nsynchronized correctly. This deployment used GPS for\ntime synchronization but due to system faults common\nto environmental sensing systems, data was collected\nwith large time offsets. In seismic deployments, offset\ndata is often never used but we show that Data Driven\nTime Synchronization can recover the synchronization\nand make the data usable. To implement Data Driven\nTime Synchronization to repair the time offsets we use\nmicroseisms as the underlying characteristics. Microseisms are waves that travel through the earth's crust\nand are independent of the seismic events used for the\nstudy of the earth's structure. We have developed a\nmodel of microseism propagation through a linear seismic array and use the model to obtain time correction\nshifts. By simulating time offsets in real data which does\nnot have offsets, we determined that this method is able\nto repair the offset to less than 0.2 seconds. Our ongoing work will attempt to refine the model to correct the\noffsets to 0.05 seconds and evaluate how errors in the\ncorrection affect seismic results such as event location.\nData Driven Time Synchronization may be applicable\nto other high data rate embedded sensing applications\nsuch as acoustic source localization.", "date": "2009", "date_type": "published", "publisher": "IEEE", "place_of_pub": "Piscataway, NJ", "pagerange": "61-72", "id_number": "CaltechAUTHORS:20101112-132017736", "isbn": "978-1-4244-5108-1", "book_title": "2009 International Conference on Information Processing in Sensor Networks", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20101112-132017736", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "CCR-0120778" }, { "agency": "Gordon and Betty Moore Foundation" } ] }, "other_numbering_system": { "items": [ { "id": "110", "name": "Caltech Tectonics Observatory" } ] }, "local_group": { "items": [ { "id": "Caltech-Tectonics-Observatory" }, { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "primary_object": { "basename": "2009Martin_IPSN.pdf", "url": "https://authors.library.caltech.edu/records/4z0ss-mcy78/files/2009Martin_IPSN.pdf" }, "resource_type": "book_section", "pub_year": "2009", "author_list": "Lukac, Martin; Davis, Paul; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/nd7b3-rs594", "eprint_id": 12265, "eprint_status": "archive", "datestamp": "2023-08-22 13:09:19", "lastmod": "2023-10-17 16:38:59", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "P\u00e9rez-Campos-Xyoli", "name": { "family": "P\u00e9rez-Campos", "given": "Xyoli" }, "orcid": "0000-0001-8970-7966" }, { "id": "Kim-YoungHee", "name": { "family": "Kim", "given": "YoungHee" }, "orcid": "0000-0002-1111-632X" }, { "id": "Husker-Allen-L", "name": { "family": "Husker", "given": "Allen" }, "orcid": "0000-0003-1139-0502" }, { "id": "Davis-P-M", "name": { "family": "Davis", "given": "Paul M." } }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" }, { "id": "Iglesias-Arturo", "name": { "family": "Iglesias", "given": "Arturo" } }, { "id": "Pacheco-Javier-F", "name": { "family": "Pacheco", "given": "Javier F." } }, { "id": "Singh-Shri-Krishna", "name": { "family": "Singh", "given": "Shri K." } }, { "id": "Manea-Vlad-Constantin", "name": { "family": "Manea", "given": "Vlad Constantin" } }, { "id": "Gurnis-M", "name": { "family": "Gurnis", "given": "Michael" }, "orcid": "0000-0003-1704-597X" } ] }, "title": "Horizontal subduction and truncation of the Cocos Plate beneath central Mexico", "ispublished": "pub", "full_text_status": "public", "keywords": "flat subduction, Middle America Trench, tear slab", "note": "\u00a9 2008 American Geophysical Union. \n\nReceived 25 June 2008; revised 13 August 2008; accepted 19 August 2008; published 27 September 2008. \n\nThis work was supported by the Tectonics Observatory at Caltech, the Center for Embedded Network Sensors (CENS) at UCLA, NSF award EAR0609707, PAPIIT-UNAM projects IX120004 and IN119505-3 and UC MEXUS project 04105384. The MASE experiment was funded by the Gordon and Betty Moore Foundation. Contribution 90 from the Tectonics Observatory. Approximately half of the stations were radio linked to the Internet allowing near-real time access to the data using software protocols designed by CENS computer scientists Igor Stubailo, Sam Irvine, Martin Lukac, Richard Guy and Vinayak Naik. We thank the many volunteers who contributed their time to the field work. We thank Luca Ferrari and an unknown reviewer for comments that improved the paper.\n\nPublished - PERgrl08.pdf
", "abstract": "Based on analysis of data from a trans-Mexico temporary broadband seismic network centered on Mexico City, we report that the subducting Cocos Plate beneath central Mexico is horizontal, and tectonically underplates the base of the crust for a distance of 250 km from the trench. It is decoupled from the crust by a very thin low viscosity zone. The plate plunges into the mantle near Mexico City but is truncated at a depth of 500 km, probably due to an E-W propagating tear in the Cocos slab. Unlike the shallow slab subduction in Peru and Chile, there is active volcanism along the Trans Mexican Volcanic Belt (TMVB) that lies much further inland than regions to either side where subduction dip is not horizontal. Geodynamical modeling indicates that a thin weak layer such as imaged by the seismic experiment can explain the flat subduction geometry.", "date": "2008-09-27", "date_type": "published", "publication": "Geophysical Research Letters", "volume": "35", "number": "18", "publisher": "American Geophysical Union", "pagerange": "L18303", "id_number": "CaltechAUTHORS:PERgrl08", "issn": "0094-8276", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:PERgrl08", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Caltech Tectonics Observatory" }, { "agency": "Center for Embedded Network Sensors (CENS), UCLA" }, { "agency": "NSF", "grant_number": "EAR-0609707" }, { "agency": "PAPIIT-UNAM", "grant_number": "IX120004" }, { "agency": "PAPIIT-UNAM", "grant_number": "IN119505-3" }, { "agency": "UC MEXUS", "grant_number": "04105384" }, { "agency": "Gordon and Betty Moore Foundation" } ] }, "other_numbering_system": { "items": [ { "id": "90", "name": "Caltech Tectonics Observatory" } ] }, "local_group": { "items": [ { "id": "Caltech-Tectonics-Observatory" }, { "id": "Caltech-Tectonics-Observatory.-MesoAmerican-Subduction-Experiment-(MASE)" }, { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1029/2008GL035127", "primary_object": { "basename": "PERgrl08.pdf", "url": "https://authors.library.caltech.edu/records/nd7b3-rs594/files/PERgrl08.pdf" }, "resource_type": "article", "pub_year": "2008", "author_list": "P\u00e9rez-Campos, Xyoli; Kim, YoungHee; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/x46kn-5ez16", "eprint_id": 34575, "eprint_status": "archive", "datestamp": "2023-08-22 11:35:55", "lastmod": "2023-10-19 20:44:55", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Spasojevi\u0107-S", "name": { "family": "Spasojevi\u0107", "given": "Sonja" } }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" } ] }, "title": "Crustal structure and apparent tectonic underplating from receiver function analysis in South Island, New Zealand", "ispublished": "pub", "full_text_status": "public", "keywords": "crustal structure; tectonic underplating; receiver functions", "note": "\u00a9 2008 by the American Geophysical Union. Received 11 May 2007; revised 3 October 2007; accepted 24 November 2007; published 24 April 2008. We want to acknowledge New Zealand\nGeoNet project and its sponsors EQC, GNS Science, and FRST for\nproviding data from NZNSN; Monica Kohler for providing the SAPSE\ndata; David Okaya for providing three-component SIGHT data; Joann\nStock for providing plate reconstruction data and useful discussion about\nthe tectonics of New Zealand; and Zhimei Yan for help with processing of\nreceiver function data. This paper has benefited from discussions with Fred\nDavey, Brian Davies, and Bruce Luyendyk and comments from two\nanonymous reviewers.\n\nPublished - Spasojevic2008.pdf
", "abstract": "We utilize seismic converted phases on more than 700 receiver functions calculated for 42 stations in the South Island, New Zealand, to infer crustal and uppermost mantle structure. We determine the crustal thickness from direct observations of conversion from the Moho interface and infer zone of the maximum thickness being located along the axis of the Southern Alps, just east from the Alpine fault. The crustal root widens from north to south in the direction perpendicular to the Alpine fault and appears to have an asymmetric structure. Stations in the alpine portion of island show evidence for prominent midcrustal conversions. Significant crustal thickening is developed in response to both the convergent component of the motion on the Alpine fault and subduction in the Fiordland region. We propose two models for a strong uppermost mantle conversion that occurs at depths between 33 and 83 km on 16 stations and forms a large continuous feature along the east coast and in the central portions of the South Island. Our preferred model attributes upper mantle conversion to tectonically underplated oceanic crust formed by late Oligocene-Miocene spreading between the Australian and Pacific plates, which was detached from the Australian plate and tectonically underplated under the South Island. An alternative model attributes the upper mantle conversions to long-lived seismic fabric created by subduction of the Gondwanaland margin.", "date": "2008-04-24", "date_type": "published", "publication": "Journal of Geophysical Research B", "volume": "113", "number": "B4", "publisher": "American Geophysical Union", "pagerange": "Art. No. B04307", "id_number": "CaltechAUTHORS:20121001-091317326", "issn": "0148-0227", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121001-091317326", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1029/2007JB005166", "primary_object": { "basename": "Spasojevic2008.pdf", "url": "https://authors.library.caltech.edu/records/x46kn-5ez16/files/Spasojevic2008.pdf" }, "resource_type": "article", "pub_year": "2008", "author_list": "Spasojevi\u0107, Sonja and Clayton, Robert W." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/keaqt-e0449", "eprint_id": 28372, "eprint_status": "archive", "datestamp": "2023-08-19 22:33:43", "lastmod": "2023-10-24 17:50:53", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Vriend-N-M", "name": { "family": "Vriend", "given": "Nathalie M." } }, { "id": "Hunt-M-L", "name": { "family": "Hunt", "given": "Melany L." }, "orcid": "0000-0001-5592-2334" }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" }, { "id": "Brennen-C-E", "name": { "family": "Brennen", "given": "Christopher Earls" } }, { "id": "Brantley-K-S", "name": { "family": "Brantley", "given": "Katherine S." } }, { "id": "Ruiz-Angulo-A", "name": { "family": "Ruiz-Angulo", "given": "Angel" }, "orcid": "0000-0002-7292-3002" } ] }, "title": "Reply to comment by B. Andreotti et al. on \"Solving the mystery of booming sand dunes\"", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 2008 by the American Geophysical Union. \n\nReceived 7 January 2008; accepted 3 March 2008; published 23 April 2008.\n\nPublished - VRI239.pdf
Supplemental Material - Figure_S1.ps
", "abstract": "This reply addresses three main issues raised in the\ncomment of Andreotti et al. [2008]. First, the turning of\nray paths in a granular material does not preclude the\npropagation of body waves and the resonance condition\ndescribed by Vriend et al. [2007]. The waveguide model\nstill holds in the dune for the observed velocities, even\nwith a velocity increase with depth as implied by Andreotti\net al. [2008]. Secondly, the method of initiation of\nspontaneous avalanching does not influence the booming\nfrequency. The frequency is independent of the source\nonce sustained booming starts; it depends on the subsurface\nstructure of the dune. Thirdly, if all data points from Vriend\net al. [2007] are included in the analysis (and not an\naverage or selection), no correlation is observed between\nthe sustained booming frequency and average particle\ndiameter.", "date": "2008-04-23", "date_type": "published", "publication": "Geophysical Research Letters", "volume": "35", "number": "L08", "publisher": "American Geophysical Union", "pagerange": "Art. No. L08307", "id_number": "CaltechAUTHORS:20111208-105043039", "issn": "0094-8276", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20111208-105043039", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1029/2008GL033202", "primary_object": { "basename": "VRI239.pdf", "url": "https://authors.library.caltech.edu/records/keaqt-e0449/files/VRI239.pdf" }, "related_objects": [ { "basename": "Figure_S1.ps", "url": "https://authors.library.caltech.edu/records/keaqt-e0449/files/Figure_S1.ps" } ], "resource_type": "article", "pub_year": "2008", "author_list": "Vriend, Nathalie M.; Hunt, Melany L.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/kxv7j-vz727", "eprint_id": 20783, "eprint_status": "archive", "datestamp": "2023-08-22 11:31:28", "lastmod": "2023-10-20 23:26:48", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Payero-J-S", "name": { "family": "Payero", "given": "Juan S." } }, { "id": "Kostoglodov-V", "name": { "family": "Kostoglodov", "given": "Vladimir" }, "orcid": "0000-0001-7169-3121" }, { "id": "Shapiro-N-M", "name": { "family": "Shapiro", "given": "Nikolai" } }, { "id": "Mikumo-Takeshi", "name": { "family": "Mikumo", "given": "Takeshi" } }, { "id": "Iglesias-Arturo", "name": { "family": "Iglesias", "given": "Arturo" } }, { "id": "P\u00e9rez-Campos-Xyoli", "name": { "family": "P\u00e9rez-Campos", "given": "Xyoli" }, "orcid": "0000-0001-8970-7966" }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" } ] }, "title": "Nonvolcanic tremor observed in the Mexican subduction zone", "ispublished": "pub", "full_text_status": "public", "keywords": "dynamic subsidence; geodynamic models; sea level", "note": "\u00a9 2008 American Geophysical Union.\n\nReceived 4 December 2007; revised 17 February 2008; accepted 28 February 2008; published 4 April 2008.\n\nThis study is based on the MASE data and partially supported by PAPIIT IN102105, CONACYT 46064, SEP-CONACYT-\nANUIES-ECOS M06-U02, and ANR-06-CEXC-005 (COHERSIS)\nproject grants. We thank Ing. Casiano Jim\u00e9nez Cruz, SSN (Mexico) for the recent seismic catalog and Kazushige Obara for some suggestions at an\ninitial stage of this study. The authors gratefully acknowledge the assistance\nof the UNAM students in numerous field works during the MASE project.\nThe MASE experiment of the Caltech Tectonics Observatory was funded\nby the Gordon and Betty Moore Foundation. Contribution 82 from the\nCaltech Tectonics Observatory.\n\nPublished - ClaytonGRL2008.pdf
Supplemental Material - 2007gl032877-fs01.jpg
Supplemental Material - 2007gl032877-fs02.jpg
Supplemental Material - 2007gl032877-fs03a.jpg
Supplemental Material - 2007gl032877-fs03b.jpg
Supplemental Material - 2007gl032877-fs04.jpg
Supplemental Material - 2007gl032877-fs05.jpg
Supplemental Material - 2007gl032877-fs06.jpg
Supplemental Material - 2007gl032877-txts01.txt
", "abstract": "Nonvolcanic tremor (NVT) activity is revealed as episodes of higher spectral amplitude at 1\u20138 Hz in daily spectrograms from the continuous seismological records in Guerrero, Mexico. The analyzed data cover a period of 2001\u20132007 when in 2001\u20132002 a large slow slip event (SSE) had occurred in the Guerrero-Oaxaca region, and then a new large SSE occurred in 2006. The tremor burst is dominated by S-waves. More than 100 strong NVT bursts were recorded in the narrow band of ~40 \u00d7 150 km^2 to the south of Iguala City and parallel to the coastline. Depths of NVT hypocenters are mostly scattered in the continental crust between 5 and 40 km depth. Tremor activity is higher during the 2001\u20132002 and 2006 SSE compared with that for the \"quiet\" period of 2003\u20132005. While resistivity pattern in Guerrero does not correlate directly with the NVT distribution, gravity and magnetic anomaly modeling favors a hypothesis that the NVT is apparently related to the dehydration and serpentinization processes.", "date": "2008-04-04", "date_type": "published", "publication": "Geophysical Research Letters", "volume": "35", "number": "7", "publisher": "American Geophysical Union", "pagerange": "Art. No. L07305", "id_number": "CaltechAUTHORS:20101112-150954054", "issn": "0094-8276", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20101112-150954054", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Gordon and Betty Moore Foundation" }, { "agency": "PAPIIT", "grant_number": "IN102105" }, { "agency": "Consejo Nacional de Ciencia y Tecnolog\u00ed (CONACYT)", "grant_number": "46064" }, { "agency": "COHERSIS", "grant_number": "SEP-CONACYT-ANUIES-ECOS M06-U02" }, { "agency": "COHERSIS", "grant_number": "ANR-06-CEXC-005" } ] }, "other_numbering_system": { "items": [ { "id": "82", "name": "Caltech Tectonics Observatory" } ] }, "local_group": { "items": [ { "id": "Caltech-Tectonics-Observatory" }, { "id": "Caltech-Tectonics-Observatory.-MesoAmerican-Subduction-Experiment-(MASE)" }, { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1029/2007GL032877", "primary_object": { "basename": "2007gl032877-fs03a.jpg", "url": "https://authors.library.caltech.edu/records/kxv7j-vz727/files/2007gl032877-fs03a.jpg" }, "related_objects": [ { "basename": "2007gl032877-fs05.jpg", "url": "https://authors.library.caltech.edu/records/kxv7j-vz727/files/2007gl032877-fs05.jpg" }, { "basename": "2007gl032877-txts01.txt", "url": "https://authors.library.caltech.edu/records/kxv7j-vz727/files/2007gl032877-txts01.txt" }, { "basename": "ClaytonGRL2008.pdf", "url": "https://authors.library.caltech.edu/records/kxv7j-vz727/files/ClaytonGRL2008.pdf" }, { "basename": "medium.png", "url": "https://authors.library.caltech.edu/records/kxv7j-vz727/files/medium.png" }, { "basename": "small.png", "url": "https://authors.library.caltech.edu/records/kxv7j-vz727/files/small.png" }, { "basename": "2007gl032877-fs01.jpg", "url": "https://authors.library.caltech.edu/records/kxv7j-vz727/files/2007gl032877-fs01.jpg" }, { "basename": "2007gl032877-fs02.jpg", "url": "https://authors.library.caltech.edu/records/kxv7j-vz727/files/2007gl032877-fs02.jpg" }, { "basename": "2007gl032877-fs03b.jpg", "url": "https://authors.library.caltech.edu/records/kxv7j-vz727/files/2007gl032877-fs03b.jpg" }, { "basename": "2007gl032877-fs04.jpg", "url": "https://authors.library.caltech.edu/records/kxv7j-vz727/files/2007gl032877-fs04.jpg" }, { "basename": "2007gl032877-fs06.jpg", "url": "https://authors.library.caltech.edu/records/kxv7j-vz727/files/2007gl032877-fs06.jpg" } ], "resource_type": "article", "pub_year": "2008", "author_list": "Payero, Juan S.; Kostoglodov, Vladimir; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/n1xbw-trg78", "eprint_id": 34577, "eprint_status": "archive", "datestamp": "2023-08-22 11:18:34", "lastmod": "2023-10-19 20:45:00", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Kedar-S", "name": { "family": "Kedar", "given": "Sharon" } }, { "id": "Longuet-Higgins-M", "name": { "family": "Longuet-Higgins", "given": "Michael" } }, { "id": "Webb-F", "name": { "family": "Webb", "given": "Frank" } }, { "id": "Graham-N-A", "name": { "family": "Graham", "given": "Nicholas" } }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert" }, "orcid": "0000-0003-3323-3508" }, { "id": "Jones-C", "name": { "family": "Jones", "given": "Cathleen" } } ] }, "title": "The origin of deep ocean microseisms in the North Atlantic Ocean", "ispublished": "pub", "full_text_status": "public", "keywords": "microseisms; wave\u2013wave interaction; acoustic resonance; wave model; Stoneley waves", "note": "\u00a9 2008 The Royal Society. Received 17 October 2007;\nAccepted 11 December 2007. The authors wish to thank Dr Robert Guza of the Scripps Institution of Oceanography and Dr. Ernesto Rodriguez of the Jet Propulsion Laboratory, California Institute of Technology, for their\ninsights and suggestions. They also wish to thank Dr Hiroo Kanamori of the Caltech Seismological\nLaboratory for his helpful comments. Maps were generated using the generic mapping tools\n(GMTs) software package. Seismic data were analysed using Lawrence Livermore National\nLaboratory's Seismic Analysis Code (SAC). Seismic data were obtained through the Incorporated\nResearch Institutions of Seismology (IRIS) database and the Canadian National Waveform\nArchive (NWFA). Data from the following networks were used: Global Seismograph Network\n(GSN), United States National Seismic Network, the International Deployment of Accelerometers\n(IDA), the Canadian National Seismograph Network (CNSN), GEOFON, the Caltech Regional\nSeismic Network and the Berkeley Digital Seismograph Network.\nThis research was carried out at the Jet Propulsion Laboratory, California Institute of\nTechnology, under a contract with the National Aeronautics and Space Administration and funded\nthrough the internal Research and Technology Development Program.\n\nPublished - Kedar2008.pdf
", "abstract": "Oceanic microseisms are small oscillations of the ground, in the frequency range of 0.05\u20130.3\u200aHz, associated with the occurrence of energetic ocean waves of half the corresponding frequency. In 1950, Longuet-Higgins suggested in a landmark theoretical paper that (i) microseisms originate from surface pressure oscillations caused by the interaction between oppositely travelling components with the same frequency in the ocean wave spectrum, (ii) these pressure oscillations generate seismic Stoneley waves on the ocean bottom, and (iii) when the ocean depth is comparable with the acoustic wavelength in water, compressibility must be considered. The efficiency of microseism generation thus depends on both the wave frequency and the depth of water. While the theory provided an estimate of the magnitude of the corresponding microseisms in a compressible ocean, its predictions of microseism amplitude heretofore have never been tested quantitatively. In this paper, we show a strong agreement between observed microseism and calculated amplitudes obtained by applying Longuet-Higgins' theory to hindcast ocean wave spectra from the North Atlantic Ocean. The calculated vertical displacements are compared with seismic data collected at stations in North America, Greenland, Iceland and Europe. This modelling identifies a particularly energetic source area stretching from the Labrador Sea to south of Iceland, where wind patterns are especially conducive to generating oppositely travelling waves of same period, and the ocean depth is favourable for efficient microseism generation through the 'organ pipe' resonance of the compression waves, as predicted by the theory. This correspondence between observations and the model predictions demonstrates that deep ocean nonlinear wave\u2013wave interactions are sufficiently energetic to account for much of the observed seismic amplitudes in North America, Greenland and Iceland.", "date": "2008-03-08", "date_type": "published", "publication": "Proceedings of the Royal Society A: Mathematical, physical, and engineering sciences", "volume": "464", "number": "2091", "publisher": "Royal Society of London", "pagerange": "777-793", "id_number": "CaltechAUTHORS:20121001-092904179", "issn": "1364-5021", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121001-092904179", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "JPL Internal Research and Technology Development Program" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1098/rspa.2007.0277", "primary_object": { "basename": "Kedar2008.pdf", "url": "https://authors.library.caltech.edu/records/n1xbw-trg78/files/Kedar2008.pdf" }, "resource_type": "article", "pub_year": "2008", "author_list": "Kedar, Sharon; Longuet-Higgins, Michael; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/7797z-9gr15", "eprint_id": 34574, "eprint_status": "archive", "datestamp": "2023-08-22 10:53:45", "lastmod": "2023-10-19 20:44:53", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Ai-Huirong-Anita", "name": { "family": "Ai", "given": "Huirong-Anita" } }, { "id": "Stock-J-M", "name": { "family": "Stock", "given": "Joann M." }, "orcid": "0000-0003-4816-7865" }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert" }, "orcid": "0000-0003-3323-3508" }, { "id": "Luyendyk-B", "name": { "family": "Luyendyk", "given": "Bruce" } } ] }, "title": "Vertical tectonics of the High Plateau region, Manihiki Plateau, Western Pacific, from seismic stratigraphy", "ispublished": "pub", "full_text_status": "restricted", "keywords": "Cretaceous; hotspot; isopach map; Manihiki Plateau; seismic reflection", "note": "\u00a9 2008 The Author(s). Received: 2 May 2006; Accepted: 19 January 2008. This article is distributed under the terms of the Creative Commons Attribution Noncommercial License which permits any noncommercial use, distribution, and reproduction in any medium, provided the original author(s) and source are credited. We thank Patricia Persaud for her insightful\ndiscussion and numerous suggestions. We also thank graduate and undergraduate students from Caltech and UC Santa Barbara for their assistance on KIWI 12. Research supported by University of\nCalifornia San Diego, Scripps Institution of Oceanography, UC Santa Barbara, and Caltech. Nathaniel B. Palmer multibeam data collection was supported by NSF OPP-0126334. Contribution 8945, Division of Geological and Planetary Sciences, California Institute of Technology.\nContribution of the Institute for Crustal Studies, University of California, Santa Barbara, number 0810.", "abstract": "The Manihiki Plateau is an elevated oceanic volcanic plateau that was formed mostly in Early Cretaceous time by hotspot activity. We analyze new seismic reflection data acquired on cruise KIWI 12 over the High Plateau region in the southeast of the plateau, to look for direct evidence of the location of the heat source and the timing of uplift, subsidence and faulting. These data are correlated with previous seismic reflection lines from cruise CATO 3, and with the results at DSDP Site 317 at the northern edge of the High Plateau. Seven key reflectors are identified from the seismic reflection profiles and the resulting isopach maps show local variations in thickness in the southeastern part of the High Plateau, suggesting a subsidence (cooling) event in this region during Late Cretaceous and up to Early Eocene time. We model this as a hotspot, active and centered on the High Plateau area during Early Cretaceous time in a near-ridge environment. The basement and Early Cretaceous volcaniclastic layers were formed by subaerial and shallow-water eruption due to the volcanic activity. After that, the plateau experienced erosion. The cessation of hotspot activity and subsequent heat loss by Late Cretaceous time caused the plateau to subside rapidly. The eastern and southern portions of the High Plateau were rifted away following the cessation of hot spot activity. As the southeastern portion of the High Plateau was originally higher and above the calcium carbonate compensation depth, it accumulated more sediments than the surrounding plateau regions. Apparently coeval with the rapid subsidence of the plateau are normal faults found at the SE edge of the plateau. Since Early Eocene time, the plateau subsided to its present depth without significant deformation.", "date": "2008-01", "date_type": "published", "publication": "Marine Geophysical Research", "volume": "29", "number": "1", "publisher": "Springer Verlag", "pagerange": "13-26", "id_number": "CaltechAUTHORS:20121001-090154547", "issn": "0025-3235", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121001-090154547", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "University of California San Diego, Scripps Institution of Oceanography" }, { "agency": "University of California Santa Barbara" }, { "agency": "Caltech" }, { "agency": "NSF", "grant_number": "OPP-0126334" } ] }, "other_numbering_system": { "items": [ { "id": "0810", "name": "University of California Santa Barbara, Institute for Crustal Studies" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1007/s11001-008-9042-0", "resource_type": "article", "pub_year": "2008", "author_list": "Ai, Huirong-Anita; Stock, Joann M.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/qjtt4-qkn59", "eprint_id": 34578, "eprint_status": "archive", "datestamp": "2023-08-22 10:00:31", "lastmod": "2023-10-19 20:45:02", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Davis-P-M", "name": { "family": "Davis", "given": "Paul M." } }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" } ] }, "title": "Application of the telegraph model to coda Q variations in southern California", "ispublished": "pub", "full_text_status": "public", "keywords": "coda; Q; scattering", "note": "\u00a9 2007 by the American Geophysical Union. Received 26 May 2006; revised 27 November 2006; accepted 3 May 2007; published 11 September 2007. This work was supported by grants from the UCLA NSF Science and Technology Center for Embedded Networked\nSensing (CENS; NSF STC award CCR-0120778) and by the Southern California Earthquake Center (SCEC). SCEC is funded by NSF Cooperative Agreement EAR-0106924 and USGS Cooperative Agreement 02HQAG0008. We thank the Southern California Earthquake Data Center (SCEDC) for supplying the coda and waveform data used in this study. This is SCEC contribution 1078. The reviewers and Associate Editor are thanked for their constructive comments. Ben Wu is thanked for help in the early part of the analysis.\n\nPublished - Davis2007.pdf
", "abstract": "We examine waveforms and data used to construct coda magnitude in southern California to estimate the spatial variation of coda Q and its dependence on frequency. Our analysis combined with independent borehole data suggests that coda is mainly generated by multiple scattering in the upper few kilometers of the crust where large impedance contrasts occur because of surface layering or fracturing. The ubiquitous observation that coda Q increases with frequency is explained as arising from multiple reverberations in the upper crust. We suggest that the telegraph model that has been successfully used to describe reflection seismogram multiples in the exploration industry may also apply to earthquakes. Under this model the apparent increase of Q with frequency is due to trapping of high-frequency energy in the upper crust. This behavior is expected if the associated reflector series has an exponential autocorrelation function, a feature of the telegraph model. At lower frequencies, trapping is less efficient. The combined effects give rise to an apparent absorption band that we suppose is superimposed on frequency-independent intrinsic attenuation. Maximum apparent attenuation occurs at wavelengths equal to the dimensions of the regions of upper crust that contain the scattering layers. At lower frequencies, trapping is less effective, and attenuation decreases as the longer-wavelength waves sample the deeper crust and upper mantle where because of overburden pressures, acoustic impedance contrasts are less extreme. By taking spectral ratios of coda waves to direct S, we estimate that intrinsic Q is high (\u223c3000) and that coda may be modeled as multiple scattered S waves in a region of anisotropic scattering. The exponential decay of the coda is a result of the perfectly reflecting surface of the Earth with backscattering from random near-surface layers causing progressive leakage and loss of energy downward into the more transparent lower crust and mantle.", "date": "2007-09-11", "date_type": "published", "publication": "Journal of Geophysical Research B", "volume": "112", "number": "B9", "publisher": "American Geophysical Union", "pagerange": "Art. No. B09302", "id_number": "CaltechAUTHORS:20121001-093602285", "issn": "0148-0227", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121001-093602285", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "CCR-0120778" }, { "agency": "Southern California Earthquake Center (SCEC)" }, { "agency": "NSF", "grant_number": "EAR-0106924" }, { "agency": "USGS", "grant_number": "02HQAG0008" } ] }, "other_numbering_system": { "items": [ { "id": "1078", "name": "Southern California Earthquake Center (SCEC)" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1029/2006JB004542", "primary_object": { "basename": "Davis2007.pdf", "url": "https://authors.library.caltech.edu/records/qjtt4-qkn59/files/Davis2007.pdf" }, "resource_type": "article", "pub_year": "2007", "author_list": "Davis, Paul M. and Clayton, Robert W." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/3qgqb-qx416", "eprint_id": 34580, "eprint_status": "archive", "datestamp": "2023-08-22 09:50:21", "lastmod": "2023-10-19 20:45:07", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Yan-Zhimei", "name": { "family": "Yan", "given": "Zhimei" } }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" } ] }, "title": "A notch structure on the Moho beneath the Eastern San Gabriel Mountains", "ispublished": "pub", "full_text_status": "restricted", "keywords": "Moho depth; receiver functions; San Andreas Fault; San Gabriel Fault; Pelona Schist; San Gabriel Mountains", "note": "\u00a9 2007 Elsevier B.V. Received 1 December 2006; received in revised form 7 June 2007; accepted 7 June 2007. Available online 16 June 2007.\nEditor: R.D. van der Hilst. We thank the Southern California Seismic Network\nand the Southern California Earthquake Data Center for providing the network data, and the IRIS data center and Monica Kohler for providing the LARSE data. This research is partially supported by USGS Contract 04HQAG0010.", "abstract": "Synthetic waveform modeling of the anomalous receiver functions for two stations in the eastern San Gabriel Mountains, California, suggests that a flat-topped notch structure exists on the Moho. North of the San Andreas Fault (SAF), the Moho depth is 36\u201338 km and is 33\u201335 km south of the San Gabriel Fault (SGF), but in-between under the Mt. Baldy block, it is only \u223c29 km. The inferred notch structure is also supported by the Pms arrival times along the SCSN and the LARSE I profiles. The shallow Moho block correlates well with the surficial exposure of the lower plate Pelona Schist or where it resides at very shallow depth. The large Moho offsets across the two major faults can be either related to differential uplifting reflected by the difference in the denudation rate and the exposure of the lower plate Pelona Schist, or it can be the result of the juxtaposition of the distinctive terranes with initially different Moho depth due to the strike-slip movements along the two major faults.", "date": "2007-08-30", "date_type": "published", "publication": "Earth and Planetary Science Letters", "volume": "260", "number": "3-4", "publisher": "Elsevier", "pagerange": "570-581", "id_number": "CaltechAUTHORS:20121001-095440250", "issn": "0012-821X", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121001-095440250", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "USGS Contract", "grant_number": "04HQAG0010" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/j.epsl.2007.06.017", "resource_type": "article", "pub_year": "2007", "author_list": "Yan, Zhimei and Clayton, Robert W." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/s0m0a-cyg09", "eprint_id": 28368, "eprint_status": "archive", "datestamp": "2023-08-19 20:48:39", "lastmod": "2023-10-24 17:50:42", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Vriend-N-M", "name": { "family": "Vriend", "given": "Nathalie M." } }, { "id": "Hunt-M-L", "name": { "family": "Hunt", "given": "Melany L." }, "orcid": "0000-0001-5592-2334" }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" }, { "id": "Brennen-C-E", "name": { "family": "Brennen", "given": "Christopher Earls" } }, { "id": "Brantley-K-S", "name": { "family": "Brantley", "given": "Katherine S." } }, { "id": "Ruiz-Angulo-A", "name": { "family": "Ruiz-Angulo", "given": "Angel" }, "orcid": "0000-0002-7292-3002" } ] }, "title": "Solving the mystery of booming sand dunes", "ispublished": "pub", "full_text_status": "public", "keywords": "booming, sand, dunes", "note": "\u00a9 2007. American Geophysical Union. \n\nReceived 4 April 2007; revised 16 May 2007; accepted 14 June 2007; published 23 August 2007. \n\n The authors would like to thank the late Ron Scott, Norman Brooks, George Rossman and Tom Heaton for their scientific suggestions and Steve Hostler and Gustavo Joseph for their guidance and help. The help of the undergraduate students Natalie Becerra, Patricio Romano-Pringles, Ransom Williams, Nora DeDontney and the late Steve Gao and many others, was essential during the field experiments at various locations. Travel and equipment support for N. M. V. was provided through funding from the Pieter Langerhuizen Lambertuszoon Fonds.\n\nPublished - VREgrl07.pdf
Supplemental Material - AnimationS1.avi
Supplemental Material - AnimationS2.avi
Supplemental Material - AnimationS3.avi
Supplemental Material - AnimationS4.avi
Supplemental Material - AudioS1.wav
Supplemental Material - AudioS2.wav
Supplemental Material - AudioS3.wav
Supplemental Material - TableS1.txt
", "abstract": "Desert booming can be heard after a natural slumping\nevent or during a sand avalanche generated by humans\nsliding down the slip face of a large dune. The sound is\nremarkable because it is composed of one dominant audible\nfrequency (70 to 105 Hz) plus several higher harmonics.\nThis study challenges earlier reports that the dunes'\nfrequency is a function of average grain size by\ndemonstrating through extensive field measurements that\nthe booming frequency results from a natural waveguide\nassociated with the dune. The booming frequency is fixed\nby the depth of the surficial layer of dry loose sand that is\nsandwiched between two regions of higher compressional\nbody wave velocity. This letter presents measurements of\nthe booming frequencies, compressional wave velocities,\ndepth of surficial layer, along with an analytical prediction\nof the frequency based on constructive interference of\npropagating waves generated by avalanching along the dune\nsurface.", "date": "2007-08-23", "date_type": "published", "publication": "Geophysical Research Letters", "volume": "34", "number": "L16", "publisher": "American Geophysical Union", "pagerange": "Art. No. L16306", "id_number": "CaltechAUTHORS:20111208-094334359", "issn": "0094-8276", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20111208-094334359", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Pieter Langerhuizen Lambertuszoon Fonds" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1029/2007GL030276", "primary_object": { "basename": "AudioS1.wav", "url": "https://authors.library.caltech.edu/records/s0m0a-cyg09/files/AudioS1.wav" }, "related_objects": [ { "basename": "TableS1.txt", "url": "https://authors.library.caltech.edu/records/s0m0a-cyg09/files/TableS1.txt" }, { "basename": "VREgrl07.pdf", "url": "https://authors.library.caltech.edu/records/s0m0a-cyg09/files/VREgrl07.pdf" }, { "basename": "AnimationS2.avi", "url": "https://authors.library.caltech.edu/records/s0m0a-cyg09/files/AnimationS2.avi" }, { "basename": "AnimationS4.avi", "url": "https://authors.library.caltech.edu/records/s0m0a-cyg09/files/AnimationS4.avi" }, { "basename": "AudioS2.wav", "url": "https://authors.library.caltech.edu/records/s0m0a-cyg09/files/AudioS2.wav" }, { "basename": "AudioS3.wav", "url": "https://authors.library.caltech.edu/records/s0m0a-cyg09/files/AudioS3.wav" }, { "basename": "AnimationS1.avi", "url": "https://authors.library.caltech.edu/records/s0m0a-cyg09/files/AnimationS1.avi" }, { "basename": "AnimationS3.avi", "url": "https://authors.library.caltech.edu/records/s0m0a-cyg09/files/AnimationS3.avi" } ], "resource_type": "article", "pub_year": "2007", "author_list": "Vriend, Nathalie M.; Hunt, Melany L.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/b55ft-m1j68", "eprint_id": 12124, "eprint_status": "archive", "datestamp": "2023-08-22 09:36:12", "lastmod": "2023-10-17 16:32:37", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Persaud-P", "name": { "family": "Persaud", "given": "Patricia" }, "orcid": "0000-0003-3462-7023" }, { "id": "P\u00e9rez-Campos-Xyoli", "name": { "family": "P\u00e9rez-Campos", "given": "Xyoli" }, "orcid": "0000-0001-8970-7966" }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" } ] }, "title": "Crustal thickness variations in the margins of the Gulf of California from receiver functions", "ispublished": "pub", "full_text_status": "public", "keywords": "Moho depth; receiver functions; lower crustal flow", "note": "\u00a9 2007 The Authors. Journal compilation \u00a9 2007 RAS. \n\nAccepted 2007 February 16. Received 2006 December 22; in original form 2006 November 28. \n\nWe thank Gene Ichinose and Harold Magistrale for providing us with the results from Ichinose et al. (1996) and Lewis et al. (2001), respectively, and Victoria Langenheim for providing the magnetic potential results from Langenheim & Jachens (2003). Supported by NSF grants EAR-0111650. Contribution no. 8974, Division of Geological and Planetary Sciences, California Institute of Technology. Partial funding for X. P\u00e9rez-Campos from UNAM-PAPIIT grants IX1210004 and IN119505\u20133.\n\nPublished - PERgji07.pdf
", "abstract": "Receiver functions (RFs) from teleseismic events recorded by the NARS-Baja array were used to map crustal thickness in the continental margins of the Gulf of California, a newly forming ocean basin. Although the upper crust is known to have split apart simultaneously along the entire length of the Gulf, little is known about the behaviour of the lower crust in this region. The RFs show clear P-to-S wave conversions from the Moho beneath the stations. The delay times between the direct P and P-to-S waves indicate thinner crust closer to the Gulf along the entire Baja California peninsula. The thinner crust is associated with the eastern Peninsular Ranges batholith (PRB). Crustal thickness is uncorrelated with topography in the PRB and the Moho is not flat, suggesting mantle compensation by a weaker than normal mantle based on seismological evidence. The approximately W\u2013E shallowing in Moho depths is significant with extremes in crustal thickness of \u223c21 and 37 km. Similar results have been obtained at the northern end of the Gulf by Lewis et al., who proposed a mechanism of lower crustal flow associated with rifting in the Gulf Extensional Province for thinning of the crust. Based on the amount of pre-Pliocene extension possible in the continental margins, if the lower crust did thin in concert with the upper crust, it is possible that the crust was thinned during the early stages of rifting before the opening of the ocean basin. In this case, we suggest that when breakup occurred, the lower crust in the margins of the Gulf was still behaving ductilely. Alternatively, the lower crust may have thinned after the Gulf opened. The implications of these mechanisms are discussed.", "date": "2007-08", "date_type": "published", "publication": "Geophysical Journal International", "volume": "170", "number": "2", "publisher": "Royal Astronomical Society", "pagerange": "687-699", "id_number": "CaltechAUTHORS:PERgji07", "issn": "0956-540X", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:PERgji07", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR-0111650" }, { "agency": "UNAM-PAPIIT", "grant_number": "IX1210004" }, { "agency": "UNAM-PAPIIT", "grant_number": "IN119505\u20133" } ] }, "other_numbering_system": { "items": [ { "id": "8974", "name": "Caltech Division of Geological and Planetary Sciences" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1111/j.1365-246X.2007.03412.x", "primary_object": { "basename": "PERgji07.pdf", "url": "https://authors.library.caltech.edu/records/b55ft-m1j68/files/PERgji07.pdf" }, "resource_type": "article", "pub_year": "2007", "author_list": "Persaud, Patricia; P\u00e9rez-Campos, Xyoli; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/1dvwn-0sk89", "eprint_id": 34582, "eprint_status": "archive", "datestamp": "2023-08-22 09:06:41", "lastmod": "2023-10-19 20:45:13", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Yan-Z", "name": { "family": "Yan", "given": "Z." } }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "R. W." }, "orcid": "0000-0003-3323-3508" } ] }, "title": "Regional mapping of the crustal structure in southern California from receiver functions", "ispublished": "pub", "full_text_status": "public", "keywords": "crustal structure; Moho depth; southern California", "note": "\u00a9 2007 by the American Geophysical Union. Received 6 July 2006; revised 8 November 2006; accepted 16 January 2007; published 25 May 2007. We thank the Southern California Seismic\nNetwork and the Southern California Earthquake Data Center for providing the network data and the IRIS data center and Monica Kohler for providing the LARSE data. We would also like to thank the reviews by Associate Editor Rodolfo Console, Eugene Humphreys, and an anonymous reviewer\nfor the improvement of this manuscript. This research is partially support by USGS contract 04HQAG0010.\n\nPublished - Yan2007b.pdf
", "abstract": "Lateral variations of the crustal structure in southern California are determined from receiver function (RF) studies using data from the Southern California Seismic Network broadband stations and Los Angeles Regional Seismic Experiment surveys. The results include crustal thickness estimates at the stations themselves, and where possible, cross sections are drawn. The large-scale Moho depth variation pattern generally correlates well with the current status of the Mesozoic batholith: Deep Moho of 35\u201339 km is observed beneath the western Peninsula Ranges, Sierra Nevada, and San Bernardino Mountains, where the batholith is relatively intact, and shallow Moho of 26\u201332 km is observed in the Mojave Desert, where the batholith is highly deformed and disrupted. High-resolution lateral variations of the crustal structure for individual geographic provinces are investigated, and distinctive features are identified. The crustal structure is strongly heterogeneous beneath the central Transverse Ranges, and deep Moho of 36\u201339 km is locally observed beneath several station groups in the western San Gabriel Mountains. Moho is relatively flat and smooth beneath the western Mojave Desert but gets shallower and complicated to the east. Anomalous RFs are observed at two stations in the eastern Mojave Desert, where a Moho step of \u223c8\u201310 km is found between the NW and SE back-azimuthal groups of station DAN in the Fenner Valley. Asymmetric extension of the Salton Trough is inferred from the Moho geometry. Depth extension of several major faults, such as the San Andreas Fault and San Gabriel Fault, to the Moho is inferred.", "date": "2007-05-25", "date_type": "published", "publication": "Journal of Geophysical Research B", "volume": "112", "number": "B5", "publisher": "American Geophysical Union", "pagerange": "Art. No. B05311", "id_number": "CaltechAUTHORS:20121001-102205324", "issn": "0148-0227", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121001-102205324", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "USGS", "grant_number": "04HQAG0010" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1029/2006JB004622", "primary_object": { "basename": "Yan2007b.pdf", "url": "https://authors.library.caltech.edu/records/1dvwn-0sk89/files/Yan2007b.pdf" }, "resource_type": "article", "pub_year": "2007", "author_list": "Yan, Z. and Clayton, R. W." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/cjvsd-xah13", "eprint_id": 34579, "eprint_status": "archive", "datestamp": "2023-08-22 08:51:49", "lastmod": "2023-10-23 16:53:50", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Downey-N-J", "name": { "family": "Downey", "given": "Nathan J." } }, { "id": "Stock-J-M", "name": { "family": "Stock", "given": "Joann M." }, "orcid": "0000-0003-4816-7865" }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" }, { "id": "Cande-S-C", "name": { "family": "Cande", "given": "Steven C." } } ] }, "title": "History of the Cretaceous Osbourn spreading center", "ispublished": "pub", "full_text_status": "public", "keywords": "tectonics; Osbourn trough; Pacific", "note": "\u00a9 2007 by the American Geophysical Union. Received 7 June 2006; revised 5 October 2006; accepted 1 November 2006; published 6 April 2007. The Palmer cruises were supported by NSF grant OPP-0126334. Subsequent data analysis was supported by NSF grant\nOPP-0338317. We thank the Captain and crew of both the R/VIB Nathaniel B. Palmer and the R/V Kilo Moana. Brian Taylor provided us the opportunity to participate in, and use data from, cruise KM0413. We also thank Steve Miller for permission to use the COOK20 data. We thank Brian Taylor and an anonymous reviewer for insightful reviews that greatly improved this paper. California Institute of Technology Division of Geological and Planetary Sciences, contribution number 9148.\n\nPublished - Downey2007a.pdf
Erratum - Downey2007a_correction.pdf
", "abstract": "The Osbourn Trough is a fossil spreading center that rifted apart the Manihiki and Hikurangi Plateaus during Cretaceous time. Previous models of the Osbourn spreading center are based on data collected near the trough axis, and therefore only constrain the history of the Osbourn spreading center during the last few Ma of spreading. Our data set includes multibeam data collected northward to the Manihiki Plateau, allowing us to examine seafloor morphology created during the entire active period of the Osbourn spreading center, as well as several additional multibeam data sets that provide the opportunity to examine the relationship between the Osbourn paleospreading center and the Cretaceous Pacific-Phoenix ridge. The axial gravity of the trough is similar to the gravity found at other extinct slow-intermediate spreading rate ridges. Magnetic field measurements indicate that spreading at the trough ceased during Chron C34. Abyssal-hill trends indicate that spreading during the early history of the Osbourn spreading center occurred at 15\u00b0\u201320\u00b0. The east-west component of this spreading explains the modern east-west offset of the Manihiki and Hikurangi Plateaus. Spreading rotated to 2\u00b0\u20135\u00b0 prior to extinction. Abyssal-hill RMS amplitudes show that a decrease in spreading rate, from >7 cm/yr to 2\u20136 cm/yr full-spreading rate, occurred \u223c2\u20136 Ma prior to ridge extinction. Our data analysis is unable to determine the exact spreading rate of the Osbourn spreading center prior to the slowing event. The temporal constraints provided by our data show that the Osbourn spreading center ceased spreading prior to 87 Ma or 93 Ma, depending on whether the Manihiki and Hikurangi Plateaus rifted at 115 Ma or 121 Ma. Our model resolves the conflict between regional models of Osbourn spreading with models based on trough characteristics by showing that spreading at the Osbourn spreading center was decoupled from Pacific-Phoenix spreading.", "date": "2007-04-06", "date_type": "published", "publication": "Journal of Geophysical Research B", "volume": "112", "number": "B4", "publisher": "American Geophysical Union", "pagerange": "Art. No. B04102", "id_number": "CaltechAUTHORS:20121001-094812502", "issn": "0148-0227", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121001-094812502", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "OPP-0126334" }, { "agency": "NSF", "grant_number": "OPP-0338317" } ] }, "other_numbering_system": { "items": [ { "id": "9148", "name": "Caltech Division of Geological and Planetary Sciences" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1029/2006JB004550", "primary_object": { "basename": "Downey2007a_correction.pdf", "url": "https://authors.library.caltech.edu/records/cjvsd-xah13/files/Downey2007a_correction.pdf" }, "related_objects": [ { "basename": "Downey2007a.pdf", "url": "https://authors.library.caltech.edu/records/cjvsd-xah13/files/Downey2007a.pdf" } ], "resource_type": "article", "pub_year": "2007", "author_list": "Downey, Nathan J.; Stock, Joann M.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/kd6zs-53138", "eprint_id": 34583, "eprint_status": "archive", "datestamp": "2023-08-22 08:42:03", "lastmod": "2023-10-19 20:45:15", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Downey-N-J", "name": { "family": "Downey", "given": "Nathan J." } }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" } ] }, "title": "A ridgelet transform method for constraining tectonic models via abyssal-hill morphology", "ispublished": "pub", "full_text_status": "public", "keywords": "ridgelet transform; abyssal hills.", "note": "\u00a9 2007 by the American Geophysical Union.\nReceived 3 August 2006; accepted 8 December 2006; published 8 March 2007. \nNBP0304 was supported by NSF grant OPP-0126334.\nSubsequent data analysis was supported by NSF grant OPP-\n0338317. We thank John Goff and an anonymous reviewer for\ntheir thorough and insightful reviews of the manuscript. We\nalso thank J. Stock, S. Cande, and N. Smith-Downey for useful\ncomments. California Institute of Technology Division of\nGeological and Planetary Sciences, contribution 9153.\n\nPublished - Downey2007b.pdf
", "abstract": "Abyssal-hill shape and orientation are related to the direction and spreading rate of paleo-spreading centers. Therefore analyzing abyssal-hill shape and trend is useful for constraining tectonic models of regions devoid of magnetic reversal anomalies. Detecting systematic changes of abyssal-hill shapes or trends, due to changes in spreading rate or direction, is not straightforward, which makes it difficult to determine appropriate regions over which to average abyssal-hill parameters. Often, however, detecting these systematic changes, where they occur, and the scale over which they occur, is of primary importance for tectonic reconstructions. We present a new method of abyssal-hill analysis that is based on the ridgelet transform, a relative of the two-dimensional wavelet transform. Our method is capable of locally estimating the width, azimuth, and root-mean-square (RMS) amplitude of abyssal-hill fabric and highlights changes in these parameters across a survey area, making it possible to identify regions created with a constant spreading rate and direction. We use three multibeam swaths, one crossing the Osbourn Trough in the southwest Pacific Basin, one crossing the East Pacific Rise, and one crossing the Mid-Atlantic Ridge, to demonstrate the utility and performance of our method.", "date": "2007-03-08", "date_type": "published", "publication": "Geochemistry, Geophysics, Geosystems", "volume": "8", "publisher": "American Geophysical Union", "pagerange": "Art. No. Q03004", "id_number": "CaltechAUTHORS:20121001-102934144", "issn": "1525-2027", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121001-102934144", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "OPP-0126334" }, { "agency": "NSF", "grant_number": "OPP-0338317" } ] }, "other_numbering_system": { "items": [ { "id": "9153", "name": "Caltech Division of Geological and Planetary Sciences" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1029/2006GC001440", "primary_object": { "basename": "Downey2007b.pdf", "url": "https://authors.library.caltech.edu/records/kd6zs-53138/files/Downey2007b.pdf" }, "resource_type": "article", "pub_year": "2007", "author_list": "Downey, Nathan J. and Clayton, Robert W." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/hc6m6-a7477", "eprint_id": 34586, "eprint_status": "archive", "datestamp": "2023-08-22 03:50:26", "lastmod": "2023-10-19 20:45:23", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Eisner-L", "name": { "family": "Eisner", "given": "L." } }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "R. W." }, "orcid": "0000-0003-3323-3508" } ] }, "title": "Simulating strong ground motion from complex sources by reciprocal Green functions", "ispublished": "pub", "full_text_status": "restricted", "keywords": "full waveform modeling; seismic hazard; finite source; rupture propagation; hazard assessment; finite difference; Los Angeles Basin", "note": "\u00a9 2005 StudiaGeo s.r.o., Prague. Received: April 22, 2003; Revised: January 15, 2005; Accepted: April 19, 2005.\nThe authors would like to thank Hiroo Kanamori, Tom Heaton, Ned Field,\nJi\u0159\u00ed Zahradn\u00edk and three anonymous reviewers and the associate editor for their valuable suggestions\nand discussion during the study. Many of the figures were made with GMT (Wessel and Smith,\n1991). This research was supported by the Southern California Earthquake Center. SCEC is funded\nby NSF Cooperative Agreement EAR-8920136 and USGS Cooperative Agreements\n14-08-0001-A0899 and 1434-HQ-97AG01718. The SCEC contribution number for this paper is\n558. Contribution number 8821 from the Division of Geological and Planetary Sciences, California\nInstitute of Technology.", "abstract": "We have developed a method to calculate site and path effects for complex heterogeneous media using synthetic Green's functions. The Green's functions are calculated numerically by imposing body forces at the site of interest and then storing the reciprocal Green's functions along arbitrary finite-fault surfaces. By using reciprocal Green's functions, we can then simulate many source scenarios for those faults because the primary numerical calculations need be done only once. The advantage of the proposed method is shown by evaluation of the site and path effects for three sites in the vicinity of the Los Angeles basin using the Southern California Velocity Model (version 2.2, Magistrale et al., 2000). In this example, we have simulated 300 source scenarios for 5 major southern California faults and compared their responses for period longer then 3 seconds at the selected sites. However, a more detailed comparison with strong motion records will be necessary before a particular hazard assessment can be made. For the tested source scenarios the results show that the variations in the peak velocity amplitudes and durations due to a source scenarios are as large as variations due to a heterogeneous velocity model.", "date": "2005-07", "date_type": "published", "publication": "Studia Geophysica et Geodaetica", "volume": "49", "number": "3", "publisher": "Springer", "pagerange": "323-342", "id_number": "CaltechAUTHORS:20121001-104059099", "issn": "0039-3169", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121001-104059099", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Southern California Earthquake Center (SCEC)" }, { "agency": "NSF", "grant_number": "EAR-8920136" }, { "agency": "USGS", "grant_number": "14-08-0001-A0899" }, { "agency": "USGS", "grant_number": "1434-HQ-97AG01718" } ] }, "other_numbering_system": { "items": [ { "id": "8821", "name": "Caltech Division of Geological and Planetary Sciences" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1007/s11200-005-0013-5", "resource_type": "article", "pub_year": "2005", "author_list": "Eisner, L. and Clayton, R. W." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/mhhqp-zyc64", "eprint_id": 34584, "eprint_status": "archive", "datestamp": "2023-08-19 15:34:37", "lastmod": "2023-10-19 20:45:18", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Baker-T", "name": { "family": "Baker", "given": "Teresa" } }, { "id": "Granat-R", "name": { "family": "Granat", "given": "Robert" } }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" } ] }, "title": "Real-time Earthquake Location Using Kirchhoff Reconstruction", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 2005 by the Seismological Society of America.\nManuscript received 4 October 2004.\nThis research was carried out at the Jet Propulsion Laboratory, California\nInstitute of Technology, under a contract with the National Aeronautics\nand Space Administration.\n\nPublished - Baker2005.pdf
", "abstract": "Real-time location of earthquakes can be achieved by using direct imaging of the recorded wave field based on a Kirchhoff reconstruction method similar to that used in the migration of seismic reflection data. The standard method of event location requires the wave arrival at each sensor to be picked and associated with an event. By using direct imaging, the event is identified once in the imaged wave field. The computation is independent of the level of seismic activity and can be carried out on a typical desktop computer. The procedure has been successfully demonstrated in two and three dimensions using data from the Southern California Seismic Network (Trinet). At higher resolutions, the reconstruction method can identify finite source effects. Further work considers extending the method by implementing full elastic theory and solving for moment tensors at all locations in the mesh.", "date": "2005-04", "date_type": "published", "publication": "Bulletin of the Seismological Society of America", "volume": "95", "number": "2", "publisher": "Seismological Society of America", "pagerange": "699-707", "id_number": "CaltechAUTHORS:20121001-103708838", "issn": "0037-1106", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121001-103708838", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1785/0120040123", "primary_object": { "basename": "Baker2005.pdf", "url": "https://authors.library.caltech.edu/records/mhhqp-zyc64/files/Baker2005.pdf" }, "resource_type": "article", "pub_year": "2005", "author_list": "Baker, Teresa; Granat, Robert; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/wy52y-1vg65", "eprint_id": 20885, "eprint_status": "archive", "datestamp": "2023-08-22 03:06:55", "lastmod": "2023-10-20 23:33:46", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Yan-Zhimei", "name": { "family": "Yan", "given": "Zhimei" } }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" }, { "id": "Saleeby-J-B", "name": { "family": "Saleeby", "given": "Jason" } } ] }, "title": "Seismic refraction evidence for steep faults cutting highly attenuated continental basement in the central Transverse ranges, California", "ispublished": "pub", "full_text_status": "public", "keywords": "central Transverse ranges; crustal structure; finite-difference methods; LARSE II; steep faults", "note": "\u00a9 2005 RAS.\n\nArticle first published online: 24 Jan. 2005.\nAccepted 2004 September 30. Received 2003 September 13; in original form.\n\n\nWe thank the many volunteers who helped with the LARSE II experiment. We would like to thank Jascha Polet, Vala Hjorleifsdottir and Javier Favela for their reviews and comments. Helpful reviews by Walter Mooney and an anonymous referee are gratefully acknowledged. This research was supported by the Southern California Earthquake Center (SCEC). The SCEC is funded by NSF Cooperative Agreement EAR-0106924 and USGS Cooperative Agreement 02HQAG0008. This paper is SCEC contribution no. 736 and the Division of Geological and Planetary Sciences, Caltech, contribution no. 8972. JS acknowledges support under NSF grant EAR-0087347.\n\nPublished - Saleeby_GJI2005.pdf
", "abstract": "A 2-D upper crustal structural profile with seven steeply dipping faults was constructed from the Los Angeles Region Seismic Experiment phase II (LARSE II) seismic refraction data recorded over the north central Transverse ranges and adjacent Mojave desert in southern California. The profile extends to a depth of approximately 4 km. The faults were identified from distinctive features in the seismic first arrival data, while the velocity structure was determined from travel times and refined by forward modelling. The resulting seismic velocity structure is correlative to the geological structure along the profile and is used to help constrain a geological cross-section. Six of the seven faults detected from the seismic data correspond directly to geologically mapped faults in the central Transverse ranges and adjacent Mojave desert. From south to north, they are the Pelona fault, the San Francisquito fault, the Clearwater fault, the San Andreas fault and two faults that cut the Portal ridge. The seventh fault is buried beneath Quaternary deposits of the western Mojave desert and appears to correlate with an additional fault that cuts Portal ridge out of the section line. The southernmost fault (the Pelona fault) separates the younger Vasquez formation in the south from the Pelona schist in the north and is determined to be an intermediate (40\u00b0\u201360\u00b0) south-dipping normal fault. This coupled with field observations indicate that the Pelona fault was instrumental in the late Oligocene\u2014early Miocene formation of the Soledad basin, and the structural ascent and exhumation of the Pelona schist along the proto-Sierra Pelona intrabasin ridge. Analogous Neogene extensional deformation is found to have affected the western Mojave desert region, where faults 6 and 7 appear to have had north side down normal displacement and to have been instrumental in forming the western Antelope basin. A 6.0 km s\u22121 basal layer to our shallow seismic structure is correlated with the Pelona schist south of the San Andreas fault and with the tectonically related Rand schist beneath the western Mojave desert. Granitic and gneissic crystalline rocks, which form regional upper plate complexes along the Vincent thrust above the Pelona schist and along the Rand thrust above the Rand schist, yield consistently low seismic velocities as compared with the expected velocities for the constituent rock types. These anomalous velocities are reconciled by the degraded structural and textural state of the upper plate crystalline rocks that resulted from extreme shearing, brittle fracturing and related retrogressive hydration reactions starting during or shortly after the latest Cretaceous\u2014early Palaeocene underthrusting of the schists. Extension, translation along the San Andreas transform system and compressional faulting with the uplift of the Transverse ranges further accentuated the basement deformations. The integrated result is that the survival of the Precambrian through Mesozoic granitic crust of the region became a rootless and highly attenuated upper crustal layer.", "date": "2005-02", "date_type": "published", "publication": "Geophysical Journal International", "volume": "160", "number": "2", "publisher": "Royal Astronomical Society", "pagerange": "651-666", "id_number": "CaltechAUTHORS:20101118-103455200", "issn": "0956-540X", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20101118-103455200", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Southern California Earthquake Center (SCEC)" }, { "agency": "NSF", "grant_number": "EAR-0106924" }, { "agency": "USGS", "grant_number": "02HQAG0008" }, { "agency": "NSF", "grant_number": "EAR-0087347" } ] }, "other_numbering_system": { "items": [ { "id": "736", "name": "Southern California Earthquake Center (SCEC)" } ] }, "local_group": { "items": [ { "id": "Caltech-Tectonics-Observatory" }, { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1111/j.1365-246X.2005.02506.x", "primary_object": { "basename": "Saleeby_GJI2005.pdf", "url": "https://authors.library.caltech.edu/records/wy52y-1vg65/files/Saleeby_GJI2005.pdf" }, "resource_type": "article", "pub_year": "2005", "author_list": "Yan, Zhimei; Clayton, Robert W.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/4ajqw-y5053", "eprint_id": 34596, "eprint_status": "archive", "datestamp": "2023-08-19 13:20:04", "lastmod": "2023-10-19 20:45:59", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Lutter-W-J", "name": { "family": "Lutter", "given": "W. J." } }, { "id": "Fuis-G-S", "name": { "family": "Fuis", "given": "G. S." } }, { "id": "Ryberg-T", "name": { "family": "Ryberg", "given": "T." } }, { "id": "Okaya-D-A", "name": { "family": "Okaya", "given": "D. A." } }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "R. W." }, "orcid": "0000-0003-3323-3508" }, { "id": "Davis-P-M", "name": { "family": "Davis", "given": "P. M." } }, { "id": "Prodehl-C", "name": { "family": "Prodehl", "given": "C." } }, { "id": "Murphy-J-M", "name": { "family": "Murphy", "given": "J. M." } }, { "id": "Langenheim-V-E", "name": { "family": "Langenheim", "given": "V. E." } }, { "id": "Benthien-M-L", "name": { "family": "Benthien", "given": "M. L." } }, { "id": "Godfrey-N-J", "name": { "family": "Godfrey", "given": "N. J." } }, { "id": "Christensen-N-I", "name": { "family": "Christensen", "given": "N. I." } }, { "id": "Thygesen-K", "name": { "family": "Thygesen", "given": "K." } }, { "id": "Thurber-C-H", "name": { "family": "Thurber", "given": "C. H." } }, { "id": "Simila-G-W", "name": { "family": "Simila", "given": "G." } }, { "id": "Keller-G-R", "name": { "family": "Keller", "given": "G. R." } } ] }, "title": "Upper Crustal Structure from the Santa Monica Mountains to the Sierra Nevada, Southern California: Tomographic Results from the Los Angeles Regional Seismic Experiment, Phase II (LARSE II)", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 2004 by the Seismological Society of America. Manuscript received 24 March 2003. This research was supported by the U.S. Geological Survey, Department of the Interior (USGS Cooperative Agreement 00HQGR0053 and USGS internal funds), National Science Foundation (NSF Cooperative\nAgreement EAR-97-25413), Southern California Earthquake Center (SCEC,\nwhich is funded by NSF Cooperative Agreements EAR 8920136 and USGS\nCooperative Agreements 14-08-0001-A0899 and 1434-HQ-97AG01718), Deutsche Forschungsgemeinschaft, and GeoForschungsZentrum Potsdam,\nGermany. The views and conclusions contained in this document are those\nof the authors and should not be interpreted as necessarily representing the\nofficial policies, either expressed or implied, of the U.S. government. Instruments\nwere supplied by IRIS/PASSCAL, University of Texas El Paso,\nGeophysical Instrument Pool Potsdam, Canadian Geological Survey, University\nof Copenhagen, SCEC, and the USGS. The SCEC Contribution Number\nfor this paper is 677. The facilities of the IRIS Consortium are supported\nby the National Science Foundation under Cooperative Agreement EAR-\n0004370. We are indebted to many government agencies, organizations,\ncompanies, and private individuals who granted permission and, in many\ncases, vital assistance to LARSE II (see table 3 in Fuis et al., 2001a). This\nmanuscript benefited from reviews by Tom Brocher, Andy Michael, and\nEgill Hauksson.\n\nPublished - Lutter2004.pdf
", "abstract": "In 1999, the U.S. Geological Survey and the Southern California Earthquake Center (SCEC) collected refraction and low-fold reflection data along a 150-km-long corridor extending from the Santa Monica Mountains northward to the Sierra Nevada. This profile was part of the second phase of the Los Angeles Region Seismic Experiment (LARSE II). Chief imaging targets included sedimentary basins beneath the San Fernando and Santa Clarita Valleys and the deep structure of major faults along the transect, including causative faults for the 1971 M 6.7 San Fernando and 1994 M 6.7 Northridge earthquakes, the San Gabriel Fault, and the San Andreas Fault. Tomographic modeling of first arrivals using the methods of Hole (1992) and Lutter et al. (1999) produces velocity models that are similar to each other and are well resolved to depths of 5-7.5 km. These models, together with oil-test well data and independent forward modeling of LARSE II refraction data, suggest that regions of relatively low velocity and high velocity gradient in the San Fernando Valley and the northern Santa Clarita Valley (north of the San Gabriel Fault) correspond to Cenozoic sedimentary basin fill and reach maximum depths along the profile of \u223c4.3 km and >3 km, respectively. The Antelope Valley, within the western Mojave Desert, is also underlain by low-velocity, high-gradient sedimentary fill to an interpreted maximum depth of \u223c2.4 km. Below depths of \u223c2 km, velocities of basement rocks in the Santa Monica Mountains and the central Transverse Ranges vary between 5.5 and 6.0 km/sec, but in the Mojave Desert, basement rocks vary in velocity between 5.25 and 6.25 km/sec. The San Andreas Fault separates differing velocity structures of the central Transverse Ranges and Mojave Desert. A weak low-velocity zone is centered approximately on the north-dipping aftershock zone of the 1971 San Fernando earthquake and possibly along the deep projection of the San Gabriel Fault. Modeling of gravity data, using densities inferred from the velocity model, indicates that different velocity-density relationships hold for both sedimentary and basement rocks as one crosses the San Andreas Fault. The LARSE II velocity model can now be used to improve the SCEC Community Velocity Model, which is used to calculate seismic amplitudes for large scenario earthquakes.", "date": "2004-04", "date_type": "published", "publication": "Bulletin of the Seismological Society of America", "volume": "94", "number": "2", "publisher": "Seismological Society of America", "pagerange": "619-632", "id_number": "CaltechAUTHORS:20121001-131459133", "issn": "0037-1106", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121001-131459133", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "USGS", "grant_number": "00HQGR0053" }, { "agency": "USGS Internal Funds" }, { "agency": "NSF", "grant_number": "EAR-97-25413" }, { "agency": "Southern California Earthquake Center (SCEC)" }, { "agency": "NSF", "grant_number": "EAR-8920136" }, { "agency": "USGS", "grant_number": "14-08-0001-A0899" }, { "agency": "USGS", "grant_number": "1434-HQ-97AG01718" }, { "agency": "Deutsche Forschungsgemeinschaft (DFG)" }, { "agency": "GeoForschungsZentrum" }, { "agency": "NSF", "grant_number": "EAR-0004370" } ] }, "other_numbering_system": { "items": [ { "id": "677", "name": "Southern California Earthquake Center (SCEC)" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1785/0120030058", "primary_object": { "basename": "Lutter2004.pdf", "url": "https://authors.library.caltech.edu/records/4ajqw-y5053/files/Lutter2004.pdf" }, "resource_type": "article", "pub_year": "2004", "author_list": "Lutter, W. J.; Fuis, G. S.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/25ywg-s2v57", "eprint_id": 34588, "eprint_status": "archive", "datestamp": "2023-08-19 11:54:14", "lastmod": "2023-10-19 20:45:29", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Nazareth-J-J", "name": { "family": "Nazareth", "given": "Julie J." } }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" } ] }, "title": "Crustal structure of the Borderland-Continent Transition Zone of southern California adjacent to Los Angeles", "ispublished": "pub", "full_text_status": "public", "keywords": "California Borderland, LARSE, transition zone, slab", "note": "\u00a9 2003 by the American Geophysical Union. Received 31 July 2000; revised 16 May 2002; accepted 11 February 2003; published 30 August 2003. We are grateful to Jeanne Hardebeck, Egill Hauksson, and Patricia Persaud for their reviews of an earlier version of this manuscript. Reviews by Robert Hawman, David Okaya, an anonymous reviewer, and the Associate Editor led to a greatly improved manuscript. We thank Collin Zelt for the use of his program XTRAMP. The map was created with GMT software [Wessel and Smith, 1991]. This work was supported by the Southern California Earthquake Center, which was funded\nby NSF Cooperative Agreement EAR-8920136 and USGS Cooperative Agreements 14-08-0001-A0899 and 1434-HQ-97AG01718. SCEC contribution 445. Contribution 8925, Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena.\n\nPublished - Nazareth2003.pdf
", "abstract": "We use data from the onshore-offshore component of Los Angeles Region Seismic Experiment (LARSE) to model the broad-scale features of the midcrust to upper mantle beneath a north-south transect that spans the continental borderland in the Los Angeles, California, region. We have developed an analysis method for wide-angle seismic data that consists primarily of refractions, lacks near-offset recordings, and contains wide gaps in coverage. Although the data restrict the analysis to the modeling of broad-scale structure, the technique allows one to explore the limits of the data and determine the resolving power of the data set. The resulting composite velocity model constrains the crustal thickness and location and width of the continent-Borderland transition zone. We find that the mid to lower crust layer velocities of the Inner Borderland are slightly lower than the corresponding layers in the average southern California crust model, while the upper mantle velocity is significantly higher. The data require the Moho to deepen significantly to the north. We constrain the transition zone to initiate between the offshore slope and the southwest Los Angeles Basin. If the Inner Borderland crust is 22 km thick, then the transition zone is constrained to initiate within a 2 km wide region beneath the southwest Los Angeles Basin, and have a width of 20\u201325 km. The strong, coherent, and continuous Pn phase suggests the Moho is coherent and laterally continuous beneath the Inner Borderland and transition zone. The Inner California Borderland seems to be modified and thickened oceanic crust, with the oceanic upper mantle intact beneath it.", "date": "2003-08-30", "date_type": "published", "publication": "Journal of Geophysical Research B", "volume": "108", "number": "B8", "publisher": "American Geophysical Union", "pagerange": "Art. No. 2404", "id_number": "CaltechAUTHORS:20121001-104758862", "issn": "0148-0227", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121001-104758862", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Southern California Earthquake Center (SCEC)" }, { "agency": "NSF", "grant_number": "EAR-8920136" }, { "agency": "USGS", "grant_number": "14-08-0001-A0899" }, { "agency": "USGS", "grant_number": "1434-HQ-97AG01718" } ] }, "other_numbering_system": { "items": [ { "id": "8925", "name": "Caltech Division of Geological and Planetary Sciences" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1029/2001JB000223", "primary_object": { "basename": "Nazareth2003.pdf", "url": "https://authors.library.caltech.edu/records/25ywg-s2v57/files/Nazareth2003.pdf" }, "resource_type": "article", "pub_year": "2003", "author_list": "Nazareth, Julie J. and Clayton, Robert W." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/tcw3t-kwf34", "eprint_id": 34599, "eprint_status": "archive", "datestamp": "2023-08-19 11:15:16", "lastmod": "2023-10-19 20:46:10", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Kohler-M-D", "name": { "family": "Kohler", "given": "M. D." } }, { "id": "Magistrale-H-W", "name": { "family": "Magistrale", "given": "H." } }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "R. W." }, "orcid": "0000-0003-3323-3508" } ] }, "title": "Mantle Heterogeneities and the SCEC Reference Three-Dimensional Seismic Velocity Model Version 3", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 2003 by the Seismological Society of America.\n\nManuscript received 12 January 2002.\nThe LARSE and LABPSE experiments were made possible by the loan\nof SCEC Portable Broadband Instrument Center and IRIS PASSCAL seismometers,\nand the support of their staffs. We thank Ken Dueker for providing\nthe large compilation of Southern California Seismic Network P-wave\ntravel-time residual data. This research was supported by the Southern California Earthquake Center. SCEC is funded by NSF Cooperative Agreement\nEAR-8920136 and USGS Cooperative Agreements 14-08-0001-\nA0899 and 1434-HQ-97AG01718. The SCEC Contribution Number for this\narticle is 630.\n\nPublished - Kohler2003.pdf
", "abstract": "We determine upper mantle seismic velocity heterogeneities below Southern California from the inversion of teleseismic travel-time residuals. Teleseismic P-wave arrival times are obtained from three temporary passive experiments and Southern California Seismic Network (SCSN) stations, producing good raypath coverage. The inversion is performed using a damped least-squares conjugate gradient method (LSQR). The inversion model element spacing is 20 km. Before the inversion, the effects of crustal velocity heterogeneities represented by the Southern California Earthquake Center (SCEC) seismic velocity model version 2 are removed from the teleseismic travel times. The P-wave inversion produces a variance reduction of 43%. S-wave velocities are determined from laboratory Vp/Vs ratios. The most prominent features imaged in the results are high P-wave velocities (+3%) in the uppermost mantle beneath the northern Los Angeles basin, and the previously reported tabular high-velocity anomaly (+3%) to depths of 200 km beneath the Transverse Ranges, crosscutting the San Andreas fault. We incorporate the upper mantle seismic velocity heterogeneities into the SCEC Southern California reference seismic velocity model. The prior accounting for the crustal velocity heterogeneity demonstrates the utility of the top-down method of the SCEC seismic velocity model development.", "date": "2003-04", "date_type": "published", "publication": "Bulletin of the Seismological Society of America", "volume": "93", "number": "2", "publisher": "Seismological Society of America", "pagerange": "757-774", "id_number": "CaltechAUTHORS:20121001-141154836", "issn": "0037-1106", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121001-141154836", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Southern California Earthquake Center (SCEC)" }, { "agency": "NSF", "grant_number": "EAR-8920136" }, { "agency": "USGS", "grant_number": "14-08-0001-A0899" }, { "agency": "USGS", "grant_number": "1434-HQ-97AG01718" } ] }, "other_numbering_system": { "items": [ { "id": "630", "name": "Southern California Earthquake Center (SCEC)" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1785/0120020017", "primary_object": { "basename": "Kohler2003.pdf", "url": "https://authors.library.caltech.edu/records/tcw3t-kwf34/files/Kohler2003.pdf" }, "resource_type": "article", "pub_year": "2003", "author_list": "Kohler, M. D.; Magistrale, H.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/ccmwe-q7b97", "eprint_id": 34597, "eprint_status": "archive", "datestamp": "2023-08-22 00:11:33", "lastmod": "2023-10-19 20:46:01", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Fuis-G-S", "name": { "family": "Fuis", "given": "Gary S." } }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" }, { "id": "Davis-P-M", "name": { "family": "Davis", "given": "Paul M." } }, { "id": "Ryberg-T", "name": { "family": "Ryberg", "given": "Trond" } }, { "id": "Lutter-W-J", "name": { "family": "Lutter", "given": "William J." } }, { "id": "Okaya-David-A", "name": { "family": "Okaya", "given": "David A." } }, { "id": "Hauksson-E", "name": { "family": "Hauksson", "given": "Egill" }, "orcid": "0000-0002-6834-5051" }, { "id": "Prodehl-C", "name": { "family": "Prodehl", "given": "Claus" } }, { "id": "Murphy-J-M", "name": { "family": "Murphy", "given": "Janice M." } }, { "id": "Benthien-M-L", "name": { "family": "Benthien", "given": "Mark L." } }, { "id": "Baher-S-A", "name": { "family": "Baher", "given": "Shirley A." } }, { "id": "Kohler-M-D", "name": { "family": "Kohler", "given": "Monica D." } }, { "id": "Thygesen-K", "name": { "family": "Thygesen", "given": "Kristina" } }, { "id": "Simila-G-W", "name": { "family": "Simila", "given": "Gerry" } }, { "id": "Keller-G-R", "name": { "family": "Keller", "given": "G. Randy" } } ] }, "title": "Fault systems of the 1971 San Fernando and 1994 Northridge earthquakes, southern California: Relocated aftershocks and seismic images from LARSE II", "ispublished": "pub", "full_text_status": "restricted", "keywords": "crustal structure; tectonics; earthquakes; seismic imaging; southern California", "note": "\u00a9 2003 Geological Society of America. \n\nManuscript received 25 March 2002; Revised manuscript received 2 October 2002; Manuscript accepted 3 October 2002. \n\nWe are indebted to many government agencies, organizations, companies, and private individuals who granted permission and, in many cases, vital assistance to LARSE II (see Table 3 in Fuis et al., 2001a). This research was supported by the U.S. Geological Survey (USGS Cooperative Agreement 00HQGR0076 and internal funds), the National Science Foundation (NSF Cooperative Agreement EAR-97-25413), the Southern California Earthquake Center (SCEC, which is funded by NSF Cooperative Agreements EAR-8920136 and USGS Cooperative Agreements 14-08-0001-A0899 and 1434-HQ-97AG01718), the Deutsche Forschungsgemeinschaft, and the GeoForschungsZentrum, Potsdam, Germany. Instruments were supplied by IRIS/ PASSCAL, University of Texas, El Paso, Geophysical Instrument Pool, Potsdam, Canadian Geological Survey, Copenhagen University, SCEC, and USGS. This is SCEC contribution 665. Reviews by Bill Ellsworth, Rufus Catchings, and Dave Wald substantially improved this paper, as did discussions with Jim Mechie, Tom Hanks, and Keith Richards-Dinger.", "abstract": "We have constructed a composite image of the fault systems of the M 6.7 San Fernando (1971) and Northridge (1994), California, earthquakes, using industry reflection and oil test well data in the upper few kilometers of the crust, relocated aftershocks in the seismogenic crust, and LARSE II (Los Angeles Region Seismic Experiment, Phase II) reflection data in the middle and lower crust. In this image, the San Fernando fault system appears to consist of a decollement that extends 50 km northward at a dip of \u223c25\u00b0 from near the surface at the Northridge Hills fault, in the northern San Fernando Valley, to the San Andreas fault in the middle to lower crust. It follows a prominent aseismic reflective zone below and northward of the main-shock hypocenter. Interpreted upward splays off this decollement include the Mission Hills and San Gabriel faults and the two main rupture planes of the San Fernando earthquake, which appear to divide the hanging wall into shingle- or wedge-like blocks. In contrast, the fault system for the Northridge earthquake appears simple, at least east of the LARSE II transect, consisting of a fault that extends 20 km southward at a dip of \u223c33\u00b0 from \u223c7 km depth beneath the Santa Susana Mountains, where it abuts the interpreted San Fernando decollement, to \u223c20 km depth beneath the Santa Monica Mountains. It follows a weak aseismic reflective zone below and southward of the main-shock hypocenter. The middle crustal reflective zone along the interpreted San Fernando decollement appears similar to a reflective zone imaged beneath the San Gabriel Mountains along the LARSE I transect, to the east, in that it appears to connect major reverse or thrust faults in the Los Angeles region to the San Andreas fault. However, it differs in having a moderate versus a gentle dip and in containing no mid-crustal bright reflections.", "date": "2003-02", "date_type": "published", "publication": "Geology", "volume": "31", "number": "2", "publisher": "Geological Society of America", "pagerange": "171-174", "id_number": "CaltechAUTHORS:20121001-133438812", "issn": "0091-7613", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121001-133438812", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "USGS", "grant_number": "00HQGR0076" }, { "agency": "USGS Internal Funds" }, { "agency": "NSF", "grant_number": "EAR-97-25413" }, { "agency": "Southern California Earthquake Center (SCEC)" }, { "agency": "NSF", "grant_number": "EAR-8920136" }, { "agency": "USGS", "grant_number": "14-08-0001-A0899" }, { "agency": "USGS", "grant_number": "1434-HQ-97AG01718" }, { "agency": "Deutsche Forschungsgemeinschaft (DFG)" }, { "agency": "GeoForschungsZentrum" } ] }, "other_numbering_system": { "items": [ { "id": "665", "name": "Southern California Earthquake Center (SCEC)" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1130/0091-7613(2003)031<0171:FSOTSF>2.0.CO;2", "resource_type": "article", "pub_year": "2003", "author_list": "Fuis, Gary S.; Clayton, Robert W.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/zbhar-an912", "eprint_id": 91354, "eprint_status": "archive", "datestamp": "2023-08-19 10:53:25", "lastmod": "2023-10-19 22:26:19", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Trampert-J", "name": { "family": "Trampert", "given": "Jeannot" } }, { "id": "Paulssen-H", "name": { "family": "Paulssen", "given": "Hanneke" } }, { "id": "Van-Wettum-A", "name": { "family": "Van Wettum", "given": "Arie" } }, { "id": "Ritsema-J", "name": { "family": "Ritsema", "given": "Jeroen" } }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert" }, "orcid": "0000-0003-3323-3508" }, { "id": "Castro-R-R", "name": { "family": "Castro", "given": "Ra\u00fal" } }, { "id": "Rebollar-C", "name": { "family": "Rebollar", "given": "Cecilio" } }, { "id": "Perez-Vertiti-A", "name": { "family": "Perez-Vertiti", "given": "Arturo" } } ] }, "title": "New array monitors seismic activity near the Gulf of California in Mexico", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 2003 American Geophysical Union. \n\nWe are grateful to IRIS DMC for agreeing to archive and distribute our continuous waveform data. Funding for this project was provided by Utrecht University, the Dutch National Science Foundation (grant number NWO-GOA-750.396.01), and the U.S. National Science Foundation (grant number EAR-0111650 of the MARGINS program). Maintenance of CICESE broadband stations is partly funded by CONACYT project 37038-T. We thank the instrumental group in the physics faculty of Utrecht University for help in the design and building of the new NARS data logger. We thank the RESNOM and RANM groups in CICESE's department of seismology for helping to install the stations. We also gratefully acknowledge the participation of Antonio Mendoza and Luis Inzunza.\n\nPublished - Trampert_et_al-2003-Eos_2C_Transactions_American_Geophysical_Union.pdf
", "abstract": "The Gulf of California rift forms a geologically young and active plate boundary that links the San Andreas strike\u2010slip fault system in California to the oceanic spreading system of the East Pacific Rise. Although this is a classical example of a transform\u2010rift plate boundary, the tectonic evolution of the Gulf of California and surrounding regions is complex and poorly understood due to a lack of geological and geophysical data. In 2002, the Network of Autonomously Recording Seismographs(NARS)\u2010Baja network was installed.lt consists of 19 broadband seismic stations deployed in the Baja\u2010California and Sonora provinces of Mexico (Figure 1). Since NARS\u2010Baja surrounds the Gulf of California rift system, it is ideal for constraining earthquake faulting processes and the crust\u2010mantle structure of the region. Moreover, NARS\u2010Baja, in combination with permanent Mexican and U.S. arrays, forms a unique linear array in excess of 4000 km that should lend itself ideally to seismological studies of the North American\u2010Pacific plate boundary on a larger scale. NARS\u2010Baja is planned to operate for at least 5 years. To promote involvement from the entire research community the data collected from the stations will be made available immediately following routine data quality checks.", "date": "2003-01-28", "date_type": "published", "publication": "Eos", "volume": "84", "number": "4", "publisher": "American Geophysical Union", "pagerange": "29-32", "id_number": "CaltechAUTHORS:20181130-094433823", "issn": "0096-3941", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20181130-094433823", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Utrecht University" }, { "agency": "Nederlandse Organisatie voor Wetenschappelijk Onderzoek (NWO)", "grant_number": "NWO-GOA-750.396" }, { "agency": "NSF", "grant_number": "EAR-0111650" }, { "agency": "Consejo Nacional de Ciencia y Tecnolog\u00eda (CONACYT)", "grant_number": "37038-T" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1029/2003eo040002", "primary_object": { "basename": "Trampert_et_al-2003-Eos_2C_Transactions_American_Geophysical_Union.pdf", "url": "https://authors.library.caltech.edu/records/zbhar-an912/files/Trampert_et_al-2003-Eos_2C_Transactions_American_Geophysical_Union.pdf" }, "resource_type": "article", "pub_year": "2003", "author_list": "Trampert, Jeannot; Paulssen, Hanneke; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/tshs2-ae515", "eprint_id": 34653, "eprint_status": "archive", "datestamp": "2023-08-19 09:42:39", "lastmod": "2023-10-19 21:21:26", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Eisner-L", "name": { "family": "Eisner", "given": "Leo" } }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" } ] }, "title": "A Full Waveform Test of the Southern California Velocity Model by the Reciprocity Method", "ispublished": "pub", "full_text_status": "restricted", "keywords": "Reciprocity, Southern California, finite difference, velocity model", "note": "\u00a9 2002 Birkh\u00e4user Verlag, Basel. Received March 3, 2001, revised February 5, 2001, accepted August 28, 2001.\nThe authors would like to thank the reviewer Harold Magistrale and the two\nanonymous reviewers for their valuable suggestions. Special thanks go to Jascha\nPolet and Dr. Donald Helmberger for their input. Many of the figures were made\nwith GMT (WESSEL and SMITH, 1991). This research was supported by the Southern California Earthquake Center. SCEC is funded by NSF Cooperative Agreement\nEAR-8920136 and USGS Cooperative Agreements 14-08-0001-A0899 and 1434-HQ-97AG01718. The SCEC contribution number for this paper is 525.", "abstract": "We apply the reciprocity method (EISNER and CLAYTON, 2001a) to compare the full\nwaveform synthetic seismograms with a large number of observed seismograms. The reciprocity method\nused in the finite-difference modeling allows for the use of high quality data observed from the earthquakes\ndistributed over the wide range of azimuths and depths. We have developed a methodology to facilitate the\ncomparison between data and synthetics using a set of attributes to characterize the seismograms. These\nattributes are maximum amplitude, time delay and coda decay of the magnitude of the displacement\nvector. For the Southern California Velocity Model, Version 1 (MAGISTRALE et al., 1996), we have found\nmisfits between data and synthetics for paths traveling outside of the sedimentary basins and the western\npart of the Los Angeles and San Fernando basins.", "date": "2002-07", "date_type": "published", "publication": "Pure and Applied Geophysics", "volume": "159", "number": "7-8", "publisher": "Springer", "pagerange": "1691-1706", "id_number": "CaltechAUTHORS:20121003-092254866", "issn": "0033-4553", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121003-092254866", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Southern California Earthquake Center (SCEC)" }, { "agency": "NSF", "grant_number": "EAR-8920136" }, { "agency": "USGS", "grant_number": "14-08-0001-A0899" }, { "agency": "USGS", "grant_number": "1434-HQ-97AG01718" } ] }, "other_numbering_system": { "items": [ { "id": "525", "name": "Southern California Earthquake Center (SCEC)" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1007/s00024-002-8703-1", "resource_type": "article", "pub_year": "2002", "author_list": "Eisner, Leo and Clayton, Robert W." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/0zxc6-z0v65", "eprint_id": 34609, "eprint_status": "archive", "datestamp": "2023-08-19 09:08:09", "lastmod": "2023-10-19 21:19:43", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Eisner-L", "name": { "family": "Eisner", "given": "Leo" } }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" } ] }, "title": "Equivalent Medium Parameters for Numerical Modeling in Media with Near-Surface Low Velocities", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 2002 by the Seismological Society of America. Manuscript received 1 April 2001. The authors are grateful to Luis Rivera for interesting insights during the development of this method. Special thanks go to Hiroo Kanamori who\nnot only followed our progress but significantly helped with the determination\nof the error criterion. Dimitri Komatitsch greatly helped to make this\nmanuscript readable and offered his experience to evaluate one of the numerical\ntests used in this article. We thank V\u00e1clav Vavry\u010duk, Kim Olsen\n(reviewer), Ivan P\u0161en\u010d\u00edk, Jeroen Tromp, Jascha Polet, Si-Dao Ni, John Etgen,\nand anonymous reviewer for their input when developing this method\nand preparing the manuscript. Many of the figures were made with Generic\nMapping Tools software (Wessel and Smith, 1991). This research was supported\nby the Southern California Earthquake Center (SCEC). The SCEC\nis funded by NSF Cooperative Agreement EAR-8920136 and U.S. Geological\nSurvey Cooperative Agreements 14-08-0001-A0899 and 1434-HQ-\n97AG01718. The SCEC Contribution Number for this article is 524. This is Contribution Number 8820 from the Division of Geological and Planetary\nSciences, California Institute of Technology.\n\nPublished - 711.full.pdf
", "abstract": "We have developed a methodology to discretize an isotropic velocity\nmodel with low velocities near the free surface for full waveform numerical modeling.\nThe method modifies the near-surface minimum velocity in a given (original)\nmodel by replacing parts of the model with equivalent medium parameters (EMP).\nThe discretized model (with EMP) has a higher minimum velocity and minimizes the\ndifference between the seismograms evaluated for the original model and the model\nwith EMP. The method is suitable for studies requiring full waveform numerical\nmodeling with a limited frequency range (such as a finite-difference full waveform\nmodeling in a sedimentary basin). The discretized model with EMP is set to match\nlocally surface-wave velocities evaluated in the original model over the frequency\nrange of interest. The difference in group velocity calculated for the original vertical\nprofile and the vertical profile with EMP provides an estimate of the error due to the\nmodification of the original model.", "date": "2002-03", "date_type": "published", "publication": "Bulletin of the Seismological Society of America", "volume": "92", "number": "2", "publisher": "Seismological Society of America", "pagerange": "711-722", "id_number": "CaltechAUTHORS:20121002-085345466", "issn": "0037-1106", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121002-085345466", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Southern California Earthquake Center (SCEC)" }, { "agency": "NSF", "grant_number": "EAR-8920136" }, { "agency": "USGS", "grant_number": "14-08-0001-A0899" }, { "agency": "USGS", "grant_number": "1434-HQ-97AG01718" } ] }, "other_numbering_system": { "items": [ { "id": "8820", "name": "Caltech Division of Geological and Planetary Sciences" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1785/0120010150", "primary_object": { "basename": "711.full.pdf", "url": "https://authors.library.caltech.edu/records/0zxc6-z0v65/files/711.full.pdf" }, "resource_type": "article", "pub_year": "2002", "author_list": "Eisner, Leo and Clayton, Robert W." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/z8291-9mm93", "eprint_id": 34604, "eprint_status": "archive", "datestamp": "2023-08-19 08:51:20", "lastmod": "2023-10-19 21:19:24", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Larson-R-L", "name": { "family": "Larson", "given": "Roger L." } }, { "id": "Pockalny-R-A", "name": { "family": "Pockalny", "given": "Robert A." } }, { "id": "Viso-R-F", "name": { "family": "Viso", "given": "Richard F." } }, { "id": "Erba-E", "name": { "family": "Erba", "given": "Elisabetta" } }, { "id": "Abrams-L-J", "name": { "family": "Abrams", "given": "Lewis J." } }, { "id": "Luyendyk-B-P", "name": { "family": "Luyendyk", "given": "Bruce P." } }, { "id": "Stock-J-M", "name": { "family": "Stock", "given": "Joann M." }, "orcid": "0000-0003-4816-7865" }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" } ] }, "title": "Mid-Cretaceous tectonic evolution of the Tongareva triple junction in the southwestern Pacific Basin", "ispublished": "pub", "full_text_status": "restricted", "keywords": "Pacific Ocean, tectonics, marine geology, submarine\ngeomorphology", "note": "\u00a9 2002 Geological Society of America.\n\nManuscript received June 1, 2001;\nRevised manuscript received September 20, 2001;\nManuscript accepted October 1, 2001.\nWe thank the personnel on Expeditions Cook-4 and Kiwi-12 for professional\nsupport at sea and J. Mammerickx for helpful discussions. R. Sutherland\nand S. Gulick provided comprehensive and useful reviews. This research is\nsponsored by National Science Foundation grant OCE-9818776 to the University\nof Rhode Island, and by funding from the University of California and the\nCalifornia Institute of Technology.", "abstract": "The trace of the ridge-ridge-ridge triple junction that connected the Pacific, Farallon, and Phoenix plates during mid-Cretaceous time originates at the northeast corner of the Manihiki Plateau near the Tongareva atoll, for which the structure is named. The triple junction trace extends >3250 km south-southeast, to and beyond a magnetic anomaly 34 bight. It is identified by the intersection of nearly orthogonal abyssal hill fabrics, which mark the former intersections of the Pacific-Phoenix and Pacific-Farallon Ridges. A distinct trough is commonly present at the intersection. A volcanic episode from 125 to 120 Ma created the Manihiki Plateau with at least twice its present volume, and displaced the triple junction southeast from the Nova-Canton Trough to the newly formed Manihiki Plateau. Almost simultaneously, the plateau was rifted by the new triple junction system, and large fragments of the plateau were rafted away to the south and east. The Tongareva triple junction originated ca. 119 Ma, when carbonate sedimentation began atop the Manihiki Plateau. Subsequent spreading rates on the Pacific-Phoenix and Pacific-Farallon Ridges averaged 18\u201320 cm/yr until 84 Ma.", "date": "2002-01", "date_type": "published", "publication": "Geology", "volume": "30", "number": "1", "publisher": "Geological Society of America", "pagerange": "67-70", "id_number": "CaltechAUTHORS:20121001-150237189", "issn": "0091-7613", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121001-150237189", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "OCE-9818776" }, { "agency": "University of California" }, { "agency": "Caltech" } ] }, "collection": "CaltechAUTHORS", "local_group": { "items": [ { "id": "Seismological-Laboratory", "value": "Seismological Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences", "value": "Division of Geological and Planetary Sciences" } ] }, "doi": "10.1130/0091-7613(2002)030<0067:MCTEOT>2.0.CO;2", "resource_type": "article", "pub_year": "2002", "author_list": "Larson, Roger L.; Pockalny, Robert A.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/r06zq-rvf32", "eprint_id": 34628, "eprint_status": "archive", "datestamp": "2023-08-19 08:27:56", "lastmod": "2023-10-20 21:52:50", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Hauksson-E", "name": { "family": "Hauksson", "given": "Egill" }, "orcid": "0000-0002-6834-5051" }, { "id": "Small-P", "name": { "family": "Small", "given": "Patrick" } }, { "id": "Hafner-K", "name": { "family": "Hafner", "given": "Katrin" } }, { "id": "Busby-R", "name": { "family": "Busby", "given": "Robert" } }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert" }, "orcid": "0000-0003-3323-3508" }, { "id": "Goltz-J-D", "name": { "family": "Goltz", "given": "James" } }, { "id": "Heaton-T-H", "name": { "family": "Heaton", "given": "Tom" }, "orcid": "0000-0003-3363-2197" }, { "id": "Hutton-K", "name": { "family": "Hutton", "given": "Kate" } }, { "id": "Kanamori-H", "name": { "family": "Kanamori", "given": "Hiroo" }, "orcid": "0000-0001-8219-9428" }, { "id": "Polet-J", "name": { "family": "Polet", "given": "Jascha" } } ] }, "title": "Southern California Seismic Network: Caltech/USGS Element of TriNet 1997-2001", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 2001 Seismological Society of America. \n\nWe thank the TriNet staff for carrying out the implementation of the TriNet system and our colleagues at CDMG for making the combined CDMG and Caltech-USGS elements\nof TriNet a reality. Funding for TriNet has been provided by\nthe Federal Emergency Management Agency (FEMA) and the California Governor's Office of Emergency Services (OES) through the Hazards Mitigation Grant Program established following the 1994 Northridge earthquake. The required 25% cost-sharing is provided by California Institute of Technology, California Trade and Commerce Agency, Caltrans, Ida H. L. Crotty, Verizon California, Donna and Greg Jenkins, Pacific Bell/CalREN, Southern California Edison, Sun Microsystems, Inc., Times Mirror Foundation, and others. Funding has also been provided by the United States Geological Survey from its special 1994 Northridge funds and internal funds, and through contract 01HQAG0007. The Southern California Earthquake Data Center (SCEDC) is also funded by the Southern California Earthquake Center (SCEC). IRIS/GSN provided funds for software support. We also thank Phil Maechling for his contributions to TriNet. P. Friberg and colleagues of ISTI wrote TriNetwatch and provided general software support. Division of Geological and Planetary Sciences contribution number 8811.\n\nPublished - Hauksson2001.pdf
", "abstract": "The California Institute of Technology (Caltech), the United\nStates Geological Survey (USGS), and the California Department of Conservation, Division of Mines and Geology\n(CDMG) are completing the implementation of TriNet, a\nmodern seismic information system for southern California.\nTriNet consists of two elements, the Caltech-USGS element\nand the CDMG element (Mori et al., 1998). The Caltech-USGS\nelement (Caltech-USGS TriNet) concentrates on rapid notification and archiving of data for seismological\napplications, while the CDMG element is focused on the\nneeds of engineering users (Hauksson et al., 2002). All three. TriNet agencies are working toward facilitating emergency response and long-term mitigation of earthquake hazards in cooperation with other agencies. The technical development of Caltech-USGS TriNet is sufficiently different from the CDMG element of TriNet to warrant a separate description. This paper provides a technical overview of the design principles of Caltech-USGS TriNet. These principles were based on a document that stated the scientific requirements of TriNet (Jones et al., 1997). We also describe the implementation of these principles using modern technology. The implementation consisted of station deployments, establishing communications links, and developing and implementing new hardware and software for data processing and information distribution. Thus, the Caltech-USGS TriNet is an integrated project extending across many disciplines, using basic ground-motion data and seismological algorithms to generate in near real-time a sophisticated earthquake knowledge base following earthquakes in southern California. Caltech-USGS TriNet applies advanced technology to record both small and large earthquakes on scale. The latest generation of broadband and strong-motion sensors with 24-bit digitizers is used to acquire high-fidelity ground-motion data. Real-time communication is a requirement to facilitate rapid processing and notification about seismicity for emergency\nmanagement. The data acquisition systems are designed to ensure redundancy and automated processing of data. To accomplish automation, high-speed computers and advanced software form the inner workings of the Caltech-USGS TriNet system. Adopting the commercial database Oracle is an important foundation of our data management system. The automated flow of data into an accessible data\ncenter and the automatic population of the database is part of our new seismic network design and is an essential feature of Caltech-USGS TriNet. The TriNet real-time systems and database have been operating online for more than two years, processing real-time data currently from more than 375 stations, or more than 1,200 high sample-rate data channels. Many of these capabilities were tested in the 1999 M_w 7.1 Hector Mine earthquake. New postprocessing and catalog-generation approaches have also been implemented in 2001. Caltech-USGS TriNet is one of the first U.S. regional seismic networks that uses digital technology on a scale of 200 or more stations, with both broadband and strongmotion sensors. In comparison, the IRIS Global Seismic Network consists of 108 stations, with plans for a total of 150 stations (Hutt and Bolton, 1999). Previous digital networks, such as TERRAscope (Kanamori et al., 1997) and the Berkeley Digital Seismic Network (BDSN) (Gee et aL, 1996), have been smaller than TriNet, with about 20 stations each. TriNet also benefits from the experience of other seismic networks around the world. The K-Net in Japan is another example of large-scale deployment of a digital network, although it is focused on strong motions (Kinoshita, 1998). Extensive developments of strong-motion networks in Taiwan and associated near-real-time processing of data employ somewhat different technology but have similar goals for information products following large earthquakes (Teng et al., 1997).", "date": "2001-11", "date_type": "published", "publication": "Seismological Research Letters", "volume": "72", "number": "6", "publisher": "Seismological Society of America", "pagerange": "690-704", "id_number": "CaltechAUTHORS:20121002-115245745", "issn": "0895-0695", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121002-115245745", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Federal Emergency Management Agency (FEMA)" }, { "agency": "California Office of Emergency Services" }, { "agency": "Caltech" }, { "agency": "California Trade and Commerce Agency" }, { "agency": "Caltrans" }, { "agency": "Ida H. L. Crotty" }, { "agency": "Verizon California" }, { "agency": "Donna and Greg Jenkins" }, { "agency": "Pacific Bell" }, { "agency": "CalREN" }, { "agency": "Southern California Edison" }, { "agency": "Sun Microsystems, Inc." }, { "agency": "Times Mirror Foundation" }, { "agency": "USGS", "grant_number": "01HQAG0007" }, { "agency": "Southern California Earthquake Center (SCEC)" } ] }, "other_numbering_system": { "items": [ { "id": "8811", "name": "Caltech Division of Geological and Planetary Sciences" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1785/gssrl.72.6.690", "primary_object": { "basename": "Hauksson2001.pdf", "url": "https://authors.library.caltech.edu/records/r06zq-rvf32/files/Hauksson2001.pdf" }, "resource_type": "article", "pub_year": "2001", "author_list": "Hauksson, Egill; Small, Patrick; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/se949-sth04", "eprint_id": 34655, "eprint_status": "archive", "datestamp": "2023-08-19 08:28:00", "lastmod": "2023-10-20 21:52:53", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Hafner-K", "name": { "family": "Hafner", "given": "Katrin" } }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" } ] }, "title": "The Southern California Earthquake Data Center (SCEDC)", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 2001 by the Seismological Society of America. \nThe SCEDC has received the bulk of its funding through the\nSouthern California Earthquake Center (NSF EAR-8920136, USGS 14-08-0001-A0899, and 1434-HQ-97AGO1718). In addition, direct funding (matched by funds\nfrom SCEC) for the current mass-storage system was provided\nby NSF (EAR 9816156). TriNet has also provided significant\ninfrastructure support through support of database\nexperts and computer hardware. Contribution number 300\nfrom SCEC and 8818 from the Seismological Laboratory at\nCaltech.\n\nPublished - Hafner2001.pdf
", "abstract": "The SCEDC is the primary archive facility for seismic information for southern California earthquakes. The data archive consists of earthquake parameters and travel-time picks from 1932 to the present, waveform recordings from 1981 to the present recorded by the Southern California Seismic Network (SCSN) and Caltech-USGS TriNet, SAR satellite images of southern California, and some regional refraction profiles of the crust and mantle. Data from portable instrument deployments after the 1992 Joshua Tree and Landers earthquakes, and from the 1994 Northridge earthquake, are also stored in this facility. The Data Center is currently archiving nearly 3,000 data channels from 375 stations. An average of 20,000 earthquakes are processed and archived each year.\n \nThe history of the SCEDC, the current state of data collection, the design of the database and archival system, user access to the system, and the plans for the future are outlined in this article. In particular, we discuss how the data from a large seismic array are stored, and we explain modern methods for accessing the data.", "date": "2001-11", "date_type": "published", "publication": "Seismological Research Letters", "volume": "72", "number": "6", "publisher": "Seismological Society of America", "pagerange": "705-711", "id_number": "CaltechAUTHORS:20121003-095023832", "issn": "0895-0695", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121003-095023832", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Southern California Earthquake Center (SCEC)" }, { "agency": "NSF", "grant_number": "EAR-8920136" }, { "agency": "USGS", "grant_number": "14-08-0001-A0899" }, { "agency": "USGS", "grant_number": "1434-HQ-97AG01718" }, { "agency": "NSF", "grant_number": "EAR-9816156" } ] }, "other_numbering_system": { "items": [ { "id": "8818", "name": "Caltech Seismological Laboratory" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1785/gssrl.72.6.705", "primary_object": { "basename": "Hafner2001.pdf", "url": "https://authors.library.caltech.edu/records/se949-sth04/files/Hafner2001.pdf" }, "resource_type": "article", "pub_year": "2001", "author_list": "Hafner, Katrin and Clayton, Robert W." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/01h4w-eba30", "eprint_id": 34611, "eprint_status": "archive", "datestamp": "2023-08-19 07:48:19", "lastmod": "2023-10-19 21:19:48", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Eisner-L", "name": { "family": "Eisner", "given": "Leo" } }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" } ] }, "title": "A Reciprocity Method for Multiple-Source Simulations", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 2001 by the Seismological Society of America. Manuscript received June 2000. The authors would like to thank Robert Graves for his input and the\ntwo reviewers Martijn de Hoop and Ji\u0159\u00ed Zahradn\u00edk for their valuable suggestions.\nThis research was supported by the Southern California Earthquake\nCenter (NSF EAR-8920136 and USGS 14-08-0001-A0899 and 1434-\nHQ-97AG01718). The SCEC Contribution Number is 523.\n\nPublished - Eisner2002a.pdf
", "abstract": "Reciprocity is applied to the situation where numerical simulations are needed for a number of source locations but relatively a few receiver positions. By invoking source-receiver reciprocity, the number of simulations can be generally reduced to three times the number of receiver positions. The procedure is illustrated for a heterogeneous medium with both single-force and double-couple sources. The numerical tests using a finite-difference implementation show that the reciprocal simulations can be performed with the same level of accuracy as the forward calculations.", "date": "2001-06", "date_type": "published", "publication": "Bulletin of the Seismological Society of America", "volume": "91", "number": "3", "publisher": "Seismological Society of America", "pagerange": "553-560", "id_number": "CaltechAUTHORS:20121002-091515102", "issn": "0037-1106", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121002-091515102", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Southern California Earthquake Center (SCEC)" }, { "agency": "NSF", "grant_number": "EAR-8920136" }, { "agency": "USGS", "grant_number": "14-08-0001-A0899" }, { "agency": "USGS", "grant_number": "1434-HQ-97AG01718" } ] }, "other_numbering_system": { "items": [ { "id": "523", "name": "Southern California Earthquake Center (SCEC)" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1785/0120000222", "primary_object": { "basename": "Eisner2002a.pdf", "url": "https://authors.library.caltech.edu/records/01h4w-eba30/files/Eisner2002a.pdf" }, "resource_type": "article", "pub_year": "2001", "author_list": "Eisner, Leo and Clayton, Robert W." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/k8b0y-cm762", "eprint_id": 34818, "eprint_status": "archive", "datestamp": "2023-08-19 06:53:48", "lastmod": "2023-10-19 21:59:46", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Keller-W-R", "name": { "family": "Keller", "given": "William R." } }, { "id": "Anderson-D-L", "name": { "family": "Anderson", "given": "Don L." } }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" } ] }, "title": "Resolution of tomographic models of the mantle beneath\n Iceland", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 2000 American Geophysical Union. Received 18 May 2000; revised August 15, 2000; accepted 27 September 2000. We thank Gillian Foulger, Bruce Julian, Cecily Wolfe, and Sean Solomon for insightful discussions and comments. This paper represents Contribution Number 8704, Division of\nGeological and Planetary Sciences, California Institute of\nTechnology. This work has been supported by NSF grant EAR\n9726252.\n\nPublished - 2000GL011798.pdf
", "abstract": "The locations of volcanic islands may be controlled by thin or extending parts of the lithosphere over a partially molten asthenosphere [Anderson and Bass, 1984; Favela and Anderson, 2000], by edge effects near the boundaries of thick cratonic lithosphere [Anderson, 1998], or by narrow jets of hot mantle rising from deep within the mantle [Campbell and Griffiths, 1992; Morgan, 1971; Wilson, 1986]. Many hotspots are found on or near ridges, at lithospheric discontinuities, or in extensional environments, so high resolution seismic images are required to determine whether it is lithospheric structure, stresses in the lithosphere, or the deep mantle that is the controlling factor for the location of these volcanoes. In this study, we perform a simple experiment in which we use basic geometrical arguments to better understand the resolution of tomographic images of the upper 400 km of the mantle under Iceland. Our results indicate that a narrow, deep seated mantle plume is not required in order to explain the observed travel time delays in this region. Results of tomographic inversions are often viewed as unique; however, recent seismic studies of the Icelandic Hotspot have illustrated the non\u2010unique nature of these models", "date": "2000-12-15", "date_type": "published", "publication": "Geophysical Research Letters", "volume": "27", "number": "24", "publisher": "American Geophysical Union", "pagerange": "3993-3996", "id_number": "CaltechAUTHORS:20121010-102151531", "issn": "0094-8276", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121010-102151531", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR-9726252" } ] }, "other_numbering_system": { "items": [ { "id": "8704", "name": "Caltech Division of Geological and Planetary Sciences" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1029/2000GL011798", "primary_object": { "basename": "2000GL011798.pdf", "url": "https://authors.library.caltech.edu/records/k8b0y-cm762/files/2000GL011798.pdf" }, "resource_type": "article", "pub_year": "2000", "author_list": "Keller, William R.; Anderson, Don L.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/hc2jv-day80", "eprint_id": 34614, "eprint_status": "archive", "datestamp": "2023-08-19 06:49:34", "lastmod": "2023-10-19 21:19:56", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Magistrale-H-W", "name": { "family": "Magistrale", "given": "Harold" } }, { "id": "Day-S-M", "name": { "family": "Day", "given": "Steven" } }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" }, { "id": "Graves-R-W", "name": { "family": "Graves", "given": "Robert" } } ] }, "title": "The SCEC Southern California Reference Three-Dimensional Seismic Velocity Model Version 2", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 2000 by the Seismological Society of America.\nManuscript received 28 July 2000.\nDiscussions with W. Silva were helpful in constructing the model.\nWe thank L. Zhu, E. Hauksson, and W. Silva for providing data and research\nproducts used in the model, and John Tinsley and Tom Brocher for\nthoughtful reviews of the manuscript. Many figures were made using the\nGMT plotting package (Wessel and Smith, 1991). This research was supported\nby the Southern California Earthquake Center (SCEC). SCEC is\nfunded by NSF Cooperative Agreement EAR-8920136 and USGS Cooperative\nAgreements 14-08-0001-A0899 and 1434-HQ-97AG01718. The\nSCEC contribution number for this paper is 509. Partial support came from\nNSF KDI program Award CMS-9980063. The Salton Trough model development\nwas supported by NSF Award EAR-9725536.\n\nPublished - Magistrale2000.pdf
", "abstract": "We describe Version 2 of the three-dimensional (3D) seismic velocity model of southern California developed by the Southern California Earthquake Center and designed to serve as a reference model for multidisciplinary research activities in the area. The model consists of detailed, rule-based representations of the major southern California basins (Los Angeles basin, Ventura basin, San Gabriel Valley, San Fernando Valley, Chino basin, San Bernardino Valley, and the Salton Trough), embedded in a 3D crust over a variable depth Moho. Outside of the basins, the model crust is based on regional tomographic results. The model Moho is represented by a surface with the depths determined by the receiver function technique. Shallow basin sediment velocities are constrained by geotechnical data. The model is implemented in a computer code that generates any specified 3D mesh of seismic velocity and density values. This parameterization is convenient to store, transfer, and update as new information and verification results become available.", "date": "2000-12", "date_type": "published", "publication": "Bulletin of the Seismological Society of America", "volume": "90", "number": "6", "publisher": "Seismological Society of America", "pagerange": "S65-S76", "id_number": "CaltechAUTHORS:20121002-095135414", "issn": "0037-1106", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121002-095135414", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Southern California Earthquake Center (SCEC)" }, { "agency": "NSF", "grant_number": "EAR-8920136" }, { "agency": "USGS", "grant_number": "14-08-0001-A0899" }, { "agency": "USGS", "grant_number": "1434-HQ-97AG01718" }, { "agency": "NSF", "grant_number": "CMS-9980063" }, { "agency": "NSF", "grant_number": "EAR-9725536" } ] }, "other_numbering_system": { "items": [ { "id": "509", "name": "Southern California Earthquake Center (SCEC)" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1785/0120000510", "primary_object": { "basename": "Magistrale2000.pdf", "url": "https://authors.library.caltech.edu/records/hc2jv-day80/files/Magistrale2000.pdf" }, "resource_type": "article", "pub_year": "2000", "author_list": "Magistrale, Harold; Day, Steven; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/7g7sf-n9e77", "eprint_id": 34919, "eprint_status": "archive", "datestamp": "2023-08-19 04:52:27", "lastmod": "2023-10-19 22:05:42", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Heinemann-J", "name": { "family": "Heinemann", "given": "J." } }, { "id": "Stock-J-M", "name": { "family": "Stock", "given": "J." }, "orcid": "0000-0003-4816-7865" }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "R. W." }, "orcid": "0000-0003-3323-3508" }, { "id": "Hafner-K", "name": { "family": "Hafner", "given": "K." } }, { "id": "Cande-S-C", "name": { "family": "Cande", "given": "S." } }, { "id": "Raymond-Carol-A", "name": { "family": "Raymond", "given": "C." }, "orcid": "0000-0002-4213-8097" } ] }, "title": "Constraints on the proposed Marie Byrd Land-Bellingshausen Plate Boundary from seismic reflection data", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 1999 American Geophysical Union.\n\nReceived 10 September 1997; accepted 29 September 1998.\n\nThis research was supported by NSF grants OPP-\n9317318 and OPP-9317872. We thank Bruce Luyendyk, Robert Bird, and Phillip Schmidt for constructive reviews that helped to improve the paper. We thank the personnel of the Nathaniel B. Palmer and of Antarctic Support Associates for their hard work to ensure the success of the data collection during these two cruises. Contribution 8532, Division of Geological and Planetary Sciences, California Institute of Technology.\n\nPublished - Heinemann1999.pdf
", "abstract": "Single-channel and multichannel marine seismic data off the coast of West Antarctica collected during two Nathaniel B. Palmer cruises (NP92-8 and NP96-2) in the vicinity of 65\u00b0S to 71\u00b0S, 220\u00b0E to 250\u00b0E, reveal a NNW trending graben. We interpret this graben to be part of the paleodivergent plate boundary between the Marie Byrd Land and Bellingshausen plates. This graben coincides with a \u2212520 nT magnetic anomaly to the NNW and a \u2212720 nT anomaly to the SSE, as well as a 20 mGal negative gravity anomaly. Seismic profiles subparallel to the graben (22 km/Ma half-spreading rate) reveal greater seafloor roughness to the NE, where seafloor spreading was slower, than to the SW (27 km/Ma half-spreading rate). These data allow the position of the Marie Byrd Land-Bellingshausen plate boundary to be constrained more precisely than has previously been possible, with a trend of N17\u00b0W from 68.52\u00b0S, 233.65\u00b0E to 68.41\u00b0S, 233.56\u00b0E. The sediment-filled graben has normal separation of sedimentary layers varying from 740\u00b130 m to 580\u00b120 m imaged in seafloor of age A33y (74 Ma).", "date": "1999-11-10", "date_type": "published", "publication": "Journal of Geophysical Research B", "volume": "104", "number": "B11", "publisher": "American Geophysical Union", "pagerange": "25321-25330", "id_number": "CaltechAUTHORS:20121016-104022644", "issn": "0148-0227", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121016-104022644", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "OPP-9317318" }, { "agency": "NSF", "grant_number": "OPP-9317872" } ] }, "other_numbering_system": { "items": [ { "id": "8532", "name": "Caltech Division of Geological and Planetary Sciences" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1029/1998JB900079", "primary_object": { "basename": "Heinemann1999.pdf", "url": "https://authors.library.caltech.edu/records/7g7sf-n9e77/files/Heinemann1999.pdf" }, "resource_type": "article", "pub_year": "1999", "author_list": "Heinemann, J.; Stock, J.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/2yps0-hag98", "eprint_id": 64445, "eprint_status": "archive", "datestamp": "2023-08-22 13:24:49", "lastmod": "2024-01-13 16:40:49", "type": "monograph", "metadata_visibility": "show", "creators": { "items": [ { "id": "Henyey-T-L", "name": { "family": "Henyey", "given": "Thomas L." } }, { "id": "Fuis-G-S", "name": { "family": "Fuis", "given": "Gary S." } }, { "id": "Benthien-M-L", "name": { "family": "Benthien", "given": "Mark L." } }, { "id": "Burdette-T-R", "name": { "family": "Burdette", "given": "Thomas R." } }, { "id": "Christofferson-S-A", "name": { "family": "Christofferson", "given": "Shari A." } }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" }, { "id": "Criley-E-E", "name": { "family": "Criley", "given": "Edward E." } }, { "id": "Davis-P-M", "name": { "family": "Davis", "given": "Paul M." } }, { "id": "Hendley-J-W-II", "name": { "family": "Hendley", "given": "James W., II" } }, { "id": "Kohler-M-D", "name": { "family": "Kohler", "given": "Monica D." } }, { "id": "Lutter-W-J", "name": { "family": "Lutter", "given": "William J." } }, { "id": "McRaney-J-K", "name": { "family": "McRaney", "given": "John K." } }, { "id": "Murphy-J-M", "name": { "family": "Murphy", "given": "Janice M." } }, { "id": "Okaya-D-A", "name": { "family": "Okaya", "given": "David A." } }, { "id": "Ryberg-T", "name": { "family": "Ryberg", "given": "Trond" } }, { "id": "Simila-G-W", "name": { "family": "Simila", "given": "Gerald W." } }, { "id": "Stauffer-P-H", "name": { "family": "Stauffer", "given": "Peter H." } } ] }, "title": "Understanding earthquake hazards in southern California - the \"LARSE\" project - working toward a safer future for Los Angeles", "ispublished": "unpub", "full_text_status": "public", "note": "Published - fs110-99.pdf
", "abstract": "The Los Angeles region is underlain by a network of active faults, including many that are deep and do not break the\nEarth's surface. These hidden faults include the previously\nunknown one responsible for the devastating January 1994\nNorthridge earthquake, the costliest quake in U.S. history. So that structures can be built or strengthened to withstand the quakes that are certain in the\nfuture, the Los Angeles Region Seismic Experiment (LARSE) is\nlocating hidden earthquake hazards beneath the region to\nhelp scientists determine where the strongest shaking will occur.", "date": "1999", "date_type": "published", "publisher": "U.S Geological Survey", "id_number": "CaltechAUTHORS:20160211-164003474", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160211-164003474", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "primary_object": { "basename": "fs110-99.pdf", "url": "https://authors.library.caltech.edu/records/2yps0-hag98/files/fs110-99.pdf" }, "resource_type": "monograph", "pub_year": "1999", "author_list": "Henyey, Thomas L.; Fuis, Gary S.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/dxwsq-6zr28", "eprint_id": 50910, "eprint_status": "archive", "datestamp": "2023-08-19 02:52:04", "lastmod": "2023-10-18 14:38:19", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Mori-Jim", "name": { "family": "Mori", "given": "Jim" } }, { "id": "Kanamori-H", "name": { "family": "Kanamori", "given": "Hiroo" }, "orcid": "0000-0001-8219-9428" }, { "id": "Davis-J-L", "name": { "family": "Davis", "given": "James" } }, { "id": "Hauksson-E", "name": { "family": "Hauksson", "given": "Egill" }, "orcid": "0000-0002-6834-5051" }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert" }, "orcid": "0000-0003-3323-3508" }, { "id": "Heaton-T-H", "name": { "family": "Heaton", "given": "Thomas" }, "orcid": "0000-0003-3363-2197" }, { "id": "Jones-L-M", "name": { "family": "Jones", "given": "Lucile" }, "orcid": "0000-0002-2690-3051" }, { "id": "Shakal-A-K", "name": { "family": "Shakal", "given": "Anthony" } }, { "id": "Porcella-R-L", "name": { "family": "Porcella", "given": "Ron" } } ] }, "title": "Major improvements in progress for Southern California Earthquake Monitoring", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 1998 American Geophysical Union. \n\nThe TriNet project is being built using existing infrastructure and with collaboration between federal and state government, university, and private sectors. Southern California's first digital network began with the installation of seismographs known as TERRAscope, made possible by a grant from the Whittier Foundation and the ARCO Foundation. Pacific Bell, through its CalREN Program, has provided new frame-relay digital communications technology for telemetry. The CUBE (Caltech-USGS Broadcast of Earthquakes) project, started in 1991, has formed a consortium of government agencies and private industry concerned with earthquake hazards in southern California. This group has built support for the project and provided valuable user input into the design of the earthquake information systems. In addition to the initial support from USGS and the current support from FEMA, numerous government and private organizations have made significant contributions to the funding. These include the National Science Foundation, California Trade and Commerce Agency, and Pacific Bell through the CalREN project. Cost-sharing of the FEMA funding is also provided by Caltech and CDMG. The Southern California Earthquake Center Data Center continues to provide facilities for data storage and distribution.\n\nPublished - eost11903.pdf
", "abstract": "Major improvements in seismic and strong-motion monitoring networks are being implemented in southern California to better meet the needs of emergency response personnel, structural engineers, and the research community in promoting earthquake hazard reduction. Known as the TriNet project, the improvements are being coordinated by the California Institute of Technology (Caltech), the U.S. Geological Survey (USGS), and the California Division of Mines and Geology (CDMG) of the state's Department of Conservation. Already the ambitious instrument and system development project has started to record and disseminate ground motions from a spatially dense and robust network of high quality seismographs.", "date": "1998-05-05", "date_type": "published", "publication": "Eos", "volume": "79", "number": "18", "publisher": "American Geophysical Union", "pagerange": "217-221", "id_number": "CaltechAUTHORS:20141028-090237921", "issn": "0096-3941", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20141028-090237921", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "USGS" }, { "agency": "Federal Emergency Management Agency (FEMA)" }, { "agency": "NSF" }, { "agency": "California Trade and Commerce Agency" }, { "agency": "Pacific Bell" }, { "agency": "Caltech" }, { "agency": "California Division of Mines and Geology" }, { "agency": "Whittier Foundation" }, { "agency": "Arco Foundation" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1029/98EO00157", "primary_object": { "basename": "eost11903.pdf", "url": "https://authors.library.caltech.edu/records/dxwsq-6zr28/files/eost11903.pdf" }, "resource_type": "article", "pub_year": "1998", "author_list": "Mori, Jim; Kanamori, Hiroo; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/s1fym-bsv04", "eprint_id": 66595, "eprint_status": "archive", "datestamp": "2023-08-22 11:00:35", "lastmod": "2023-10-18 18:36:57", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Fuis-G-S", "name": { "family": "Fuis", "given": "Gary S." } }, { "id": "Okaya-David-A", "name": { "family": "Okaya", "given": "David A." } }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" }, { "id": "Lutter-W-J", "name": { "family": "Lutter", "given": "William J." } }, { "id": "Ryberg-T", "name": { "family": "Ryberg", "given": "Trond" } }, { "id": "Brocher-T-M", "name": { "family": "Brocher", "given": "Thomas M." } }, { "id": "Henyey-T-M", "name": { "family": "Henyey", "given": "Thomas M." } }, { "id": "Benthien-M-L", "name": { "family": "Benthien", "given": "Mark L." } }, { "id": "Davis-P-M", "name": { "family": "Davis", "given": "Paul M." } }, { "id": "Mori-Jim", "name": { "family": "Mori", "given": "James" } }, { "id": "Catchings-R-D", "name": { "family": "Catchings", "given": "Rufus D." } }, { "id": "ten-Brink-U", "name": { "family": "ten Brink", "given": "Uri S." } }, { "id": "Kohler-M-D", "name": { "family": "Kohler", "given": "Monica D." } }, { "id": "Klitgord-K-D", "name": { "family": "Klitgord", "given": "Kim D." } }, { "id": "Bohannon-R-G", "name": { "family": "Bohannon", "given": "Robert G." } } ] }, "title": "Images of Crust Beneath Southern California Will Aid Study of Earthquakes and Their Effects", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 1996 American Geophysical Union. \n\nThe National Earthquake Hazards Reduction Program and the National Science Foundation funded this experiment. We thank David Hill, Thomas Holzer, and Walter Mooney for reviews of early versions of this paper.\n\nPublished - Fuis_et_al-1996-Eos,_Transactions_American_Geophysical_Union.pdf
", "abstract": "The Whittier Narrows earthquake of 1987 and the Northridge earthquake of 1991 highlighted the earthquake hazards associated with buried faults in the Los Angeles region. A more thorough knowledge of the subsurface structure of southern California is needed to reveal these and other buried faults and to aid us in understanding how the earthquake-producing machinery works in this region.", "date": "1996-04-30", "date_type": "published", "publication": "EOS Transactions", "volume": "77", "number": "18", "publisher": "American Geophysical Union", "pagerange": "173-176", "id_number": "CaltechAUTHORS:20160502-142008606", "issn": "0096-3941", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160502-142008606", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "National Earthquake Hazards Reduction Program (NEHRP)" }, { "agency": "NSF" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1029/96EO00112", "primary_object": { "basename": "Fuis_et_al-1996-Eos,_Transactions_American_Geophysical_Union.pdf", "url": "https://authors.library.caltech.edu/records/s1fym-bsv04/files/Fuis_et_al-1996-Eos,_Transactions_American_Geophysical_Union.pdf" }, "resource_type": "article", "pub_year": "1996", "author_list": "Fuis, Gary S.; Okaya, David A.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/nypa4-2nr39", "eprint_id": 47422, "eprint_status": "archive", "datestamp": "2023-08-20 07:26:07", "lastmod": "2023-10-26 20:35:08", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Fliedner-M-M", "name": { "family": "Fliedner", "given": "Moritz M." } }, { "id": "Ruppert-S", "name": { "family": "Ruppert", "given": "Stanley" } }, { "id": "Malin-P-E", "name": { "family": "Malin", "given": "P. E." } }, { "id": "Park-S-K", "name": { "family": "Park", "given": "S. K." } }, { "id": "Jiracek-G", "name": { "family": "Jiracek", "given": "G." } }, { "id": "Phinney-R-A", "name": { "family": "Phinney", "given": "R. A." } }, { "id": "Saleeby-J-B", "name": { "family": "Saleeby", "given": "J. B." } }, { "id": "Wernicke-B-P", "name": { "family": "Wernicke", "given": "B." }, "orcid": "0000-0002-7659-8358" }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "R." }, "orcid": "0000-0003-3323-3508" }, { "id": "Keller-R-A", "name": { "family": "Keller", "given": "R." } }, { "id": "Miller-K", "name": { "family": "Miller", "given": "K." } }, { "id": "Jones-C", "name": { "family": "Jones", "given": "C." } }, { "id": "Luetgert-J-H", "name": { "family": "Luetgert", "given": "J. H." } }, { "id": "Mooney-W-D", "name": { "family": "Mooney", "given": "W. D." } }, { "id": "Oliver-H", "name": { "family": "Oliver", "given": "H." } }, { "id": "Klemperer-S-L", "name": { "family": "Klemperer", "given": "S. L." } }, { "id": "Thompson-G-A", "name": { "family": "Thompson", "given": "G. A." } } ] }, "title": "Three-dimensional crustal structure of the southern Sierra Nevada from seismic fan profiles and gravity modeling", "ispublished": "pub", "full_text_status": "restricted", "note": "\u00a9 1996 Geological Society of America.\n\nManuscript received August 21, 1995;\nRevised manuscript received December 21, 1995;\nManuscript accepted December 22, 1995.\n\nThe Southern Sierra Continental Dynamics project is\nsupported by the National Science Foundation (NSF)\ngrant EAR-91-19263 to Duke University; this work was\nsupported by NSF grants EAR-92-04998 and EAR-94-\n05577 to Stanford University and Department of Energy\ncontract W-7405-ENG-48 to Lawrence Livermore National\nLaboratory. The seismic data were collected with\nsupport from the U.S. Geological Survey and the Program\nfor Array Seismic Studies of the Continental Lithosphere (PASSCAL) and are available from the Incorporated\nResearch Institutions for Seismology (IRIS)\nData Management Center, via http://www.iris.washing\nton.edu/. We thank Tom Parsons and an anonymous reviewer\nfor helpful reviews.", "abstract": "Traveltime data from the 1993 Southern Sierra Nevada Continental Dynamics seismic refraction experiment reveal low crustal velocities in the southern Sierra Nevada and Basin and Range province of California (6.0 to 6.6 km/s), as well as low upper mantle velocities (7.6 to 7.8 km/s). The crust thickens from southeast to northwest along the axis of the Sierra Nevada from 27 km in the Mojave Desert to 43 km near Fresno, California. A crustal welt is present beneath the Sierra Nevada, but the deepest Moho is found under the western slopes, not beneath the highest topography. A density model directly derived from the crustal velocity model but with constant mantle density satisfies the pronounced negative Bouguer anomaly associated with the Sierra Nevada, but shows large discrepancies of >50 mgal in the Great Valley and in the Basin and Range province. Matching the observed gravity with anomalies in the crust alone is not possible with geologically reasonable densities; we require a contribution from the upper mantle, either by lateral density variations or by a thinning of the lithosphere under the Sierra Nevada and the Basin and Range province. Such a model is consistent with the interpretation that the uplift of the present Sierra Nevada is caused and dynamically supported by asthenospheric upwelling or lithospheric thinning under the Basin and Range province and eastern Sierra Nevada.", "date": "1996-04", "date_type": "published", "publication": "Geology", "volume": "24", "number": "4", "publisher": "Geological Society of America", "pagerange": "367-370", "id_number": "CaltechAUTHORS:20140723-100821423", "issn": "0091-7613", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140723-100821423", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR-91-19263" }, { "agency": "NSF", "grant_number": "EAR-92-04998" }, { "agency": "NSF", "grant_number": "EAR-94-05577" }, { "agency": "Department of Energy (DOE)", "grant_number": "W-7405-ENG-48" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "corp_creators": { "items": [ "Southern Sierra Nevada Continental Dynamics Working Group" ] }, "doi": "10.1130/0091-7613(1996)024<0367:TDCSOT>2.3.CO;2", "resource_type": "article", "pub_year": "1996", "author_list": "Fliedner, Moritz M.; Ruppert, Stanley; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/xs4dw-gbs39", "eprint_id": 34893, "eprint_status": "archive", "datestamp": "2023-08-20 07:09:46", "lastmod": "2023-10-19 22:04:13", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Wernicke-B-P", "name": { "family": "Wernicke", "given": "Brian" }, "orcid": "0000-0002-7659-8358" }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert" }, "orcid": "0000-0003-3323-3508" }, { "id": "Ducea-Mihai-N", "name": { "family": "Ducea", "given": "Mihai" }, "orcid": "0000-0002-5322-0782" }, { "id": "Jones-Craig-H", "name": { "family": "Jones", "given": "Craig H." } }, { "id": "Parker-Stephen", "name": { "family": "Parker", "given": "Stephen" } }, { "id": "Ruppert-Stan", "name": { "family": "Ruppert", "given": "Stan" } }, { "id": "Saleeby-J-B", "name": { "family": "Saleeby", "given": "Jason" } }, { "id": "Snow-J-Kent", "name": { "family": "Snow", "given": "J. Kent" } }, { "id": "Squires-Livia", "name": { "family": "Squires", "given": "Livia" } }, { "id": "Fliedner-Moritz", "name": { "family": "Fliedner", "given": "Moritz" } }, { "id": "Jiracek-George", "name": { "family": "Jiracek", "given": "George" } }, { "id": "Keller-Randy", "name": { "family": "Keller", "given": "Randy" } }, { "id": "Klemperer-Simon", "name": { "family": "Klemperer", "given": "Simon" } }, { "id": "Luetgert-James", "name": { "family": "Luetgert", "given": "James" } }, { "id": "Malin-Peter", "name": { "family": "Malin", "given": "Peter" } }, { "id": "Miller-Kate", "name": { "family": "Miller", "given": "Kate" } }, { "id": "Mooney-Walter-D", "name": { "family": "Mooney", "given": "Walter" } }, { "id": "Oliver-Howard", "name": { "family": "Oliver", "given": "Howard" } }, { "id": "Phinney-Robert-A", "name": { "family": "Phinney", "given": "Robert" } } ] }, "title": "Origin of High Mountains in the Continents: The Southern Sierra Nevada", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 1996 American Association for the Advancement of Science. \n\n30 August 1995; accepted 14 November 1995. \n\nSupported by the Continental Dynamics Program of the National Science Foundation (EAR-9120690 to S.P., EAR-9120688 to G.J., EAR-9119263 to P.M., and EAR-9120689 to R.P.), the Department of Energy (DE-FG03-93ER14311 to R.C.), the U.S. Navy (China Lake Naval Weapons Center), and the U.S. Air Force (Office of Scientific Research). Key logistical support was provided by the National Park Service, Bureau of Land Management, and U.S. Forest Service.\n\nSubmitted - Origin_of_High_Mountains_in_the_Continents.pdf
", "abstract": "Active and passive seismic experiments show that the southern Sierra, despite standing 1.8 to 2.8 kilometers above its surroundings, is underlain by crust of similar seismic thickness, about 30 to 40 kilometers. Thermobarometry of xenolith suites and magnetotelluric profiles indicate that the upper mantle is eclogitic to depths of 60 kilometers beneath the western and central parts of the range, but little subcrustal lithosphere is present beneath the eastern High Sierra and adjacent Basin and Range. These and other data imply the crust of both the High Sierra and Basin and Range thinned by a factor of 2 since 20 million years ago, at odds with purported late Cenozoic regional uplift of some 2 kilometers.", "date": "1996-01-12", "date_type": "published", "publication": "Science", "volume": "271", "number": "5246", "publisher": "American Association for the Advancement of Science", "pagerange": "190-193", "id_number": "CaltechAUTHORS:20121015-105100386", "issn": "0036-8075", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121015-105100386", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR-9120690" }, { "agency": "NSF", "grant_number": "EAR-9120688" }, { "agency": "NSF", "grant_number": "EAR-9119263" }, { "agency": "NSF", "grant_number": "EAR-9120689" }, { "agency": "Department of Energy (DOE)", "grant_number": "DE-FG03-93ER14311" }, { "agency": "U. S. Navy (China Lake Naval Weapons Center)" }, { "agency": "Air Force Office of Scientific Research (AFOSR)" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1126/science.271.5246.190", "primary_object": { "basename": "Origin_of_High_Mountains_in_the_Continents.pdf", "url": "https://authors.library.caltech.edu/records/xs4dw-gbs39/files/Origin_of_High_Mountains_in_the_Continents.pdf" }, "resource_type": "article", "pub_year": "1996", "author_list": "Wernicke, Brian; Clayton, Robert; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/284b2-4fy38", "eprint_id": 64367, "eprint_status": "archive", "datestamp": "2023-08-22 10:45:05", "lastmod": "2024-01-13 16:40:31", "type": "monograph", "metadata_visibility": "show", "creators": { "items": [ { "id": "Kohler-M-D", "name": { "family": "Kohler", "given": "Monica D." } }, { "id": "Davis-P-M", "name": { "family": "Davis", "given": "Paul M." } }, { "id": "Liu-Hong", "name": { "family": "Liu", "given": "Hong" } }, { "id": "Benthien-M-L", "name": { "family": "Benthien", "given": "Mark" } }, { "id": "Gao-Shangxing", "name": { "family": "Gao", "given": "Shangxing" } }, { "id": "Fuis-G-S", "name": { "family": "Fuis", "given": "Gary S." } }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" }, { "id": "Okaya-David-A", "name": { "family": "Okaya", "given": "David A." } }, { "id": "Mori-Jim", "name": { "family": "Mori", "given": "James" } } ] }, "title": "Data Report for the 1993 Los Angeles Region Seismic Experiment (LARSE93), Southern California: a passive study from Seal Beach northeastward through the Mojave Desert", "ispublished": "unpub", "full_text_status": "public", "note": "USGS-OFR-96-85.\n\nWe wish to thank the dozens of scientists without whose help this experiment would have been nearly impossible. Our thanks go to Marcos Alvarez, Joyjeet Bhowmik, Armando\nBurciaga, Bob Busby, Cheryl Contopoulos, Ed Criley, H. Ekstrom, Jim Fowler, Doug Given, Katrin Hafner, Thomas Henyey, Craig Jones, Brian Laird, Aaron Martin, Steve Michnik, Janice Murphy, Julie Norris, Guang-yu Pei, Robert Phinney, Michelle Robertson, Craig Scrivner, and\nJohn Van Schaak. Many of these scientists, students, and volunteers spent their time in the field deploying and monitoring the array instruments, providing us with instruments and equipment, and providing follow-up maintenance. We thank Tim Ahem, Rick Braman, and the staff of the IRIS DMC for assistance and use of the DMC facilities. This work was supported by the Southern California Earthquake Center and the National Science Foundation.\n\nPublished - kohler_ofr_96_85.pdf
", "abstract": "This report contains a description of the first part of the Los Angeles Region Seismic Experiment (LARSE). To date, LARSE has consisted of two experiments: passive, which took\nplace in fall, 1993 (LARSE93), and active, which took place in fall, 1994 (LARSE94). The goal of the 1993 experiment was to collect waveform data from local and distant earthquakes to obtain three-dimensional images of lower crust and upper mantle structure in Southern California, particularly under the San Gabriel Mountains and across the San Andreas fault. During LARSE93, approximately 88 stations were deployed in a 175-km-long, linear array\nacross the Los Angeles basin, San Gabriel Mountains, and Mojave Desert northeast of Los Angeles by scientists from the U.S. Geological Survey, University of California at Los Angeles, California Institute of Technology, and University of Southern California. Reftek recorders were deployed one km apart through the San Gabriel Mountains, and two km apart in the Mojave Desert. This data set has since been complemented by the results of LARSE94 comprising land\nrefraction and deep-crustal seismic reflection profiles from offshore airgun and onshore explosion sources. These additional data sets will be useful in distinguishing crustal structures from adjacent upper mantle structures. During the four weeks of continuous recording, over 150\nteleseismic and over 450 local (M_L \u2265 2.0) events were recorded at each site. Both teleseismic and local sources provided a wide range of raypath azimuths. The teleseismic events include a number of earthquakes with epicenters in the Aleutian Island, Kamchatka, Kuril Island, mid-Atlantic\nRidge, Solomon Island, Japan, Fiji Island, Peru, and Chile regions. The local events include aftershocks of recent Southern California earthquakes. The final products of data\nprocessing are 1) half-hour files containing the continuous wavefonn data recorded at each station for each day of the experiment, 2) 150-second time-windowed waveform segments\ncontaining local, regional, and teleseismic event arrivals, and 3) one-hour time-windowed waveform segments containing regional and teleseismic event arrivals. Array instrumentation, recorded events, and data processing will be described in this report.", "date": "1996", "date_type": "published", "publisher": "U. S. Geological Survey", "id_number": "CaltechAUTHORS:20160209-170454533", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160209-170454533", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Southern California Earthquake Center (SCEC)" }, { "agency": "NSF" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "primary_object": { "basename": "kohler_ofr_96_85.pdf", "url": "https://authors.library.caltech.edu/records/284b2-4fy38/files/kohler_ofr_96_85.pdf" }, "resource_type": "monograph", "pub_year": "1996", "author_list": "Kohler, Monica D.; Davis, Paul M.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/n9qp7-n8894", "eprint_id": 35005, "eprint_status": "archive", "datestamp": "2023-08-22 10:43:32", "lastmod": "2023-10-19 23:37:54", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Heaton-T-H", "name": { "family": "Heaton", "given": "Thomas" }, "orcid": "0000-0003-3363-2197" }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert" }, "orcid": "0000-0003-3323-3508" }, { "id": "Davis-J", "name": { "family": "Davis", "given": "James" } }, { "id": "Hauksson-E", "name": { "family": "Hauksson", "given": "Egill" }, "orcid": "0000-0002-6834-5051" }, { "id": "Jones-L-M", "name": { "family": "Jones", "given": "Lucille" }, "orcid": "0000-0002-2690-3051" }, { "id": "Kanamori-H", "name": { "family": "Kanamori", "given": "Hiroo" }, "orcid": "0000-0001-8219-9428" }, { "id": "Mori-Jim", "name": { "family": "Mori", "given": "James" } }, { "id": "Porcella-R-L", "name": { "family": "Porcella", "given": "Ron" } }, { "id": "Shakal-A-K", "name": { "family": "Shakal", "given": "Tony" } } ] }, "title": "The TriNet Project", "ispublished": "unpub", "full_text_status": "restricted", "keywords": "Accelerograph; seismic; strong motion; network; California; early warning.", "note": "\u00a9 1996 Elsevier Science Ltd.", "abstract": "TriNet is a collaborative project of the California Institute of Technology, the California Division of\nMines and Geology, and the U.S. Geological Survey to develop a digital seismographic network in\nsouthern California. TriNet will provide ground motion data having unprecedented frequency bandwidth\nand dynamic range throughout southern California, including urbanized areas. All stations will have 3-\ncomponent, high-dynamic-range, strong-motion force balance accelerometers. Ill addition, all stations\nwill have either real-time or dial-up digital telemetry. Many stations will have high-gain seismometers,\nmany of which will be of the force-balance type with broad frequency responses. TriNet will enhance the\ntraditional products of the existing regional seismographic network and strong-motion networks, and\nimportant new products will be developed. Major products of the TriNet project are: 1) near-real-time\nmonitoring and cataloging of earthquakes in southern California, 2) broad-band ground motions from\nteleseismic earthquakes and other seismic sources, 3) strong-motion recordings from significant\nearthquakes, 4) near-real-time shaking intensity maps for emergency management, and 5) a pilot system\nfor early warning of seismic shaking. Many other agencies (e.g., lifeline operators, emergency\nmanagement agencies, etc.) are being included in the TriNet development.", "date": "1996", "date_type": "published", "publisher": "Elsevier Science", "pagerange": "Paper No. 2136", "id_number": "CaltechAUTHORS:20121022-111806120", "isbn": "9780080428222", "book_title": "Eleventh World Conference on Earthquake Engineering : Acapulco, Mexico, June 23-28, 1996 : 11WCEE", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121022-111806120", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "resource_type": "book_section", "pub_year": "1996", "author_list": "Heaton, Thomas; Clayton, Robert; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/b8aep-bvv90", "eprint_id": 34902, "eprint_status": "archive", "datestamp": "2023-08-22 09:17:57", "lastmod": "2023-10-19 22:04:47", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Rowan-L-R", "name": { "family": "Rowan", "given": "Linda R." } }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" } ] }, "title": "The three-dimensional structure of Kilauea Volcano, Hawaii, from travel time tomography", "ispublished": "pub", "full_text_status": "public", "keywords": "Seismology: Structure of the crust; Volcanology: Magma migration; Exploration Geophysics: Oceanic structures; Information Related to Geographic Region: Pacific Ocean; Seismology: Body waves", "note": "\u00a9 1993 American Geophysical Union. \n\nReceived 30 November 1990; accepted 21 October 1992.\n\nWe would like to thank Phyllis Ho-Liu and Hua-Wei Zhou for their help and advice throughout this project. We appreciate the reviews and useful comments on the manuscript from Jim Westphal and Hiroo Kanamori. We appreciate the patient and critical reviews by two anonymous reviewers and Stuart Sipkin. We would also like to thank Carl Johnson, Bob Koyanagi and Paul Okubo for providing us with the data set for 1986 and some useful discussions on our interpretations of the tomographic images. The first author would like to add a special thanks to Robert P. Sharp for including me on a field trip to the Big Island so I could see and understand the dynamic beauty of Kilauea Volcano at least on the surface. This work was partially supported by the contracts USGS 14-08-0001-G1774 and by EAR-83-511371. Contribution No. 4942 from the Division of Geological and Planetary Sciences, Caltech.\n\nPublished - Rowan1993.pdf
", "abstract": "A linear, travel time tomography study of the most active shield volcano of the world, Kilauea Volcano, Hawaii, was undertaken to determine the lateral heterogeneities produced by its intricate magmatic and tectonic environment. Kilauea provides an ideal setting to do tomography because of its dense seismograph array and many local earthquakes that allow excellent ray coverage of complex subsurface features. Local P wave data from \u223c 12,295 events were inverted using a one-dimensional layered velocity model. Inversions were done for two cell sizes (5\u00d75\u00d75 km and 1\u00d71\u00d71 km) to resolve structural regions on different length scales. This study provided a view of the average velocity variations relative to a one-dimensional velocity model. Analysis and interpretation of the tomographic images allowed us to infer the following model. The main shallow magma reservoir is delineated by a slow velocity region southeast of the summit from 0 to 2 km depth. There is a distinct high velocity region centered northwest of the summit from 0 to 2 km depth that represents a cap of dense, intrusive dikes surrounding the magma chamber. We suggest that the shallow reservoir is a narrow, compartmentalized region of sills and dikes, centered just south-southeast of Halemaumau caldera. Below the main reservoir, the summit is imaged as a slightly fast region from 5 to 10 km in the coarse model indicating that the main conduit is structurally defined by an intrusive dike complex until about 10 km. The rift zones of Kilauea are imaged as major, high velocity entities, widening to the south with depth until 6 km. These fast anomalies are related to the sheeted dike complexes along the rifts. On a finer scale, slow anomalies suggest the presence of magma pockets centered at 0\u20132 km depth beneath Mauna Ulu, Makaopuhi and Puu Oo, along the east rift zone (ERZ). Two significant high velocity regions along the lower ERZ near Kalalua and Kaliu are inferred to represent intrusive barriers to magma injection along the shallow (0\u20134 km) ERZ conduit. The southwest rift zone may have an intrusive barrier related to a high velocity region just southwest of Mauna Iki. The Hilina and Kaoiki fault zones are imaged as slow features at shallow depths (< 5 km) related to the open fractures and scarps along the normal faults. The Koae fault system is imaged as a slightly fast shallow structure (< 6 km) possibly related to intrusive diking from the adjacent rift zones that fill and may even induce the extensional structures associated with this complex fault zone. Continued inversions with the immense amount of seismic data collected for Hawaiian events will allow the detailed development of a three-dimensional structural model for Kilauea. Such a model will be extremely useful to seismologists and petrologists alike for understanding the tectonic growth and magmatic evolution of this dynamic shield volcano.", "date": "1993-03-10", "date_type": "published", "publication": "Journal of Geophysical Research B", "volume": "98", "number": "B3", "publisher": "American Geophysical Union", "pagerange": "4355-4375", "id_number": "CaltechAUTHORS:20121015-130957429", "issn": "0148-0227", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121015-130957429", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "USGS", "grant_number": "14-08-0001-G1774" }, { "agency": "NSF", "grant_number": "EAR-83-511371" } ] }, "other_numbering_system": { "items": [ { "id": "4942", "name": "Caltech Division of Geological and Planetary Sciences" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1029/92JB02531", "primary_object": { "basename": "Rowan1993.pdf", "url": "https://authors.library.caltech.edu/records/b8aep-bvv90/files/Rowan1993.pdf" }, "resource_type": "article", "pub_year": "1993", "author_list": "Rowan, Linda R. and Clayton, Robert W." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/k00cv-6cf89", "eprint_id": 34934, "eprint_status": "archive", "datestamp": "2023-08-22 09:09:10", "lastmod": "2024-01-13 05:56:09", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Hide-R", "name": { "family": "Hide", "given": "R." } }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "R. W." }, "orcid": "0000-0003-3323-3508" }, { "id": "Hager-B-H", "name": { "family": "Hager", "given": "B. H." }, "orcid": "0000-0002-5643-1374" }, { "id": "Spieth-M-A", "name": { "family": "Spieth", "given": "M. A." } }, { "id": "Voorhdes-C-V", "name": { "family": "Voorhdes", "given": "C. V." } } ] }, "title": "Topographic Core-Mantle Coupling and Fluctuations in the Earth's Rotation", "ispublished": "unpub", "full_text_status": "public", "keywords": "Earth sciences\u2014Mathematical models; Geophysics\u2014Mathematical models", "note": "\u00a9 1993 by the International Union of Geodesy and Geophysics\nand the American Geophysical Union. We thank Don Anderson, Jean Dickey, Olafur Gudmundsson, David Stevenson, and Charles Yoder for helpful comments on various aspects of this work. We also thank Dr. Dickey and other members of\nthe Space Geodesy Science and Applications Group of the Jet Propulsion Laboratory for facilitating this collaborative study. Jeremy Bloxham kindly provided coefficients for his core flow model. Partial support was provided by NASA grants NAG5-819 and NAGS-315 to RWC and BHH.\n\nPublished - Hide1993.pdf
", "abstract": "Astronomically-determined irregular fluctuations in the Earth's rotation vector on decadal time scales can be used to estimate the fluctuating torque on the lower surface of the Earth's mantle produced by magnetohydrodynamic flow in the underlying liquid metallic core. A method has been proposed for testing the hypothesis that the torque is due primarily to fluctuating dynamic pressure forces acting on irregular topographic features of the core-mantle boundary and also on the equatorial bulge. The method exploits (a) geostrophically-constrained models of fluid motions in the upper reaches of the core based on geomagnetic secular variation data, and (b) patterns of the topography of the CMB based on the mantle flow models constrained by data from seismic tomography, determinations of long wave-length anomalies of the Earth's gravitational field and other geophysical and geodetic data. According to the present study, the magnitude of the axial component of the torque implied by determinations of irregular changes in the length of the day is compatible with models of the Earth's deep interior characterized by the presence of irregular CMB topography of effective \"height\" no more than about 0.5 km (about 6% of the equatorial bulge) and strong horizontal variations in the properties of the D\u2033 layer at the base of the mantle. The investigation is now being extended to cover a wider range of epochs and also the case of polar motion on decadal time scales produced by fluctuations in the equatorial components of the torque.", "date": "1993", "date_type": "published", "publisher": "American Geophysical Union", "place_of_pub": "Washington, DC", "pagerange": "107-120", "id_number": "CaltechAUTHORS:20121016-145941398", "isbn": "9780875904672", "book_title": "Relating Geophysical Structures and Processes: The Jeffreys Volume", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121016-145941398", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA", "grant_number": "NAG5-819" }, { "agency": "NASA", "grant_number": "NAGS-315" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "contributors": { "items": [ { "id": "Aki-K", "name": { "family": "Aki", "given": "Keiiti" } }, { "id": "Dmowska-R", "name": { "family": "Dmowska", "given": "Renata" } } ] }, "doi": "10.1029/GM076p0107", "primary_object": { "basename": "Hide1993.pdf", "url": "https://authors.library.caltech.edu/records/k00cv-6cf89/files/Hide1993.pdf" }, "resource_type": "book_section", "pub_year": "1993", "author_list": "Hide, R.; Clayton, R. W.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/f4q0d-kk403", "eprint_id": 34921, "eprint_status": "archive", "datestamp": "2023-08-22 08:45:00", "lastmod": "2023-10-19 22:06:10", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Davies-J-H", "name": { "family": "Davies", "given": "J. Huw" } }, { "id": "Gudmundsson-O", "name": { "family": "Gudmundsson", "given": "Olafur" } }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "R. W." }, "orcid": "0000-0003-3323-3508" } ] }, "title": "Spectra of mantle shear wave velocity structure", "ispublished": "pub", "full_text_status": "public", "keywords": "body waves; inversion; stochastic; traveltime variance", "note": "\u00a9 1992 John Wiley & Sons. Accepted 1991 September 26. Received 1991 May 21. Article first published online: 2 Apr 2007. This work was supported by NSF awards EAR83-17623 and EAR83-51371. HD wishes to acknowledge the support of an NERC post-doctoral research fellowship, during the final stages of writing. Malcolm Sambridge and Bruce Buffett read an earlier draft of this paper, which led to significant improvements. Contribution number 5063, Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA.\n\nPublished - Davies1992.pdf
", "abstract": "We applied the stochastic method of Gudmundsson, Davies & Clayton (1990) (which was applied to ISC P-wave data) to teleseismic ISC S-wave data to obtain an independent estimate of mantle structure. We inverted the variance of S-wave traveltime residuals of bundles of rays to obtain a description of the spectrum of lateral heterogeneity as a function of depth through the mantle. The technique yields robust estimates of the traveltime scattering power (the product of a characteristic scalelength of heterogeneity and the mean square of slowness perturbations). We can estimate the characteristic scalelength (half-width), from the autocovariance; which can be reconstructed from the spectra. Hence by division, we can estimate the root mean square slowness. By extrapolating the variance of bundles of rays to bundles of zero cross-sectional area we can also estimate the scale-incoherent signal (which is a plausible estimate of the noise in the data), which is removed from the data.\nWe find that most of the structure generating shear wave traveltime residuals is located in the uppermost mantle. About half of the structure is short scale (harmonic degree l > 50). The large-scale structure (l > 50) has a half-width of about 500 km in the upper half of the mantle. This S-wave half-width is consistent with the P-wave half-widths determined by Gudmundsson et al. (1990). The S-wave half-width in the lower half of the mantle is poorly constrained. It varies from 500 to 3000 km, which spans the better constrained value of 1200 km found by Gudmundsson et al. (1990) for P-waves. The incoherent scatter suggests that the signal-to-noise ratio of the S-wave data set is around 1.5.\nAssuming that the compressional and shear wave velocity variations are correlated then the signal weighted value of the ratio d In (V_s)/d In (V_p) is \u2248 2, as also found in normal mode studies. This is much larger than the value of \u2248 0.8\u20131.4 suggested by laboratory experiments undertaken at atmospheric pressure. There is no evidence of periodicity in the traveltime autocovariance; this suggests little or no periodicity in the underlying convection. The short half-width through most of the mantle suggests high Rayleigh number convection, with its attendant small-scale structures. The power decreases by an order of magnitude or more in going from the upper mantle to the lower mantle, the same as found by Gudmundsson et al. (1990) for P-waves. This large difference suggests either a change in convective regime and/or a difference in the temperature sensitivity of elastic constants in both layers. The increased short-scale structure at the top of the mantle suggests that a large part of the seismic signature at this boundary is compositional, since one would expect a red spectrum for a thermal boundary layer. The derived spectra between l\u2248 10 and l\u2248 50 are similar in shape to spectra from the mantle convection simulations of Glatzmaier (1988) with a Rayleigh number of 10^6-10^7, which would suggest layered convection, if the comparison is valid.", "date": "1992-03", "date_type": "published", "publication": "Geophysical Journal International", "volume": "108", "number": "3", "publisher": "Royal Astronomical Society", "pagerange": "865-882", "id_number": "CaltechAUTHORS:20121016-110257109", "issn": "0956-540X", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121016-110257109", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR83-17623" }, { "agency": "NSF", "grant_number": "EAR83-51371" } ] }, "other_numbering_system": { "items": [ { "id": "5063", "name": "Caltech Division of Geological and Planetary Sciences" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1111/j.1365-246X.1992.tb03476.x", "primary_object": { "basename": "Davies1992.pdf", "url": "https://authors.library.caltech.edu/records/f4q0d-kk403/files/Davies1992.pdf" }, "resource_type": "article", "pub_year": "1992", "author_list": "Davies, J. Huw; Gudmundsson, Olafur; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/hqe4p-rqd43", "eprint_id": 34937, "eprint_status": "archive", "datestamp": "2023-08-20 01:06:10", "lastmod": "2023-10-19 22:07:07", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Stork-C", "name": { "family": "Stork", "given": "Christof" } }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" } ] }, "title": "Using constraints to address the instabilities of automated\n prestack velocity analysis", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 1992 Society of Exploration Geophysicists. Manuscript received by the Editor April 25, 1990; revised manuscript received August 12, 1991. This work summarizes some of my (Christof Stork) experience with thesis research. I appreciate the inspiration, wisdom, and support of my co-author while pursuing this work, which proved to be more compIicated than was expected at the outset. Numerous other people (Biondo Biondi, Ken Bube, James DiSeana, John Etgen, Paul Fowler, Sam Gray, Jean Luc Guiziou, Gene Humphreys, Bob Langan, Ronan Lebras, Larry Lines, John Louie, Peter Mora, Chuck Moser, Fabio Rocca, John Scales, Allan Skorpen, Jay Thorseth, John Toldi, Jos van Trier, Sven Treitel, John Vidale, Marty Williams, Dan Whitmore, and Marta Woodward among others) have my gratitude for their insightful comments. Some aspects of this work were performed during my\npost-doctoral position at the Stanford Exploration Project.\nThis research was funded by a grant from Amoco and Robert W. Clayton's Presidential Young Investigators award. I thank Amoco, Arco, and Chevron for allowing me to pursue this work while employed with them for the summer. My exposure to data and seismic exploration through these companies were essential to this work. My wife Terri was instrumental in enabling me to finish this paper.\nThis paper is contribution no. 4868 of the Department of\nGeological Sciences of the California Institute of Technology.\n\nPublished - Stork1992.pdf
", "abstract": "Generalized prestack velocity analysis methods that use an automated approach to resolve laterally variable interval velocity fields are beset by a series of problems. The problem of resolving lateral velocity variations has inherent complications that prevent automated methods from being robust enough to be applied routinely to data from a variety of geologic provinces. The use of automated prestack velocity analysis methods will not eliminate the step of carefully producing an initial velocity model derived from regional geologic information and an interpretation of a conventionally processed section. For the methods to regularly produce useful additional information, the unique characteristics of each application must be input into the prestack velocity analysis with the use of inversion constraints. These constraints serve either to adapt the generalized prestack velocity analysis to a focused objective in a particular area or to provide iterative, interpretational tools that help the user produce a velocity model.", "date": "1992-03", "date_type": "published", "publication": "Geophysics", "volume": "57", "number": "3", "publisher": "Society of Exploration Geophysicists", "pagerange": "404-419", "id_number": "CaltechAUTHORS:20121016-154241761", "issn": "0016-8033", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121016-154241761", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Amoco" }, { "agency": "Presidential Young Investigator" } ] }, "other_numbering_system": { "items": [ { "id": "4868", "name": "Caltech Division of Geological and Planetary Sciences" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1190/1.1443255", "primary_object": { "basename": "Stork1992.pdf", "url": "https://authors.library.caltech.edu/records/hqe4p-rqd43/files/Stork1992.pdf" }, "resource_type": "article", "pub_year": "1992", "author_list": "Stork, Christof and Clayton, Robert W." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/ws1dq-9de14", "eprint_id": 34835, "eprint_status": "archive", "datestamp": "2023-08-20 01:02:38", "lastmod": "2023-10-19 22:00:59", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Graves-R-W", "name": { "family": "Graves", "given": "Robert W." } }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" } ] }, "title": "Modeling path effects in three-dimensional basin structures", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 1992 Seismological Society of America.\n\nManuscript received 19 February 1991.\n\nWe would like to thank Amoco Foundation Inc. for the generous fellowship support of R. W. G. during this study. Some of the computations were done on a Convex C1/XP purchased under NSF Grant EAR-8721205. We also thank Donald V. Helmberger and Paul G. Somerville for suggestions to this work. Contribution no. 4988, Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, California.\n\nPublished - Graves1992.pdf
", "abstract": "Path effects for seismic wave propagation within three-dimensional (3-D) basin structures are analyzed using a reciprocal source experiment. In this experiment, a numerical simulation is performed in which a point source is excited at a given location and then the wave field is propagated and recorded throughout a 3-D grid of points. Using the principle of reciprocity, source and receiver locations are reversed. This allows the modeling of path effects into a particular observation site for all possible source locations using only one simulation. The numerical technique is based on the use of paraxial extrapolators and currently tracks only acoustic waves. However, the method is capable of handling arbitrary media variations; thus, effects due to focusing, diffraction, and the generation of multiple reflections and refractions are modeled quite well.\n\nThe application of this technique to model path effects for local earthquakes recorded at stations in the Los Angeles area of southern California indicates the strong influence of the 3-D crustal basins of this region on the propagation of seismic energy. The modeling results show that the Los Angeles, San Fernando, and San Gabriel basins create strong patterns of focusing and defocusing for paths into these stations from various source locations. These simulations correlate well with earthquake data recorded at both stations. By comparing these calculations with earthquake data, we can begin to evaluate the importance of these basin effects on observed patterns of strong ground motions.", "date": "1992-02", "date_type": "published", "publication": "Bulletin of the Seismological Society of America", "volume": "82", "number": "1", "publisher": "Seismological Society of America", "pagerange": "81-103", "id_number": "CaltechAUTHORS:20121010-155410178", "issn": "0037-1106", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121010-155410178", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Amoco Foundation, Inc." }, { "agency": "NSF", "grant_number": "EAR-8721205" } ] }, "other_numbering_system": { "items": [ { "id": "4988", "name": "Caltech Division of Geological Planetary Sciences" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "primary_object": { "basename": "Graves1992.pdf", "url": "https://authors.library.caltech.edu/records/ws1dq-9de14/files/Graves1992.pdf" }, "resource_type": "article", "pub_year": "1992", "author_list": "Graves, Robert W. and Clayton, Robert W." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/gtg8a-k8c94", "eprint_id": 34889, "eprint_status": "archive", "datestamp": "2023-08-20 00:11:48", "lastmod": "2023-10-19 22:04:07", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Gudmundsson-O", "name": { "family": "Gudmundsson", "given": "Olafur" } }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" } ] }, "title": "A 2-D synthetic study of global traveltime tomography", "ispublished": "pub", "full_text_status": "public", "keywords": "earth structure, inversion, traveltimes", "note": "\u00a9 1991 John Wiley & Sons, Inc.\n\nAccepted 1991 January 15. Received 1990 September 10.\n\nArticle first published online: 2 Apr. 2007.\n\nThis work was supported by NSF awards EAR83-17623 and\nEAR83-51371. O.G. was supported by a fellowship from the\nPhillips Petroleum Company. Contribution no. 4890, from\nthe Division of Geological and Planetary Sciences, Caltech.\n\nPublished - Gudmundsson1991.pdf
", "abstract": "A 2-D synthetic test study of global traveltime inversion for deep seated earth structure has been undertaken. This was done by generating traveltime residual data using reasonable models for earth structure. The data were then inverted by similar methods to those applied in global studies of earth structure. Our results indicate that models of the aspherical structure in the lower mantle based on traveltime data are only partially successful and only at the largest scales (harmonic degree \u22643) and that maps of the core-mantle boundary based on traveltimes are unsuccessful.", "date": "1991-07", "date_type": "published", "publication": "Geophysical Journal International", "volume": "106", "number": "1", "publisher": "Royal Astronomical Society", "pagerange": "53-65", "id_number": "CaltechAUTHORS:20121015-101011522", "issn": "0956-540X", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121015-101011522", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR83-17623" }, { "agency": "NSF", "grant_number": "EAR83-51371" }, { "agency": "Phillips Petroleum Company" } ] }, "other_numbering_system": { "items": [ { "id": "4890", "name": "Caltech Division of Geological and Planetary Sciences" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1111/j.1365-246X.1991.tb04600.x", "primary_object": { "basename": "Gudmundsson1991.pdf", "url": "https://authors.library.caltech.edu/records/gtg8a-k8c94/files/Gudmundsson1991.pdf" }, "resource_type": "article", "pub_year": "1991", "author_list": "Gudmundsson, Olafur and Clayton, Robert W." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/t8njg-4mw21", "eprint_id": 35664, "eprint_status": "archive", "datestamp": "2023-08-19 23:36:46", "lastmod": "2024-01-13 05:57:25", "type": "book", "metadata_visibility": "show", "creators": { "items": [ { "id": "Hauksson-E", "name": { "family": "Hauksson", "given": "Egill" }, "orcid": "0000-0002-6834-5051" }, { "id": "Jones-L-M", "name": { "family": "Jones", "given": "Lucile" }, "orcid": "0000-0002-2690-3051" }, { "id": "Mori-Jim", "name": { "family": "Mori", "given": "James" } }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert" }, "orcid": "0000-0003-3323-3508" }, { "id": "Heaton-T-H", "name": { "family": "Heaton", "given": "Thomas" }, "orcid": "0000-0003-3363-2197" }, { "id": "Kanamori-H", "name": { "family": "Kanamori", "given": "Hiroo" }, "orcid": "0000-0001-8219-9428" }, { "id": "Helmberger-D-V", "name": { "family": "Helmberger", "given": "Don" } } ] }, "title": "Southern California Seismographic Network; report to the U.S. Geological Survey, August 21, 1990", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 1991 U.S. Geological Survey.\n\nPublished - 91-38.pdf
", "abstract": "On August 21, 1990, the U. S. Geological Survey held a meeting to\nreview the status of regional seismic networks in the United States. The\npurpose of the meeting was to provide information to the U.S.G.S. to assist\nthem in setting priorities for future funding of seismic networks in a time\nof increasingly tight budgets. Each of the networks was therefore asked to\nprepare a report describing their goals and accomplishments. Three\nspecific questions were raised: how the objectives of the network have\nbeen met, the potential for future productivity and opportunities for\nadditional funding.", "date": "1991-01", "date_type": "published", "publisher": "U.S. Geological Survey", "id_number": "CaltechAUTHORS:20121127-093130762", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121127-093130762", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.3133/ofr9138", "primary_object": { "basename": "91-38.pdf", "url": "https://authors.library.caltech.edu/records/t8njg-4mw21/files/91-38.pdf" }, "resource_type": "book", "pub_year": "1991", "author_list": "Hauksson, Egill; Jones, Lucile; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/yrfwh-rn587", "eprint_id": 34939, "eprint_status": "archive", "datestamp": "2023-08-19 23:17:31", "lastmod": "2023-10-19 22:07:10", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Humphreys-E-D", "name": { "family": "Humphreys", "given": "Eugene D." } }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" } ] }, "title": "Tomographic Image of the Southern California Mantle", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 1990 American Geophysical Union. Received 10 November 1987; revised June 6, 1990; accepted 13 June 1990. We would like to thank Eric Ivans, Charlie Knox, Cliff Thurber, Ray Weldon, and anonymous reviewers for helpful comments on this paper. This research was supported by NSF grant EAR-8804953 and by NSF contract EAR-83-51371 and USGS contract 14-08-0001-01774. Contribution number 4932, Division of Geological and Planetary Sciences, California Institute of Technology.\n\nPublished - Humphreys1990.pdf
", "abstract": "P wave teleseismic travel time delays recorded by the Southern California Array are inverted by the method of backprojection tomography to obtain images of variations in the P wave velocity structure to a depth of 750 km. Two major upper mantle features arc resolved: one beneath the Transverse Ranges region and another beneath the Salton Trough region. The Transverse Ranges feature appears as a curtainlike, east trending, high-velocity anomaly. This feature is \u223c60 km thick, extends most deeply on its eastern end (to \u223c250 km), and attains a maximum velocity \u22123% greater than average southern California mantle of the same depth. The Salton Trough feature, which is not as well resolved as the Transverse Ranges feature, is composed of low velocities in the upper 70\u2013100 km. These P wave velocities arc depressed 3\u20134% compared to average southern California mantle. Tests of the inversion indicate the major aspects of the imaged structure are authentic.", "date": "1990-11-10", "date_type": "published", "publication": "Journal of Geophysical Research B", "volume": "95", "number": "B12", "publisher": "American Geophysical Union", "pagerange": "19725-19746", "id_number": "CaltechAUTHORS:20121017-071833562", "issn": "0148-0227", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121017-071833562", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR-8804953" }, { "agency": "NSF", "grant_number": "EAR-8351371" }, { "agency": "USGS", "grant_number": "14-08-0001-G1774" } ] }, "other_numbering_system": { "items": [ { "id": "4932", "name": "Caltech Division of Geological and Planetary Sciences" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1029/JB095iB12p19725", "primary_object": { "basename": "Humphreys1990.pdf", "url": "https://authors.library.caltech.edu/records/yrfwh-rn587/files/Humphreys1990.pdf" }, "resource_type": "article", "pub_year": "1990", "author_list": "Humphreys, Eugene D. and Clayton, Robert W." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/nddyy-42792", "eprint_id": 34958, "eprint_status": "archive", "datestamp": "2023-08-22 07:40:50", "lastmod": "2023-10-19 22:08:24", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Gudmundsson-O", "name": { "family": "Gudmundsson", "given": "O." } }, { "id": "Davies-J-H", "name": { "family": "Davies", "given": "J. H." } }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "R. W." }, "orcid": "0000-0003-3323-3508" } ] }, "title": "Stochastic analysis of global traveltime data: mantle heterogeneity and random errors in the ISC data", "ispublished": "pub", "full_text_status": "public", "keywords": "heterogeneity; mantle; power spectrum; random error; traveltime; variance", "note": "\u00a9 1990 John Wiley and Sons.\nAccepted 1989 December 18; Received 1989 December 12; in original form 1989 March 16.\nWe appreciate helpful comments by Don L. Anderson,\nDave Stevenson and Hiroo Kanamori. This manuscript was\ngreatly improved by the critical review of Bryndis Bimir and\nHiroo Kanamori. This work was supported by NSF awards\nEAR83-17623 and EAR83-51371. The Phillips Petroleum\nCompany provided fellowship support for O.G. This study\nwas only possible because of the tremendous service\nperformed by the ISC. Contribution 4748, Division of\nGeological and Planetary Sciences, California Institute of\nTechnology, Pasadena, California.\n\nPublished - Gudmundsson1990.pdf
", "abstract": "Analysis of global traveltime data has been formulated in terms of the stochastic properties of the Earth's heterogeneity pattern and random errors in the data. The formalism relates the coherency of traveltime residuals within bundles of rays (summary rays) of varying size to the spherical harmonic power spectrum of the slowness field of the medium. It has been applied to mantle P-wave data from the ISC catalogue. The measure of coherency is the variance within summary rays. It is estimated within bins in source depth, epicentral distance and the scale size of the area defining a summary ray. The variance at infinitesimal scale length represents the incoherent component of the data (random errors). The variation of the variance with scale length contains information about the autocorrelation function or power spectrum of slowness perturbations within the Earth. The variation with epicentral distance reflects the depth variation of the spectrum. The formalism accounts for the uneven distribution (clustering) of stations and events.\nWe find that estimates of random errors correlate well with complexities on the traveltime curve of P-waves. The variance peaks at 1.0\u20132.0 s^2 at \u0394 \u2248 20\u00b0, where triplications occur on the traveltime curve, drops to 0.15\u20130.8s^2 at teleseismic distances, and rises to 0.4\u20131.3 s^2 approaching the core shadow, where the traveltime curves of P-waves and PcP-waves merge. These estimates should be considered upper bounds for the random error variance of the data. The signal to random noise ratio in the teleseismic ISC P-wave data is about S/N \u2248 2.\nInversion of the scale-dependent structural signal in the data yields models that concentrate heterogeneity strongly in the upper mantle. The product of correlation length and power drops by about two orders of magnitude from the surface of the Earth to the lower mantle. About half of this quantity in the upper mantle is due to small-scale features (<300km). The lower mantle is devoid of small-scale structure. It contains 0.1 per cent velocity variations at a characteristic scale of about 1000km. This corresponds to a spectral band-width of l \u2248 7. The D\u2033 layer at the bottom 100\u2013200 km of the mantle shows up as a distinct layer in our results. It has 0.3 per cent velocity variations at a characteristic scale of 350km. The top of the lower mantle contains 0.3 per cent velocity variations on a scale of 500km and also contains some small-scale power.\nThese results are compatible with previous deterministic lower mantle studies, although some details differ. The strength of heterogeneity in the upper mantle may obscure attempts to model the Earth's deep interior.", "date": "1990-07", "date_type": "published", "publication": "Geophysical Journal International", "volume": "102", "number": "1", "publisher": "Royal Astronomical Society", "pagerange": "25-43", "id_number": "CaltechAUTHORS:20121017-163209315", "issn": "0956-540X", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121017-163209315", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR83-17623" }, { "agency": "NSF", "grant_number": "EAR83-51371" }, { "agency": "Phillips Petroleum Company" } ] }, "other_numbering_system": { "items": [ { "id": "4748", "name": "Caltech Division of Geological and Planetary Sciences" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1111/j.1365-246X.1990.tb00528.x", "primary_object": { "basename": "Gudmundsson1990.pdf", "url": "https://authors.library.caltech.edu/records/nddyy-42792/files/Gudmundsson1990.pdf" }, "resource_type": "article", "pub_year": "1990", "author_list": "Gudmundsson, O.; Davies, J. H.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/8bp5w-zpr23", "eprint_id": 34652, "eprint_status": "archive", "datestamp": "2023-08-22 07:37:06", "lastmod": "2023-10-19 21:21:24", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Zhou-Hua-Wei", "name": { "family": "Zhou", "given": "Hua-Wei" } }, { "id": "Anderson-D-L", "name": { "family": "Anderson", "given": "Don L." } }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" } ] }, "title": "Modeling of residual spheres for subduction zone earthquakes: 1. Apparent slab penetration signatures in the NW Pacific caused by deep diffuse mantle anomalies", "ispublished": "pub", "full_text_status": "public", "keywords": "Seismology: Structure of the lithosphere and upper mantle; Seismology: Earthquake dynamics; Information Related to Geographic Region: Pacific Ocean; Seismology: Body waves; Seismology: Structure of mantle and core; Tectonophysics: Composition and state of the Earth's interior", "note": "\u00a9 1990 American Geophysical Union. Received February 10, 1988; revised October 9, 1989; accepted September 21, 1989. This research was supported by National Science Foundation grants EAR 83-17623 and EAR 85-09350. Contribution No. 4585, Division of\nGeological and Planetary Sciences, California Institute of Technology.\n\nPublished - Zhou1990.pdf
", "abstract": "We have computed focal residual spheres for 145 subduction zone earthquakes along the northwest edge of the Pacific using regional and global mantle velocity models from tomographic inversions. The mantle models explain much of the observed residual sphere data and, to a certain extent, suggest the location of mantle velocity heterogeneities which are responsible for various residual sphere patterns. For most deep events considered, the fast slablike residual sphere anomalies are caused by diffuse heterogeneities, mainly of deep lower mantle and receiver mantle origin rather than by an extension of the slab. The region immediately below the deepest earthquakes, depths of 650\u20131500 km, has an effect usually smaller than or comparable to the effect of other regions of the mantle. Without a proper account of the teleseismic effect, attributing the long-wavelength anomalies of the residual sphere to near-source slab effects alone, or even primarily, is not valid. The fast bands in many observed residual spheres agree with seismicity trends. Once the deep mantle and receiver mantle effects are removed, these may give the approximate orientation, but not the depth extent, of near-source fast velocities. For most deep earthquakes under Japan the predominant fast band is subhorizontal rather than near vertical. This type feature would be overlooked in conventional residual sphere studies using only steeply diving rays and cosine weighting of the data.", "date": "1990-05-10", "date_type": "published", "publication": "Journal of Geophysical Research B", "volume": "95", "number": "B5", "publisher": "American Geophysical Union", "pagerange": "6799-6827", "id_number": "CaltechAUTHORS:20121003-091115992", "issn": "0148-0227", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121003-091115992", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR 83-17623" }, { "agency": "NSF", "grant_number": "EAR 85-09350" } ] }, "other_numbering_system": { "items": [ { "id": "4585", "name": "Caltech Division of Geological and Planetary Sciences" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1029/JB095iB05p06799", "primary_object": { "basename": "Zhou1990.pdf", "url": "https://authors.library.caltech.edu/records/8bp5w-zpr23/files/Zhou1990.pdf" }, "resource_type": "article", "pub_year": "1990", "author_list": "Zhou, Hua-Wei; Anderson, Don L.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/21a4p-nvw13", "eprint_id": 34894, "eprint_status": "archive", "datestamp": "2023-08-19 22:46:13", "lastmod": "2023-10-19 22:04:19", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Zhou-Hua-Wei", "name": { "family": "Zhou", "given": "Hua-Wei" } }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" } ] }, "title": "P and S Wave Travel Time Inversions for Subducting Slab\n Under the Island Arcs of the Northwest Pacific", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 1990 American Geophysical Union. Received 26 September 1988; revised November 10, 1989; accepted 5 October 1989. We thank Don L. Anderson for stimulating discussions and critical reading of the manuscript. Some useful comments by T. Tanimoto are appreciated. Several thorough, anonymous reviews improved the text. Work was supported by National Science Foundation grants EAR 83-17623. Contribution No. 4627, Division of Geological and Planetary Sciences, California Institute of Technology.\n\nPublished - Zhou1990b.pdf
", "abstract": "We have observed slablike high P and S velocity anomalies around the Wadati-Benioff zone under island arcs of the northwest Pacific through travel time tomographic inversions. Nineteen years of International Seismological Centre travel time residuals for events and stations in this large region are used. Analyses of resolution and noise show that the images are generally well resolved. The images illustrate that slab anomalies are continuous along strike in most parts of the upper mantle of the region and become contorted and generally broadened with depth. Near the bottom of the upper mantle, fingering of the slabs, including segmenting and spreading, is indicated. The fast anomalies associated with the Japan, Izu-Bonin, and Mariana subduction zones tend to flatten to subhorizontal at depth, while downward spreading may occur under parts of the Mariana and Kurile arcs. The fast anomalies below 700 km are not in the shape of a single coherent sheet. The principal compressional axes of focal mechanisms in the region consistently follow the downdip direction of the high-velocity slab, even when it bends to subhorizontal at depth. The depth at which compression begins to dominate the downdip stress regime in the slab apparently depends on bending of the slab and its dip. Slab fingering and intense deep seismicity probably are the consequence of the slab encountering a barrier of some form around the \"670-km\" discontinuity.", "date": "1990-05-10", "date_type": "published", "publication": "Journal of Geophysical Research B", "volume": "95", "number": "B5", "publisher": "American Geophysical Union", "pagerange": "6829-6851", "id_number": "CaltechAUTHORS:20121015-111307619", "issn": "0148-0227", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121015-111307619", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR 83-17623" } ] }, "other_numbering_system": { "items": [ { "id": "4627", "name": "Caltech Division of Geological and Planetary Sciences" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1029/JB095iB05p06829", "primary_object": { "basename": "Zhou1990b.pdf", "url": "https://authors.library.caltech.edu/records/21a4p-nvw13/files/Zhou1990b.pdf" }, "resource_type": "article", "pub_year": "1990", "author_list": "Zhou, Hua-Wei and Clayton, Robert W." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/k0xsg-a9r18", "eprint_id": 34957, "eprint_status": "archive", "datestamp": "2023-08-19 22:30:57", "lastmod": "2023-10-19 22:08:20", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Graves-R-W", "name": { "family": "Graves", "given": "R. W." } }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "R. W." }, "orcid": "0000-0003-3323-3508" } ] }, "title": "Modeling acoustic waves with paraxial extrapolators", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 1990 Society of Exploration Geophysicists.\nPresented at the 57th Annual International Meeting, Society of Exploration Geophysicists; Received March 3, 1989; revised September 22, 1989; Issue Date March 1990.\nWe would like to thank Amoco Foundation Inc. for the\ngenerous fellowship support of R. W. G. during this study.\nSome of the computations were done on a Convex C1/XP\npurchased under NSF grant EAR-8721205. Cindy Arvesen\nassisted with the drafting of figures.\nContribution 4746, Division of Geological and Planetary\nSciences, California Institute of Technology, Pasadena, California.\n\nPublished - Graves1990.pdf
", "abstract": "Modeling by paraxial extrapolators is applicable to wave-propagation problems in which most of the energy is traveling within a restricted angular cone about a principal axis of the problem. Using this technique, frequency-domain finite-difference solutions accurate for propagation angles out to 60\u00b0 are readily generated for both two-dimensional (2-D) and three-dimensional (3-D) models. Solutions for 3-D problems are computed by applying the 2-D paraxial operators twice, once along the x-axis and once along the y-axis, at each extrapolation step. The azimuthal anisotropy inherent to this splitting technique is essentially eliminated by adding a phase-correction operator to the extrapolation system. For heterogeneous models, scattering effects are incorporated by determining transmission and reflection coefficients at structural boundaries within the media. The direct forward-scattered waves are modeled with a single pass of the extrapolation operator in the paraxial direction for each frequency. The first-order backscattered energy is then modeled by extrapolation (in the opposite direction) of the reflected field determined on the first pass. Higher order scattering can be included by sweeping through the model with more passes. The chief advantages of the paraxial approach are (1) active storage is reduced by one dimension compared to solutions which must track both forward-scattered and backscattered waves simultaneously; thus, realistic 3-D problems can fit on today's computers, (2) the decomposition in frequency allows the technique to be implemented on highly parallel machines, (3) attenuation can be modeled as an arbitrary function of frequency, and (4) only a small number of frequencies are needed to produce movie-like time slices.", "date": "1990-03", "date_type": "published", "publication": "Geophysics", "volume": "55", "number": "3", "publisher": "Society of Exploration Geophysicists", "pagerange": "306-319", "id_number": "CaltechAUTHORS:20121017-161014406", "issn": "0016-8033", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121017-161014406", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR-8721205" }, { "agency": "Amoco Foundation Inc." } ] }, "other_numbering_system": { "items": [ { "id": "4746", "name": "Caltech Division of Geological and Planetary Sciences" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1190/1.1442838", "primary_object": { "basename": "Graves1990.pdf", "url": "https://authors.library.caltech.edu/records/k0xsg-a9r18/files/Graves1990.pdf" }, "resource_type": "article", "pub_year": "1990", "author_list": "Graves, R. W. and Clayton, R. W." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/n21w7-jrw19", "eprint_id": 34637, "eprint_status": "archive", "datestamp": "2023-08-19 21:07:34", "lastmod": "2024-01-13 05:55:32", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Hager-B-H", "name": { "family": "Hager", "given": "Bradford H." }, "orcid": "0000-0002-5643-1374" }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" } ] }, "title": "Constraints on the Structure of Mantle Convection Using Seismic Observations, Flow Models, and the Geoid", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 1989 Gordon and Breach Science Publishers.\nThe research reported in this chapter was supported by NASA contract NAG5-315\nand NSF contract EAR-8351371 and by a Sloan Foundation Fellowship to Bradford\nH. Hager. The graphics were made possible in part by a grant from the W.M. Keck\nFoundation. We would like to specifically acknowledge the valuable contributions of\nRobert P. Comer and Mark A. Richards, who played central roles in the research\nreviewed here. Encouragement and valuable reviews of the manuscript were provided\nby Richard J. O'Connell and Walter Kiefer. Contribution number 4342, Division of Geological and Planetary Sciences. California Institute of Technology, Pasadena, CA 91125.\nAn updated summary of further progress in this area in the over two years since this\npaper was completed can be found in Hager and Richards (1989).", "abstract": "The establishment of the theory of plate tectonics in the late 1960s has left\nlittle doubt that the mantle is convecting. The plates themselves form the cold\nupper thermal boundary layer of the mantle convection system; the cooling of\noceanic plates as they move away from midoceanic ridges provides the\nmechanism by which the Earth loses most of its heat (e.g., Sclater et al.,\n1980; O'Connell and Hager, 1980). The mantle is in turn cooled by the cold\nslabs that plunge into Earth's interior at subduction zones.\n\nAlthough plate tectonics implies that convective motions in the mantle are\nthe dominant mechanism for heat transport, and we can measure the surface\nmotions associated with it, we are remarkably ignorant of even the gross\nfeatures of the interior flow field associated with this mantle circulation. Only\nat subduction zones, where seismicity presumably marks the particle trajectories\nof the cold descending boundary layer, do we have direct evidence for\nthe interior flow pattern and state of stress. Most of what is understood, or\nthought to be understood, about convection in the Earth's interior is based on\ncomparison of simplified models to observations taken at the surface.\n\nExamples of these models of mantle convection are given in the other\nchapters of this book, as well as in the general geophysical literature. These\ninclude studies of convection in media with uniform rheology (Busse, this\nvolume; Jarvis and Peltier, this volume), interpretation of travel time anomalies\nfrom deep earthquakes in terms of simple thermal models of subducted\nslabs (Jordan eta!., this volume), interpretation of geochemical anomalies in\nterms of models of the distribution of mantle heterogeneities (Hart and\nZindler, this volume), and interpretation of changes in the Earth's shape and\nrotational parameters in terms of models of mantle rheology (Peltier, this\nvolume).\n\nIn order to be useful, models must be simple enough to understand, and\nyet contain enough of the essential physics to be applicable. The line\nbetween oversimplification and overwhelming complexity is a fine one, and\nits positioning is a matter of subjective judgement, particularly when some\nobservations have a fairly small signal to noise ratio. The ultimate test of a\nparticular model is whether it can satisfy, within their uncertainties, the\nobservations. If it cannot it must be rejected, although unfortunately, the\nconverse is not true. The more types of observations a model can satisfy,\nhowever, the more likely it is to be correct.", "date": "1989", "date_type": "published", "publisher": "Gordon and Breach Science Publishers", "place_of_pub": "New York", "pagerange": "657-763", "id_number": "CaltechAUTHORS:20121002-141328164", "isbn": "9780677221205", "book_title": "Mantle Convection: Plate Tectonics and Global Dynamics", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121002-141328164", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA", "grant_number": "NAG5-315" }, { "agency": "NSF", "grant_number": "EAR-8351371" }, { "agency": "Alfred P. Sloan Foundation" }, { "agency": "W. M. Keck Foundation" } ] }, "other_numbering_system": { "items": [ { "id": "4342", "name": "Caltech Division of Geological and Planetary Sciences" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "contributors": { "items": [ { "id": "Peltier-W-R", "name": { "family": "Peltier", "given": "W. R." } } ] }, "resource_type": "book_section", "pub_year": "1989", "author_list": "Hager, Bradford H. and Clayton, Robert W." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/r30w5-z9x12", "eprint_id": 34917, "eprint_status": "archive", "datestamp": "2023-08-19 20:54:51", "lastmod": "2023-10-19 22:05:33", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Ho-Liu-Phyllis", "name": { "family": "Ho-Liu", "given": "Phyllis" } }, { "id": "Kanamori-H", "name": { "family": "Kanamori", "given": "Hiroo" }, "orcid": "0000-0001-8219-9428" }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" } ] }, "title": "Applications of attenuation tomography to Imperial Valley and Coso-Indian Wells Region, southern California", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 1988 American Geophysical Union. \n\nReceived 18 March 1987; accepted 6 March 1988.\n\nWe thank Chris Sanders for valuable suggestions in the early stage of this study and providing us with the\nCoso data set and Marianne Walck for providing us with the\nresults obtained in the Coso-Indian Wells study (Figure 7). We also thank Christof Stork for supplying the three-dimensional ray-tracing code. Discussions with Art Frankel, Carl Johnson, Kerry Sieh, Richard Stead, and John Vidale have been very helpful. We also thank Luciana Astiz, E. Kissling, Harold Magistrale, William Menke, Richard Stead, John Vidale, and two anonymous reviewers for reviewing the manuscript. This work is supported by USGS grant 14-08-0001-G1171 and in part by a grant from the Keck\nFoundation. Contribution no. 4437, from the Division of Geological and Planetary Sciences, California Institute of Technology.\n\nPublished - Ho-Liu1988.pdf
", "abstract": "Spatial variations in seismic wave attenuation were tomographically imaged from observed S to P wave amplitude ratios in the Imperial Valley and Coso-Indian Wells regions of southern California. In the Coso-Indian Wells region a highly attenuating body (S wave quality factor Q_\u03b2 \u2248 30) coincides with a slow P wave anomaly mapped by Walck and Clayton (1987). This coincidence suggests the presence of a 3- to 5-km depth magmatic or hydrothermal body in the Indian Wells region. In the Imperial Valley, slow P wave travel time anomalies and highly attenuating S wave anomalies were found in the Brawley seismic zone at a depth of 8\u201312 km. The effective S wave quality factor is very low (Q_\u03b2 \u2248 20), and the P wave velocity is 10% slower than the surrounding areas. These results suggest either magmatic or hydrothermal intrusions, or fractures at depth, possibly related to active shear in the Brawley seismic zone. This attenuation tomographic technique is shown to be useful in delineating the spatial variations in seismic wave attenuation and in estimating the effective seismic quality factor of attenuation anomalies.", "date": "1988-09-10", "date_type": "published", "publication": "Journal of Geophysical Research B", "volume": "93", "number": "B9", "publisher": "American Geophysical Union", "pagerange": "10501-10520", "id_number": "CaltechAUTHORS:20121016-103928185", "issn": "0148-0227", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121016-103928185", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "USGS", "grant_number": "14-08-0001-G1171" }, { "agency": "W. M. Keck Foundation" } ] }, "other_numbering_system": { "items": [ { "id": "4437", "name": "Caltech Division of Geological and Planetary Sciences" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1029/JB093iB09p10501", "primary_object": { "basename": "Ho-Liu1988.pdf", "url": "https://authors.library.caltech.edu/records/r30w5-z9x12/files/Ho-Liu1988.pdf" }, "resource_type": "article", "pub_year": "1988", "author_list": "Ho-Liu, Phyllis; Kanamori, Hiroo; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/t7evy-qkp36", "eprint_id": 34906, "eprint_status": "archive", "datestamp": "2023-08-19 20:30:46", "lastmod": "2023-10-19 22:05:03", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "LeBras-R-J", "name": { "family": "LeBras", "given": "Ronan" } }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" } ] }, "title": "An iterative inversion of back-scattered acoustic waves", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 1988 Society of Exploration Geophysicists.\nPresented at the 54th Annual International Meeting, Society of Exploration Geophysicists, 1984. Manuscript received by the Editor August 27, 1986; revised manuscript received September 4, 1987.\nWe would like to thank John Louie and Christof Stork\nfrom Caltech for their help and suggestions. We would also\nlike to thank Prof. Albert Tarantola from I.P.G. (Paris) for\nsuggesting the iterative method presented here. This work was\npartially supported by a National Science Foundation PYI\naward to RWC.\nContribution no. 4353 from the Division of Geological and\nPlanetary Science, California Institute of Technology.\n\nPublished - LeBras_Geophys1988p501.pdf
", "abstract": "The application of the Born approximation to the\nscattered wave field, followed by a WKBJ and far-field\napproximation on the propagation Green's function for\na slowly varying background medium, leads to a simple\nintegral relation between the density and bulk-modulus\nanomalies superimposed on the background medium\nand the scattered wave field. An iterative inversion\nscheme based on successive back-projections of the\nwave field is used to reconstruct the two acoustic parameters.\nThe scheme, when applied to data generated\nusing the direct integral relation, shows that the variations\nof the parameters can be reconstructed. The procedure\nis readily applicable to actual data, since every\niterative step is essentially a prestack Kirchhoff migration\nfollowed by the application of the direct Born\napproximation and far-field operator.", "date": "1988-04", "date_type": "published", "publication": "Geophysics", "volume": "53", "number": "4", "publisher": "Society of Exploration Geophysicists", "pagerange": "501-508", "id_number": "CaltechAUTHORS:20121015-162705193", "issn": "0016-8033", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121015-162705193", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF" } ] }, "other_numbering_system": { "items": [ { "id": "4353", "name": "Caltech Division of Geological and Planetary Sciences" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1190/1.1442481", "primary_object": { "basename": "LeBras_Geophys1988p501.pdf", "url": "https://authors.library.caltech.edu/records/t7evy-qkp36/files/LeBras_Geophys1988p501.pdf" }, "resource_type": "article", "pub_year": "1988", "author_list": "LeBras, Ronan and Clayton, Robert W." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/0bnam-0tk04", "eprint_id": 34901, "eprint_status": "archive", "datestamp": "2023-08-19 20:24:49", "lastmod": "2023-10-19 22:04:44", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Humphreys-E", "name": { "family": "Humphreys", "given": "Eugene" } }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" } ] }, "title": "Adaptation of back projection tomography to seismic travel time problems", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 1988 American Geophysical Union.\n\nReceived 29 December 1986; accepted 19 November 1987.\n\nThis work has benefited from many discussions with Rob Comer, John Fawcett, and Tom Hearn, a group of people\nbrought together at the California Institute of Technology (Caltech) by their mutual interest in the theory and application of back projection tomography. We would like to thank Bob Langan and anonymous reviewers who contributed to the quality of this paper. This study was supported by the U.S. Geological Survey (USGS 14-08-0001-G1171) and by an NSF-PYI award to RWC. Contribution 4502 from the Seismological Laboratory, Caltech.\n\nPublished - Humphreys1988.pdf
", "abstract": "A back projection method of reconstruction is adapted to invert seismic travel time data for velocity structure. Adaptations are made so that the inhomogeneous and anisotropic ray sets and the three-dimensional geometries commonly dealt with in seismic experiments can be handled with greater success. Jacobi iteration, deconvolution, and ray weighting work well in augmenting the basic back projection method to produce a well-focused image. These methods succeed by amounts that depend on the quality of the ray coverage. Also, the ability to reconstruct an accurate image when the data include moderate amounts of noise is shown to be good. Comparison of inversions produced with back projection tomography and with damped least squares indicate that the two methods are comparable in their ability to reconstruct an image of the actual structure. The back projection approach, however, is much more computer efficient. In practice, this allows for the construction of more detailed inversions.", "date": "1988-02-10", "date_type": "published", "publication": "Journal of Geophysical Research B", "volume": "93", "number": "B2", "publisher": "American Geophysical Union", "pagerange": "1073-1085", "id_number": "CaltechAUTHORS:20121015-130930076", "issn": "0148-0227", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121015-130930076", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "USGS", "grant_number": "14-08-0001-G1171" }, { "agency": "NSF" } ] }, "other_numbering_system": { "items": [ { "id": "4502", "name": "Caltech Seismological Laboratory" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1029/JB093iB02p01073", "primary_object": { "basename": "Humphreys1988.pdf", "url": "https://authors.library.caltech.edu/records/0bnam-0tk04/files/Humphreys1988.pdf" }, "resource_type": "article", "pub_year": "1988", "author_list": "Humphreys, Eugene and Clayton, Robert W." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/xa8j7-5gg04", "eprint_id": 34886, "eprint_status": "archive", "datestamp": "2023-08-19 20:23:10", "lastmod": "2023-10-19 22:03:58", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Louie-J-N", "name": { "family": "Louie", "given": "John N." } }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" }, { "id": "LeBras-R-J", "name": { "family": "LeBras", "given": "Ronan J." } } ] }, "title": "Three-dimensional imaging of steeply dipping structure near the San Andreas fault, Parkfield, California", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 1988 Society of Exploration Geophysicists.\n\nPresented at the 54th Annual International Meeting, Society of Exploration Geophysicists, Atlanta. Manuscript received by the Editor June 2,\n1987; revised manuscript received July 27, 1987.\n\nDigital data from the COCORP Parkfield survey were\nkindly provided by S. Kaufman of Cornell University. The\nwork was supported by a generous fellowship from the Amoco Foundation and by grants from Sun Oil Co. and the Keck Foundation.\nContribution no. 4475, Division of Geological and Planetary\nSciences, California institute of Technology.\n\nPublished - Louie1988.pdf
", "abstract": "Shot gathers from the Parkfield, California, deep crustal seismic reflection line, recorded in 1977 by COCORP, reveal coherent events having horizontal to reverse moveouts. These events were migrated using a multioffset three-dimensional Kirchhoff summation method. This method is a ray-equation back projection inversion of the acoustic wave field, which is valid under the Born, WKBJ, and far-field assumptions. Migration of full-wave acoustic synthetics, having the same limitations in geometric coverage as the COCORP survey, demonstrates the utility of the imaging process. The images obtained from back projection of the survey data suggest that the Gold Hill fault carries ultramafic rocks from the surface to 3 km depth at a dip greater than 45 degrees, where it joins the San Andreas fault, which may cut through more homogeneous materials at shallow depths. To the southwest, a 2 km Tertiary sedimentary section appears to terminate against a near-vertical fault. The zone between this fault and the San Andreas may be floored at 3 km by flat-lying ultramafics. Lateral velocity inhomogeneities are not accounted for in the migration but, in this case, do not seriously hinder the reconstruction of reflectors.", "date": "1988-02", "date_type": "published", "publication": "Geophysics", "volume": "53", "number": "2", "publisher": "Society of Exploration Geophysicists", "pagerange": "176-185", "id_number": "CaltechAUTHORS:20121015-083555128", "issn": "0016-8033", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121015-083555128", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Amoco Foundation" }, { "agency": "Sun Oil Co." }, { "agency": "W. M. Keck Foundation" } ] }, "other_numbering_system": { "items": [ { "id": "4775", "name": "Caltech Division of Geological and Planetary Sciences" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1190/1.1442452", "primary_object": { "basename": "Louie1988.pdf", "url": "https://authors.library.caltech.edu/records/xa8j7-5gg04/files/Louie1988.pdf" }, "resource_type": "article", "pub_year": "1988", "author_list": "Louie, John N.; Clayton, Robert W.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/fsybt-58j06", "eprint_id": 70324, "eprint_status": "archive", "datestamp": "2023-08-19 20:14:23", "lastmod": "2023-10-20 22:10:15", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Graves-R-W", "name": { "family": "Graves", "given": "Robert W." } }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" } ] }, "title": "Acoustic wavefield propagation using paraxial extrapolators", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 1988 ACM.", "abstract": "Modeling by paraxial extrapolators is applicable to wave propagation problems in which most of the energy is traveling within a restricted angular cone about a principle axis of the problem. Frequency domain finite-difference solutions are readily generated by using this technique. Input models can be described either by specifying velocities or appropriate media parameters on a two or three dimensional grid of points. For heterogeneous models, transmission and reflection coefficients are determined at structural boundaries within the media. The direct forward scattered waves are modeled with a single pass of the extrapolator operator in the paraxial direction for each frequency. The first-order back scattered energy can then be modeled by extrapolation (in the opposite direction) of the reflected field determined on the first pass. Higher order scattering can be included by sweeping through the model with more passes. \n\nThe chief advantages of the paraxial approach are 1) active storage is reduced by one dimension as compared to solutions which must track both up-going and down-going waves simultaneously, thus even realistic three dimensional problems can fit on today's computers, 2) the decomposition in frequency allows the technique to be implemented on highly parallel machines such the hypercube, 3) attenuation can be modeled as an arbitrary function of frequency, and 4) only a small number of frequencies are needed to produce movie-like time slices. \n\nBy using this method a wide range of seismological problems can be addressed, including strong motion analysis of waves in three-dimensional basins, the modeling of VSP reflection data, and the analysis of whole earth problems such as scattering at the core-mantle boundary or the effect of tectonic boundaries on long-period wave propagation.", "date": "1988-01", "date_type": "published", "publisher": "ACM", "place_of_pub": "New York, NY", "pagerange": "1157-1175", "id_number": "CaltechAUTHORS:20160913-164049112", "isbn": "0-89791-278-0", "book_title": "C3P Proceedings of the third conference on Hypercube concurrent computers and applications", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160913-164049112", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "contributors": { "items": [ { "id": "Fox-Geoffrey", "name": { "family": "Fox", "given": "Geoffrey" } } ] }, "doi": "10.1145/63047.63069", "resource_type": "book_section", "pub_year": "1988", "author_list": "Graves, Robert W. and Clayton, Robert W." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/jcvy3-6y868", "eprint_id": 34649, "eprint_status": "archive", "datestamp": "2023-08-19 19:27:13", "lastmod": "2023-10-19 21:21:17", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Louie-J-N", "name": { "family": "Louie", "given": "John N." } }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" } ] }, "title": "The nature of deep crustal structures in the Mojave Desert, California", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 1987 Royal Astronomical Society.\n\nPublished - Louie1987.pdf
", "abstract": "The character of multi-offset reflections from the deep crust in the Mojave Desert are examined to reveal the physical nature of the reflecting structures. We focus on distinguishing classical abrupt discontinuities, such as traditional models of the Conrad and Moho boundaries, from more unusual structures. Finite-difference modeling and simple interference relations show that pre-critical reflections exhibiting an increase in peak frequency with offset arise from thinly-layered horizontal structures, while reflections from step discontinuities show no change in frequency with offset. In the deep crust thin layers may result from sill intrusion or fault motion.\n\nThe sense of changes in Poisson's ratio and the relative strength of density changes determine whether reflection amplitudes will increase or decrease with offset. A simple linear regression on pre-critical reflection amplitudes against offset is adequate to separate reflections arising from increases in Poisson's ratio from those arising from decreases in Poisson's ratio and/or density changes. The latter condition may be the result of strong anisotropy or the presence of pore fluid. Comparisons of the properties of major deep reflectors across the Mojave Desert suggest that the effects of tectonic motion and fluid injection have penetrated all levels of the crust.", "date": "1987-04", "date_type": "published", "publication": "Geophysical Journal of the Royal Astronomical Society", "volume": "89", "number": "1", "publisher": "Royal Astronomical Society", "pagerange": "125-131", "id_number": "CaltechAUTHORS:20121003-082623801", "issn": "0016-8009", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121003-082623801", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1111/j.1365-246X.1987.tb04398.x", "primary_object": { "basename": "Louie1987.pdf", "url": "https://authors.library.caltech.edu/records/jcvy3-6y868/files/Louie1987.pdf" }, "resource_type": "article", "pub_year": "1987", "author_list": "Louie, John N. and Clayton, Robert W." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/gh6k9-11c90", "eprint_id": 34650, "eprint_status": "archive", "datestamp": "2023-08-22 05:11:14", "lastmod": "2023-10-19 21:21:19", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Walck-M-C", "name": { "family": "Walck", "given": "Marianne C." } }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" } ] }, "title": "P wave velocity variations in the Coso Region, California, derived from local earthquake travel times", "ispublished": "pub", "full_text_status": "public", "keywords": "Seismology: Body waves; Seismology: Seismicity; Seismology: Structure of the crust; Tectonophysics: Physics of magma and magma bodies", "note": "\u00a9 1987 by the American Geophysical Union. Received 30 December 1985; revised September 17, 1986; accepted 7 October 1986. This study was supported by the U.S. Department of Energy under contract DE-AC04-76DP00789 and by the U.S. Geological Survey under contract 14-08-0001-G1171. Some of the\ngraphics and computational facilities were provided by the W. M. Keck Foundation. We thank Chris Sanders and Hiroo Kanamori for their close cooperation during this study and their critical reviews of the manuscript. The assistance of Carl Johnson and Doug Given of the USGS Pasadena office was invaluable in obtaining the earthquake data. Greg Elbring provided computer graphics expertise. Contribution 4251, Division of Geological and Planetary Sciences, California\nInstitute of Technology, Pasadena, California.\n\nPublished - Walck1987.pdf
", "abstract": "Inversion of 4036 P wave travel time residuals from 429 local earthquakes using a tomographic scheme provides information about three-dimensional upper crustal velocity variations in the Indian Wells Valley-Coso region of southeastern California. The residuals are calculated relative to a Coso-specific velocity model, corrected for station elevation, weighted, and back-projected along their ray paths through models defined with layers of blocks. Slowness variations in the surface layer reflect local geology, including slow velocities for the sedimentary basins of Indian Wells and Rose valleys and relatively fast velocities for the Sierra Nevada and Argus Mountains. In the depth range of 3\u20135 km the inversion images an area of reduced compressional velocity in western and northern Indian Wells Valley but finds no major velocity variations beneath the Coso volcanic field to the north. These results are consistent with a recent study of anomalous shear wave attenuation in the Coso region. Between 5 and 10 km depth, low-velocity areas (7% slow) appear at the southern end of the Coso volcanics, reaching east to the Coso Basin. Numerical tests of the inversion's resolution and sensitivity to noise indicate that these major anomalies are significant and well-resolved, while other apparent velocity variations in poorly sampled areas are probably artifacts. The seismic data alone are not sufficient to uniquely characterize the physical state of these low-velocity regions. Because of the Coso region's history of Pleistocene bimodal volcanism, high heat flow, geothermal activity, geodetic deformation, and seismic activity, one possibility is to link the zones of decreased P velocity to contemporary magmatic activity.", "date": "1987-01-10", "date_type": "published", "publication": "Journal of Geophysical Research B", "volume": "92", "number": "B1", "publisher": "American Geophysical Union", "pagerange": "393-405", "id_number": "CaltechAUTHORS:20121003-083629607", "issn": "0148-0227", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121003-083629607", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Department of Energy (DOE)", "grant_number": "DE-AC04-76DP00789" }, { "agency": "USGS", "grant_number": "14-08-0001-G1171" } ] }, "other_numbering_system": { "items": [ { "id": "4251", "name": "Caltech Division of Geological and Planetary Sciences" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1029/JB092iB01p00393", "primary_object": { "basename": "Walck1987.pdf", "url": "https://authors.library.caltech.edu/records/gh6k9-11c90/files/Walck1987.pdf" }, "resource_type": "article", "pub_year": "1987", "author_list": "Walck, Marianne C. and Clayton, Robert W." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/vrysd-fd314", "eprint_id": 34829, "eprint_status": "archive", "datestamp": "2023-08-19 18:58:35", "lastmod": "2023-10-19 22:00:43", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Vidale-J-E", "name": { "family": "Vidale", "given": "John E." } }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" } ] }, "title": "A stable free-surface boundary condition for two-dimensional\n elastic finite-difference wave simulation", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 1986 Society of Exploration Geophysicists. \nManuscript received by the Editor May 20. 1985; revised manuscript received April 7, 1986. \nThis work was partly supported by AFSOR contract F19628-83-K-0010, and a research grant from Ametek Inc. J.E.V. was supported by an NSF fellowship. Critical reviews by John Louie, Heidi Houston, and anonymous reviewers were helpful.\nContribution no. 4227, from the Div. of Geological and\nPlanet. Sciences, California Institute of Technology, Pasadena, CA, 91125.\n\nPublished - Vidale1986.pdf
", "abstract": "Two of the persistent problems in finite-difference solutions of the elastic wave equation are the limited stability range of the free-surface boundary condition and the boundary condition's treatment of lateral variations in velocity and density. The centered-difference approximation presented by Alterman and Karal (1968), for example, remains stable only for \u03b2/\u03b1 greater than 0.30, where \u03b2 and \u03b1 are the shear (S) and compressional (P) wave velocities. The one-sided approximation (Alterman and Rotenberg, 1969) and composed approximation (Ilan et al., 1975) have similar restrictions. The revised composed approximation of Ilan and Loewenthal (1976) overcomes this restriction, but cannot handle laterally varying media properly.", "date": "1986-12", "date_type": "published", "publication": "Geophysics", "volume": "51", "number": "12", "publisher": "Society of Exploration Geophysicists", "pagerange": "2247-2249", "id_number": "CaltechAUTHORS:20121010-140337303", "issn": "0016-8033", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121010-140337303", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Air Force Office of Scientific Research (AFOSR)", "grant_number": "F19628-83-K-0010" }, { "agency": "Ametek Inc." }, { "agency": "NSF" } ] }, "other_numbering_system": { "items": [ { "id": "4227", "name": "Caltech Division of Geological and Planetary Sciences" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1190/1.1442078", "primary_object": { "basename": "Vidale1986.pdf", "url": "https://authors.library.caltech.edu/records/vrysd-fd314/files/Vidale1986.pdf" }, "resource_type": "article", "pub_year": "1986", "author_list": "Vidale, John E. and Clayton, Robert W." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/ne3t8-am891", "eprint_id": 34924, "eprint_status": "archive", "datestamp": "2023-08-22 04:50:04", "lastmod": "2023-10-19 22:06:23", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Frankel-A", "name": { "family": "Frankel", "given": "Arthur" } }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" } ] }, "title": "Finite Difference Simulations of Seismic Scattering: Implications for the Propagation of Short-Period Seismic Waves in the Crust and Models of Crustal Heterogeneity", "ispublished": "pub", "full_text_status": "public", "keywords": "Seismology: Body waves; Seismology: Structure of the crust; Seismology: Structure of the lithosphere and upper mantle", "note": "\u00a9 1986 American Geophysical Union.\nReceived 18 August 1985; revised January 30, 1986; accepted 30 January 1986.\nJohn Vidale developed and implemented a substantial\nportion of the finite difference codes used in this study. W. Menke, P. E. Malin, J. Boatwright, T. C. Hanks, D. J. Andrews, E. Cranswick, and an anonymous reviewer provided useful comments on the manuscript. We particularly thank one of the Associate Editors of JGR for suggestions which significantly improved the paper.\nThe research in this paper was carried out by the Jet Propulsion Laboratory and the Seismological Laboratory, California Institute of Technology, and was sponsored by the Sun Oil Company, Ametek\nCorporation, and the National Aeronautics and Space Administration.\nContribution 4249 of the Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena.\n\nPublished - Frankel1986.pdf
", "abstract": "Synthetic seismograms produced by the finite difference method are used to study the scattering of elastic and acoustic waves in two-dimensional media with random spatial variations in seismic velocity. The results of this study provide important insights about the propagation of short-period (< 1 s) seismic waves in the earth's crust and place significant constraints on the fluctuation spectrum of crustal heterogeneity on length scales from tens of kilometers to tens of meters. The synthetic seismograms are analyzed to determine the variation in travel times and waveforms across arrays of receivers. The apparent attenuation caused by scattering and the time decay and amplitude of the seismic coda are also quantified with the numerical simulations. Random media with Gaussian and exponential correlation functions are considered, as well as a self-similar medium with equal variations in seismic velocity over a broad range of length scales. These media differ in the spectral falloff of their velocity fluctuations at wavelengths smaller than 2\u03c0 times the correlation distance a. The synthetic seismograms demonstrate that a random medium with self-similar velocity fluctuations at length scales less than about 50 km (a \u2265 10 km) can explain both travel time anomalies reported for teleseismic arrivals across large-scale seismic arrays (e.g., LASA and NORSAR) and the presence of seismic coda at frequencies of 30 Hz and greater commonly observed in microearthquake waveforms. Media with Gaussian and exponential correlation functions in velocity do not account for both sets of observations for reasonable standard deviations in velocity (\u226410%). The scattering attenuation (Q^(\u22121)) observed in the simulations for Gaussian media is peaked at ka between 1 and 2, where k is the seismic wave number. The observed attenuation in exponential media increases with frequency for ka < 1 and remains about constant for 1 \u2264 ka \u2264 5.6. At high frequencies (ka > 5), the self-similar medium is characterized by a scattering Q that is constant with frequency, whereas theory predicts that the apparent Q in an exponential medium is proportional to frequency. These alternative models of crustal heterogeneity can thus be tested by improved measurements of the frequency dependence of crustal Q at frequencies greater than about 1 Hz, assuming that scattering is responsible for most of the attenuation at these frequencies. Measurements of the time decay of the synthetic coda waves clearly show that the single scattering model of coda decay is not appropriate in the presence of moderate amounts of scattering attenuation (scattering Q \u2264 200). In these cases, Q values derived from the coda decay rate using the single scattering theory do not correspond to the transmission Q of the medium. The cross correlation of synthetic waveforms observed for an array of receivers along the free surface is observed to be dependent on the correlation distance of the medium. The self-similar random medium proposed here for the crust produces waveform variations at high frequencies (15\u201330 Hz) similar to those reported for actual small-scale seismic arrays with apertures of hundreds of meters.", "date": "1986-05-10", "date_type": "published", "publication": "Journal of Geophysical Research B", "volume": "91", "number": "B6", "publisher": "American Geophysical Union", "pagerange": "6465-6489", "id_number": "CaltechAUTHORS:20121016-125457564", "issn": "0148-0227", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121016-125457564", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Sun Oil Co." }, { "agency": "Ametek Corporation" }, { "agency": "NASA" } ] }, "other_numbering_system": { "items": [ { "id": "4249", "name": "Caltech Division of Geological and Planetary Sciences" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1029/JB091iB06p06465", "primary_object": { "basename": "Frankel1986.pdf", "url": "https://authors.library.caltech.edu/records/ne3t8-am891/files/Frankel1986.pdf" }, "resource_type": "article", "pub_year": "1986", "author_list": "Frankel, Arthur and Clayton, Robert W." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/avyky-ctb75", "eprint_id": 34944, "eprint_status": "archive", "datestamp": "2023-08-19 18:31:20", "lastmod": "2023-10-19 22:07:25", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Hearn-T-M", "name": { "family": "Hearn", "given": "Thomas M." } }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" } ] }, "title": "Lateral velocity variations in Southern California. II. Results for the lower crust from Pn waves", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 1986 by the Seismological Society of America. Manuscript received 6 August 1985. This study was supported by a research contract with the U.S. Geological Survey (14-08-001-21210) and a grant from the Sun Oil Company. Part of the graphics and computing facilities used in this study were provided by the W. M. Keck Foundation. We thank Eugene Humphreys, Leon Silver, and Hiroo Kanamori for their suggestions and reviews.\n\nPublished - Hearn1986b.pdf
", "abstract": "A tomographic inversion of the Pn arrivals in Southern California yields new information about wave velocities and topography on the Moho discontinuity. We produce maps of Pn velocity and Pn station delays. The Pn velocities do not show the dramatic correlation with surface faults that is found for the shallower Pg arrivals (Hearn and Clayton, 1986). This implies that the lower crust and mantle are largely decoupled from the upper crust. Undoubtedly, this is due to the different responses of the brittle upper crust and the ductile lower crust to tectonic and isostatic stresses. Detachment faults must play an important role in separating the crust.\nIn general, velocities on the American plate are higher than on the Pacific plate, but no distinct transition is observed. The Colorado River region has extremely thin crust due to basin-and-range type extension. The Transverse Ranges have a small root as seen in the station delays and which also results in slightly lower Pn velocities there. The Peninsula Ranges also have slow Pn velocities, but they do not have late station delays. Any root to the Peninsula Ranges must be very narrow. Isostatic balance must be maintained primarily through lateral density contrasts.", "date": "1986-04", "date_type": "published", "publication": "Bulletin of the Seismological Society of America", "volume": "76", "number": "2", "publisher": "Seismological Society of America", "pagerange": "511-520", "id_number": "CaltechAUTHORS:20121017-092616257", "issn": "0037-1106", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121017-092616257", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "USGS", "grant_number": "14-08-001-21210" }, { "agency": "Sun Oil Co." } ] }, "other_numbering_system": { "items": [ { "id": "4196", "name": "Caltech Seismological Laboratory" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "primary_object": { "basename": "Hearn1986b.pdf", "url": "https://authors.library.caltech.edu/records/avyky-ctb75/files/Hearn1986b.pdf" }, "resource_type": "article", "pub_year": "1986", "author_list": "Hearn, Thomas M. and Clayton, Robert W." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/t7bfm-mcp76", "eprint_id": 34942, "eprint_status": "archive", "datestamp": "2023-08-19 18:31:16", "lastmod": "2023-10-19 22:07:20", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Hearn-T-M", "name": { "family": "Hearn", "given": "Thomas M." } }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" } ] }, "title": "Lateral velocity variations in southern California. I. Results for the upper crust from Pg waves", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 1986 by the Seismological Society of America. Manuscript received 6 August 1985. This study was supported by a research contract with the U.S. Geological Survey (14-08-001-21210) and a grant from the Sun Oil Company. Part of the graphics and computing facilities used in this study were provided by the W. M. Keck Foundation. We thank Eugene Humphreys, Leon Silver, and Hiroo Kanamori for their suggestions and reviews.\n\nPublished - Hearn1986a.pdf
", "abstract": "The plate boundary and major crustal blocks in southern California are imaged by a tomographic backprojection of the Pg first arrivals recorded by the Southern California Array. The method, formulated specifically for local earthquake arrival times, is a fast, iterative alternative to direct least-squares techniques. With it, we solve the combined problem of determining refractor velocity perturbations and source and station delays. Resolution and variance are found empirically by using synthetic examples.\nA map showing lateral velocity variations at a depth of approximately 10 km is presented. The results show a strong correlation with surface tectonic features. Clear velocity contrasts exist across the San Andreas, the San Jacinto, and the Garlock faults. The Mojave region has the slowest velocities while the Peninsula Ranges have the highest. The San Jacinto block has velocities intermediate between Mojave and Peninsula Range velocities, and also has early station delays. This may indicate that the San Jacinto block has overridden Mojave material on a shallow detachment surface. No velocity variations are found associated with the Transverse Ranges, which we interpret to mean that the surface batholithic rocks in this area do not extend to Pg depths.", "date": "1986-04", "date_type": "published", "publication": "Bulletin of the Seismological Society of America", "volume": "76", "number": "2", "publisher": "Seismological Society of America", "pagerange": "495-509", "id_number": "CaltechAUTHORS:20121017-082856409", "issn": "0037-1106", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121017-082856409", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "USGS", "grant_number": "14-08-001-21210" }, { "agency": "Sun Oil Co." } ] }, "other_numbering_system": { "items": [ { "id": "4195", "name": "Caltech Seismological Laboratory" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "primary_object": { "basename": "Hearn1986a.pdf", "url": "https://authors.library.caltech.edu/records/t7bfm-mcp76/files/Hearn1986a.pdf" }, "resource_type": "article", "pub_year": "1986", "author_list": "Hearn, Thomas M. and Clayton, Robert W." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/exsxt-3td65", "eprint_id": 34947, "eprint_status": "archive", "datestamp": "2023-08-19 18:05:57", "lastmod": "2023-10-19 22:07:34", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Vidale-J-E", "name": { "family": "Vidale", "given": "John" } }, { "id": "Helmberger-D-V", "name": { "family": "Helmberger", "given": "Donald V." } }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" } ] }, "title": "Finite-difference seismograms for SH waves", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 1985 by the Seismological Society of America. Manuscript received 25 March 1985. This work was partly supported by Air Force-Cambridge Grant F19628-83-K-0010. J. E. V. was supported by an NSF Fellowship. Art Frankel aided in the development of the FD program. We thank Heidi Houston and an anonymous reviewer for their suggestions.\n\nPublished - Vidale1985.pdf
", "abstract": "The accuracy of the finite-difference method for generating synthetic seismograms of SH wave propagation in cylindrically symmetric media is discussed. The finite-difference method has the advantage that arbitrary density and velocity fields in the medium may be specified. A point source is generated by a simple transformation of a line source. The accuracy of the finite-difference seismograms in flat- and dipping-layered media is confirmed by comparison with the generalized ray method. A source radiation pattern is inserted by introducing a \"near-field\" which has permanent displacement near the source.\nStrong motion synthetics are constructed with this new method for the 1968 Borrego Mountain earthquake as recorded at El Centro. Good fits to the data are achieved using the laterally varying model determined by a detailed refraction survey and the source parameters determined by teleseismic waveform modeling. Shallow faulting is no longer necessary to explain the long-period surface-wave development.", "date": "1985-12", "date_type": "published", "publication": "Bulletin of the Seismological Society of America", "volume": "75", "number": "6", "publisher": "Seismological Society of America", "pagerange": "1765-1782", "id_number": "CaltechAUTHORS:20121017-100933090", "issn": "0037-1106", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121017-100933090", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Air Force-Cambridge", "grant_number": "F19628-83-K-0010" }, { "agency": "NSF Graduate Research Fellowship" } ] }, "other_numbering_system": { "items": [ { "id": "4015", "name": "Caltech Seismological Laboratory" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "primary_object": { "basename": "Vidale1985.pdf", "url": "https://authors.library.caltech.edu/records/exsxt-3td65/files/Vidale1985.pdf" }, "resource_type": "article", "pub_year": "1985", "author_list": "Vidale, John; Helmberger, Donald V.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/wg7d6-wrg54", "eprint_id": 34966, "eprint_status": "archive", "datestamp": "2023-08-19 17:37:59", "lastmod": "2023-10-19 22:08:57", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Hager-B-H", "name": { "family": "Hager", "given": "Bradford H." }, "orcid": "0000-0002-5643-1374" }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" }, { "id": "Richards-M-A", "name": { "family": "Richards", "given": "Mark A." } }, { "id": "Comer-R-P", "name": { "family": "Comer", "given": "Robert P." } }, { "id": "Dziewonski-A-M", "name": { "family": "Dziewonski", "given": "Adam M." } } ] }, "title": "Lower mantle heterogeneity, dynamic topography and the geoid", "ispublished": "pub", "full_text_status": "restricted", "note": "\u00a9 1985 Nature Publishing Group.\nReceived 2 July; accepted 29 October 1984.\nWe thank D. L. Anderson, C. Chase, R. J. O'Connell and D.\nJ. Stevenson for helpful comments. This work was supported\nby NASA grants NAG5-315, NSG-7610, NAS5-27226, NSF\ngrant EAR-8317623, by the Alfred P. Sloan Foundation\n(B.H.H.), and by a Bantrell Postdoctoral Fellowship (R.P.C.).\nContribution no. 4065, Division of Geological and Planetary\nSciences, California Institute of Technology.", "abstract": "Density contrasts in the lower mantle, inferred using seismic tomography, drive viscous flow; this results in kilometres of dynamically maintained topography at the core-mantle boundary and at the Earth's surface. The total gravity field due to interior density contrasts and dynamic boundary topography predicts the longest-wavelength components of the geoid remarkably well. Neglecting dynamic surface deformation leads to geoid anomalies of opposite sign to those observed.", "date": "1985-02-14", "date_type": "published", "publication": "Nature", "volume": "313", "number": "6003", "publisher": "Nature Publishing Group", "pagerange": "541-546", "id_number": "CaltechAUTHORS:20121018-093742377", "issn": "0028-0836", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121018-093742377", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA", "grant_number": "NAG5-315" }, { "agency": "NASA", "grant_number": "NSG-7610" }, { "agency": "NASA", "grant_number": "NAS5-27226" }, { "agency": "NSF", "grant_number": "EAR-8317623" }, { "agency": "Alfred P. Sloan Foundation" }, { "agency": "Bantrell Fellowship" } ] }, "other_numbering_system": { "items": [ { "id": "4065", "name": "Caltech Division of Geological and Planetary Sciences" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1038/313541a0", "resource_type": "article", "pub_year": "1985", "author_list": "Hager, Bradford H.; Clayton, Robert W.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/7br4j-7tt68", "eprint_id": 34915, "eprint_status": "archive", "datestamp": "2023-08-19 17:17:10", "lastmod": "2023-10-19 22:05:28", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Frankel-A", "name": { "family": "Frankel", "given": "Arthur" } }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" } ] }, "title": "A finite-difference simulation of wave propagation in two-dimensional random media", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 1984 Seismological Society of America.\nManuscript received 17 May 1984.\nWe thank William Menke and Peter Malin for useful discussions about scattering. The microearthquake\ndata from the Toktogul network (Figure 15) were analyzed while one of the authors (A.F.) was a\nresearch associate at the Lamont-Doherty Geological Observatory. The research for this paper was\nsupported by a grant from the Sun Oil Company. A.F. was supported by a postdoctoral Bantrell Fellowship.\n\nPublished - Franke1984.pdf
", "abstract": "A finite-difference algorithm is used to generate synthetic seismograms for waves propagating through two-dimensional random media. The media have a significant component of their material properties varying randomly over length scales smaller than the seismic wavelength and are meant to approximate the heterogeneity of the crust and upper mantle. The finite-difference technique retains all multiply scattered and diffracted waves, and also accounts for transmission losses.\n\nThe synthetic seismograms clearly exhibit coda and apparent attenuation caused by scattering. For a medium with a white wavenumber spectrum of velocity fluctuations, the coda is higher frequency than the initial pulse. The apparent attenuation is greatest when the scatterer size is comparable to the seismic wavelength. The spectra of the coda generally increase in frequency as the scatterers decrease in size. Examples demonstrate how scattering can produce spectra with broad peaks and sharp fall-offs that can make the determination of the source spectra and corner frequencies of small earthquakes extremely difficult.", "date": "1984-12", "date_type": "published", "publication": "Bulletin of the Seismological Society of America", "volume": "74", "number": "6", "publisher": "Seismological Society of America", "pagerange": "2167-2186", "id_number": "CaltechAUTHORS:20121016-095531858", "issn": "0037-1106", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121016-095531858", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Sun Oil Co." }, { "agency": "Bantrell Fellowship" } ] }, "other_numbering_system": { "items": [ { "id": "4079", "name": "Caltech Seismological Laboratory" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "primary_object": { "basename": "Franke1984.pdf", "url": "https://authors.library.caltech.edu/records/7br4j-7tt68/files/Franke1984.pdf" }, "resource_type": "article", "pub_year": "1984", "author_list": "Frankel, Arthur and Clayton, Robert W." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/kgtdg-br691", "eprint_id": 34904, "eprint_status": "archive", "datestamp": "2023-08-19 17:17:06", "lastmod": "2023-10-19 22:04:55", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Fawcett-J-A", "name": { "family": "Fawcett", "given": "John A." } }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" } ] }, "title": "Tomographic reconstruction of velocity anomalies", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 1984 Seismological Society of America.\n\nManuscript received 1 March 1984.\n\nThis paper is based upon a chapter of the first author's Ph.D. Thesis at the California Institute of\nTechnology. This chapter was written under the supervision of the second author and Professor H. B.\nKeller, whom we would like to thank for his suggestions and encouragement. We would also like to\nthank Professor J. B. Keller at Stanford for his helpful critiques of earlier versions of this paper.\nThe first author (J. F.) was supported financially at the California Institute of Technology by the\nU.S. Department of Energy and the Natural Sciences and Engineering Research Council of Canada. At\nStanford, financial support for this research was provided by the Air Force Office of Scientific Research,\nthe Army Research Office, the Office of Naval Research, and the National Science Foundation.\n\nPublished - Fawcett1984.pdf
", "abstract": "An approximate inversion formula is proposed for the reconstruction of slowness anomalies in a known depth varying background field. The data are observed travel-time perturbations for reflections from a known planar reflector. The limitations of the formula are discussed and numerical examples are given.", "date": "1984-12", "date_type": "published", "publication": "Bulletin of the Seismological Society of America", "volume": "74", "number": "6", "publisher": "Seismological Society of America", "pagerange": "2201-2219", "id_number": "CaltechAUTHORS:20121015-150102123", "issn": "0037-1106", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121015-150102123", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Department of Energy (DOE)" }, { "agency": "Natural Sciences and Engineering Research Council of Canada (NSERC)" }, { "agency": "Air Force Office of Scientific Research (AFOSR)" }, { "agency": "Army Research Office (ARO)" }, { "agency": "Office of Naval Research (ONR)" }, { "agency": "NSF" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "primary_object": { "basename": "Fawcett1984.pdf", "url": "https://authors.library.caltech.edu/records/kgtdg-br691/files/Fawcett1984.pdf" }, "resource_type": "article", "pub_year": "1984", "author_list": "Fawcett, John A. and Clayton, Robert W." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/aev0g-8he08", "eprint_id": 34830, "eprint_status": "archive", "datestamp": "2023-08-19 17:10:40", "lastmod": "2023-10-19 22:00:46", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Walck-M-C", "name": { "family": "Walck", "given": "Marianne C." } }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" } ] }, "title": "Analysis of upper mantle structure using wave field continuation of P waves", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 1984 Seismological Society of America. Manuscript received 15 March 1984. The authors thank Don Anderson, Hiroo Kanamori, and Steve Grand for reviewing the manuscript. This work was supported by Sun Oil Co., National Science Foundation Grant EAR811-5236, and NASA\nContract NSG-7610.\n\nPublished - Walck1984.pdf
", "abstract": "Wave field continuation transforms seismic record section data directly into velocity-depth space, simultaneously providing an estimate of model nonuniqueness. This inversion, previously used for reflection and refraction data, converts readily to spherical earth problems through simple adjustments in each of the two linear transformations: the slant stack and downward continuation. Because the time resolution inherent in the data transforms to depth resolution in the model space, this method is extremely useful for analysis of data compatibility with preexisting models and direct comparison between data sets, as well as the complete inversion of raw data for structure. Wave field inversion demands densely sampled, digital data, and assumes source coherency and lateral homogeneity along the profile.\n\nWe test this technique for upper mantle analysis using a previously studied, large, array-recorded data set representative of structure beneath the Gulf of California. We compare slant stacks and downward continuations of both synthetic and data record sections to illustrate the method's resolution capability. Wave field continuation proves particularly useful in comparing entire data sets to various models; even subtle structural differences are resolvable given good data quality.", "date": "1984-10", "date_type": "published", "publication": "Bulletin of the Seismological Society of America", "volume": "74", "number": "5", "publisher": "Seismological Society of America", "pagerange": "1703-1719", "id_number": "CaltechAUTHORS:20121010-143010960", "issn": "0037-1106", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121010-143010960", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR811-5236" }, { "agency": "NASA", "grant_number": "NSG-7610" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "primary_object": { "basename": "Walck1984.pdf", "url": "https://authors.library.caltech.edu/records/aev0g-8he08/files/Walck1984.pdf" }, "resource_type": "article", "pub_year": "1984", "author_list": "Walck, Marianne C. and Clayton, Robert W." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/qcsec-hfg47", "eprint_id": 34951, "eprint_status": "archive", "datestamp": "2023-08-19 16:59:36", "lastmod": "2023-10-19 22:07:57", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Humphreys-E", "name": { "family": "Humphreys", "given": "Eugene" } }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" }, { "id": "Hager-B-H", "name": { "family": "Hager", "given": "Bradford H." }, "orcid": "0000-0002-5643-1374" } ] }, "title": "A tomographic image of mantle structure beneath Southern California", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 1984 American Geophysical Union. Received January 18, 1984; revised March 15, 1984; accepted March 16, 1984. We thank Sue Raikes for providing most of the teleseismic direct P wave data used in this study, and Marianne Walck for the regional P wave data. Tom Hearn kindly made available his P n time-term results. This work was supported under USGS contract #14-08-0001-21210 and NASA contract NAG-5315. Contribution #4022, Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125.\n\nPublished - Humphreys1984.pdf
", "abstract": "We determined the variations in seismic structure beneath southern California by using a tomographic method of inversion on teleseismic P delays recorded with the Southern California Array. The algorithm employed was a modified form of an Algebraic Reconstruction Technique (ART) used in medical X\u2010ray imaging. Deconvolution with an empirically estimated point spread function was also used to help in focusing the image. \nThe inversion reveals two prominent features beneath the region. The first is a thin, vertical wedge directly beneath the Transverse Ranges that is 2\u20103% faster than the surrounding region. This feature deepens to the east, attaining a maximum depth of about 250 km beneath the San Bernardino Mountains. The second feature is a major zone of low velocity material that is 2\u20104% slow under the Salton Trough rift valley, extending to a depth of about 125 km. Two possible explanations for the spatial association of the Transverse Ranges with the velocity anomaly below are lithospheric subduction or small\u2010scale sublithospheric convection in the region of the Big Bend of the San Andreas Fault. The low velocity anomaly beneath the Salton Trough is consistent with convective upwelling there.", "date": "1984-07", "date_type": "published", "publication": "Geophysical Research Letters", "volume": "11", "number": "7", "publisher": "American Geophysical Union", "pagerange": "625-627", "id_number": "CaltechAUTHORS:20121017-115856637", "issn": "0094-8276", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121017-115856637", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "USGS", "grant_number": "14-08-0001-21210" }, { "agency": "NASA", "grant_number": "NAG-5315" } ] }, "other_numbering_system": { "items": [ { "id": "4022", "name": "Caltech Division of Geological and Planetary Sciences" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1029/GL011i007p00625", "primary_object": { "basename": "Humphreys1984.pdf", "url": "https://authors.library.caltech.edu/records/qcsec-hfg47/files/Humphreys1984.pdf" }, "resource_type": "article", "pub_year": "1984", "author_list": "Humphreys, Eugene; Clayton, Robert W.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/b82z7-xxy77", "eprint_id": 34941, "eprint_status": "archive", "datestamp": "2023-08-19 14:55:52", "lastmod": "2023-10-19 22:07:18", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "McMechan-G-A", "name": { "family": "McMechan", "given": "George A." } }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" }, { "id": "Mooney-W-D", "name": { "family": "Mooney", "given": "Walter D." } } ] }, "title": "Application of Wave Field Continuation to the Inversion of Refraction Data", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 1982 American Geophysical Union. Received Apri1 15, 1981;\nrevised October 9, 1981; accepted October 16, 1981. We thank the sponsors of the Stanford Exploration Project for providing financial and computing support, the U. S.\nGeological Survey for providing the Mojave Desert data, CONOCO for providing the first marine data set, and Digicon for the second. Contribution 950 from the Earth Physics Branch.\n\nPublished - McMechan1982.pdf
", "abstract": "Three examples of the inversion of refraction data by downward continuation illustrate the applicability of the method to field data. The first example is a refraction profile from the Mojave Desert, California. These data are spatially aliased and contain clear evidence of lateral inhomogeneity. The inversion in this case produces a broken image in the slowness-depth domain due to the lateral inhomogeneity, but a useful average velocity model is still obtained. The second example is a shallow marine reflection profile. Here, the truncation effects due to the finite horizontal aperture of the recording cable produce artifacts in the slowness-depth domain. The velocity model is, however, distinct from these artifacts, and the presence of strong precritical reflections aids in the inversion. The third example is another shallow marine reflection profile. The inversion of these data illustrate the utilization of constraints provided by multiples as well as primary arrivals.", "date": "1982-02-10", "date_type": "published", "publication": "Journal of Geophysical Research B", "volume": "87", "number": "B2", "publisher": "American Geophysical Union", "pagerange": "927-935", "id_number": "CaltechAUTHORS:20121017-081646220", "issn": "0148-0227", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121017-081646220", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Stanford Exploration Project" } ] }, "other_numbering_system": { "items": [ { "id": "950", "name": "Earth Physics Branch" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1029/JB087iB02p00927", "primary_object": { "basename": "McMechan1982.pdf", "url": "https://authors.library.caltech.edu/records/b82z7-xxy77/files/McMechan1982.pdf" }, "resource_type": "article", "pub_year": "1982", "author_list": "McMechan, George A.; Clayton, Robert W.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/98jtk-e8434", "eprint_id": 34828, "eprint_status": "archive", "datestamp": "2023-08-19 14:28:52", "lastmod": "2023-10-19 22:00:41", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" }, { "id": "Stolt-R-H", "name": { "family": "Stolt", "given": "Robert H." } } ] }, "title": "A Born-WKBJ inversion method for acoustic reflection data", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 1981 Society of Exploration Geophysicists. \nManuscript received by the Editor July 30, 1980; revised manuscript received April 20, 1981. \nWe would like to thank the sponsors of the Stanford Exploration Project for their support.\n\nPublished - Clayton1981.pdf
", "abstract": "Density and bulk modulus variations in an acoustic earth are separately recoverable from standard reflection surveys by utilizing the amplitude-versus-offset information present in the observed wave fields. Both earth structure and a variable background velocity can be accounted for by combining the Born and WKBJ approximations, in a \"before stack\" migration with two output sections, one for density variations and the other for bulk modulus variations. For the inversion, the medium is considered to be composed of a known low-spatial frequency variation (the background) plus an unknown high-spatial frequency variation in bulk modulus and density (the reflectivity). The division between the background and the reflectivity depends upon the frequency content of the source. For constant background parameters, computations are done in the Fourier domain, where the first part of the algorithm includes a frequency shift identical to that in an F-K migration. The modulus and density variations are then determined by observing in a least-squares sense amplitude versus offset wavenumber. For a spatially variable background, WKBJ Green's operators that model the direct wave in a medium with a smoothly varying background are used. A downward continuation with these operators removes the effects of variable velocity from the problem, and, consequently, the remainder of the inversion essentially proceeds as if the background were constant. If the background is strictly depth dependent, the inversion can be expressed in closed form. The method neglects multiples and surface waves and it is restricted to precritical reflections. Density is distinguishable from bulk modulus only if a sufficient range of precritical incident angles is present in the data.", "date": "1981-11", "date_type": "published", "publication": "Geophysics", "volume": "46", "number": "11", "publisher": "Society of Exploration Geophysicists", "pagerange": "1559-1567", "id_number": "CaltechAUTHORS:20121010-132926440", "issn": "0016-8033", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121010-132926440", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Stanford Exploration Project" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1190/1.1441162", "primary_object": { "basename": "Clayton1981.pdf", "url": "https://authors.library.caltech.edu/records/98jtk-e8434/files/Clayton1981.pdf" }, "resource_type": "article", "pub_year": "1981", "author_list": "Clayton, Robert W. and Stolt, Robert H." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/chqy3-em494", "eprint_id": 34824, "eprint_status": "archive", "datestamp": "2023-08-19 14:12:02", "lastmod": "2023-10-19 22:00:32", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" }, { "id": "McMechan-G-A", "name": { "family": "McMechan", "given": "George A." } } ] }, "title": "Inversion of refraction data by wave field continuation", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 1981 Society of Exploration Geophysicists. Manuscript received by the Editor February 21, 1980: revised manuscript received September 15. 1980. During the course of this project, one of the authors (G.M.) was on leave at the Stanford Exploration Project, Dept. of Geophysics,\nStanford University, which provided superb computing\nfacilities. Critical reviews of the paper by R. Stolt, C. Chapman, M. Yedlin, W. Mooney, and D. Hill were much appreciated. The Imperial Valley refraction data were kindly provided by the USGS, one of the sponsors of the Stanford Exploration Project. In particular, the aid of J. Healy, W. Mooney, W. Kohler, and J. Roloff of the USGS was invaluable. The work was supported in part by the Department of Energy, Mines and Resources, Canada. Contribution from the Earth Physics Branch no. 868.\n\nPublished - Clayton1980.pdf
", "abstract": "The process of wave equation continuation (migration) is adapted for refraction data in order to produce velocity-depth models directly from the recorded data. The procedure consists of two linear transformations: a slant stack of the data produces a wave field in the p - \u03c4 plane which is then downward continued using \u03c4 = O as the imaging condition. The result is that the data wave field is linearly transformed from the time-distance domain into the slowness-depth domain, where the velocity profile can be picked directly. No travel-time picking is involved, and all the data are present throughout the inversion. The method is iterative because it is necessary to specify a velocity function for the continuation. The solution produced by a given iteration is used as the continuation velocity function for the next step. Convergence is determined when the output wave field images the same velocity-depth function as was input to the continuation. The method obviates the problems associated with determining the envelope of solutions that are consistent with the observations, since the time resolution in the data is transformed into a depth resolution in the slowness-depth domain. The method is illustrated with several synthetic examples, and with a refraction line recorded in the Imperial Valley, California.", "date": "1981-06", "date_type": "published", "publication": "Geophysics", "volume": "46", "number": "6", "publisher": "Society of Exploration Geophysicists", "pagerange": "860-868", "id_number": "CaltechAUTHORS:20121010-114753811", "issn": "0016-8033", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121010-114753811", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Department of Energy (DOE)" }, { "agency": "Mines and Resources, Canada" } ] }, "other_numbering_system": { "items": [ { "id": "868", "name": "Earth Physics Branch" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1190/1.1441224", "primary_object": { "basename": "Clayton1980.pdf", "url": "https://authors.library.caltech.edu/records/chqy3-em494/files/Clayton1980.pdf" }, "resource_type": "article", "pub_year": "1981", "author_list": "Clayton, Robert W. and McMechan, George A." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/5svpn-t7303", "eprint_id": 34827, "eprint_status": "archive", "datestamp": "2023-08-19 13:13:20", "lastmod": "2023-10-19 22:00:39", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" }, { "id": "Bj\u00f6rn-E", "name": { "family": "Bj\u00f6rn", "given": "Engquist" } } ] }, "title": "Absorbing boundary conditions for wave-equation migration", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 1980 Society of Exploration Geophysicists. Manuscript received by the Editor February 1, 1979: revised manuscript received September 6, 1979. Support for this research was provided by the sponsoring members of the Stanford Exploration Project. The authors also wish to thank Prof. Jon F. Claerbout for suggesting the B3 boundary condition.\n\nPublished - Clayton1980b.pdf
", "abstract": "The standard boundary conditions used at the sides of a seismic section in wave-equation migration generate\nartificial reflections. These reflections from the edges of the computational grid appear as artifacts in the final\nsection. Padding the section with zero traces on either side adds to the cost of migration and simply delays the\ninevitable reflections.\nWe develop stable absorbing boundary conditions that annihilate almost all of the artificial reflections. This\nis demonstrated analytically and with synthetic examples. The absorbing boundary conditions presented can\nbe used with any of the different types of finite-difference wave-equation migration, at essentially no extra cost.", "date": "1980-05", "date_type": "published", "publication": "Geophysics", "volume": "45", "number": "5", "publisher": "Society of Exploration Geophysicists", "pagerange": "895-904", "id_number": "CaltechAUTHORS:20121010-131529211", "issn": "0016-8033", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121010-131529211", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Stanford Exploration Project" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1190/1.1441094", "primary_object": { "basename": "Clayton1980b.pdf", "url": "https://authors.library.caltech.edu/records/5svpn-t7303/files/Clayton1980b.pdf" }, "resource_type": "article", "pub_year": "1980", "author_list": "Clayton, Robert W. and Bj\u00f6rn, Engquist" }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/abkvm-tqn63", "eprint_id": 34955, "eprint_status": "archive", "datestamp": "2023-08-19 13:01:42", "lastmod": "2023-10-19 22:08:12", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Lines-L-R", "name": { "family": "Lines", "given": "L. R." } }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "R. W." }, "orcid": "0000-0003-3323-3508" }, { "id": "Ulrych-T-J", "name": { "family": "Ulrych", "given": "T. J." } } ] }, "title": "Impulse response models for noisy vibroseis data", "ispublished": "pub", "full_text_status": "restricted", "note": "\u00a9 1980 European Association of Geoscientists and Engineers.\n\nRevised version of a paper read at the Fortieth meeiing of the European Association of Exploration Geophysicists, Dublin, June 1978; final version received December 1978; Issue published online: 27 April 2006; Article first published online: 27 April 2006.\n\nWe thank Ralph Wiggins for discussions related to this paper. This research was initially funded by the National Research Council of Canada.\n\nVibroseis is a registered trademark of Continental Oil Company.", "abstract": "A new method of Vibroseis deconvolution has been recently proposed by the authors. This discussion describes the effects of noise on the application of this method. The initial deconvolution step involves estimating the spectrum of the Vibroseis wavelet by homomorphic filtering. It is shown that noise causes problems with phase estimation. Hence, the Vibroseis wavelet is assumed to be zero phase. Examples demonstrate that zero phase cepstral filtering is a robust wavelet estimation approach for noisy data. The second step of the deconvolution method forms an impulse response model by a spectral extension method. Although this step can improve the resolution of seismic arrivals, it must be applied with caution in view of the deleterious effects of noise.", "date": "1980-02", "date_type": "published", "publication": "Geophysical Prospecting", "volume": "28", "number": "1", "publisher": "Wiley-Blackwell", "pagerange": "49-59", "id_number": "CaltechAUTHORS:20121017-151019510", "issn": "0016-8025", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121017-151019510", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "National Research Council of Canada" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1111/j.1365-2478.1980.tb01210.x", "resource_type": "article", "pub_year": "1980", "author_list": "Lines, L. R.; Clayton, R. W.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/j3wv6-med46", "eprint_id": 34673, "eprint_status": "archive", "datestamp": "2023-08-19 10:59:05", "lastmod": "2023-10-19 21:22:22", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert" }, "orcid": "0000-0003-3323-3508" }, { "id": "Engquist-B", "name": { "family": "Engquist", "given": "Bj\u00f6rn" } } ] }, "title": "Absorbing boundary conditions for acoustic and elastic wave equations", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 1977 Seismological Society of America. Manuscript received May 11, 1977. We thank Professor Jon Claerbout for his valuable suggestions, and the sponsors of the Stanford\nExploration Project for their financial support.\n\nPublished - Clayton1977.pdf
", "abstract": "Boundary conditions are derived for numerical wave simulation that minimize artificial reflections from the edges of the domain of computation. In this way acoustic and elastic wave propagation in a limited area can be efficiently used to describe physical behavior in an unbounded domain. The boundary conditions are based on paraxial approximations of the scalar and elastic wave equations. They are computationally inexpensive and simple to apply, and they reduce reflections over a wide range of incident angles.", "date": "1977-12", "date_type": "published", "publication": "Bulletin of the Seismological Society of America", "volume": "67", "number": "6", "publisher": "Seismological Society of America", "pagerange": "1529-1540", "id_number": "CaltechAUTHORS:20121003-133313333", "issn": "0037-1106", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121003-133313333", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Stanford Exploration Project" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "primary_object": { "basename": "Clayton1977.pdf", "url": "https://authors.library.caltech.edu/records/j3wv6-med46/files/Clayton1977.pdf" }, "resource_type": "article", "pub_year": "1977", "author_list": "Clayton, Robert and Engquist, Bj\u00f6rn" }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/qezcj-dqm16", "eprint_id": 34658, "eprint_status": "archive", "datestamp": "2023-08-19 10:49:50", "lastmod": "2023-10-19 21:21:35", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Lines-L-R", "name": { "family": "Lines", "given": "L. R." } }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "R. W." }, "orcid": "0000-0003-3323-3508" } ] }, "title": "A new approach to Vibroseis deconvolution", "ispublished": "pub", "full_text_status": "restricted", "note": "\u00a9 1977 John Wiley & Sons, Inc. Article first published online: 27 Apr. 2006. Paper presented at the CSEG National Convention, May 1976, Calgary, Alta., Canada.\nWe would like to thank Tad Ulrych of the University of British Columbia,\nRalph Wiggins of Western Geophysical, and Sven Treitel of Amoco Research\nfor stimulating discussions on vibroseis wavelets and vibroseis deconvolution.\nWe are also grateful to George Brinkworth, Stan Jones, and Bill Davitt\nof Chevron Standard for their assistance in supplying data and plotting\nfacilities for this project. This research was financially supported by a National Research Council of Canada grant (#1804) to Dr. T. Ulrych.", "abstract": "A method is proposed to obviate the shortcomings of conventional deconvolution approaches applied to vibroseis data. The vibroseis wavelet reduces the time domain resolution of the earth's impulse response by restricting its passband. The spectrum of the wavelet is assumed to be a \"low quefrency\" phenomenon, and hence it can be estimated by low cut cepstral filtering. The wavelet's amplitude spectrum can then be removed by spectral division. By using an approach which is consistent with the principle of maximum entropy, the undetermined portions of the seismogram's Fourier transform can be filled in by autoregressive prediction. The process of initially deconvolving in a restricted passband reduces the enhancement of noise contaminated parts of the spectrum, and the spectral extension scheme increases the time domain resolution of the process.", "date": "1977-09", "date_type": "published", "publication": "Geophysical Prospecting", "volume": "25", "number": "3", "publisher": "Wiley-Blackwell", "pagerange": "417-433", "id_number": "CaltechAUTHORS:20121003-101325161", "issn": "0016-8025", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121003-101325161", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "National Research Council of Canada", "grant_number": "1804" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1111/j.1365-2478.1977.tb01179.x", "resource_type": "article", "pub_year": "1977", "author_list": "Lines, L. R. and Clayton, R. W." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/xxxpg-y2176", "eprint_id": 34672, "eprint_status": "archive", "datestamp": "2023-08-19 10:29:37", "lastmod": "2023-10-19 21:22:20", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" }, { "id": "Ulrych-T-J", "name": { "family": "Ulrych", "given": "Tadeusz J." } } ] }, "title": "A Restoration Method for Impulsive Functions", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 1977 IEEE. Manuscript received April 26, 1976; revised August 5, 1976.\n\nPublished - Clayton1977b.pdf
", "abstract": "A method is presented for enhancing the resolution of impulsive functions which have been degraded by a known convolutional disturbance and by the addition of white noise. An autoregressive model is employed to represent the spectrum of the ideally resolved impulsive function. The method is flexible in that it allows constraints to be incorporated into the resolution scheme. Two quite diverse examples are presented as illustration.", "date": "1977-03", "date_type": "published", "publication": "IEEE Transactions on Information Theory", "volume": "23", "number": "2", "publisher": "IEEE", "pagerange": "262-264", "id_number": "CaltechAUTHORS:20121003-132402117", "issn": "0018-9448", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121003-132402117", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1109/TIT.1977.1055682", "primary_object": { "basename": "Clayton1977b.pdf", "url": "https://authors.library.caltech.edu/records/xxxpg-y2176/files/Clayton1977b.pdf" }, "resource_type": "article", "pub_year": "1977", "author_list": "Clayton, Robert W. and Ulrych, Tadeusz J." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/8yp8w-ygx72", "eprint_id": 34674, "eprint_status": "archive", "datestamp": "2023-08-19 10:12:14", "lastmod": "2023-10-19 21:22:25", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Rob W." }, "orcid": "0000-0003-3323-3508" }, { "id": "Wiggins-R-A", "name": { "family": "Wiggins", "given": "Ralph A." } } ] }, "title": "Source shape estimation and deconvolution of teleseismic bodywaves", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 1976 John Wiley & Sons, Inc.\nReceived 1976 April 8. \nArticle first published online: 2 Apr 2007.\nThis research was supported by the National Research Council of Canada under operating grant A8854.\n\nPublished - Clayton1976b.pdf
", "abstract": "We consider the deconvolution of a suite of teleseismic recordings of the same event in order to separate source and transmission path phenomena. The assumption of source uniformity may restrict the range of muths and distances of the seismograms included in the suite. The source shape is estimated by separately averaging the log amplitude spectra and the phase spectra of the recordings. This method of source estimation uses the redundant source information contained in secondary arrivals. The necessary condition for this estimator to resolve the source wavelet is that the travel times of the various secondary arrivals be evenly distributed with respect to the initial arrivals. The subsequent deconvolution of the seismograms is carried out by spectral division with two modifications. The first is the introduction of a minimum allowable source spectral amplitude termed the waterlevel. This parameter constrains the gain of the deconvolution filter in regions where the seismogram has little or no information, and also trades-off arrival time resolution with arrival amplitude resolution. The second modification, designed to increase the time domain resolution of the deconvolution, is the extension of the frequency range of the transmission path impulse response spectrum beyond the optimal passband (the passband of the seismograms). The justification for the extension lies in the fact that the impulse response of the transmission path is itself a series of impulses which means its spectrum is not band-limited. Thus, the impulse response is best represented by a continuous spectrum rather than one which is set to zero outside the optimal passband. This continuity is achieved by a recursive application of a unit-step prediction operator determined by Burg's maximum entropy algorithm. The envelopes of the deconvolution are used to detect the presence of phase shifted arrivals.", "date": "1976-10", "date_type": "published", "publication": "Geophysical Journal of the Royal Astronomical Society", "volume": "47", "number": "1", "publisher": "Royal Astronomical Society", "pagerange": "151-177", "id_number": "CaltechAUTHORS:20121003-140453786", "issn": "0016-8009", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121003-140453786", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "National Research Council of Canada", "grant_number": "A8854" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1111/j.1365-246X.1976.tb01267.x", "primary_object": { "basename": "Clayton1976b.pdf", "url": "https://authors.library.caltech.edu/records/8yp8w-ygx72/files/Clayton1976b.pdf" }, "resource_type": "article", "pub_year": "1976", "author_list": "Clayton, Rob W. and Wiggins, Ralph A." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/1s07d-4tp66", "eprint_id": 34949, "eprint_status": "archive", "datestamp": "2023-08-19 10:07:25", "lastmod": "2023-10-19 22:07:44", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Ulrych-T-J", "name": { "family": "Ulrych", "given": "Tad J." } }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Rob W." }, "orcid": "0000-0003-3323-3508" } ] }, "title": "Time series modelling and maximum entropy", "ispublished": "pub", "full_text_status": "restricted", "note": "\u00a9 1976 Elsevier Scientific Publishing Company.\n\nAccepted for publication January 5, 1976.\n\nThis research has been generously supported by a\ngrant-in-aid from the National Research Council of\nCanada (A1804 to T.J.U.).", "abstract": "This paper briefly reviews the principles of maximum entropy spectral analysis and the closely related problem of autoregressive time series modelling. The important aspect of model identification is discussed with particular emphasis on the representation of harmonic processes with noise in terms of autoregressive moving-average models. It is shown that this representation leads to a spectral estimator proposed by Pisarenko in 1973.", "date": "1976-08", "date_type": "published", "publication": "Physics of the Earth and Planetary Interiors", "volume": "12", "number": "2-3", "publisher": "Elsevier", "pagerange": "188-200", "id_number": "CaltechAUTHORS:20121017-113347306", "issn": "0031-9201", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121017-113347306", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "National Research Council of Canada (NRCC)", "grant_number": "A1804" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/0031-9201(76)90047-9", "resource_type": "article", "pub_year": "1976", "author_list": "Ulrych, Tad J. and Clayton, Rob W." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/eqe1q-dsf84", "eprint_id": 34956, "eprint_status": "archive", "datestamp": "2023-08-19 09:55:30", "lastmod": "2023-10-19 22:08:16", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Ulrych-T-J", "name": { "family": "Ulrych", "given": "Tad J." } }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "R. W." }, "orcid": "0000-0003-3323-3508" } ] }, "title": "Comment on 'Second-Order Statistical Structure of Geomagnetic Field Reversals' by P. S. Naidu", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 1976 by the American Geophysical Union. Received May 16, 1975; accepted August 18, 1975.\n\nPublished - Ulyrch1976.pdf
", "abstract": "In a recent paper, Naidu [1975] has proposed that the reversal intervals of the geomagnetic field for the period 0-76 m.y. are not independent. In fact, the author has fitted a first order autoregressive moving average model to the data published by Heirtzler et al. [1968]. This conclusion, if true, is of importance because it suggests that the mechanism governing the reversals of the geomagnetic dynamo possesses a memory.", "date": "1976-02-10", "date_type": "published", "publication": "Journal of Geophysical Research", "volume": "81", "number": "5", "publisher": "American Geophysical Union", "pagerange": "1033-1033", "id_number": "CaltechAUTHORS:20121017-153345464", "issn": "0148-0227", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121017-153345464", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1029/JB081i005p01033", "primary_object": { "basename": "Ulyrch1976.pdf", "url": "https://authors.library.caltech.edu/records/eqe1q-dsf84/files/Ulyrch1976.pdf" }, "resource_type": "article", "pub_year": "1976", "author_list": "Ulrych, Tad J. and Clayton, R. W." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/3dskp-b5651", "eprint_id": 34660, "eprint_status": "archive", "datestamp": "2023-08-19 09:54:21", "lastmod": "2023-10-19 21:21:43", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" }, { "id": "McClary-B", "name": { "family": "McClary", "given": "Barbara" } }, { "id": "Wiggins-R-A", "name": { "family": "Wiggins", "given": "Ralph A." } } ] }, "title": "Comments on the Paper: \"Phase Distortion and Hilbert Transformation In Multiply Reflected and Refracted Body Waves\", by G. L. Choy and P. G. Richards", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 1976 by the Seismological Society of America. Manuscript received June 27, 1975.\n\nPublished - Clayton1976.pdf
", "abstract": "In a recent paper Choy and Richards (1975) have demonstrated that phase-shifted\narrivals can introduce systematic travel-time errors due to relative changes in the peak\nand trough positions of the arrival wavelets. The method they suggest to correct the\nproblem is to cross-correlate an estimated zero-phase-shifted wavelet with the seismogram\nafter all the arrivals have been restored to a zero phase shift. The peaks of the\ncross-correlation are then taken as the reference times for the arrivals. This method is\nawkward to use in practice because the arrivals will in general be phase-shifted by various\nangles that are not usually known a priori. This necessitates that each arrival be treated\nseparately by searching for the correct restoring phase shift. The purpose of this note is\nto point out the existence of a much easier method which is simply to compute the\nenvelope of the cross-correlation of the seismogram with an estimated zero-phase-shifted\nwavelet (Helmberger and Wiggins, 1971).", "date": "1976-02", "date_type": "published", "publication": "Bulletin of the Seismological Society of America", "volume": "66", "number": "1", "publisher": "Seismological Society of America", "pagerange": "325-326", "id_number": "CaltechAUTHORS:20121003-102703573", "issn": "0037-1106", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121003-102703573", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "primary_object": { "basename": "Clayton1976.pdf", "url": "https://authors.library.caltech.edu/records/3dskp-b5651/files/Clayton1976.pdf" }, "resource_type": "article", "pub_year": "1976", "author_list": "Clayton, Robert W.; McClary, Barbara; et el." } ]