[ { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/xt6cg-mb010", "eprint_id": 103649, "eprint_status": "archive", "datestamp": "2023-08-19 22:48:51", "lastmod": "2023-10-20 16:33:11", "type": "article", "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 M." }, "orcid": "0000-0002-2690-3051" } ] }, "title": "Seismicity, Stress State, and Style of Faulting of the Ridgecrest-Coso Region from the 1930s to 2019: Seismotectonics of an Evolving Plate Boundary Segment", "ispublished": "pub", "full_text_status": "restricted", "note": "\u00a9 2020 Seismological Society of America. \n\nManuscript received 30 January 2020; Published online 2 June 2020. \n\nThis research was supported by the U.S. Geological Survey/ National Earthquake Hazards Reduction Program (USGS/NEHRP) Grant Numbers G16AP00147 and G18AP00028; National Science Foundation Award Numbers EAR\u20101550704 and EAR\u20101818582; the Gordon and Betty Moore Foundation Grant Number 5229 to California Institute of Technology (Caltech), and by the Southern California Earthquake Center (SCEC, Contribution Number 10075). SCEC is funded by NSF Cooperative Agreement EAR\u20101600087 and USGS Cooperative Agreement G17AC00047. The authors used Generic Mapping Tools (GMT) from Wessel et al. (2013) to make the figures. The Southern California Seismic Network (SCSN) is partially funded by USGS Cooperative Agreements G19AS00034, G20AP00037, and CalOES Agreement 6012\u20102017 with Caltech. The authors appreciate comprehensive reviews by I. Wong and R. Weldon, and the support provided by more than 20 SCSN and Southern California Earthquake Data Center (SCEDC) staff members who maintain stations and communications systems, as well as data flow, processing, and archiving. The authors thank H. Kanamori for assistance with the magnitude calculations in the Appendix. \n\nData and Resources: We have used waveforms and parametric data from the California Institute of Technology/U.S. Geological Survey (Caltech/USGS) Southern California Seismic Network (SCSN; doi: 10.7914/SN/CI); stored at the Southern California Earthquake Data Center (doi: 10.7909/C3WD3xH1). Caltech began operating a seismic network in the late 1920s and seismic stations in the Ridgecrest area in 1947. The hypocenters and magnitudes from 1930 to 1980 are from the Caltech/USGS southern California earthquake catalog (Hutton et al., 2010). The seismicity parameters from 1981 to the end of 2019 are from the waveform\u2010relocated catalog as described by Hauksson et al. (2012). However, we use GrowClust for relocating the most recent version of this catalog (Trugman and Shearer, 2017). All of the Ridgecrest\u2010Coso seismicity was detected by the SCSN automated picker and reviewed by data analysts, except for some of the events in the 2019 Ridgecrest sequence that have not yet been reviewed. In some of the figures, we also included the 1980 seismicity from the SCSN catalog to include the beginning of the 1980\u20131981 Indian Wells Valley swarms. More information about Global Centroid Moment Tensors (Global CMT) can be found at https://www.globalcmt.org (last accessed January 2020). Earthquake information is also available in National Earthquake Information Center at https://earthquake.usgs.gov (last accessed April 2020).", "abstract": "Decadal scale variations in the seismicity rate in the Ridgecrest\u2010Coso region, part of the Eastern California Shear Zone, included seismic quiescence from the 1930s to the early 1980s, followed by increased seismicity until the 2019 M_w 6.4 and 7.1 Ridgecrest sequence. This sequence exhibited complex rupture on almost orthogonal faults and triggered aftershocks over an area of \u223c90\u2009\u2009km long by \u223c5\u201310\u2009\u2009km wide, which is a fraction of the area of the previously seismically active Indian Wells Valley and Coso range region. During the last 40 yr, the seismicity has been predominantly the result of strike\u2010slip motion, extending north from the Garlock fault, along the Little Lake and Airport Lake fault zones, and approaching the southernmost Owens Valley fault to the north. The Coso range forms an extensional stepover between these two strike\u2010slip fault systems. This evolution of a plate boundary zone is driven by the northwestward motion of the Sierra Nevada, and crustal extension along the southwestern edge of the Basin and Range Province. Stress inversion of focal mechanisms shows that the postseismic stress state consists of almost horizontal \u03c31 and vertical \u03c32\u2060. The \u03c31 is spatially rotated across the Coso range stepover with \u03c31\u2010trending \u223cN17\u00b0\u2009E to the north, whereas, along the M_w 7.1 mainshock rupture, the trend is \u223cN6\u00b0\u2009E\u2060. The friction angles as measured between fault strikes and the \u03c31 trends correspond to a frictional coefficient of 0.75, suggesting average fault strength. In comparison, the mature Garlock fault has a smaller frictional coefficient of 0.28, similar to weak faults like the San Andreas fault. Thus, it appears that the heterogeneously oriented and spatially distributed but strong Ridgecrest\u2010Coso faults accommodate seismicity at seemingly random places and times within the region and are in the process of self\u2010organizing to form a major throughgoing plate\u2010boundary segment.", "date": "2020-08-01", "date_type": "published", "publication": "Bulletin of the Seismological Society of America", "volume": "110", "number": "4", "publisher": "Seismological Society of America", "pagerange": "1457-1473", "id_number": "CaltechAUTHORS:20200602-152530281", "issn": "0037-1106", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200602-152530281", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "USGS", "grant_number": "G16AP00147" }, { "agency": "USGS", "grant_number": "G18AP00028" }, { "agency": "NSF", "grant_number": "EAR\u20101550704" }, { "agency": "NSF", "grant_number": "EAR\u20101818582" }, { "agency": "Gordon and Betty Moore Foundation", "grant_number": "5229" }, { "agency": "Southern California Earthquake Center (SCEC)" }, { "agency": "NSF", "grant_number": "EAR\u20101600087" }, { "agency": "USGS", "grant_number": "G17AC00047" }, { "agency": "USGS", "grant_number": "G19AS00034" }, { "agency": "USGS", "grant_number": "G20AP00037" }, { "agency": "California Office of Emergency Services", "grant_number": "6012\u20102017" } ] }, "other_numbering_system": { "items": [ { "id": "10075", "name": "Southern California Earthquake Center" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1785/0120200051", "resource_type": "article", "pub_year": "2020", "author_list": "Hauksson, Egill and Jones, Lucile M." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/n2dcq-py879", "eprint_id": 100678, "eprint_status": "archive", "datestamp": "2023-08-22 03:29:10", "lastmod": "2023-10-23 16:12:13", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Jones-L-M", "name": { "family": "Jones", "given": "Lucile M." }, "orcid": "0000-0002-2690-3051" } ] }, "title": "Empowering the public with earthquake science", "ispublished": "pub", "full_text_status": "restricted", "keywords": "Communication; Natural hazards; Seismology", "note": "\u00a9 2020 Springer Nature Limited. \n\nPublished 13 January 2020. \n\nThe author thanks the supporters of the Dr. Lucy Jones Center for Science and Society. \n\nThe author declares no competing interests.", "abstract": "Risk communication in the aftermath of an earthquake can provide actionable information to help vulnerable societies prevent further damage. It is most effective when scientists convey what they know about earthquakes and earthquake risk, instead of focusing on the unknowns.", "date": "2020-01", "date_type": "published", "publication": "Nature Reviews Earth & Environment", "volume": "1", "number": "1", "publisher": "Springer", "pagerange": "2-3", "id_number": "CaltechAUTHORS:20200113-124437246", "issn": "2662-138X", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200113-124437246", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "Seismological-Laboratory" } ] }, "doi": "10.1038/s43017-019-0007-4", "resource_type": "article", "pub_year": "2020", "author_list": "Jones, Lucile M." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/70mgv-ae886", "eprint_id": 73666, "eprint_status": "archive", "datestamp": "2023-08-22 19:42:53", "lastmod": "2023-10-24 15:35:14", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Hauksson-E", "name": { "family": "Hauksson", "given": "Egill" }, "orcid": "0000-0002-6834-5051" }, { "id": "Meier-M-A", "name": { "family": "Meier", "given": "Men-Andrin" }, "orcid": "0000-0002-2949-8602" }, { "id": "Ross-Z-E", "name": { "family": "Ross", "given": "Zachary E." }, "orcid": "0000-0002-6343-8400" }, { "id": "Jones-L-M", "name": { "family": "Jones", "given": "Lucile M." }, "orcid": "0000-0002-2690-3051" } ] }, "title": "Evolution of seismicity near the southernmost terminus of the San Andreas Fault: Implications of recent earthquake clusters for earthquake risk in southern California", "ispublished": "pub", "full_text_status": "restricted", "keywords": "seismicity; San Andreas fault; Coulomb stress; seismotectonics; earthqauke interaction; earthquake risk", "note": "\u00a9 2017 American Geophysical Union. \n\nReceived 27 NOV 2016; Accepted 20 JAN 2017; Accepted article online 24 JAN 2017; Published online 9 FEB 2017. \n\nSupported by USGS/NEHRP: G16AP00147, National Science Foundation (NSF): EAR-1550704, and Southern California Earthquake Center (contribution 7176) and funded by NSF EAR-1033462 and USGS G12AC20038. Figures done with PMG from Wessel et al. [2013]. Used data are from the Caltech/USGS SCSN; doi:10.7914/SN/CI; stored at Southern California Earthquake Data Center (SCEDC) doi:10.7909/C3WD3xH1.", "abstract": "Three earthquake clusters that occurred in the direct vicinity of the southern terminus of the San Andreas Fault (SAF) in 2001, 2009, and 2016 raised significant concern regarding possible triggering of a major earthquake on the southern SAF, which has not ruptured in more than 320\u2009years. These clusters of small and moderate earthquakes with M\u2009\u2264\u20094.8 added to an increase in seismicity rate in the northern Brawley seismic zone that began after the 1979 M_w 6.5 Imperial Valley earthquake, in contrast to the quiet from 1932 to 1979. The clusters so far triggered neither small nor large events on the SAF. The mostly negative Coulomb stress changes they imparted on the SAF may have reduced the likelihood that the events would initiate rupture on the SAF, although large magnitude earthquake triggering is poorly understood. The relatively rapid spatial and temporal migration rates within the clusters imply aseismic creep as a possible driver rather than fluid migration.", "date": "2017-02-16", "date_type": "published", "publication": "Geophysical Research Letters", "volume": "44", "number": "3", "publisher": "American Geophysical Union", "pagerange": "1293-1301", "id_number": "CaltechAUTHORS:20170124-110939458", "issn": "0094-8276", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170124-110939458", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "USGS", "grant_number": "G16AP00147" }, { "agency": "NSF", "grant_number": "EAR-1550704" }, { "agency": "Southern California Earthquake Center (SCEC)" }, { "agency": "NSF", "grant_number": "EAR-1033462" }, { "agency": "USGS", "grant_number": "G12AC20038" } ] }, "other_numbering_system": { "items": [ { "id": "7176", "name": "Southern California Earthquake Center" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1002/2016GL072026", "resource_type": "article", "pub_year": "2017", "author_list": "Hauksson, Egill; Meier, Men-Andrin; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/2mxn9-rxp70", "eprint_id": 66098, "eprint_status": "archive", "datestamp": "2023-08-20 10:37:03", "lastmod": "2023-10-18 17:08:43", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Field-E-H", "name": { "family": "Field", "given": "Edward H." } }, { "id": "Jordan-T-H", "name": { "family": "Jordan", "given": "Thomas H." } }, { "id": "Jones-L-M", "name": { "family": "Jones", "given": "Lucile M." }, "orcid": "0000-0002-2690-3051" }, { "id": "Michael-A-J", "name": { "family": "Michael", "given": "Andrew J." } }, { "id": "Blanpied-M-L", "name": { "family": "Blanpied", "given": "Michael L." } } ] }, "title": "The Potential Uses of Operational Earthquake Forecasting", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 2016 Seismological Society of America. \n\nPublished Online 3 February 2016. \n\nThe meeting to address potential uses of OEF was supported by the U.S. Geological Survey (USGS) John Wesley Powell Center for Analysis and Synthesis (https://powellcenter.usgs.gov; last accessed April 2015), the Southern California Earthquake Center (SCEC; http://www.scec.org; last accessed April 2015), and the USGS Science Application for Risk Reduction program (SAFRR; http://www.usgs.gov/natural_hazards/safrr; last accessed April 2015). Useful comments were also provided by Kate Long of the California Emergency Management Agency, who was unable to attend the conference. Finally, we thank Sue Perry, John Vidale, and an anonymous Seismological Review Letters reviewer for their extensive and influential comments. This is SCEC Contribution Number 6029. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the United States Government. \n\nParticipants in the Potential Uses of Operational Earthquake Forcasting (OEF) Workshop were Norm Abrahamson, Pacific Gas and Electric (PG&E); Shawna Ackerman, California Earthquake Authority (CEA); Jill Barnes, LA Unified; Michael Blanpied, USGS, Reston; Ann Bostrom, University of Washington; Kenneth Campbell, CoreLogic; Paul Earle, USGS, Golden; Edward Field, USGS, Golden; Delphine Fitzenz, Risk Management Solutions (RMS); Matt Gerstenberger, Institute of Geological and Nuclear Sciences (GNS) New Zealand; Jeanne Hardebeck, USGS, Menlo Park; Austin Holland, Oklahoma Geological Survey; Kishor Jaiswal, USGS, Golden; Lucile Jones, USGS, Pasadena; Thomas Jordan, University of Southern California (USC); Connie Lackey, Providence Medical Centers; Herby Lissade, Caltrans Division of Research, Innovation, and System Information (DRI); Nico Luco, USGS, Golden; Warner Marzocchi, INGV, Italy; Andrew Michael, USGS, Menlo Park; Kevin Milner, USC; Morgan Page, USGS, Pasadena; Jaesung Park, Nephila Capital; Mark Petersen, USGS, Golden; Keith Porter, University of Colorado, Boulder; Peter Powers, USGS, Golden; John Schelling, Washington Emergency Management Division; Deanna >Sellnow, University of Central Florida; Timothy Sellnow, University of Central Florida; Nilesh Shome, RMS; Christopher Terzich, Wells Fargo; Daniel Trugman, University of California San Diego (UCSD); Terry Tullis, Brown University; Loren Turner, Caltrans DRI; Nicholas van der Elst, USGS, Pasadena; David Wald, USGS, Golden; and Anne Wein, USGS, Menlo Park.\n\n
Published - 313.full.pdf
", "abstract": "This article reports on a workshop held to explore the potential uses of operational earthquake forecasting (OEF). We discuss the current status of OEF in the United States and elsewhere, the types of products that could be generated, the various potential users and uses of OEF, and the need for carefully crafted communication protocols. Although operationalization challenges remain, there was clear consensus among the stakeholders at the workshop that OEF could be useful.", "date": "2016-03", "date_type": "published", "publication": "Seismological Research Letters", "volume": "87", "number": "2A", "publisher": "Seismological Society of America", "pagerange": "313-322", "id_number": "CaltechAUTHORS:20160413-074847668", "issn": "0895-0695", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160413-074847668", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "USGS" }, { "agency": "Southern California Earthquake Center (SCEC)" } ] }, "doi": "10.1785/0220150174", "primary_object": { "basename": "313.full.pdf", "url": "https://authors.library.caltech.edu/records/2mxn9-rxp70/files/313.full.pdf" }, "resource_type": "article", "pub_year": "2016", "author_list": "Field, Edward H.; Jordan, Thomas H.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/e2pxz-g6m67", "eprint_id": 37915, "eprint_status": "archive", "datestamp": "2023-08-19 14:51:22", "lastmod": "2023-10-23 19:32:07", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "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" }, { "id": "Bilham-R", "name": { "family": "Bilham", "given": "Roger" } }, { "id": "Boese-M", "name": { "family": "Boese", "given": "Maren" } }, { "id": "Chen-Xiaowei", "name": { "family": "Chen", "given": "Xiaowei" } }, { "id": "Fielding-E-J", "name": { "family": "Fielding", "given": "Eric J." }, "orcid": "0000-0002-6648-8067" }, { "id": "Galetzka-J", "name": { "family": "Galetzka", "given": "John" } }, { "id": "Hudnut-K-W", "name": { "family": "Hudnut", "given": "Kenneth W." }, "orcid": "0000-0002-3168-4797" }, { "id": "Hutton-K", "name": { "family": "Hutton", "given": "Kate" } }, { "id": "Jones-L-M", "name": { "family": "Jones", "given": "Lucile M." }, "orcid": "0000-0002-2690-3051" }, { "id": "Kanamori-H", "name": { "family": "Kanamori", "given": "Hiroo" }, "orcid": "0000-0001-8219-9428" }, { "id": "Shearer-P-M", "name": { "family": "Shearer", "given": "Peter M." }, "orcid": "0000-0002-2992-7630" }, { "id": "Steidl-J", "name": { "family": "Steidl", "given": "Jamie" } }, { "id": "Treiman-J", "name": { "family": "Treiman", "given": "Jerry" } }, { "id": "Wei-Shengji", "name": { "family": "Wei", "given": "Shengji" } }, { "id": "Yang-Wenzheng", "name": { "family": "Yang", "given": "Wenzheng" } } ] }, "title": "Report on the August 2012 Brawley Earthquake Swarm in Imperial Valley, Southern California", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 2013 Seismological Society of America. \n\nWe thank the personnel of the United States Geological Survey (USGS)\u2013California Institute of Technology (Caltech)\nSouthern California Seismic Network (SCSN) for picking the\narrival times and archiving the seismograms and the Southern\nCalifornia Earthquake Data Center for distributing the data.\nTerraSAR-X data are copyright 2012 DLR and were provided\nunder the Group on Earth Observation (GEO) Geohazard\nSupersite program project prlund_GEO0927. E. Hauksson and W. Yang were supported by the National Earthquake Hazards Reduction Program/USGS Grant 12HQPA0001. This research was also supported by the Southern California Earthquake Center (SCEC), which is funded by National Science Foundation (NSF) Cooperative Agreement EAR-0529922 and USGS Cooperative Agreement 07HQAG0008. This paper is Contribution 1678 of SCEC and Contribution 10083 of the Division of Geological and Planetary Sciences, Caltech, Pasadena, California. We thank K. Marty (Imperial Valley College) and S. Williams (consulting geologist from Imperial, California) for help with fieldwork. The high-rate GPS data were processed and provided by S. Owen from the Jet Propulsion Laboratory (JPL). Part of this research was supported by the National Aeronautics and Space Administration (NASA) Earth Surface and Interior focus area and performed at the JPL, Caltech. We thank G. Fuis and D. Hill for reviews and J. Hole for valuable\ndiscussions about the tectonics and velocity structure. J. Stock's participation was supported by NSF Grant OCE-0742253. The University of California at Santa Barbara operates the Wildlife Liquefaction Array facility, with funding through the George E. Brown, Jr., Network for Earthquake Engineering Simulation program of the NSF under Award CMMI-0927178. Most figures were done using GMT (Wessel and Smith, 1998).\n\nPublished - 177.full.pdf
Supplemental Material - Brawley_2012_slipmodel_table.txt
Supplemental Material - Brawley_2012_stress_drops_table.txt
", "abstract": "The 2012 Brawley earthquake swarm occurred in the Brawley Seismic Zone (BSZ) within the Imperial Valley of southern California (Fig. 1). The BSZ is the northernmost extensional segment of the Pacific\u2013North America plate boundary system. Johnson and Hill (1982) used the distribution of seismicity since the 1930s to outline the geographical extent of the BSZ, defining boundaries of the BSZ as shown in Figure 1. Its north\u2013south extent ranges from the northern section of the Imperial fault, starting approximately 10 km north of the United States\u2013Mexico international border and connecting to the southern end of the San Andreas fault, where it terminates in the Salton Sea. Larsen and Reilinger (1991), who defined a similar geographical extent of the BSZ, argued that the BSZ was migrating to the northwest, which they associated with the propagation of the Gulf of California rift system into the North American continent. During the seismically active period of the 1970s, the BSZ produced close to half of the earthquakes recorded in California (Johnson and Hill, 1982; Hutton et al., 2010). However, for two decades following the 1979 Imperial Valley mainshock M_w 6.4 and its aftershock sequence, the BSZ was much less active. In general, the BSZ seismicity is indicative of right-lateral strike-slip plate motion accompanied by crustal thinning as well as possible associated fluid movements in the crust (Chen and Shearer, 2011). The 2012 Brawley swarm produced more than 600 events recorded by the United States Geological Survey (USGS)\u2013California Institute of Technology (Caltech) Southern California Seismic Network (SCSN). Other monitoring instruments in the region, such as the Global Positioning System (GPS) network, creepmeters, and the Wildlife Liquefaction Array (WLA) also recorded signals from the largest events. In addition, Interferometric Synthetic Aperture Radar (InSAR) satellites collected images from space.", "date": "2013-03", "date_type": "published", "publication": "Seismological Research Letters", "volume": "84", "number": "2", "publisher": "Seismological Society of America", "pagerange": "177-189", "id_number": "CaltechAUTHORS:20130412-114502163", "issn": "0895-0695", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130412-114502163", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "USGS", "grant_number": "12HQPA0001" }, { "agency": "Southern California Earthquake Center (SCEC)" }, { "agency": "NSF", "grant_number": "EAR-0529922" }, { "agency": "USGS", "grant_number": "07HQAG0008" }, { "agency": "NASA" }, { "agency": "NSF", "grant_number": "OCE-0742253" }, { "agency": "NSF", "grant_number": "CMMI-0927178" } ] }, "other_numbering_system": { "items": [ { "id": "10083", "name": "Caltech Division of Geological and Planetary Sciences" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1785/0220120169", "primary_object": { "basename": "177.full.pdf", "url": "https://authors.library.caltech.edu/records/e2pxz-g6m67/files/177.full.pdf" }, "related_objects": [ { "basename": "Brawley_2012_slipmodel_table.txt", "url": "https://authors.library.caltech.edu/records/e2pxz-g6m67/files/Brawley_2012_slipmodel_table.txt" }, { "basename": "Brawley_2012_stress_drops_table.txt", "url": "https://authors.library.caltech.edu/records/e2pxz-g6m67/files/Brawley_2012_stress_drops_table.txt" } ], "resource_type": "article", "pub_year": "2013", "author_list": "Hauksson, Egill; Stock, Joann; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/hzfyx-wn593", "eprint_id": 25432, "eprint_status": "archive", "datestamp": "2023-08-19 06:23:09", "lastmod": "2023-10-24 15:52:09", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Perry-S", "name": { "family": "Perry", "given": "Sue" } }, { "id": "Jones-L-M", "name": { "family": "Jones", "given": "Lucile" }, "orcid": "0000-0002-2690-3051" }, { "id": "Cox-D", "name": { "family": "Cox", "given": "Dale" } } ] }, "title": "Developing a Scenario for Widespread Use: Best Practices, Lessons Learned", "ispublished": "pub", "full_text_status": "public", "keywords": "decision making, disasters, earthquake engineering, earthquakes, emergency services, national security, risk analysis, social sciences", "note": "\u00a9 2011 Earthquake Engineering Research Institute.\n\nReceived 25 January 2010; accepted 14 May 2010.\n\nPublished - Perry2011p15823Earthq_Spectra.pdf
", "abstract": "The ShakeOut Scenario is probably the most widely known and used earthquake scenario created to date. Much of the credit for its widespread dissemination and application lies with scenario development criteria that focused on the needs and involvement of end users and with a suite of products that tailored communication of the results to varied end users, who ranged from emergency managers to the general public, from corporations to grassroots organizations. Products were most effective when they were highly visual, when they emphasized the findings of social scientists, and when they communicated the experience of living through the earthquake. This paper summarizes the development criteria and the products that made the ShakeOut Scenario so widely known and used, and it provides some suggestions for future improvements.", "date": "2011-05", "date_type": "published", "publication": "Earthquake Spectra", "volume": "27", "number": "2", "publisher": "Earthquake Engineering Research Institute", "pagerange": "263-272", "id_number": "CaltechAUTHORS:20110926-092227680", "issn": "8755-2930", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20110926-092227680", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "doi": "10.1193/1.3574445", "primary_object": { "basename": "Perry2011p15823Earthq_Spectra.pdf", "url": "https://authors.library.caltech.edu/records/hzfyx-wn593/files/Perry2011p15823Earthq_Spectra.pdf" }, "resource_type": "article", "pub_year": "2011", "author_list": "Perry, Sue; Jones, Lucile; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/wewtm-44e21", "eprint_id": 23141, "eprint_status": "archive", "datestamp": "2023-08-19 05:42:09", "lastmod": "2023-10-23 17:58:33", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Jordan-T-H", "name": { "family": "Jordan", "given": "Thomas H." } }, { "id": "Jones-L-M", "name": { "family": "Jones", "given": "Lucile M." }, "orcid": "0000-0002-2690-3051" } ] }, "title": "Reply to 'A Second Opinion on \"Operational Earthquake Forecasting: Some Thoughts on Why and How,\" by Thomas H. Jordan and Lucile M. Jones,' by Stuart Crampin", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 2011 Seismological Society of America.\n\nPublished - Jordan2011p13208Seismol_Res_Lett.pdf
", "abstract": "In folklore, a \"silver bullet\" is an effective weapon against were-wolves and witches. In earthquake prediction, a silver bullet is a diagnostic precursor\u2014a signal observed before an earthquake that indicates with high probability the location, time, and magnitude of the impending event (Jordan 2006). In his comment, Crampin (2010) claims that shear-wave splitting (SWS) observations provide a silver bullet. He asserts that seismology is thus capable of raising earthquake forecasting out of the low-probability environment to which we assigned it in our recent opinion piece (Jordan and Jones 2010).", "date": "2011-03", "date_type": "published", "publication": "Seismological Research Letters", "volume": "82", "number": "2", "publisher": "Seismological Society of America", "pagerange": "231-232", "id_number": "CaltechAUTHORS:20110328-142809288", "issn": "0895-0695", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20110328-142809288", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "doi": "10.1785/gssrl.82.2.231", "primary_object": { "basename": "Jordan2011p13208Seismol_Res_Lett.pdf", "url": "https://authors.library.caltech.edu/records/wewtm-44e21/files/Jordan2011p13208Seismol_Res_Lett.pdf" }, "resource_type": "article", "pub_year": "2011", "author_list": "Jordan, Thomas H. and Jones, Lucile M." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/rjz9a-6w571", "eprint_id": 19109, "eprint_status": "archive", "datestamp": "2023-08-19 02:57:17", "lastmod": "2023-10-20 19:22:28", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Jordan-T-H", "name": { "family": "Jordan", "given": "Thomas H." } }, { "id": "Jones-L-M", "name": { "family": "Jones", "given": "Lucile M." }, "orcid": "0000-0002-2690-3051" } ] }, "title": "Operational Earthquake Forecasting: Some Thoughts on Why and How", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 2010 Seismological Society of America.\n\nPublished - Jordan2010p10793Seismol_Res_Lett.pdf
", "abstract": "The goal of operational earthquake forecasting is to provide the public with authoritative information on the time dependence of regional seismic hazards.", "date": "2010-07", "date_type": "published", "publication": "Seismological Research Letters", "volume": "81", "number": "4", "publisher": "Seismological Society of America", "pagerange": "571-574", "id_number": "CaltechAUTHORS:20100719-113818032", "issn": "0895-0695", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20100719-113818032", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "doi": "10.1785/gssrl.81.4.571", "primary_object": { "basename": "Jordan2010p10793Seismol_Res_Lett.pdf", "url": "https://authors.library.caltech.edu/records/rjz9a-6w571/files/Jordan2010p10793Seismol_Res_Lett.pdf" }, "resource_type": "article", "pub_year": "2010", "author_list": "Jordan, Thomas H. and Jones, Lucile M." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/wzkg3-mks77", "eprint_id": 64360, "eprint_status": "archive", "datestamp": "2023-08-19 19:21:36", "lastmod": "2024-01-13 16:40:24", "type": "monograph", "metadata_visibility": "show", "creators": { "items": [ { "id": "Jones-L-M", "name": { "family": "Jones", "given": "Lucy" }, "orcid": "0000-0002-2690-3051" }, { "id": "Bernknopf-R", "name": { "family": "Bernknopf", "given": "Richard" } }, { "id": "Cannon-S", "name": { "family": "Cannon", "given": "Susan" } }, { "id": "Cox-D-A", "name": { "family": "Cox", "given": "Dale A." } }, { "id": "Gaydos-L", "name": { "family": "Gaydos", "given": "Len" } }, { "id": "Keeley-J-E", "name": { "family": "Keeley", "given": "Jon" } }, { "id": "Kohler-M-D", "name": { "family": "Kohler", "given": "Monica" } }, { "id": "Lee-Homa", "name": { "family": "Lee", "given": "Homa" } }, { "id": "Ponti-D", "name": { "family": "Ponti", "given": "Daniel" }, "orcid": "0000-0002-2437-5144" }, { "id": "Ross-S", "name": { "family": "Ross", "given": "Stephanie" } }, { "id": "Schwarzbach-S", "name": { "family": "Schwarzbach", "given": "Steven" } }, { "id": "Shulters-M", "name": { "family": "Shulters", "given": "Michael" } }, { "id": "Ward-A-W", "name": { "family": "Ward", "given": "A. Wesley" } }, { "id": "Wein-A", "name": { "family": "Wein", "given": "Anne" } } ] }, "title": "Increasing Resiliency to Natural Hazards\u2014A Strategic Plan for the Multi-Hazards Demonstration Project in Southern California", "ispublished": "unpub", "full_text_status": "public", "note": "Published - ofr_2007-1255_print.pdf
", "abstract": "The U.S. Geological Survey (USGS) is initiating a new\nproject designed to improve resiliency to natural hazards\nin southern California through the application of science to\ncommunity decision making and emergency response. The\nMulti-Hazards Demonstration Project will assist the region's\ncommunities to reduce their risk from natural hazards by\ndirecting new and existing research towards the community's\nneeds, improving monitoring technology, producing innovative\nproducts, and improving dissemination of the results.\nThe natural hazards to be investigated in this project include coastal erosion, earthquakes, floods, landslides, tsunamis, and wildfires.\n\nAmericans are more at risk from natural hazards now\nthan at any other time in our Nation's history. Southern California, in particular, has one of the Nation's highest potentials for extreme catastrophic losses due to natural hazards, with estimates of expected losses exceeding $3 billion per year. These losses can only be reduced through the decisions of the southern California community itself. To be effective, these decisions must be guided by the best information about hazards, risk, and the cost-effectiveness of mitigation technologies. The USGS will work with collaborators to set the direction of the research and to create multi-hazard risk frameworks where communities can apply the results of scientific research to their decision-making processes. Partners include state, county, city, and public-lands government agencies, public and private utilities, companies with a significant impact and presence\nin southern California, academic researchers, the Federal\nEmergency Management Agency (FEMA), National Oceanic\nand Atmospheric Administration (NOAA), and local emergency\nresponse agencies.\n\nPrior to the writing of this strategic plan document,\nthree strategic planning workshops were held in February and\nMarch 2006 at the USGS office in Pasadena to explore potential relationships. The goal of these planning sessions was to determine the external organizations' needs for mitigation efforts before potential natural hazard events, and response efforts during and after the event. On the basis of input from workshop participants, four priority areas were identified for future research to address. They are (1) helping decision makers design planning scenarios, (2) improving upon the mapping of multiple hazards in urban areas, (3) providing real-time information from monitoring networks, and (4)\nintegrating information in a risk and decision-making analysis. Towards this end, short-term and out-year goals have been outlined with the priorities in mind.\n\nFirst-year goals are (1) to engage the user community to\nestablish the structures and processes for communications and interactions, (2) to develop a program to create scenarios of anticipated disasters, beginning in the first year with a scenario of a southern San Andreas earthquake that triggers secondary hazards, (3) to compile existing datasets of geospatial data, and (4) to target research efforts to support more complete and robust products in future years. Both the first-year and out-year goals have been formulated around a working-group structure that builds on existing research strengths within the\nUSGS. The project is intended to demonstrate how developments in methodology and products can lead to improvement in our management of natural hazards in an urban environment for application across the Nation.", "date": "2007", "date_type": "published", "publisher": "U.S. Geological Survey", "id_number": "CaltechAUTHORS:20160209-164027845", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160209-164027845", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "primary_object": { "basename": "ofr_2007-1255_print.pdf", "url": "https://authors.library.caltech.edu/records/wzkg3-mks77/files/ofr_2007-1255_print.pdf" }, "resource_type": "monograph", "pub_year": "2007", "author_list": "Jones, Lucy; Bernknopf, Richard; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/hgmfx-5ma59", "eprint_id": 44969, "eprint_status": "archive", "datestamp": "2023-08-19 13:10:34", "lastmod": "2023-10-26 17:27:40", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Hardebeck-J-L", "name": { "family": "Hardebeck", "given": "Jeanne L." } }, { "id": "Boatwright-J", "name": { "family": "Boatwright", "given": "John" } }, { "id": "Dreger-D-S", "name": { "family": "Dreger", "given": "Douglas" } }, { "id": "Goel-R", "name": { "family": "Goel", "given": "Rakesh" } }, { "id": "Graizer-V", "name": { "family": "Graizer", "given": "Vladimir" } }, { "id": "Hudnut-K-W", "name": { "family": "Hudnut", "given": "Kenneth" }, "orcid": "0000-0002-3168-4797" }, { "id": "Ji-Chen", "name": { "family": "Ji", "given": "Chen" }, "orcid": "0000-0002-0350-5704" }, { "id": "Jones-L-M", "name": { "family": "Jones", "given": "Lucile" }, "orcid": "0000-0002-2690-3051" }, { "id": "Langbein-J", "name": { "family": "Langbein", "given": "John" } }, { "id": "Lin-Jian", "name": { "family": "Lin", "given": "Jian" } }, { "id": "Roeloffs-E", "name": { "family": "Roeloffs", "given": "Evelyn" } }, { "id": "Simpson-R", "name": { "family": "Simpson", "given": "Robert" } }, { "id": "Stark-K", "name": { "family": "Stark", "given": "Keith" } }, { "id": "Stein-R-S", "name": { "family": "Stein", "given": "Ross" } }, { "id": "Tinsley-J-C", "name": { "family": "Tinsley", "given": "John C." } } ] }, "title": "Preliminary Report on the 22 December 2003, M 6.5 San Simeon, California Earthquake", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 2004 Seismological Society of America. The California Integrated Seismic Network is funded by the USGS internal and external programs, the USGS Advanced National Seismic System, the California Governor's Office of Emergency Services, and the California Geological Survey. We thank the staff of the CISN Northern California Management Center and the NCEDC for their efforts to make rapid reports such as this one possible. We also thank the staff of CGS (CISN Engineering Center) for making strong-motion data available and for dispatching field crews to retrieve strong-motion data and rapid processing on the day of the earthquake. We thank IRIS/DMC for making teleseismic data available in near real-time. We thank Jascha Polet for providing the Caltech/CISN CMT solution for the San Simeon mainshock, and Colin Williams for information about the Paso Robles hot springs. John Filson of USGS and Tim McCrink, Jerry Treimann, and Bill Bryant of CGS assisted with geological investigations. The following people assisted with the BARD/SCIGN GPS vectors: Duncan Agnew, Yehuda Bock, John Galetzka, Ken Hurst, Nancy King, Jessica Murray, Doug Neuhauser, Jerry Svarc, Chris Walls, Frank Webb. We thank Gary Puis, Andrew Michael, and William Ellsworth for helpful reviews of the manuscript. We thank Debi Kilb at the SIO Visualization Center for making the aftershock data available in 3D online.\n\nPublished - 155.full.pdf
", "abstract": "The M_w 6.5 San Simeon earthquake struck the central California coast on 22 December 2003 at 19:15:56 UTC (11:15:56 am local time.) The epicenter was located 11 km northeast of the town of San Simeon, and 39 km west-northwest of Paso Robles (Figure 1), as reported by the California Integrated Seismic Network (CISN, the California region of the Advanced National Seismic System [ANSS]). The mainshock nucleated at 35.702\u00b0N, 121.108\u00b0W and a depth of 7.1 km, and the rupture propagated unilaterally to the southeast. The strong directivity of the rupture resulted in a concentration of damage and aftershock activity to the southeast of the hypocenter. The worst earthquake damage occurred in Paso Robles, where two people died in the collapse of an unreinforced masonry building. The accurate and rapid earthquake information provided in near real-time by CISN/ANSS to the Governor's Office of Emergency Services made it possible to focus emergency response in the source area, although the earthquake was felt from San Francisco to Los Angeles.", "date": "2004-03", "date_type": "published", "publication": "Seismological Research Letters", "volume": "75", "number": "2", "publisher": "Seismological Society of America", "pagerange": "155-172", "id_number": "CaltechAUTHORS:20140416-082151294", "issn": "0895-0695", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140416-082151294", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "USGS" }, { "agency": "California Governor's Office of Emergency Services (OES)" }, { "agency": "California Geological Survey" } ] }, "doi": "10.1785/gssrl.75.2.155", "primary_object": { "basename": "155.full.pdf", "url": "https://authors.library.caltech.edu/records/hgmfx-5ma59/files/155.full.pdf" }, "resource_type": "article", "pub_year": "2004", "author_list": "Hardebeck, Jeanne L.; Boatwright, John; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/cmdc7-jc506", "eprint_id": 37187, "eprint_status": "archive", "datestamp": "2023-08-19 09:23:55", "lastmod": "2023-10-23 17:03:02", "type": "article", "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 M." }, "orcid": "0000-0002-2690-3051" }, { "id": "Hutton-K", "name": { "family": "Hutton", "given": "Kate" } } ] }, "title": "The 1999 M_w 7.1 Hector Mine, California, Earthquake Sequence: Complex Conjugate Strike-Slip Faulting", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 2002 Seismological Society of America. \n\nManuscript received 10 December 2000. \n\nMost figures were done using GMT (Wessel and Smith, 1991) and Zmap (Wiemer, 2000). This research was supported by U.S. Geological Survey Grant Numbers 99HQGR0039 and 01HQGR038 to Caltech and grants from the Southern California Earthquake Center. SCEC is funded by NSF Cooperative Agreement Number EAR-8920136 and USGS Cooperative Agreement Numbers 14-08-0001-A0899 and 1434-HQ-97AG01718. SCEC Contribution Number 553. Contribution Number 8748, Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena.\n\nPublished - 1154.full.pdf
", "abstract": "The 1999 M_w 7.1 Hector Mine mainshock showed right-lateral strike-slip faulting, with an initial strike of N6\u00b0W and vertical dip. The mainshock was preceded within 20 hours by 18 recorded foreshocks of 1.5 \u2264 M \u2264 3.8 within a few kilometers distance of the mainshock hypocenter. The aftershocks delineate how the Hector Mine earthquake ruptured with strike N6\u00b0W to the south for a distance of 15 km, and possibly to the north for a distance of several kilometers. The two largest aftershocks of M 5.9 and M 5.7 occurred near the north and south ends of the first mainshock rupture segment. The second segment of rupture, starting 15 km to the south away from the mainshock hypocenter, delineated by strike-slip and thrust-faulting aftershocks, extends 10 km farther away with a strike of S140\u00b0E along the Bullion fault. The aftershocks also outline an unusual third rupture segment, extending from about 5 km south of the hypocenter with a strike of N30\u00b0W to N35\u00b0W for a distance of 20 km. Approximately 10 to 25 km farther to the north and west of the mainshock epicenter, several clusters form a complex aftershock distribution. Three-dimensional Vp and Vp/Vs models of the region exhibit only small regional changes, as is typical for the Mojave region. Nonetheless, the mainshock rupture started within a region of rapidly varying Vp, and at least three regions of low Vp/Vs are imaged within the aftershock zone. The rate of decay for the Hector Mine earthquake sequence has been slightly above the mean for both p-values and b-values in southern California. The focal mechanisms of the aftershocks and the state of stress are consistent with strike-slip faulting, including a component of normal faulting most prominent to the north. The orientation of the regional maximum horizontal stress, the variation in orientation of the mainshock fault segments by 30\u00b0, and scattered distribution of aftershocks suggest that the mainshock and aftershock deformation field exhibit volumetric shear deformation accommodated by complex conjugate sets of strike-slip faults.", "date": "2002-05", "date_type": "published", "publication": "Bulletin of the Seismological Society of America", "volume": "92", "number": "4", "publisher": "Seismological Society of America", "pagerange": "1154-1170", "id_number": "CaltechAUTHORS:20130228-074444230", "issn": "0037-1106", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130228-074444230", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "USGS", "grant_number": "99HQGR0039" }, { "agency": "USGS", "grant_number": "01HQGR038" }, { "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": "8748", "name": "Caltech Division of Geological and Planetary Sciences" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "primary_object": { "basename": "1154.full.pdf", "url": "https://authors.library.caltech.edu/records/cmdc7-jc506/files/1154.full.pdf" }, "resource_type": "article", "pub_year": "2002", "author_list": "Hauksson, Egill; Jones, Lucile M.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/a3435-hm644", "eprint_id": 37143, "eprint_status": "archive", "datestamp": "2023-08-19 09:23:40", "lastmod": "2023-10-23 17:00:31", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Graizer-V", "name": { "family": "Graizer", "given": "Vladimir" } }, { "id": "Shakal-A-K", "name": { "family": "Shakal", "given": "Anthony" } }, { "id": "Scrivner-C-W", "name": { "family": "Scrivner", "given": "Craig" } }, { "id": "Hauksson-E", "name": { "family": "Hauksson", "given": "Egill" }, "orcid": "0000-0002-6834-5051" }, { "id": "Polet-J", "name": { "family": "Polet", "given": "Jasha" } }, { "id": "Jones-L-M", "name": { "family": "Jones", "given": "Lucy" }, "orcid": "0000-0002-2690-3051" } ] }, "title": "TriNet Strong-Motion Data from the M 7.1 Hector Mine, California, Earthquake of 16 October 1999", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 2002 by the Seismological Society of America. \n\nManuscript received 23 January 2001. \n\nThe TriNet networks extend their appreciation to the individuals and organizations that have permitted and cooperated in the installation of seismic strong-motion equipment on their property. The records presented in this paper were made possible through the efforts of technicians who installed and maintained these stations. The authors thank Bill Bryant for providing a digital file of the surface rupture associated with the Hector Mine earthquake. The authors also thank Tianquing Cao for assistance in digitizing and data processing, and Jim Agnew and Hamid Haddadi for reviewing the manuscript. The manuscript benefited from comments of Michael Rymer and two anonymous reviewers.\n\nPublished - 1525.full.pdf
", "abstract": "The M_w 7.1 Hector Mine earthquake of October 16, 1999 was recorded by more than 300 stations of TriNet, which is administered cooperatively by the California Division of Mines and Geology's California Strong Motion Instrumentation Program (CDMG/CSMIP), California Institute of Technology, and the U.S. Geological Survey (USGS). The earthquake occurred in a remote part of the Mojave Desert, approximately 190 km northeast of downtown Los Angeles, and there were no strong-motion stations close to the surface rupture. The nearest station, Hector, is about 27 km north of the epicenter; it recorded a peak horizontal ground acceleration of 0.33g. The two next closest stations, Amboy and Joshua Tree, are to the east and south, both at epicentral distances of about 50 km; each recorded peak ground accelerations of about 0.2g. The new digital instruments installed for the TriNet project recorded a large set of reliable data at epicentral distances up to 275 km. These data can significantly improve empirical peak ground motion attenuation relationships, which are usually developed for distances only up to 100 km (Boore et al., 1993, 1997) because adequate data have not been available at greater distances. \nHector Mine peak ground motions demonstrate reasonable agreement with empirical attenuation relationships for acceleration. In contrast, higher than expected ground velocities and displacements were recorded at epicentral distances of about 150 to 220 km, especially in the Los Angeles sedimentary basin, where anomalously high-amplitude displacements with periods of 6 to 7 sec were recorded in Los Angeles, Long Beach, and other areas. These long-period surface- or basin-generated waves can have significant effects on large structures. \nThe M_w 7.3 Landers earthquake of 1992 similarly produced strong, long-period waves in the basin. The peak ground motions produced by the Landers earthquake were on average 1.6 times higher than for the Hector Mine earthquake in the Los Angeles area. \nGround-motion data recorded by digital instruments were uniformly processed in the frequency band 0.067 to 46 Hz (0.022\u201315 sec). The processed data set includes records from 213 ground-response stations. In an effort to make strong-motion data available quickly to the engineering and scientific communities, important records from this event were made available by file transfer protocol (ftp) beginning the day of the earthquake.", "date": "2002-05", "date_type": "published", "publication": "Bulletin of the Seismological Society of America", "volume": "92", "number": "4", "publisher": "Seismological Society of America", "pagerange": "1525-1542", "id_number": "CaltechAUTHORS:20130226-102342193", "issn": "0037-1106", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130226-102342193", "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": "10.1785/0120000925", "primary_object": { "basename": "1525.full.pdf", "url": "https://authors.library.caltech.edu/records/a3435-hm644/files/1525.full.pdf" }, "resource_type": "article", "pub_year": "2002", "author_list": "Graizer, Vladimir; Shakal, Anthony; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/zcpmq-zc011", "eprint_id": 42588, "eprint_status": "archive", "datestamp": "2023-08-19 05:11:50", "lastmod": "2023-10-25 16:50:16", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Behr-J", "name": { "family": "Behr", "given": "Jeff" } }, { "id": "Bryant-B", "name": { "family": "Bryant", "given": "Bill" } }, { "id": "Given-D", "name": { "family": "Given", "given": "Doug" } }, { "id": "Gross-K", "name": { "family": "Gross", "given": "Karl" } }, { "id": "Hafner-K", "name": { "family": "Hafner", "given": "Katrin" } }, { "id": "Hardebeck-J-L", "name": { "family": "Hardebeck", "given": "Jeanne" } }, { "id": "Hauksson-E", "name": { "family": "Hauksson", "given": "Egill" }, "orcid": "0000-0002-6834-5051" }, { "id": "Heaton-T-H", "name": { "family": "Heaton", "given": "Tom" }, "orcid": "0000-0003-3363-2197" }, { "id": "Hough-S-E", "name": { "family": "Hough", "given": "Susan" }, "orcid": "0000-0002-5980-2986" }, { "id": "Hudnut-K-W", "name": { "family": "Hudnut", "given": "Ken" }, "orcid": "0000-0002-3168-4797" }, { "id": "Hutton-K", "name": { "family": "Hutton", "given": "Kate" } }, { "id": "Jones-L-M", "name": { "family": "Jones", "given": "Lucy" }, "orcid": "0000-0002-2690-3051" }, { "id": "Kanamori-H", "name": { "family": "Kanamori", "given": "Hiroo" }, "orcid": "0000-0001-8219-9428" }, { "id": "Kendrick-K", "name": { "family": "Kendrick", "given": "Katherine" } }, { "id": "King-N", "name": { "family": "King", "given": "Nancy" } }, { "id": "Maechling-P", "name": { "family": "Maechling", "given": "Phil" } }, { "id": "Meltzner-A-J", "name": { "family": "Meltzner", "given": "Aron" }, "orcid": "0000-0002-2955-0896" }, { "id": "Ponti-D", "name": { "family": "Ponti", "given": "Dan" }, "orcid": "0000-0002-2437-5144" }, { "id": "Rockwell-T", "name": { "family": "Rockwell", "given": "Tom" } }, { "id": "Shakal-A-K", "name": { "family": "Shakal", "given": "Anthony" } }, { "id": "Simons-M", "name": { "family": "Simons", "given": "Mark" }, "orcid": "0000-0003-1412-6395" }, { "id": "Stark-K", "name": { "family": "Stark", "given": "K." } }, { "id": "Wald-D-J", "name": { "family": "Wald", "given": "David" } }, { "id": "Wald-L-A", "name": { "family": "Wald", "given": "Lisa" } }, { "id": "Zhu-Lupei", "name": { "family": "Zhu", "given": "Lupei" } } ] }, "title": "Preliminary Report on the 16 October 1999 M 7.1 Hector Mine, California, Earthquake", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 2000 Seismological Society of America. \n\nScientists from the U.S. Geological Survey, Southern California Earthquake Center, and California Division of Mines and Geology. \n \nWe acknowledge Andy Michael and Nano Seeber for helpful and timely reviews of this manuscript. We thank Lt. Col. James J. Tabak, Captain Teitzel, Mr. Paul \"Kip\" Otis-Deihl, the Explosive Ordinance Disposal Section, the Range Operations Section, Range Control, and the command and personnel of Marine Corp Air Ground Combat Center, Twenty-Nine Palms, California, for their tremendous assistance and cooperation in facilitating field investigations. We also thank CW04 T. Murphy, 1st Lt. J. Ochwatt, and SPC4 B. V. Cabanban, Jr. of the Los Alamitos Army Aviation Support Facility, California Army National Guard. The TriNet project is funded by FEMA/OES, USGS, and Caltech private-sector partners. We acknowledge the Southern California Integrated GPS Network (sponsored by the W M. Keck Foundation, NASA, NSF, USGS, SCEC) for providing data used in this study. SCEC is funded by NSF Cooperative Agreement EAR-8920136, USGS Cooperative Agreement 1434-HQ-97AG01718, and California Department of\nTransportation Contract 59A0050. Caltech Seismology Laboratory contribution #8685. SCEC contribution #494.\n\nPublished - Simons_2000p11.pdf
", "abstract": "The M_w 7.1 Hector Mine, California, earthquake occurred\nat 9:46 GMT on 16 October 1999. The event caused minimal\ndamage because it was located in a remote, sparsely populated part of the Mojave Desert, approximately 47 miles\neast-southeast of Barstow, with epicentral coordinates\n34.59\u00b0N 116.27\u00b0W and a hypocentral depth of 5 \u00b1 3 km.\nTwelve foreshocks, M 1.9-3.8, preceded the mainshock during\nthe previous twelve hours. All of these events were\nlocated close to the hypocenter of the mainshock.", "date": "2000-01", "date_type": "published", "publication": "Seismological Research Letters", "volume": "71", "number": "1", "publisher": "Seismological Society of America", "pagerange": "11-23", "id_number": "CaltechAUTHORS:20131120-102150806", "issn": "0895-0695", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20131120-102150806", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR-8920136" }, { "agency": "USGS", "grant_number": "1434-HQ-97AG01718" }, { "agency": "California Department of Transportation", "grant_number": "59A0050" }, { "agency": "Federal Emergency Management Agency (FEMA)" }, { "agency": "Caltech" } ] }, "other_numbering_system": { "items": [ { "id": "494", "name": "Southern California Earthquake Center (SCEC)" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1785/gssrl.71.1.11", "primary_object": { "basename": "Simons_2000p11.pdf", "url": "https://authors.library.caltech.edu/records/zcpmq-zc011/files/Simons_2000p11.pdf" }, "resource_type": "article", "pub_year": "2000", "author_list": "Behr, Jeff; Bryant, Bill; 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/8ksyz-mqe95", "eprint_id": 48041, "eprint_status": "archive", "datestamp": "2023-08-19 02:28:24", "lastmod": "2023-10-26 21:29:46", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Michael-A-J", "name": { "family": "Michael", "given": "Andrew J." } }, { "id": "Jones-L-M", "name": { "family": "Jones", "given": "Lucile M." }, "orcid": "0000-0002-2690-3051" } ] }, "title": "Seismicity Alert Probabilities at Parkfield, California, Revisited", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 1998, by the Seismological Society of America. Manuscript received 5 November 1996. This article has benefited from reviews mad comments from Duncan Agnew, Bill Bakun, Bill Ellsworth, Lind Gee, Dave Jackson, Allan Lindh, Paul Reasenberg, Jim Savage, and an anonymous reviewer.\n\nPublished - 117.full.pdf
", "abstract": "For a decade, the U.S. Geological Survey has used the Parkfield Earthquake Prediction Experiment scenario document to estimate the probability that earthquakes observed on the San Andreas fault near Parkfield will turn out to be foreshocks followed by the expected magnitude 6 mainshocks. During this time, we have learned much about the seismogenic process at Parkfield, about the long-term probability of the Parkfield mainshock, and about the estimation of these types of probabilities. The probabilities for potential foreshocks at Parkfield are reexamined and revised in light of these advances. As part of this process, we have confirmed both the rate of foreshocks before strike-slip earthquakes in the San Andreas physiographic province and the uniform distribution of foreshocks with magnitude proposed by earlier studies. Compared to the earlier assessment, these new estimates of the long-term probability of the Parkfield mainshock are lower, our estimate of the rate of background seismicity is higher, and we find that the assumption that foreshocks at Parkfield occur in a unique way is not statistically significant at the 95% confidence level. While the exact numbers vary depending on the assumptions that are made, the new alert probabilities are lower than previously estimated. Considering the various assumptions and the statistical uncertainties in the input parameters, we also compute a plausible range for the probabilities. The range is large, partly due to the extra knowledge that exists for the Parkfield segment, making us question the usefulness of these numbers.", "date": "1998-02", "date_type": "published", "publication": "Bulletin of the Seismological Society of America", "volume": "88", "number": "1", "publisher": "Seismological Society of America", "pagerange": "117-130", "id_number": "CaltechAUTHORS:20140806-073545323", "issn": "0037-1106", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140806-073545323", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "primary_object": { "basename": "117.full.pdf", "url": "https://authors.library.caltech.edu/records/8ksyz-mqe95/files/117.full.pdf" }, "resource_type": "article", "pub_year": "1998", "author_list": "Michael, Andrew J. and Jones, Lucile M." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/95pnv-z3r95", "eprint_id": 37025, "eprint_status": "archive", "datestamp": "2023-08-19 01:03:57", "lastmod": "2023-10-23 16:03:36", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Jones-L-M", "name": { "family": "Jones", "given": "Lucile M." }, "orcid": "0000-0002-2690-3051" }, { "id": "Hauksson-E", "name": { "family": "Hauksson", "given": "Egill" }, "orcid": "0000-0002-6834-5051" } ] }, "title": "The seismic cycle in southern California: Precursor or response?", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 1997 American Geophysical Union. \n\nReceived December 3, 1996; accepted January 8, 1997. \n\nWe are grateful for the reviews and insightful comments from Sue Hough, Hiroo Kanamori and Bill Ellsworth. One of us (EH) was partially supported by USGS Grant 1434-94-G-2440. Contribution number 5792, Division of Geological and Planetary Sciences, California Institute of Technology.\n\nPublished - grl9964.pdf
", "abstract": "The seismicity rate (M \u2265 3.0) in southern California shows two cycles with periods of high activity (90 events/year), from 1945\u20131952 and 1969\u20131992, and lower activity (60\u201370 events /year) from 1952\u20131969 and 1992-present. Abrupt drops in the seismicity rate occur after the 1952 Kern County (M7.5) and the 1992 Landers (M7.3) earthquakes. The sudden increase in 1969 does not coincide with any major event but approximates the time needed to reaccumulate the seismic moment released in the 1952 earthquake. This temporal correlation with the preceding earthquake suggests that the seismic cycle (lower seismicity after a major earthquake and higher seismicity before the next major earthquake) should be interpreted as a response to the first earthquake rather than a precursor to the second. Southern California is now at a rate of seismicity as low as it experienced in the 1950s and 1960s.", "date": "1997-02-15", "date_type": "published", "publication": "Geophysical Research Letters", "volume": "24", "number": "4", "publisher": "American Geophysical Union", "pagerange": "469-472", "id_number": "CaltechAUTHORS:20130220-135938167", "issn": "0094-8276", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130220-135938167", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "USGS", "grant_number": "1434-94-G-2440" } ] }, "collection": "CaltechAUTHORS", "other_numbering_system": { "items": [ { "id": "5792", "name": "Caltech Division of Geological and Planetary Sciences" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory", "value": "Seismological Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences", "value": "Division of Geological and Planetary Sciences" } ] }, "doi": "10.1029/97GL00188", "primary_object": { "basename": "grl9964.pdf", "url": "https://authors.library.caltech.edu/records/95pnv-z3r95/files/grl9964.pdf" }, "resource_type": "article", "pub_year": "1997", "author_list": "Jones, Lucile M. and Hauksson, Egill" }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/nk56d-5cv13", "eprint_id": 52340, "eprint_status": "archive", "datestamp": "2023-08-20 07:31:17", "lastmod": "2023-10-18 19:46:57", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Jones-L-M", "name": { "family": "Jones", "given": "Lucile M." }, "orcid": "0000-0002-2690-3051" } ] }, "title": "Earthquake prediction: The interaction of public policy and science", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 1996 National Academy of Sciences.\n\nThis paper was presented at a colloquium entitled \"Earthquake Prediction: The Scientific Challenge,\" organized by Leon Knopoff (Chair), Keiiti Aki, Clarence R. Allen, James R. Rice, and Lynn R. Sykes, held February 10 and 11, 1995, at the National Academy of Sciences in Irvine, CA.\n\nPublished - PNAS-1996-Jones-3721-5.pdf
", "abstract": "Earthquake prediction research has searched for both informational phenomena, those that provide information about earthquake hazards useful to the public, and causal phenomena, causally related to the physical processes governing failure on a fault, to improve our understanding of those processes. Neither informational nor causal phenomena are a subset of the other. I propose a classification of potential earthquake predictors of informational, causal, and predictive phenomena, where predictors are causal phenomena that provide more accurate assessments of the earthquake hazard than can be gotten from assuming a random distribution. Achieving higher, more accurate probabilities than a random distribution requires much more information about the precursor than just that it is causally related to the earthquake.", "date": "1996-04-30", "date_type": "published", "publication": "Proceedings of the National Academy of Sciences of the United States of America", "volume": "93", "number": "9", "publisher": "National Academy of Sciences", "pagerange": "3721-3725", "id_number": "CaltechAUTHORS:20141203-134205721", "issn": "0027-8424", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20141203-134205721", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "doi": "10.1073/pnas.93.9.3721", "pmcid": "PMC39428", "primary_object": { "basename": "PNAS-1996-Jones-3721-5.pdf", "url": "https://authors.library.caltech.edu/records/nk56d-5cv13/files/PNAS-1996-Jones-3721-5.pdf" }, "resource_type": "article", "pub_year": "1996", "author_list": "Jones, Lucile M." }, { "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/75gem-dg705", "eprint_id": 52067, "eprint_status": "archive", "datestamp": "2023-08-20 06:27:53", "lastmod": "2023-10-18 19:31:36", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Hauksson-E", "name": { "family": "Hauksson", "given": "Egill" }, "orcid": "0000-0002-6834-5051" }, { "id": "Hutton-K", "name": { "family": "Hutton", "given": "Kate" } }, { "id": "Kanamori-H", "name": { "family": "Kanamori", "given": "Hiroo" }, "orcid": "0000-0001-8219-9428" }, { "id": "Jones-L-M", "name": { "family": "Jones", "given": "Lucile" }, "orcid": "0000-0002-2690-3051" }, { "id": "Mori-Jim", "name": { "family": "Mori", "given": "James" } }, { "id": "Hough-S-E", "name": { "family": "Hough", "given": "Susan" }, "orcid": "0000-0002-5980-2986" }, { "id": "Roquemore-G", "name": { "family": "Roquemore", "given": "Glenn" } } ] }, "title": "Preliminary Report on the 1995 Ridgecrest Earthquake Sequence in Eastern California", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 1995 by the Seismological Society of America. \n\nWe are grateful to the seismic analysts of Caltech and the USGS for quick and competent processing of the earthquake data. We thank K. Sieh and B. Wernicke for geological insights. This research was partially supported by USGS grant 1434-94-G-2440, USGS cooperative agreement 1434-92-A-0960, and NSF grant 94-16119 to Caltech. Southern California Earthquake Center publication 226. Contribution 5604, Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena. We thank Frank Monastero and Allan Katzenstein for assistance with the field effort.\n\nPublished - HKsrl95.pdf
", "abstract": "The Ridgecrest earthquake sequence began on 17 August 1995 with a M_L 5.4 earthquake. As of October 3, 1995, the Southern California Seismic Network (SCSN) had recorded over 4,500 events in the sequence, with eight events of M \u2265 4.0. These earthquakes are occurring along the eastern edge of the Indian Wells Valley along a small stretch of the thoroughgoing Eastern California Shear Zone (ECSZ). Previous large events within the ECSZ include the 1992 (M_w 7.3) Landers earthquake sequence and the 1872 (M 7.6) Owens Valley earthquake. The only large earthquake to occur near Indian Wells Valle, was the 1946 Walker Pass (M 6.0) earthquake on an unknown fault in the Sierra Nevada mountains to the west. The ECSZ transfers some of the relative motion between the North America and Pacific Plates away from the San Andreas fault to the western Great Basin of the Basin and Range province.", "date": "1995-11", "date_type": "published", "publication": "Seismological Research Letters", "volume": "66", "number": "6", "publisher": "Seismological Society of America", "pagerange": "54-60", "id_number": "CaltechAUTHORS:20141121-154232585", "issn": "0895-0695", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20141121-154232585", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "USGS", "grant_number": "1434-94-G-2440" }, { "agency": "USGS", "grant_number": "1434-92-A-0960" }, { "agency": "NSF", "grant_number": "94-16119" } ] }, "other_numbering_system": { "items": [ { "id": "226", "name": "Southern California Earthquake Center (SCEC)" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1785/gssrl.66.6.54", "primary_object": { "basename": "HKsrl95.pdf", "url": "https://authors.library.caltech.edu/records/75gem-dg705/files/HKsrl95.pdf" }, "resource_type": "article", "pub_year": "1995", "author_list": "Hauksson, Egill; Hutton, Kate; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/g250h-16g08", "eprint_id": 35695, "eprint_status": "archive", "datestamp": "2023-08-20 06:02:45", "lastmod": "2023-10-20 20:29:53", "type": "article", "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 M." }, "orcid": "0000-0002-2690-3051" }, { "id": "Hutton-K", "name": { "family": "Hutton", "given": "Kate" } } ] }, "title": "The 1994 Northridge earthquake sequence in California:\n Seismological and tectonic aspects", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 1995 American Geophysical Union. \n\nReceived November 15, 1994; revised March 3, 1995; accepted March 13, 1995. \n\nJ. Unruh, J. Scott, and D. Wald provided helpful critical reviews. We are grateful to the seismic analysts of Caltech and the USGS for quick and competent processing of the earthquake data. This research was partially supported by USGS grant 1434-94-G-2440, USGS cooperative agreement 1434-92-A-0960, and NSF grant 94-16119 to Caltech. Southern California Earthquake Center publication 125. Contribution 5463, Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena.\n\nPublished - 95JB00865.pdf
", "abstract": "The M_w 6.7 Northridge earthquake occurred on January 17, 1994, beneath the San Fernando Valley. Two seismicity clusters, located 25 km to the south and 35 km to the north-northwest, preceded the mainshock by 7 days and 16 hours, respectively. The mainshock hypocenter was relatively deep, at 19 km depth in the lower crust. It had a thrust faulting focal mechanism with a rake of 100\u00b0 on a fault plane dipping 35\u00b0 to the south-southwest and striking N75\u00b0W. Because the mainshock did not rupture the surface, its association with surficial geological features remains difficult to resolve. Nonetheless, its occurrence reemphasized the seismic hazard of concealed faults associated with the contractional deformation of the Transverse Ranges. The Northridge earthquake is part of the temporal increase in earthquake activity in the Los Angeles area since 1970. The mainshock was followed by an energetic aftershock sequence. Eight aftershocks of M \u2265 5.0 and 48 aftershocks of 4 \u2264 M \u2264 5 occurred between January 17 and September 30, 1994. The aftershocks extend over most of the western San Fernando Valley and Santa Susana Mountains. They form a diffuse spatial distribution around the mainshock rupture plane, illuminating a previously unmapped thrust ramp, extending from 7\u201310 km depth into the lower crust to a depth of 23 km. No flattening of the aftershock distribution is observed near its bottom. At shallow depths, above 7\u201310 km, the thrust ramp is topped by a dense distribution of aftershock hypocenters bounded by some of the surficial faults. The dip of the ramp increases from east to west. The west side of the aftershock zoae is characterized by a dense, steeply dipping, and north-northeast striking planar cluster of aftershocks that exhibited mostly thrust faulting. These events coincided with the Gillibrand Canyon lateral ramp. Along the east side of the aftershock zone the aftershocks also exhibited primarily thrust faulting focal mechanisms. The focal mechanisms of the aftershocks were dominated by thrust faulting in the large aftershocks, with some strike-slip and normal faulting in the smaller aftershocks. The 1971 San Fernando and the 1994 Northridge earthquakes ruptured partially abutting fault surfaces on opposite sides of a ridge. Both earthquakes accommodated north-south contractional deformation of the Transverse Ranges. The two earthquakes differ primarily in the dip direction of the faults and the depth of faulting. The 1971 north-northeast trend of left-lateral faulting (Chatsworth trend) was not activated in 1994.", "date": "1995-07", "date_type": "published", "publication": "Journal of Geophysical Research B", "volume": "100", "number": "B7", "publisher": "American Geophysical Union", "pagerange": "12,335-12,355", "id_number": "CaltechAUTHORS:20121128-095539910", "issn": "0148-0227", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121128-095539910", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "USGS", "grant_number": "1434-94-G-2440" }, { "agency": "USGS", "grant_number": "1434-92-A-0960" }, { "agency": "NSF", "grant_number": "94-16119" } ] }, "other_numbering_system": { "items": [ { "id": "5463", "name": "Caltech Division of Geological and Planetary Sciences" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1029/95JB00865", "primary_object": { "basename": "95JB00865.pdf", "url": "https://authors.library.caltech.edu/records/g250h-16g08/files/95JB00865.pdf" }, "resource_type": "article", "pub_year": "1995", "author_list": "Hauksson, Egill; Jones, Lucile M.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/579x8-mcc53", "eprint_id": 35550, "eprint_status": "archive", "datestamp": "2023-08-20 04:49:00", "lastmod": "2023-10-20 19:08:06", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Jones-L-M", "name": { "family": "Jones", "given": "L." }, "orcid": "0000-0002-2690-3051" }, { "id": "Aki-Keiiti", "name": { "family": "Aki", "given": "K." } }, { "id": "Boore-D", "name": { "family": "Boore", "given": "D." } }, { "id": "Celebi-M", "name": { "family": "Celebi", "given": "M." } }, { "id": "Donnellan-A", "name": { "family": "Donnellan", "given": "A." } }, { "id": "Hall-J-F", "name": { "family": "Hall", "given": "J." }, "orcid": "0000-0002-7863-5060" }, { "id": "Harris-R", "name": { "family": "Harris", "given": "R." } }, { "id": "Hauksson-E", "name": { "family": "Hauksson", "given": "E." }, "orcid": "0000-0002-6834-5051" }, { "id": "Heaton-T-H", "name": { "family": "Heaton", "given": "T." }, "orcid": "0000-0003-3363-2197" }, { "id": "Hough-S-E", "name": { "family": "Hough", "given": "S." }, "orcid": "0000-0002-5980-2986" }, { "id": "Hudnut-K-W", "name": { "family": "Hudnut", "given": "K." }, "orcid": "0000-0002-3168-4797" }, { "id": "Hutton-K", "name": { "family": "Hutton", "given": "K." } }, { "id": "Johnston-M-L", "name": { "family": "Johnston", "given": "M." } }, { "id": "Joyner-W", "name": { "family": "Joyner", "given": "W." } }, { "id": "Kanamori-H", "name": { "family": "Kanamori", "given": "H." }, "orcid": "0000-0001-8219-9428" }, { "id": "Marshall-G", "name": { "family": "Marshall", "given": "G." } }, { "id": "Michael-A", "name": { "family": "Michael", "given": "A." } }, { "id": "Mori-Jim", "name": { "family": "Mori", "given": "J." } }, { "id": "Murray-M", "name": { "family": "Murray", "given": "M." } }, { "id": "Ponti-D", "name": { "family": "Ponti", "given": "D." }, "orcid": "0000-0002-2437-5144" }, { "id": "Reasenberg-P", "name": { "family": "Reasenberg", "given": "P." } }, { "id": "Schwartz-D", "name": { "family": "Schwartz", "given": "D." } }, { "id": "Seeber-L", "name": { "family": "Seeber", "given": "L." } }, { "id": "Shakal-A-K", "name": { "family": "Shakal", "given": "A." } }, { "id": "Simpson-R", "name": { "family": "Simpson", "given": "R." } }, { "id": "Thio-H", "name": { "family": "Thio", "given": "H." } }, { "id": "Tinsley-J", "name": { "family": "Tinsley", "given": "J." } }, { "id": "Todorovska-M", "name": { "family": "Todorovska", "given": "M." } }, { "id": "Trifunac-M-D", "name": { "family": "Trifunac", "given": "M." } }, { "id": "Wald-D", "name": { "family": "Wald", "given": "D." } }, { "id": "Zoback-M-L", "name": { "family": "Zoback", "given": "M. L." } } ] }, "title": "The Magnitude 6.7 Northridge, California, Earthquake of 17 January 1994", "ispublished": "pub", "full_text_status": "restricted", "note": "\u00a9 1994 American Association for the Advancement of Science. \n\nWe thank W. Ellsworth and R. Page for insightful and constructive reviews. Sponsored by NSF through the Southern California Earthquake Center, the U.S. Geological Survey, and NASA.", "abstract": "The most costly American earthquake since 1906 struck Los Angeles on 17 January 1994. The magnitude 6.7 Northridge earthquake\nresulted from more than 3 meters of reverse slip on a 1 5-kilometer-long south-dipping thrust fault that raised the Santa Susana mountains\nby as much as 70 centimeters. The fault appears to be truncated by the fault that broke in the 1971 San Fernando earthquake at a depth\nof 8 kilometers. Of these two events, the Northridge earthquake caused many times more damage, primarily because its causative fault\nis directly under the city. Many types of structures were damaged, but the fracture of welds in steel-frame buildings was the greatest\nsurprise. The Northridge earthquake emphasizes the hazard posed to Los Angeles by concealed thrust faults and the potential for strong\nground shaking in moderate earthquakes.", "date": "1994-10-21", "date_type": "published", "publication": "Science", "volume": "266", "number": "5184", "publisher": "American Association for the Advancement of Science", "pagerange": "389-397", "id_number": "CaltechAUTHORS:20121120-075947813", "issn": "0036-8075", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121120-075947813", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF" }, { "agency": "Southern California Earthquake Center (SCEC)" }, { "agency": "USGS" }, { "agency": "NASA" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1126/science.266.5184.389", "resource_type": "article", "pub_year": "1994", "author_list": "Jones, L.; Aki, K.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/2nyje-fry81", "eprint_id": 48075, "eprint_status": "archive", "datestamp": "2023-08-20 04:19:04", "lastmod": "2023-10-17 15:50:06", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Jones-L-M", "name": { "family": "Jones", "given": "Lucile M." }, "orcid": "0000-0002-2690-3051" } ] }, "title": "Foreshocks, Aftershocks, and Earthquake Probabilities: Accounting for the Landers Earthquake", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 1994, by the Seismological Society of America. Manuscript received 2 August 1993. I would like to thank Andy Michael, Egill Hauksson, Jim Savage, and especially Tom Heaton for careful and thoughtful reviews of this article.\n\nPublished - 892.full.pdf
", "abstract": "The equation to determine the probability that an earthquake occurring near a major fault will be a foreshock to a mainshock on that fault is modified to include the case of aftershocks to a previous earthquake occurring near the fault. The addition of aftershocks to the background seismicity makes its less probable that an earthquake will be a foreshock, because nonforeshocks have become more common. As the aftershocks decay with time, the probability that an earthquake will be a foreshock increases. However, fault interactions between the first mainshock and the major fault can increase the long-term probability of a characteristic earthquake on that fault, which will, in turn, increase the probability that an event is a foreshock, compensating for the decrease caused by the aftershocks.", "date": "1994-06", "date_type": "published", "publication": "Bulletin of the Seismological Society of America", "volume": "84", "number": "3", "publisher": "Seismological Society of America", "pagerange": "892-899", "id_number": "CaltechAUTHORS:20140806-111429292", "issn": "0037-1106", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140806-111429292", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "primary_object": { "basename": "892.full.pdf", "url": "https://authors.library.caltech.edu/records/2nyje-fry81/files/892.full.pdf" }, "resource_type": "article", "pub_year": "1994", "author_list": "Jones, Lucile M." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/5a0gw-8n386", "eprint_id": 42750, "eprint_status": "archive", "datestamp": "2023-08-20 03:15:33", "lastmod": "2023-10-25 22:59:36", "type": "article", "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 M." }, "orcid": "0000-0002-2690-3051" }, { "id": "Hutton-K", "name": { "family": "Hutton", "given": "Kate" } }, { "id": "Eberhard-Phillips-Donna", "name": { "family": "Eberhard-Phillips", "given": "Donna" } } ] }, "title": "The 1992 Landers Earthquake Sequence: Seismological Observations", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 1993 American Geophysical Union. \n\nReceived April 12, 1993; revised August 10, 1993; accepted August 19, 1993. \n\nD. Oppenheimer, M. Rymer, J. Dolan, and two Journal of Geophysical Research reviewers, C. Thurber and S. Jaume, provided helpful critical reviews. We thank K. Sieh for stimulating discussions about the tectonics of the Landers earthquake and for providing a map of the surface rupture. We are grateful to the seismic analysts of Caltech and the USGS for quick and competent processing of the earthquake data. This research was partially supported by USGS grant 14-08-0001-G1761 and USGS cooperative agreement 1434-92-A-0960 to Caltech and the Southern California Earthquake Center (SCEC) under NSF cooperative agreement EAR-8920136 and USGS cooperative agreement 14-08-0001-0899. SCEC publication 54. Contribution 5268, Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena.\n\nPublished - jgrb9241.pdf
Submitted - The_1992_Landers_Earthquake_Sequence.pdf
", "abstract": "The (M_W 6.1, 7.3, 6.2) 1992 Landers earthquakes began on April 23 with the M_W6.1 1992 Joshua Tree preshock and form the most substantial earthquake sequence to occur in California in the last 40 years. This sequence ruptured almost 100 km of both surficial and concealed faults and caused aftershocks over an area 100 km wide by 180 km long. The faulting was predominantly strike slip and three main events in the sequence had unilateral rupture to the north away from the San Andreas fault. The M_W6.1 Joshua Tree preshock at 33\u00b0N58\u2032 and 116\u00b0W19\u2032 on 0451 UT April 23 was preceded by a tightly clustered foreshock sequence (M\u22644.6) beginning 2 hours before the mainshock and followed by a large aftershock sequence with more than 6000 aftershocks. The aftershocks extended along a northerly trend from about 10 km north of the San Andreas fault, northwest of Indio, to the east-striking Pinto Mountain fault. The M_w7.3 Landers mainshock occurred at 34\u00b0N13\u2032 and 116\u00b0W26\u2032 at 1158 UT, June 28, 1992, and was preceded for 12 hours by 25 small M\u22643 earthquakes at the mainshock epicenter. The distribution of more than 20,000 aftershocks, analyzed in this study, and short-period focal mechanisms illuminate a complex sequence of faulting. The aftershocks extend 60 km to the north of the mainshock epicenter along a system of at least five different surficial faults, and 40 km to the south, crossing the Pinto Mountain fault through the Joshua Tree aftershock zone towards the San Andreas fault near Indio. The rupture initiated in the depth range of 3\u20136 km, similar to previous M\u223c5 earthquakes in the region, although the maximum depth of aftershocks is about 15 km. The mainshock focal mechanism showed right-lateral strike-slip faulting with a strike of N10\u00b0W on an almost vertical fault. The rupture formed an arclike zone well defined by both surficial faulting and aftershocks, with more westerly faulting to the north. This change in strike is accomplished by jumping across dilational jogs connecting surficial faults with strikes rotated progressively to the west. A 20-km-long linear cluster of aftershocks occurred 10\u201320 km north of Barstow, or 30\u201340 km north of the end of the mainshock rupture. The most prominent off-fault aftershock cluster occurred 30 km to the west of the Landers mainshock. The largest aftershock was within this cluster, the M_w6.2 Big Bear aftershock occurring at 34\u00b0N10\u2032 and 116\u00b0W49\u2032 at 1505 UT June 28. It exhibited left-lateral strike-slip faulting on a northeast striking and steeply dipping plane. The Big Bear aftershocks form a linear trend extending 20 km to the northeast with a scattered distribution to the north. The Landers mainshock occurred near the southernmost extent of the Eastern California Shear Zone, an 80-km-wide, more than 400-km-long zone of deformation. This zone extends into the Death Valley region and accommodates about 10 to 20% of the plate motion between the Pacific and North American plates. The Joshua Tree preshock, its aftershocks, and Landers aftershocks form a previously missing link that connects the Eastern California Shear Zone to the southern San Andreas fault.", "date": "1993-11", "date_type": "published", "publication": "Journal of Geophysical Research B", "volume": "98", "number": "B11", "publisher": "American Geophysical Union", "pagerange": "19835-19858", "id_number": "CaltechAUTHORS:20131127-090400676", "issn": "0148-0227", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20131127-090400676", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "USGS", "grant_number": "14-08-0001-G1761" }, { "agency": "USGS", "grant_number": "1434-92-A-0960" }, { "agency": "Southern California Earthquake Center (SCEC)" }, { "agency": "NSF", "grant_number": "EAR-8920136" }, { "agency": "USGS", "grant_number": "14-08-0001-0899" } ] }, "other_numbering_system": { "items": [ { "id": "54", "name": "Southern California Earthquake Center (SCEC)" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1029/93JB02384", "primary_object": { "basename": "The_1992_Landers_Earthquake_Sequence.pdf", "url": "https://authors.library.caltech.edu/records/5a0gw-8n386/files/The_1992_Landers_Earthquake_Sequence.pdf" }, "related_objects": [ { "basename": "jgrb9241.pdf", "url": "https://authors.library.caltech.edu/records/5a0gw-8n386/files/jgrb9241.pdf" } ], "resource_type": "article", "pub_year": "1993", "author_list": "Hauksson, Egill; Jones, Lucile M.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/v23rd-n3c69", "eprint_id": 37447, "eprint_status": "archive", "datestamp": "2023-08-20 02:36:06", "lastmod": "2023-10-23 17:28:29", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Sieh-K-E", "name": { "family": "Sieh", "given": "Kerry" }, "orcid": "0000-0002-7311-2447" }, { "id": "Jones-L-M", "name": { "family": "Jones", "given": "Lucile" }, "orcid": "0000-0002-2690-3051" }, { "id": "Hauksson-E", "name": { "family": "Hauksson", "given": "Egill" }, "orcid": "0000-0002-6834-5051" }, { "id": "Hudnut-K-W", "name": { "family": "Hudnut", "given": "Kenneth" }, "orcid": "0000-0002-3168-4797" }, { "id": "Eberhard-Phillips-D", "name": { "family": "Eberhard-Phillips", "given": "Donna" } }, { "id": "Heaton-T-H", "name": { "family": "Heaton", "given": "Thomas" }, "orcid": "0000-0003-3363-2197" }, { "id": "Hough-S-E", "name": { "family": "Hough", "given": "Susan" }, "orcid": "0000-0002-5980-2986" }, { "id": "Hutton-K", "name": { "family": "Hutton", "given": "Kate" } }, { "id": "Kanamori-H", "name": { "family": "Kanamori", "given": "Hiroo" }, "orcid": "0000-0001-8219-9428" }, { "id": "Lilje-A", "name": { "family": "Lilje", "given": "Anne" } }, { "id": "Lindvall-S-C", "name": { "family": "Lindvall", "given": "Scott" } }, { "id": "McGill-S-F", "name": { "family": "McGill", "given": "Sally F." } }, { "id": "Mori-Jim", "name": { "family": "Mori", "given": "James" } }, { "id": "Rubin-C-M", "name": { "family": "Rubin", "given": "Charles" } }, { "id": "Spotila-J-A", "name": { "family": "Spotila", "given": "James A." } }, { "id": "Stock-J-M", "name": { "family": "Stock", "given": "Joann" }, "orcid": "0000-0003-4816-7865" }, { "id": "Thio-Hong-Kie", "name": { "family": "Thio", "given": "Hong Kie" } }, { "id": "Treiman-J", "name": { "family": "Treiman", "given": "Jerome" } }, { "id": "Wernicke-B-P", "name": { "family": "Wernicke", "given": "Brian" }, "orcid": "0000-0002-7659-8358" }, { "id": "Zachariasen-J", "name": { "family": "Zachariasen", "given": "Judith" } } ] }, "title": "Near-Field Investigations of the Landers Earthquake Sequence, April to July 1992", "ispublished": "pub", "full_text_status": "restricted", "note": "\u00a9 1993 American Association for the Advancement of Science. \n\nWe thank D. Agnew, A. Densmore, J. Dolan, K. Gross, D. Jackson, S. Larsen, M. Lisowski, M. Rymer, Z. Shen, and J. Svarc for helpful discussions and assistance. We also thank the seismic analysts of the Southern California Seismographic Network who have processed the Landers earthquake data, including R. Dollar, R. Geary, D. Given, W. Huston, S. Perry-Huston, R. Robb, and L. Wald. Data collection and processing partially supported by the Caltech Earthquake Research Affiliates Emergency Earthquake Fund and by the Southern California Earthquake Center (contribution number 25), which is funded by the National Science Foundation and the U.S. Geological Survey. Additional support from Division of Geological and Planetary Sciences, California Institute of Technology (contribution number 5217).", "abstract": "The Landers earthquake, which had a moment magnitude (M_w) of 7.3, was the largest earthquake to strike the contiguous United States in 40 years. This earthquake resulted from the rupture of five major and many minor right-lateral faults near the southern end of the eastern California shear zone, just north of the San Andreas fault. Its M_w 6.1 preshock and M_w 6.2 aftershock had their own aftershocks and foreshocks. Surficial geological observations are consistent with local and far-field seismologic observations of the earthquake. Large surficial offsets (as great as 6 meters) and a relatively short rupture length (85 kilometers) are consistent with seismological calculations of a high stress drop (200 bars), which is in turn consistent with an apparently long recurrence interval for these faults.", "date": "1993-04-09", "date_type": "published", "publication": "Science", "volume": "260", "number": "5105", "publisher": "American Association for the Advancement of Science", "pagerange": "171-176", "id_number": "CaltechAUTHORS:20130311-145649896", "issn": "0036-8075", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130311-145649896", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Caltech Earthquake Research Affiliates Emergency Earthquake Fund" }, { "agency": "Southern California Earthquake Center (SCEC)" }, { "agency": "NSF" }, { "agency": "USGS" } ] }, "other_numbering_system": { "items": [ { "id": "25", "name": "Southern California Earthquake Center (SCEC)" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1126/science.260.5105.171", "resource_type": "article", "pub_year": "1993", "author_list": "Sieh, Kerry; Jones, Lucile; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/ctp96-14x06", "eprint_id": 35608, "eprint_status": "archive", "datestamp": "2023-08-20 02:32:06", "lastmod": "2023-10-20 19:12:57", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Kanamori-H", "name": { "family": "Kanamori", "given": "Hiroo" }, "orcid": "0000-0001-8219-9428" }, { "id": "Mori-Jim", "name": { "family": "Mori", "given": "Jim" } }, { "id": "Hauksson-E", "name": { "family": "Hauksson", "given": "Egill" }, "orcid": "0000-0002-6834-5051" }, { "id": "Heaton-T-H", "name": { "family": "Heaton", "given": "Thomas H." }, "orcid": "0000-0003-3363-2197" }, { "id": "Hutton-K", "name": { "family": "Hutton", "given": "L. Katherine" } }, { "id": "Jones-L-M", "name": { "family": "Jones", "given": "Lucile M." }, "orcid": "0000-0002-2690-3051" } ] }, "title": "Determination of earthquake energy release and M_L using TERRAscope", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 1993 Seismological Society of America. \n\nManuscript received 22 June 1992. \n\nThis research was partially supported by the U.S. Geological Survey Grant 14-08-0001-G1774 and grants from the L. K. Whittier Foundation and Arco Foundation. Contribution No. 5177, Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, California 91125.\n\nPublished - 330.full.pdf
", "abstract": "We estimated the energy radiated by earthquakes in southern California using on-scale very broadband recordings from TERRAscope. The method we used involves time integration of the squared ground-motion velocity and empirical determination of the distance attenuation function and the station corrections. The time integral is typically taken over a duration of 2 min after the P-wave arrival. The attenuation curve for the energy integral we obtained is given by q(r) = cr^(\u2212n)exp(\u2212kr)(r^2 = \u0394^2 + h_(ref)^2) with c = 0.49710, n = 1.0322, k = 0.0035 km^(\u22121), and h_(ref) = 8 km, where \u0394 is the epicentral distance. A similar method was used to determine M_L using TERRAscope data. The station corrections for M_L are determined such that the M_L values determined from TERRAscope agree with those from the traditional optical Wood-Anderson seismographs. For 1.5 < M_L < 6.0, a linear relationship log E_S = 1.96 M_L + 9.05 (E_S in ergs) was obtained. However, for events with M_L > 6.5, M_L saturates. The ratio E_S/M_0 (M_0: seismic moment), a measure of the average stress drop, for six earthquakes, the 1989 Montebello earthquake (M_L = 4.6), the 1989 Pasadena earthquake (M_L = 4.9), the 1990 Upland earthquake (M_L = 5.2), the 1991 Sierra Madre earthquake (M_L = 5.8), the 1992 Joshua Tree earthquake (M_L = 6.1), and the 1992 Landers earthquake (M_w = 7.3), are about 10 times larger than those of the others that include the aftershocks of the 1987 Whittier Narrows earthquake, the Sierra Madre earthquake, the Joshua Tree earthquake, and the two earthquakes on the San Jacinto fault. The difference in the stress drop between the mainshock and their large aftershocks may be similar to that between earthquakes on a fault with long and short repeat times. The aftershocks, which occurred on the fault plane where the mainshock slippage occurred, had a very short time to heal, hence a low stress drop. The repeat time of the major earthquakes on the frontal fault systems in the Transverse Ranges in southern California is believed to be very long, a few thousand years. Hence, the events in the Transverse Ranges may have higher stress drops than those of the events occurring on faults with shorter repeat times, such as the San Andreas fault and the San Jacinto fault. The observation that very high stress-drop events occur in the Transverse Ranges and the Los Angeles Basin has important implications for the regional seismic potential. The occurrence of these high stress-drop events near the bottom of the seismogenic zone strongly suggests that these fault systems are capable of supporting high stress that will eventually be released in major seismic events. Characterization of earthquakes in terms of the E_S/M_0 ratio using broadband data will help delineate the spatial distribution of seismogenic stresses in the Los Angeles basin and the Transverse Ranges.", "date": "1993-04", "date_type": "published", "publication": "Bulletin of the Seismological Society of America", "volume": "83", "number": "2", "publisher": "Seismological Society of America", "pagerange": "330-346", "id_number": "CaltechAUTHORS:20121121-113646769", "issn": "0037-1106", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121121-113646769", "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": "L. K. Whittier Foundation" }, { "agency": "Arco Foundation" } ] }, "other_numbering_system": { "items": [ { "id": "5177", "name": "Caltech Division of Geological and Planetary Sciences" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "primary_object": { "basename": "330.full.pdf", "url": "https://authors.library.caltech.edu/records/ctp96-14x06/files/330.full.pdf" }, "resource_type": "article", "pub_year": "1993", "author_list": "Kanamori, Hiroo; Mori, Jim; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/evt10-jmq07", "eprint_id": 48047, "eprint_status": "archive", "datestamp": "2023-08-20 02:32:16", "lastmod": "2023-10-26 21:29:59", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Hutton-K", "name": { "family": "Hutton", "given": "L. K." } }, { "id": "Jones-L-M", "name": { "family": "Jones", "given": "L. M." }, "orcid": "0000-0002-2690-3051" } ] }, "title": "Local magnitudes and apparent variations in seismicity rates in Southern California", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 1993, by the Seismological Society of America. Manuscript received 17 June 1992. We thank Tom Heaton, Egill Hauksson, and especially Paul Reasenberg for constructive critical\nreviews. We also thank Paul Roberts for all his help in finding and transporting the large number of paper seismograms we looked at in this study. One of us (L.K.H.) was partially supported by USGS grant 14-08-0001-A613 for this work. California Institute of Technology Contribution 5175.\n\nPublished - 313.full.pdf
", "abstract": "Redetermination of local magnitudes for moderate earthquakes recorded by the Southern California Seismographic Network (SCSN) from 1932 to 1990 has shown that the magnitudes have not been consistently determined over that time period. The amplitudes of ground velocities recorded on Wood-Anderson instruments were systematically overestimated prior to 1944 compared to present reading procedures, leading to a significant overestimation of local magnitudes. In addition, the change from human to computerized estimation of event magnitude from a suite of amplitudes in 1975 led to slightly lower event magnitudes for the time after 1975 compared to the time before. These changes contribute to an apparently higher rate of seismicity in the 1930s and 1940s than later in the catalog, which had been interpreted as a decrease in seismicity rate after the 1952 Kern County (M_w 7.5) earthquake. Wood-Anderson amplitudes have been reread and consistent magnitudes recalculated using uniform procedures for all earthquakes with a catalog magnitude of 4.5 and greater within the SCSN from 1932 to 1943 and those with a catalog magnitude of 4.8 and greater from 1944 to 1990 so as to create a complete list of all earthquakes with a modern local magnitude of 5.0 or greater. Using these new magnitudes, we find that the rate of M_L 5.0 and greater earthquakes in southern California over this 59-year period to be Poissonian, with no changes in rate significant above the 90% level. From this rate, in any 30-year period, the Poissonian probability of a M \u2267 6 earthquake is 99.7%, the probability of an M \u2267 7 earthquake is 65%, and the probability of an M \u2267 8 event is 18%.", "date": "1993-04", "date_type": "published", "publication": "Bulletin of the Seismological Society of America", "volume": "83", "number": "2", "publisher": "Seismological Society of America", "pagerange": "313-329", "id_number": "CaltechAUTHORS:20140806-084837635", "issn": "0037-1106", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140806-084837635", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "USGS", "grant_number": "14-08-0001-A613" } ] }, "other_numbering_system": { "items": [ { "id": "5175", "name": "Caltech Division of Geological and Planetary Sciences" } ] }, "primary_object": { "basename": "313.full.pdf", "url": "https://authors.library.caltech.edu/records/evt10-jmq07/files/313.full.pdf" }, "resource_type": "article", "pub_year": "1993", "author_list": "Hutton, L. K. and Jones, L. M." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/y780k-84g32", "eprint_id": 51063, "eprint_status": "archive", "datestamp": "2023-08-20 00:15:24", "lastmod": "2023-10-18 16:00:30", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Agnew-D-C", "name": { "family": "Agnew", "given": "Duncan Carr" } }, { "id": "Jones-L-M", "name": { "family": "Jones", "given": "Lucile M." }, "orcid": "0000-0002-2690-3051" } ] }, "title": "Prediction probabilities from foreshocks", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 1991 by the American Geophysical Union.\n\nPaper number 91JB00191.\n\nReceived August 17, 1990;\nrevised January 14, 1991;\naccepted January 18, 1991.\n\nWe thank the members of the Working Group\non Short-term Earthquake Alerts for the Southern San Andreas Fault,\nespecially Brad Hager and Dave Jackson, for raising some of the issues\nthat led to this paper. We have benefited greatly from reviews by Andy\nMichael, Dave Jackson (again), Al Lindh, and especially Mark Mathews.\nWe also thank Paul Reasenberg for comments and for providing the\ndeclustered CALNET data. Preparation of this paper was in part supported\nby U.S. Geological Survey grant 14-08-0001-G1763.\n\nPublished - jgrb8104.pdf
", "abstract": "When any earthquake occurs, the possibility that it might be a foreshock increases the probability that a larger earthquake will occur nearby within the next few days. Clearly, the probability of a very large earthquake ought to be higher if the candidate foreshock were on or near a fault capable of producing that very large mainshock, especially if the fault is towards the end of its seismic cycle. We derive an expression for the probability of a major earthquake characteristic to a particular fault segment, given the occurrence of a potential foreshock near the fault. To evaluate this expression, we need: (1) the rate of background seismic activity in the area, (2) the long-term probability of a large earthquake on the fault, and (3) the rate at which foreshocks precede large earthquakes, as a function of time, magnitude, and spatial location. For this last function we assume the average properties of foreshocks to moderate earthquakes in California: (1) the rate of mainshock occurrence after foreshocks decays roughly as t^(\u22121), so that most foreshocks are within three days of their mainshock, (2) foreshocks and mainshocks occur within 10 km of each other, and (3) the fraction of mainshocks with foreshocks increases linearly as the magnitude threshold for foreshocks decreases, with 50% of the mainshocks having foreshocks with magnitudes within three units of the mainshock magnitude (within three days). We apply our results to the San Andreas, Hayward, San Jacinto, and Imperial faults, using the probabilities of large earthquakes from the report of the Working Group on California Earthquake Probabilities (1988). The magnitude of candidate event required to produce a 1% probability of a large earthquake on the San Andreas fault within three days ranges from a high of 5.3 for the segment in San Gorgonio Pass to a low of 3.6 for the Carrizo Plain.", "date": "1991-07-10", "date_type": "published", "publication": "Journal of Geophysical Research B", "volume": "96", "number": "B7", "publisher": "American Geophysical Union", "pagerange": "11959-11971", "id_number": "CaltechAUTHORS:20141030-112146641", "issn": "0148-0227", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20141030-112146641", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "USGS", "grant_number": "14-08-0001-G1763" } ] }, "doi": "10.1029/91JB00191", "primary_object": { "basename": "jgrb8104.pdf", "url": "https://authors.library.caltech.edu/records/y780k-84g32/files/jgrb8104.pdf" }, "resource_type": "article", "pub_year": "1991", "author_list": "Agnew, Duncan Carr and Jones, Lucile M." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/sx791-s0w60", "eprint_id": 37194, "eprint_status": "archive", "datestamp": "2023-08-19 23:59:20", "lastmod": "2023-10-23 17:03:16", "type": "article", "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 M." }, "orcid": "0000-0002-2690-3051" } ] }, "title": "The 1988 and 1990 Upland Earthquakes: Left-Lateral Faulting Adjacent to the Central Transverse Ranges", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 1991 American Geophysical Union. \n\nManuscript Accepted: 11 February 1991; Manuscript Received: 19 October 1990. \n\nAndy Michael, Jim Mori, Doug Morton, and Kerry Sieh provided helpful critical reviews. We thank Doug Morton and Kerry Sieh for stimulating discussions about the tectonics of the central Transverse Ranges. We are grateful to the seismic analysts of Caltech and the USGS for quick and competent processing of the earthquake data. One of us (E.H.) was supported by USGS grant 14-08-0001-G1761 and NSF grant ERA9014787 for this work. Division of Geological and Planetary Sciences, California Institute of Technology, contribution 4929.\n\nPublished - jgrb8176.pdf
", "abstract": "Two earthquakes (M_L=4.6 and M_L=5.2) occurred at almost the same location in Upland, southern California, in June 1988 and February 1990 and had similar strike-slip focal mechanisms with left-lateral motion on a northeast striking plane. The focal mechanisms and aftershock locations showed that the causative fault was the San Jose fault, an 18-km-long concealed fault that splays west-southwest from the frontal fault of the central Transverse Ranges. Left-lateral strike-slip faults adjacent to the frontal faults may play an important role in the deformation of the Transverse Ranges and the Los Angeles basin as suggested by these Upland earthquakes, the left-lateral strike-slip 1988 (M_L=4.9) Pasadena earthquake on the Raymond fault, 30 km to the west of Upland, and scattered background seismicity along other active left-lateral faults. These faults may transfer slip away from part of the frontal fault toward the south. Alternatively, these faults could represent secondary faulting related to the termination of the northwest striking right-lateral strike-slip faults to the south of the range front. The 1988 and 1990 Upland earthquakes ruptured abutting or possibly overlapping segments of the San Jose fault. The edges of the overlapping aftershock zones, which are sharply defined, together with background seismicity, outline a 14-km-long aseismic segment of the San Jose fault. The 1988 mainshock originated at 9.5 km depth and caused aftershocks between 5 and 12 km. In contrast, the 1990 mainshock focus occurred at the top of its aftershock zone, at 5 km, and caused aftershocks down to 13 km depth. These deep aftershocks tapered off within 2 weeks. The rate of occurrence of aftershocks in magnitude-time space was the same for both sequences. The state of stress reflected in the focal mechanisms of the aftershocks is identical to that determined from background activity and did not change with time during the aftershock sequence. The constant stress state suggests that the 1988 and 1990 events did not completely release all the stored slip on that segment of the fault. The presence of 14 km of unbroken fault, the abrupt temporal termination of deep aftershocks, and the constant stress state all suggest that a future moderate-sized earthquake (M_L=6.0\u20136.5) on the San Jose fault is possible with a rupture length of at least 14 km and possibly 18 km.", "date": "1991-05", "date_type": "published", "publication": "Journal of Geophysical Research B", "volume": "96", "number": "B5", "publisher": "American Geophysical Union", "pagerange": "8143-8165", "id_number": "CaltechAUTHORS:20130228-100455470", "issn": "0148-0227", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130228-100455470", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "USGS", "grant_number": "14-08-0001-G1761" }, { "agency": "NSF", "grant_number": "ERA9014787" } ] }, "other_numbering_system": { "items": [ { "id": "4929", "name": "Caltech Division of Geologic and Planetary Sciences" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1029/91JB00481", "primary_object": { "basename": "jgrb8176.pdf", "url": "https://authors.library.caltech.edu/records/sx791-s0w60/files/jgrb8176.pdf" }, "resource_type": "article", "pub_year": "1991", "author_list": "Hauksson, Egill and Jones, Lucile M." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/31b24-y0y50", "eprint_id": 88012, "eprint_status": "archive", "datestamp": "2023-08-19 23:40:56", "lastmod": "2023-10-18 21:36:20", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Hutton-K", "name": { "family": "Hutton", "given": "L. Katherine" } }, { "id": "Jones-L-M", "name": { "family": "Jones", "given": "Lucille" }, "orcid": "0000-0002-2690-3051" }, { "id": "Hauksson-E", "name": { "family": "Hauksson", "given": "Egill" }, "orcid": "0000-0002-6834-5051" }, { "id": "Given-D-D", "name": { "family": "Given", "given": "Douglas D." } } ] }, "title": "Seismotectonics of southern California", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 1991 Geological Society of America.", "abstract": "Southern California straddles the boundary between the North American and the Pacific plates. The relative motion between these two plates has been determined from paleomagnetic lineations in the Gulf of California, from global solutions to known slip rates along plate boundaries, from geology, and from geodesy (Minster and Jordan, 1978; Minster and Jordan, 1978; DeMets and others, 1987) to be primarily horizontal at a rate of about 48 mm/yr (DeMets and others, 1987). This results in one of the highest levels of seismicity in the conterminous United States (e.g., Evernden, 1970). In southern California, the deformation is spread over a large area, encompassing numerous normal, strike-slip, and reverse faults. A majority of the plate motion appears to be accommodated by the San Andreas fault, with the rest distributed among the dozen or so other major faults (Weldon and Humphreys, 1986). This is in contrast to the plate boundary in northern California, where the plate motion is more concentrated near the San Andreas fault than it is in southern California (e.g., Hill and others, this volume). The diffuse deformational pattern leads to the high level of seismic activity and to a complicated tectonic structure.", "date": "1991-01-01", "date_type": "published", "publisher": "Geological Society of America", "place_of_pub": "Boulder, CO", "pagerange": "133-152", "id_number": "CaltechAUTHORS:20180719-141906842", "isbn": "9780813753065", "book_title": "Neotectonics of North America", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180719-141906842", "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": "Slemmons-D-B", "name": { "family": "Slemmons", "given": "D. Burton" } }, { "id": "Engdahl-E-R", "name": { "family": "Engdahl", "given": "E. R." } }, { "id": "Zoback-M-D", "name": { "family": "Zoback", "given": "Mark D." } }, { "id": "Blackwell-D-D", "name": { "family": "Blackwell", "given": "David D." } } ] }, "doi": "10.1130/DNAG-CSMS-NEO.133", "resource_type": "book_section", "pub_year": "1991", "author_list": "Hutton, L. Katherine; Jones, Lucille; et el." }, { "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/r74hf-x7r36", "eprint_id": 51034, "eprint_status": "archive", "datestamp": "2023-08-19 23:29:17", "lastmod": "2024-01-13 16:11:49", "type": "monograph", "metadata_visibility": "show", "creators": { "items": [ { "id": "Jones-L-M", "name": { "family": "Jones", "given": "Lucile M." }, "orcid": "0000-0002-2690-3051" }, { "id": "Sieh-K-E", "name": { "family": "Sieh", "given": "Kerry" }, "orcid": "0000-0002-7311-2447" }, { "id": "Agnew-D-C", "name": { "family": "Agnew", "given": "Duncan" } }, { "id": "Allen-C-R", "name": { "family": "Allen", "given": "Clarence" } }, { "id": "Bilham-R", "name": { "family": "Bilham", "given": "Roger" } }, { "id": "Ghilarducci-M", "name": { "family": "Ghilarducci", "given": "Mark" } }, { "id": "Hager-B-H", "name": { "family": "Hager", "given": "Bradford" }, "orcid": "0000-0002-5643-1374" }, { "id": "Hauksson-E", "name": { "family": "Hauksson", "given": "Egill" }, "orcid": "0000-0002-6834-5051" }, { "id": "Hudnut-K-W", "name": { "family": "Hudnut", "given": "Kenneth" }, "orcid": "0000-0002-3168-4797" }, { "id": "Jackson-D-D", "name": { "family": "Jackson", "given": "David D." } }, { "id": "Sylvester-A-G", "name": { "family": "Sylvester", "given": "Arthur" } }, { "id": "Aki-Keiti", "name": { "family": "Aki", "given": "Keiti" } }, { "id": "Wyatt-F", "name": { "family": "Wyatt", "given": "Frank" } } ] }, "title": "Short-term earthquake hazard assessment for the San Andreas Fault in southern California", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 1991 USGS.\n\nPublished - OFR_91-32.pdf
", "abstract": "The southernmost 200 km of the San Andreas fault in California, from Cajon Pass\nsoutheast to Bombay Beach on the Salton Sea (Figure 1), has not produced a major earthquake\nwithin the historic record. Both geodetic evidence of continuing strain accumulation (Savage et al,\n1986) and the occurrence of recent prehistoric large earthquakes (Sieh, 1986; Sieh and Williams,\n1990), however, lead us to conclude that this fault segment will eventually produce great\nearthquakes that pose one of the greatest hazards to southern California. An estimated 1.0-1.5\nmillion people now live adjacent to the San Andreas fault within the projected zone of severe\nshaking for such an earthquake. A magnitude 7.5 to 8.0 earthquake on this segment would also\ncause widespread damage to San Bernardino, Imperial, Riverside, Orange, and Los Angeles\ncounties, which together have over 12 million inhabitants. For these reasons, the Southern San\nAndreas Fault Working Group was formed in 1989 to recommend how the scientific community\nmight best respond to anomalous geophysical activity along the fault, increase our understanding\nof regional seismotectonics, and offer timely scientific advice to state and local governments.", "date": "1991", "date_type": "published", "publisher": "U.S. Geological Survey", "id_number": "CaltechAUTHORS:20141029-154001569", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20141029-154001569", "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": "OFR_91-32.pdf", "url": "https://authors.library.caltech.edu/records/r74hf-x7r36/files/OFR_91-32.pdf" }, "resource_type": "monograph", "pub_year": "1991", "author_list": "Jones, Lucile M.; Sieh, Kerry; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/9gwme-ts911", "eprint_id": 37066, "eprint_status": "archive", "datestamp": "2023-08-19 22:36:23", "lastmod": "2023-10-23 16:05:56", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Jones-L-M", "name": { "family": "Jones", "given": "Lucile M." }, "orcid": "0000-0002-2690-3051" }, { "id": "Sieh-K-E", "name": { "family": "Sieh", "given": "Kerry E." }, "orcid": "0000-0002-7311-2447" }, { "id": "Hauksson-E", "name": { "family": "Hauksson", "given": "Egill" }, "orcid": "0000-0002-6834-5051" }, { "id": "Hutton-K", "name": { "family": "Hutton", "given": "L. Katherine" } } ] }, "title": "The 3 December 1988 Pasadena, California earthquake: Evidence for strike-slip motion on the Raymond fault", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 1990 Seismological Society of America. \n\nManuscript received 18 September 1989. \n\nWe thank Jim Mori and Donna Eberhart-Phillips for constructive reviews. E. Hauksson was supported by USGS Grant 14-08-0001-G1328. L.K. Hutton was supported by USGS Cooperative Agreement 14-08-001-A0613. This study would have been impossible without the hard work and dedication of the analysts who process the data of the Southern California Seismic Network. Contribution Number 4774, Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, California.\n\nPublished - 474.full.pdf
", "abstract": "The Pasadena earthquake (M_L = 4.9) occurred on 3 December 1988, at a depth of 16 km. The hypocenters of the earthquake and its aftershocks define a east-northeast striking, steeply northwest-dipping surface that projects up to the active surficial trace of the Raymond fault. One of the nodal planes of the focal mechanism of the earthquake parallels the Raymond fault with left-lateral strike-slip movement on that plane, and is consistent with geomorphic and paleoseismic evidence that the Raymond fault is dominantly a left-lateral strike-slip fault. The existence of a component of sinistral slip along the Raymond fault had been suspected prior to the earthquake, but the northward dip of the fault and the prominent scarp along the western portion of its trace had led most workers to conclude that slip along the fault was dominantly reverse.", "date": "1990-04", "date_type": "published", "publication": "Bulletin of the Seismological Society of America", "volume": "80", "number": "2", "publisher": "Seismological Society of America", "pagerange": "474-482", "id_number": "CaltechAUTHORS:20130222-084926736", "issn": "0037-1106", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130222-084926736", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "USGS", "grant_number": "14-08-0001-G1328" }, { "agency": "USGS", "grant_number": "14-08-001-A0613" } ] }, "other_numbering_system": { "items": [ { "id": "4774", "name": "Caltech Division of Geological and Planetary Sciences" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "primary_object": { "basename": "474.full.pdf", "url": "https://authors.library.caltech.edu/records/9gwme-ts911/files/474.full.pdf" }, "resource_type": "article", "pub_year": "1990", "author_list": "Jones, Lucile M.; Sieh, Kerry E.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/zed8v-n4f12", "eprint_id": 69474, "eprint_status": "archive", "datestamp": "2023-08-19 22:16:16", "lastmod": "2024-01-13 16:53:07", "type": "monograph", "metadata_visibility": "show", "creators": { "items": [ { "id": "Wald-L-A", "name": { "family": "Wald", "given": "Lisa A." } }, { "id": "Given-D-D", "name": { "family": "Given", "given": "Douglas D." } }, { "id": "Jones-L-M", "name": { "family": "Jones", "given": "Lucile M." }, "orcid": "0000-0002-2690-3051" }, { "id": "Hutton-K", "name": { "family": "Hutton", "given": "L. Katherine" } } ] }, "title": "The Southern California network bulletin, January - December, 1989", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 1990 USGS.\n\nPublished - ofr90-483.pdf
", "abstract": "The California Institute of Technology together with the Pasadena Office of the\nU.S. Geological Survey operates a network of approximately 280 remote seismometers\nin southern California. Signals from these sites are telemetered to the central processing\nsite at the Caltech Seismological Laboratory in Pasadena. These signals are continuously\nmonitored by computers that detect and record thousands of earthquakes each year. Phase\narrival times for these events are picked by human analysts and archived along with digital\nseismograms. All data aquisition, processing and archiving is achieved using the CUSP\nsystem. These data are used to compile the Southern California Catalog of Earthquakes;\na list beginning in 1932 that currently contains more than 180,000 events. This data set\nis critical to the evaluation of earthquake hazard in California and to the advancement of\ngeoscience as a whole.\nThis and previous Network Bulletins are intended to serve several purposes. The most\nimportant goal is to make Network data more accessible to current and potential users. It\nis also important to document the details of Network operation, because only with a full\nunderstanding of the process by which the data are produced can researchers use the data\nresponsibly.", "date": "1990", "date_type": "published", "publisher": "U.S. Geological Survey", "id_number": "CaltechAUTHORS:20160805-110747941", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160805-110747941", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "primary_object": { "basename": "ofr90-483.pdf", "url": "https://authors.library.caltech.edu/records/zed8v-n4f12/files/ofr90-483.pdf" }, "resource_type": "monograph", "pub_year": "1990", "author_list": "Wald, Lisa A.; Given, Douglas D.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/6n61f-k5z50", "eprint_id": 38345, "eprint_status": "archive", "datestamp": "2023-08-19 21:44:41", "lastmod": "2023-10-23 20:04:39", "type": "article", "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 M." }, "orcid": "0000-0002-2690-3051" } ] }, "title": "The 1987 Whittier Narrows earthquake sequence in Los Angeles, southern California: Seismological and tectonic analysis", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 1989 by the American Geophysical Union. \n\nReceived August 9, 1988; revised January 11, 1989; accepted January 14, 1989. \n\nWe are grateful to all of the people who were involved in the collection of data from this earthquake. Paul Spudich, Andy Michael, and Chuck Bufe all provided data from portable recording systems deployed during the aftershock sequence. Kate Hutton supplied the magnitude data and, of course, supervised the network processing at Caltech. Greg Perkins kindly provided the Whittier Narrows blast data. We have benefited from stimulating discussions about this earthquake with Thorn Davis, Andy Michael, and Ross Stein. We thank Andy Michael, David Oppenheimer, Ross Stein, Chris Sanders, an anonymous reviewer, and John K. McRaney for critically reviewing the manuscript. This research was partially supported by USGS grant 14-08-0001-G1328 and USGS cooperative agreement 14-08-0001-A0264.\n\nPublished - jgrb7122.pdf
", "abstract": "The October 1, 1987, Whittier Narrows earthquake (M_L = 5.9) was located at 34\u00b02.96\u2032N, 118\u00b04.86\u2032W, at a depth of 14.6\u00b10.5 km in the northeastern Los Angeles basin. The focal mechanism of the mainshock derived from first motion polarities shows pure thrust motion on west striking nodal planes with dips of 25\u00b0\u00b15\u00b0 and 65\u00b0\u00b15\u00b0, respectively. The aftershocks define an approximately circular surface that dips gently to the north, centered at the hypocenter of the mainshock with a diameter of 4\u20136 km. Hence the spatial distribution of the mainshock and aftershocks as well as the focal mechanisms of the mainshock indicate that the causative fault was a 25\u00b0 north dipping thrust fault striking west and is confined to depths from 10 to 16 km. Although most of the 59 aftershock focal mechanisms presented here document a complex sequence of faulting, they are consistent with deformation of the hanging wall caused by the thrust faulting observed in the mainshock. A cluster of reverse faulting events on north striking planes occurred within hours after the mainshock, 2 km to the west of the mainshock. The largest aftershock (M_L = 5.3) occurred on October 4 and showed mostly right-lateral faulting on the same north-northwest striking plane within the hanging wall. Similarly, several left-lateral focal mechanisms are observed near the eastern edge of the mainshock rupture. The earthquake and calibration blast arrival time data were inverted to obtain two refined crustal velocity models and a set of station delays. When relocating the blast using the new models and delays, the absolute hypocentral location bias is less than 0.5 km. The mainshock was followed by nearly 500 locatable aftershocks, which is a small number of aftershocks for this magnitude mainshock. The decay rate of aftershock occurrences with time was fast, while the b value was low (0.67\u00b10.05) for a Los Angeles basin sequence.", "date": "1989-07", "date_type": "published", "publication": "Journal of Geophysical Research B", "volume": "94", "number": "B7", "publisher": "American Geophysical Union", "pagerange": "9569-9589", "id_number": "CaltechAUTHORS:20130508-091114900", "issn": "0148-0227", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130508-091114900", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "USGS", "grant_number": "14-08-0001-G1328" }, { "agency": "USGS", "grant_number": "14-08-0001-A0264" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1029/JB094iB07p09569", "primary_object": { "basename": "jgrb7122.pdf", "url": "https://authors.library.caltech.edu/records/6n61f-k5z50/files/jgrb7122.pdf" }, "resource_type": "article", "pub_year": "1989", "author_list": "Hauksson, Egill and Jones, Lucile M." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/576gg-rzz15", "eprint_id": 35677, "eprint_status": "archive", "datestamp": "2023-08-22 06:24:05", "lastmod": "2023-10-20 20:28:42", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Heaton-T-H", "name": { "family": "Heaton", "given": "Thomas H." }, "orcid": "0000-0003-3363-2197" }, { "id": "Jones-L-M", "name": { "family": "Jones", "given": "Lucile M." }, "orcid": "0000-0002-2690-3051" } ] }, "title": "Seismological research issues in the San Diego region", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 1989 Southern California Earthquake Preparedness Project.\n\nPublished - Heaton_1989p42.pdf
", "abstract": "What is the nature of earthquake ground motions that can be expected in San Diego's\nforeseeable future? Although this is the most basic of questions underlying the adequate design\nof structures to resist earthquakes, answers to this question are disturbingly uncertain. A\nreasonable assumption is that future earthquake ground motions will be similar to those that have\noccurred in the past. When compared with San Francisco or Los Angeles, San Diego has\nhistorically experienced relatively mild earthquake shaking. Unfortunately, San Diego's written\nhistory is very short compared to the time scales of earthquake repetition. Are there sources of\nearthquakes that may cause damage in San Diego and what is their frequency? Mapping of\ngeologic structures and the study of patterns of small earthquakes are the primary tools for\nrecognizing potentially active faults. There are features in both the geologic structure and the\nseismicity that are suggestive of major active faults that could pose a serious hazard to San\nDiego. Furthermore, there is evidence that the rate of occurrence of small earthquakes has\nincreased within the last 5 years when compared with the previous 50 years. However, these\nfeatures are not well studied or understood.\nEven if the potential sources of earthquakes were well understood, the problem of anticipating the\nrange of future ground motions is difficult. The nature of shaking from earthquakes is strongly\naffected by the nature of seismic wave propagation through complex geologic structures (path\neffects). Although path effects are likely to be of great importance in San Diego, relatively little\nspecific information is available.", "date": "1989-06", "date_type": "published", "publisher": "Southern California Earthquake Preparedness Project", "id_number": "CaltechAUTHORS:20121127-134135015", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121127-134135015", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "contributors": { "items": [ { "id": "Roquemore-G", "name": { "family": "Roquemore", "given": "Glenn" } } ] }, "primary_object": { "basename": "Heaton_1989p42.pdf", "url": "https://authors.library.caltech.edu/records/576gg-rzz15/files/Heaton_1989p42.pdf" }, "resource_type": "book_section", "pub_year": "1989", "author_list": "Heaton, Thomas H. and Jones, Lucile M." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/q5jy8-1xh81", "eprint_id": 48540, "eprint_status": "archive", "datestamp": "2023-08-22 06:19:57", "lastmod": "2023-10-17 19:25:43", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Magistrale-H-W", "name": { "family": "Magistrale", "given": "Harold" } }, { "id": "Jones-L-M", "name": { "family": "Jones", "given": "Lucile" }, "orcid": "0000-0002-2690-3051" }, { "id": "Kanamori-H", "name": { "family": "Kanamori", "given": "Hiroo" }, "orcid": "0000-0001-8219-9428" } ] }, "title": "The Superstition Hills, California, earthquakes of 24 November 1987", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 1989, by the Seismological Society of America. Manuscript received 11 April 1988. We thank Iris Lutz and Bob Daniel of Unocal Geothermal Division for kindly supplying supplementary data from seismograph station KNB. Doug Given deployed the temporary strong-motion instrument at KNB. We also thank Caltech and USGS seismic data analysts Steve Bryant, Dean Dougherty, Riley Geary, Lisa Stack, and Kathy Watts for their hard work in timing the earthquakes. Chris Sanders, Doug Given, and Walter Arabasz provided thoughtful reviews. This work was supported by the U.S. Geological Survey under contract 14-08-0001-G1354. Contribution No. 4624, Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, California.\n\nPublished - 239.full.pdf
", "abstract": "The 24 November 1987 Superstition Hills earthquakes occurred on the conjugate northwest-striking right-lateral Superstition Hills fault and a previously unknown northeast-striking left-lateral structure defined by a lineation of hypocenters extending from the Superstition Hills fault to the Brawley seismic zone. Master event locations of the earthquakes using Caltech-USGS seismic network data reveal the following. The first main shock (33\u00b0 4.9\u2032 N, 115\u00b0 47.7\u2032, h = 10.6 km, M_S = 6.2, 0154 GMT), on the northeast striking structure and its foreshocks co-locate. Events on the northeast structure cluster in space and time, and some aftershocks occur in the Brawley seismic zone. The second main shock (33\u00b0 0.9\u2032 N, 115\u00b0 50.9\u2032 W, h = 1.9 km, M_S = 6.6, 1315 GMT), on the Superstition Hills fault, was 12 hr after the first main shock and initiated at shallow depth where the two trends join. Aftershocks of the second main shock lie in a northwest trend between the Superstition Hills and Superstition Mountain faults and have a sharply defined western edge. The extent of the northwest-trend aftershocks is not coincident with surface rupture on the Superstition Hills fault. In general, the earthquakes in the northeast trend are deep and the earthquakes in the northwest trend are shallow. We compare the earthquake distribution to the distribution of crystalline basement rocks defined from a refraction study of Fuis et al. (1982). The earthquake locations and extent of aftershock activity appear to be controlled by the presence of crystalline basement rocks.", "date": "1989-04", "date_type": "published", "publication": "Bulletin of the Seismological Society of America", "volume": "79", "number": "2", "publisher": "Seismological Society of America", "pagerange": "239-251", "id_number": "CaltechAUTHORS:20140814-082634292", "issn": "0037-1106", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140814-082634292", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "USGS", "grant_number": "14-08-0001-G1354" } ] }, "other_numbering_system": { "items": [ { "id": "4624", "name": "Caltech Division of Geological and Planetary Sciences" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "primary_object": { "basename": "239.full.pdf", "url": "https://authors.library.caltech.edu/records/q5jy8-1xh81/files/239.full.pdf" }, "resource_type": "article", "pub_year": "1989", "author_list": "Magistrale, Harold; Jones, Lucile; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/jz6ht-fxr67", "eprint_id": 98503, "eprint_status": "archive", "datestamp": "2023-08-19 21:29:33", "lastmod": "2023-10-18 17:25:09", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Reasenberg-P-A", "name": { "family": "Reasenberg", "given": "Paul A." } }, { "id": "Jones-L-M", "name": { "family": "Jones", "given": "Lucile M." }, "orcid": "0000-0002-2690-3051" } ] }, "title": "Earthquake Hazard After a Mainshock in California", "ispublished": "pub", "full_text_status": "restricted", "note": "\u00a9 1989 American Association for the Advancement of Science. \n\nReceived 20 September 1988; accepted 23 December 1988. \n\nWe thank M. V. Matthews for providing technical assistance throughout the study, B. Ellsworth and Y. Ogata for helpful discussions and suggestions, and R. D. Brown, for initially stimulating our interest in\nthis problem.", "abstract": "After a strong earthquake, the possibility of the occurrence of either significant aftershocks or an even stronger mainshock is a continuing hazard that threatens the resumption of critical services and reoccupation of essential but partially damaged structures. A stochastic parametric model allows determination of probabilities for aftershocks and larger mainshocks during intervals following the mainshock. The probabilities depend strongly on the model parameters, which are estimated with Bayesian statistics from both the ongoing aftershock sequence and from a suite of historic California aftershock sequences. Probabilities for damaging aftershocks and greater mainshocks are typically well-constrained after the first day of the sequence, with accuracy increasing with time.", "date": "1989-03-03", "date_type": "published", "publication": "Science", "volume": "243", "number": "4895", "publisher": "American Association for the Advancement of Science", "pagerange": "1173-1176", "id_number": "CaltechAUTHORS:20190906-160046980", "issn": "0036-8075", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190906-160046980", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "Seismological-Laboratory" } ] }, "doi": "10.1126/science.243.4895.1173", "resource_type": "article", "pub_year": "1989", "author_list": "Reasenberg, Paul A. and Jones, Lucile M." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/1j0jc-p6w75", "eprint_id": 37347, "eprint_status": "archive", "datestamp": "2023-08-19 21:02:54", "lastmod": "2023-10-23 17:23:33", "type": "article", "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 M." }, "orcid": "0000-0002-2690-3051" } ] }, "title": "The July 1986 Oceanside (M_L = 5.3) earthquake sequence in the Continental Borderland, Southern California", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 1988 Seismological Society of America. \n\nManuscript received 25 April 1988. \n\nWe thank J. McRaney, J. Eaton, A. Michael, and C. Nicholson for critically reviewing the manuscript. Dr. Jos\u00e9 Frez C. provided information about the polarity of stations located in Baja California, Mexico. A. Michael made his computer programs available for the stress inversion. J. Pacheco and J. N\u00e1b\u011blek provided a preprint of their paper. This research was supported by USGS Grant 14-08-0001-G1328 and USGS Contract 14-08-0001-A0264. The manuscript by typed by Desser Moton.\n\nPublished - 1885.full.pdf
", "abstract": "An earthquake of M_L = 5.3 occurred at 32\u00b058.7\u2032N, 117\u00b051.5\u2032W southwest of Oceanside in San Diego County at 13:47 13 July 1986 (UT). This main shock was followed by an extensive aftershock sequence, with 55 events of M_L \u2267 3.0 during July 1986. The epicenters of the main shock and aftershocks are located at the northern end of the San Diego Trough-Bahia Soledad fault zone (SDT-BS) where it changes strike from northwest to a more westerly direction through a left offset or a bend in the fault. The northwest-striking SDT-BS is one of three strike-slip fault systems that constitute the offshore Agua Blanca fault system. The spatial distribution of the aftershocks indicates a unilateral 7- to 9-km long rupture to the east-southeast away from the epicenter of the main shock. The focal mechanism of the main shock also has an east-southeast striking and south-dipping plane with mostly reverse movement on it. Focal mechanisms of the M_L \u2267 3.0 aftershocks show both reverse and strike-slip movement. The reverse focal mechanisms indicate that this sequence may have occurred on a thrust fault that provides for a left stepping offset or a bend in the San Diego Trough fault as movement is transferred to the west along the Santa Cruz-Catalina Island escarpment. Some of the aftershocks that are located to the southeast of the main shock and have strike-slip focal mechanisms suggest activation of the northwest-trending San Diego Trough fault. A stress inversion of the focal mechanism data shows that the maximum principal stress determined from the focal mechanisms of the main shock and 22 aftershocks that occurred within 36 hours of the main shock has an azimuth of S30\u00b0W plunging 18\u00b0. The maximum principal stress determined from 30 aftershocks that occurred from 15 July to 2 October 1986 has an azimuth of S20\u00b0W, plunging 18\u00b0. The \u03c6-values (the measure of the relative sizes of the principal stresses) are approximately 0.07 and 0.1, respectively, indicating that the intermediate and minimum principal stress are of similar magnitude. The results of the stress inversion, and the focal mechanisms that showed reverse faulting, suggest that the Inner Continental Borderland offshore from Oceanside is not currently a pure-strike-slip tectonic regime but rather a strike-slip mixed with reverse faulting regime. When the 52 aftershock focal mechanisms are divided into four groups and the stress inversion is repeated, the change in stress can be described as a progressive counter-clockwise rotation of 14\u00b0 of the orientation of the maximum principal stress to a more southerly direction, with the greatest change in stress orientation observed shortly after the main shock. The abundance of aftershocks may be related to the large temporal variation in stress orientation that, in turn, may have resulted from the small stress drop of the main shock.", "date": "1988-12", "date_type": "published", "publication": "Bulletin of the Seismological Society of America", "volume": "78", "number": "6", "publisher": "Seismological Society of America", "pagerange": "1885-1906", "id_number": "CaltechAUTHORS:20130306-113443403", "issn": "0037-1106", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130306-113443403", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "USGS", "grant_number": "14-08-0001-G1328" }, { "agency": "USGS", "grant_number": "14-08-0001-A0264" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "primary_object": { "basename": "1885.full.pdf", "url": "https://authors.library.caltech.edu/records/1j0jc-p6w75/files/1885.full.pdf" }, "resource_type": "article", "pub_year": "1988", "author_list": "Hauksson, Egill and Jones, Lucile M." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/kstpx-sda68", "eprint_id": 37011, "eprint_status": "archive", "datestamp": "2023-08-19 20:30:29", "lastmod": "2023-10-23 16:02:37", "type": "article", "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 M." }, "orcid": "0000-0002-2690-3051" }, { "id": "Davis-T-L", "name": { "family": "Davis", "given": "Thomas L." } }, { "id": "Hutton-K", "name": { "family": "Hutton", "given": "L. Katherine" } }, { "id": "Brady-A-G", "name": { "family": "Brady", "given": "A. Gerald" } }, { "id": "Reasenberg-P-A", "name": { "family": "Reasenberg", "given": "Paul A." } }, { "id": "Michael-A-J", "name": { "family": "Michael", "given": "Andrew J." } }, { "id": "Yerkes-R-F", "name": { "family": "Yerkes", "given": "Robert F." } }, { "id": "Williams-P", "name": { "family": "Williams", "given": "Patrick" } }, { "id": "Reagor-G", "name": { "family": "Reagor", "given": "Glen" } }, { "id": "Stover-C-W", "name": { "family": "Stover", "given": "Carl W." } }, { "id": "Bent-A-L", "name": { "family": "Bent", "given": "Allison L." } }, { "id": "Shakal-A-K", "name": { "family": "Shakal", "given": "Anthony K." } }, { "id": "Etheredge-E", "name": { "family": "Etheredge", "given": "Edwin" } }, { "id": "Porcella-R-L", "name": { "family": "Porcella", "given": "Ronald L." } }, { "id": "Bufe-C-G", "name": { "family": "Bufe", "given": "Charles G." } }, { "id": "Johnston-M-J-S", "name": { "family": "Johnston", "given": "Malcolm J. S." } }, { "id": "Cranswick-E", "name": { "family": "Cranswick", "given": "Edward" } } ] }, "title": "The 1987 Whittier Narrows Earthquake in the Los Angeles Metropolitan Area, California", "ispublished": "pub", "full_text_status": "restricted", "note": "\u00a9 1988 American Association for the Advancement of Science. \n\nReceived 20 November 1987; accepted 4 February 1988. \n\nThis research was supported by internal and external elements of the National Earthquake Hazards Reduction Program of the U.S. Geological Survey.", "abstract": "The Whittier Narrows earthquake sequence (local magnitude, M_L = 5.9), which\ncaused over $358-million damage, indicates that assessments of earthquake hazards in\nthe Los Angeles metropolitan area may be underestimated. The sequence ruptured a\npreviously unidentified thrust fault that may be part of a large system of thrust faults\nthat extends across the entire east-west length of the northern margin of the Los\nAngeles basin. Peak horizontal accelerations from the main shock, which were\nmeasured at ground level and in structures, were as high as 0.6g (where g is the\nacceleration of gravity at sea level) within 50 kilometers of the epicenter. The\ndistribution of the modified Mercalli intensity VII reflects a broad north-south\nelongated zone of damage that is approximately centered on the main shock epicenter.", "date": "1988-03-18", "date_type": "published", "publication": "Science", "volume": "239", "number": "4846", "publisher": "American Association for the Advancement of Science", "pagerange": "1409-1412", "id_number": "CaltechAUTHORS:20130220-090842835", "issn": "0036-8075", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130220-090842835", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "USGS" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1126/science.239.4846.1409", "resource_type": "article", "pub_year": "1988", "author_list": "Hauksson, Egill; Jones, Lucile M.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/2kqps-7vc75", "eprint_id": 98684, "eprint_status": "archive", "datestamp": "2023-08-19 19:55:49", "lastmod": "2023-10-18 17:33:49", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Zoback-M-D", "name": { "family": "Zoback", "given": "Mark D." }, "orcid": "0000-0002-8851-2099" }, { "id": "Zoback-M-L", "name": { "family": "Zoback", "given": "Mary Lou" } }, { "id": "Mount-V-S", "name": { "family": "Mount", "given": "Van S." } }, { "id": "Suppe-J", "name": { "family": "Suppe", "given": "John" } }, { "id": "Eaton-J-P", "name": { "family": "Eaton", "given": "Jerry P." } }, { "id": "Healy-J-H", "name": { "family": "Healy", "given": "John H." } }, { "id": "Oppenheimer-David", "name": { "family": "Oppenheimer", "given": "David" }, "orcid": "0000-0002-6569-3640" }, { "id": "Reasenberg-P-A", "name": { "family": "Reasenberg", "given": "Paul" } }, { "id": "Jones-L-M", "name": { "family": "Jones", "given": "Lucile M." }, "orcid": "0000-0002-2690-3051" }, { "id": "Raleigh-C-B", "name": { "family": "Raleigh", "given": "C. Barry" } }, { "id": "Wong-Ivan-G", "name": { "family": "Wong", "given": "Ivan G." } }, { "id": "Scotti-O", "name": { "family": "Scotti", "given": "Oona" } }, { "id": "Wentworth-C-M", "name": { "family": "Wentworth", "given": "Carl" } } ] }, "title": "New Evidence on the State of Stress of the San Andreas Fault System", "ispublished": "pub", "full_text_status": "restricted", "note": "\u00a9 1987 American Association for the Advancement of Science. \n\nReceived 27 July 1987; accepted 5 October 1987. \n\nWe thank A. Lachenbruch, J. Savage, R. Weldon, A. McGarr, and an anonymous reviewer for comments on earlier versions of this manuscript and for suggesting important improvements.", "abstract": "Contemporary in situ tectonic stress indicators along the San Andreas fault system in central California show northeast-directed horizontal compression that is nearly perpendicular to the strike of the fault. Such compression explains recent uplift of the Coast Ranges and the numerous active reverse faults and folds that trend nearly parallel to the San Andreas and that are otherwise unexplainable in terms of strike-slip deformation. Fault-normal crustal compression in central California is proposed to result from the extremely low shear strength of the San Andreas and the slightly convergent relative motion between the Pacific and North American plates. Preliminary in situ stress data from the Cajon Pass scientific drill hole (located 3.6 kilometers northeast of the San Andreas in southern California near San Bernardino, California) are also consistent with a weak fault, as they show no right-lateral shear stress at \u223c2-kilometer depth on planes parallel to the San Andreas fault.", "date": "1987-11-20", "date_type": "published", "publication": "Science", "volume": "238", "number": "4830", "publisher": "American Association for the Advancement of Science", "pagerange": "1105-1111", "id_number": "CaltechAUTHORS:20190917-135250189", "issn": "0036-8075", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190917-135250189", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "doi": "10.1126/science.238.4830.1105", "resource_type": "article", "pub_year": "1987", "author_list": "Zoback, Mark D.; Zoback, Mary Lou; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/h1kjw-a3n85", "eprint_id": 48710, "eprint_status": "archive", "datestamp": "2023-08-19 18:59:00", "lastmod": "2023-10-17 20:22:15", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Jones-L-M", "name": { "family": "Jones", "given": "Lucile M." }, "orcid": "0000-0002-2690-3051" }, { "id": "Hutton-K", "name": { "family": "Hutton", "given": "L. Katherine" } }, { "id": "Given-D-D", "name": { "family": "Given", "given": "Douglas D." } }, { "id": "Allen-C-R", "name": { "family": "Allen", "given": "Clarence R." } } ] }, "title": "The July 1986 North Palm Springs, California, Earthquake - The North Palm Springs, California, Earthquake Sequence of July 1986", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 1986 Seismological Society of America.\n\nAnalysis of this earthquake would have been impossible without the hard work and dedication of the\nCaltech and U.S. Geological Survey seismic data analysts, Riley Geary, Kathy Watts, Steven Bryant,\nRobert Norris, and Ruth Hannah. The temporary analog seismic stations were operated in the field by\nRob Wesson, Craig Nicholson, John Coakley, and Gonzalo Mendoza of the U.S. Geological Survey. The\nP-wave arrival times from the temporary stations were supplied by Rob Wesson, Rex Allen, and Craig\nNicholson. Egill Hauksson and Susanna Gross of the University of Southern California helped in the\npreparation of data for analysis. Tom Heaton, Steve Hartzell, and Egill Hauksson supplied critical\nreviews. Caltech's contributions to this study were funded in part by U.S. Geological Survey Cooperative\nAgreement No. 14-08-0001-A0257.\n\nPublished - 1830.full.pdf
", "abstract": "An M_L = 5.9 earthquake occurred at 09:20 (UTC) on 8 July 1986 approximately 12 km northwest of the community of North Palm Springs, California. The epicenter of this earthquake was located between the Mission Creek and Banning strands of the San Andreas fault system at 34\u00b00.0'N, 116\u00b036.4'W. In this section of the San Andreas fault system, there is is a high level of diffuse microseismic activity, and it is not clear which of the many mapped fault traces is presently the most active strand (e.g., Allen, 1957; Matti et aI., 1985). The hypocentral distribution of the aftershocks as well as the focal mechanisms of the main shock and a few dozen aftershocks together suggest that the earthquake probably occurred on the Banning fault.", "date": "1986-12", "date_type": "published", "publication": "Bulletin of the Seismological Society of America", "volume": "76", "number": "6", "publisher": "Seismological Society of America", "pagerange": "1830-1837", "id_number": "CaltechAUTHORS:20140820-085429117", "issn": "0037-1106", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140820-085429117", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "USGS", "grant_number": "14-08-0001-A0257" } ] }, "other_numbering_system": { "items": [ { "id": "4394", "name": "Caltech Division of Geological and Planetary Sciences" } ] }, "primary_object": { "basename": "1830.full.pdf", "url": "https://authors.library.caltech.edu/records/h1kjw-a3n85/files/1830.full.pdf" }, "resource_type": "article", "pub_year": "1986", "author_list": "Jones, Lucile M.; Hutton, L. Katherine; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/w4hzt-gsw87", "eprint_id": 49146, "eprint_status": "archive", "datestamp": "2023-08-19 18:31:32", "lastmod": "2023-10-17 21:10:19", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Jones-L-M", "name": { "family": "Jones", "given": "Lucile M." }, "orcid": "0000-0002-2690-3051" }, { "id": "Dollar-R-S", "name": { "family": "Dollar", "given": "Robert S." } } ] }, "title": "Evidence of basin-and-range extensional tectonics in the Sierra Nevada: The Durrwood Meadows swarm, Tulare county, California (1983-1984)", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 1986, by the Seismological Society of America. Manuscript received 28 June 1985. We are indebted to Jerry Eaton, Jean Taylor, Ed Corbett, and Carl Johnson for their help in obtaining data for this study. We also thank Egill Hauksson, Jerry Eaton, James Hileman, and Bob Wallace for helpful criticism of the manuscript. Carol Horn and Linda Rosenthal typed the manuscript.\n\nPublished - 439.Jones.full.pdf
", "abstract": "An extensive earthquake swarm occurred at Durrwood Meadows in the southern Sierra Nevada of eastern California during late 1983 and 1984. It was located within a 100-km-long linear belt of seismicity that cuts through the southern Sierra Nevada along a north-southward strike. This seismic belt has been characterized by swarms and was one of the most seismically active features in southern California during 1984. The Durrwood Meadows swarm itself was characterized by a complex spatial distribution and a simple pattern of focal mechanisms. At the beginning of the swarm, the earthquakes were located along a northwestward trend; later, periods of high seismicity were distributed along a northeastward trend forming a Y-shaped structure, and along other, northward and northwestward trends. In spite of this spatial complexity, the focal mechanisms of the 35 M_L \u2267 3.0 earthquakes within the swarm are all similar to each other, with almost pure normal faulting along a north-southward strike. The strikes of the nodal planes in the focal mechanisms and the spatial distribution of epicenters form an en-echelon pattern. The consistency of the focal mechanisms with each other and the en-echelon pattern of epicenters imply a homogenous stress field and a discontinuous fault structure. The 100-km-long linear belt of seismicity in an area with no throughgoing fault structure is interpreted as a basin-and-range normal fault beginning to form within the Sierra Nevada.", "date": "1986-04", "date_type": "published", "publication": "Bulletin of the Seismological Society of America", "volume": "76", "number": "2", "publisher": "Seismological Society of America", "pagerange": "439-461", "id_number": "CaltechAUTHORS:20140902-144459626", "issn": "0037-1106", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140902-144459626", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "primary_object": { "basename": "439.Jones.full.pdf", "url": "https://authors.library.caltech.edu/records/w4hzt-gsw87/files/439.Jones.full.pdf" }, "resource_type": "article", "pub_year": "1986", "author_list": "Jones, Lucile M. and Dollar, Robert S." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/z2ncp-57a24", "eprint_id": 49195, "eprint_status": "archive", "datestamp": "2023-08-19 18:06:26", "lastmod": "2023-10-17 21:12:24", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Jones-L-M", "name": { "family": "Jones", "given": "Lucile M." }, "orcid": "0000-0002-2690-3051" } ] }, "title": "Foreshocks and time-dependent earthquake hazard assessment in southern California", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 1985, by the Seismological Society of America. Manuscript received 25 April 1985. The author would like to thank J. Pechmann, P. Reasenburg, and A. Lindh for constructive reviews\nof this manuscript. W. Ellsworth, E. Hauksson, and T. Heaton also gave helpful advice and criticism. This work was conducted while the author was a National Research Council Fellow at the U.S. Geological Survey.\n\nPublished - 1669.full.pdf
", "abstract": "The probability that an earthquake in southern California (M \u2267 3.0) will be followed by an earthquake of larger magnitude within 5 days and 10 km (i.e., will be a foreshock) is 6 \u00b1 0.5 per cent (1 S.D.), and is not significantly dependent on the magnitude of the possible foreshock between M = 3 and M = 5. The probability that an earthquake will be followed by an M \u2267 5.0 main shock, however, increases with magnitude of the foreshock from less than 1 per cent at M \u2267 3 to 6.5 \u00b1 2.5 per cent (1 S.D.) at M \u2267 5. The main shock will most likely occur in the first hour after the foreshock, and the probability that a main shock will occur decreases with elapsed time from the occurrence of the possible foreshock by approximately the inverse of time. Thus, the occurrence of an earthquake of M \u2267 3.0 in southern California increases the earthquake hazard within a small space-time window several orders of magnitude above the normal background level.", "date": "1985-12", "date_type": "published", "publication": "Bulletin of the Seismological Society of America", "volume": "75", "number": "6", "publisher": "Seismological Society of America", "pagerange": "1669-1679", "id_number": "CaltechAUTHORS:20140903-114903288", "issn": "0037-1106", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140903-114903288", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "USGS" }, { "agency": "National Research Council" } ] }, "primary_object": { "basename": "1669.full.pdf", "url": "https://authors.library.caltech.edu/records/z2ncp-57a24/files/1669.full.pdf" }, "resource_type": "article", "pub_year": "1985", "author_list": "Jones, Lucile M." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/byn28-sxz10", "eprint_id": 48514, "eprint_status": "archive", "datestamp": "2023-08-19 17:42:15", "lastmod": "2023-10-17 19:24:49", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Shedlock-K-M", "name": { "family": "Shedlock", "given": "Kaye M." } }, { "id": "Jones-L-M", "name": { "family": "Jones", "given": "Lucile M." }, "orcid": "0000-0002-2690-3051" }, { "id": "Xiufang-M", "name": { "family": "Xiufang", "given": "Ma" } } ] }, "title": "Determination of elastic wave velocity and relative hypocenter locations using refracted waves. II. Application to the Haicheng, China, aftershock sequence", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 1985 Seismological Society of America.\n\nManuscript received 4 June 1984.\n\nWe are grateful to K. Aki, S. Cohn, R. McCaffrey, P. Molnar, S. Roecker, R. Stewart, and R. Wesso for their thought-provoking questions and discussions with us. We are also grateful to Gu Gongxu and Xu Shaoxie of the Institute of Geophysics, State Seismological Bureau, Beijing, People's Republic of China, for their encouragement and patience, and for making this work possible. We also wish to thank X. Jiang, the Liaoning Provincial Seismological Bureau, G. Wei, and the Shadong Provincial Seismological\nBureau for making us feel so welcome and for sharing their data with us. We also wish to thank S. Luria for her assistance in the preparation of this manuscript, and R. Ricotta and P. McDowell for drafting the figures.\n\nPublished - 427.full.pdf
", "abstract": "We located the aftershocks of the 4 February 1975 Haicheng, China, aftershock sequence using an arrival time difference (ATD) simultaneous inversion method for determining the near-source (in situ) velocity and the location of the aftershocks with respect to a master event. The aftershocks define a diffuse zone, 70 km \u00d7 25 km, trending west-northwest, perpendicular to the major structural trend of the region. The main shock and most of the large aftershocks have strike-slip fault plane solutions. The preferred fault plane strikes west-northwest, and the inferred sense of motion is left-lateral. The entire Haicheng earthquake sequence appears to have been the response of an intensely faulted range boundary to a primarily east-west crustal compression and/or north-south extension. The calculated upper mantle P-wave velocity is 7.6 \u00b1 0.09 km/sec, and the inferred crustal thickness is between 31 and 32.5 km. The low upper mantle velocity and thin crust may be indicative of local lithospheric extension.", "date": "1985-04", "date_type": "published", "publication": "Bulletin of the Seismological Society of America", "volume": "75", "number": "2", "publisher": "Seismological Society of America", "pagerange": "427-439", "id_number": "CaltechAUTHORS:20140813-132521738", "issn": "0037-1106", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140813-132521738", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "primary_object": { "basename": "427.full.pdf", "url": "https://authors.library.caltech.edu/records/byn28-sxz10/files/427.full.pdf" }, "resource_type": "article", "pub_year": "1985", "author_list": "Shedlock, Kaye M.; Jones, Lucile M.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/vx628-9fa84", "eprint_id": 49179, "eprint_status": "archive", "datestamp": "2023-08-19 17:11:09", "lastmod": "2023-10-17 21:11:41", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Wesnousky-S-G", "name": { "family": "Wesnousky", "given": "S. G." } }, { "id": "Jones-L-M", "name": { "family": "Jones", "given": "L. M." }, "orcid": "0000-0002-2690-3051" }, { "id": "Scholz-C-H", "name": { "family": "Scholz", "given": "C. H." } }, { "id": "Deng-Q", "name": { "family": "Deng", "given": "Qidong" } } ] }, "title": "Historical seismicity and rates of crustal deformation along the margins of the Ordos block, north China", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 1984, by the Seismological Society of America. Manuscript received 7 November 1983. Paul Richards and David Simpson provided critical reviews of the manuscript. We thank Peter\nMolnar for advice and for providing several preprints of his work. The research was supported by NSF Contract CEE 82-06853.\n\nPublished - 1767.full.pdf
", "abstract": "Earthquakes in China show an empirical relation between seismic moment (M_0) and the areal distribution of Modified Mercalli intensities VI and VIII (log M_0 = 16.66 + 0.91 log A^(VIII) and log M_0 = 14.35 + 1.16 log A^(VI), where A and M_0 are measured in squared kilometers and Newton-meter, respectively). The empirical relations may be used to estimate M_0 for historical earthquakes in China to within a factor of three, on average, when sufficient isoseismal data exist. This observation and an extensive collection of isoseismal maps are used to estimate M_0 for large earthquakes that occurred along the margins of the Ordos block during the last 700 yr. Focal parameters of the historical events are inferred from the orientation and displacements across Quaternary faults. Average rates of crustal deformation are then estimated from the 700-yr historical record with formulas that relate the occurrence rate of seismic moment in a region to rates of crustal strain. The Shanxi and northern Ningxia graben systems are situated along the eastern and northwestern edges of the Ordos block, respectively. Normal faults in the two systems trend northeasterly and are characterized by a component of right-lateral slip. The deformation resulting from slip during earthquakes in each of the respective fault systems is estimated at about 0.5 to 1.0 mm/yr of both right-lateral shear and north by northwest extension. The Weihe graben system bounds the southern edge of the Ordos block, strikes easterly and conjugate to the Shanxi and northern Ningxia fault systems, and exhibits left-lateral normal fault displacements. The average rate of deformation across Weihe is described by about 1.0 mm/yr of north by northwest extension and 1.5 mm/yr left-lateral east-west shear. The Hetao fault system delineates the northern edge of the Ordos block and displays Quaternary faults similar in orientation and mechanism to that observed in Weihe. Although mapped faults in Hetao exhibit evidence of Quaternary displacement, crustal deformation rates are not estimated because there exists no historical record of large earthquakes in the area. In southern Ningxia, at the southwest boundary of the Ordos block, deformation occurs by slip on left-lateral strike-slip faults oriented in an easterly azimuth and thrust faults with strikes ranging from southeast to south. The average deformation rate in southern Ningxia is found to be about 4.0 mm/yr of east by northeast contraction and 10.0 mm/yr of left-lateral shear. Deformation of each of the fault systems is consistent with a regional compressive stress that trends northeast and results in an average of about 3.0 mm/yr each of contraction at N70\u00b0E and extension of N160\u00b0E across the entire region. Inasmuch as uncertainties in estimates of M0 for historical earthquakes are about a factor of three, a similar uncertainty is attached to rates of crustal strain determined in this manner.", "date": "1984-10", "date_type": "published", "publication": "Bulletin of the Seismological Society of America", "volume": "74", "number": "5", "publisher": "Seismological Society of America", "pagerange": "1767-1783", "id_number": "CaltechAUTHORS:20140903-090747620", "issn": "0037-1106", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140903-090747620", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "CEE 82-06853" } ] }, "other_numbering_system": { "items": [ { "id": "3686", "name": "Columbia University Lamont-Doherty Geological Observatory" } ] }, "primary_object": { "basename": "1767.full.pdf", "url": "https://authors.library.caltech.edu/records/vx628-9fa84/files/1767.full.pdf" }, "resource_type": "article", "pub_year": "1984", "author_list": "Wesnousky, S. G.; Jones, L. M.; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/anjbz-2yv43", "eprint_id": 38336, "eprint_status": "archive", "datestamp": "2023-08-19 17:07:19", "lastmod": "2023-10-23 20:04:11", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Jones-L-M", "name": { "family": "Jones", "given": "Lucile M." }, "orcid": "0000-0002-2690-3051" }, { "id": "Han-Weibin", "name": { "family": "Han", "given": "Weibin" } }, { "id": "Hauksson-E", "name": { "family": "Hauksson", "given": "Egill" }, "orcid": "0000-0002-6834-5051" }, { "id": "Jin-Anshu", "name": { "family": "Jin", "given": "Anshu" } }, { "id": "Zhang-Yaoguo", "name": { "family": "Zhang", "given": "Yaoguo" } }, { "id": "Luo-Zhuoli", "name": { "family": "Luo", "given": "Zhuoli" } } ] }, "title": "Focal mechanisms and aftershock locations of the Songpan earthquakes of August 1976 in Sichuan, China", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 1984 by the American Geophysical Union. \n\nReceived September 13, 1983; revised March 5, 1984; accepted March 30, 1984. \n\nThis research was conducted under the auspices of the protocol for scientific exchange between the State Seismology Bureau (SSB) (of the People's Republic of China) and the U.S. Geological Survey (USGS) (of the United States of America). The research was supported by the USGS under Earthquake Hazard Reduction Act contract USGS 1408000120620 and by the SSB. We would like to thank the Institute of Geophysics of the SSB for their hospitality in Beijing and especially Xu Shaoxie for his help in arranging this project. We would also like to thank the Sichuan Provincial Seismology Bureau, especially Li Xinghai and Hong Xiangming, for their support and hospitality during the 2 months of work in Chengdu. We also thank Bill Bakun for supplying us with the HP-85 computer for use in Chengdu and Gerardo Suarez for supplying advice, help, and programs for the synthetic seismograms. Mary Ann Luckman and Kazuko Nagao drafted the figures. Paul Richards and David Simpson critically reviewed the manuscript. Lamont-Doherty Contribution Number 3669.\n\nPublished - jgrb4880.pdf
", "abstract": "The precursory swarm, three mainshocks (M = 7.2,6.7, 7.2), and aftershocks of the Songpan earthquakes have been reanalyzed using both local and teleseismic data. The three mainshocks of this sequence occurred on the Huya fault over a 7-day period. Relocations of the aftershocks using local arrival times show that three fault strands were activated during this sequence. Each mainshock occurred on a separate strand, each one south of the strand activated in the previous mainshock, and the aftershock zones of each mainshock appear to abut rather than overlap. Fault plane solutions determined by matching teleseismic P waveforms at World-Wide Standard Seismograph Network stations with synthetic seismograms are consistent with the observed aftershock zones. The first and third mainshocks (M_0 = 1.3 \u00d710^(19) and 8.4 \u00d7 10^(18) N m, respectively) showed almost identical senses of motion, a combination of reverse and left-lateral strike-slip motion, on parallel strands, striking N15\u00b0W, that were separated by a large rightstepping en echelon offset. The second mainshock (M_0 = 4.0 \u00d7 10^(18) N m), occurred in this offset on a fault at a steep angle (\u223c125\u00b0) to the other two strands and showed almost pure reverse motion. Differences in the orientations of the slip vectors of the three mainshocks show that the first mainshock increased the normal and shear stresses on the fault segment that moved in the second mainshock and that the second mainshock decreased the normal stress on the fault segment activated by the third mainshock. These changes in normal stresses may have given rise to the longer time between the first and second events (5 days) as compared with the time between the second and third events (30 hours). A precursory swarm that preceded the Songpan sequence by 3 years occurred in a volume that surrounded the northernmost part of the planar aftershock zone. The time between the start of the swarm and the mainshocks and the magnitude of the largest event in the swarm are similar to those seen for precursory swarms in Soviet Central Asia.", "date": "1984-09", "date_type": "published", "publication": "Journal of Geophysical Research B", "volume": "89", "number": "B9", "publisher": "American Geophysical Union", "pagerange": "7697-7707", "id_number": "CaltechAUTHORS:20130507-152627576", "issn": "0148-0227", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130507-152627576", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "USGS", "grant_number": "1408000120620" }, { "agency": "State Seismology Bureau (China)" } ] }, "other_numbering_system": { "items": [ { "id": "3669", "name": "Lamont-Doherty Geological Observatory" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1029/JB089iB09p07697", "primary_object": { "basename": "jgrb4880.pdf", "url": "https://authors.library.caltech.edu/records/anjbz-2yv43/files/jgrb4880.pdf" }, "resource_type": "article", "pub_year": "1984", "author_list": "Jones, Lucile M.; Han, Weibin; et el." }, { "id": "https://authors.library.caltech.eduhttps://authors.library.caltech.edu/records/nm8qy-pma80", "eprint_id": 49174, "eprint_status": "archive", "datestamp": "2023-08-19 17:04:53", "lastmod": "2023-10-17 21:11:29", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Jones-L-M", "name": { "family": "Jones", "given": "Lucile M." }, "orcid": "0000-0002-2690-3051" } ] }, "title": "Foreshocks (1966-1980) in the San Andreas system, California", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 1984 Seismological Society of America.\n\nManuscript received 28 November 1983.\n\nThe author thanks all of those who supplied data from California, including Allan Lindh, Robert\nCocheram, Jerry Eaton, Kate Hutton, Carl Johnson, and Art Frankel. This work was supported by NSF\nGrant EAR82-08387 and by the author's Lamont Postdoctoral Fellowship. Terry Engelder and Egill\nHauksson critically reviewed the manuscript.\n\nPublished - 1361.full.pdf
", "abstract": "The spatial and temporal distributions of seismicity preceding moderate (ML \u2267 5.0) main shocks in the San Andreas fault system in California have been analyzed to recognize and characterize the patterns of foreshock occurrence. Of 20 main shocks in the San Andreas system, 7, or 35 per cent, have been preceded by immediate foreshock sequences that included events within 1 day and 5 km of the main shocks. A possible correlation of the rate of foreshock occurrence with type of faulting was found such that none of the four main shocks with reverse faulting had foreshocks while 44 per cent of the strike-slip earthquakes had foreshocks. Some enhanced seismic activity was also observed at relatively large distances from the main shock (13 to 30 km) 1 to 5 days before 40 per cent of the main shocks but this activity cannot be clearly distinguished from the background seismicity. Of the seven immediate foreshock sequences, only two had the swarm-like appearance of the class II foreshocks defined by Mogi. The other foreshock sequences appear to be single events (sometimes with their own aftershocks) preceding the respective main shocks. Four of these sequences are spatially correlated with distinct physical discontinuities in their faults between the hypocenters of the foreshock and main shock, and similar discontinuities may also be associated with the other sequences. The durations of the foreshock sequences were found to decrease as the depths of the main shocks increase from 3 to 11 km, which has been interpreted as a dependence on stress. To account for this stress dependence of the duration and the presence of discontinuities, a model for foreshocks occurrence is presented. This model proposes that foreshocks may represent a process of delayed multiple rupture and that the delay between occurrence of foreshock and main shock might represent the time needed for static fatigue to break the stronger rock at the discontinuity in the fault.", "date": "1984-08", "date_type": "published", "publication": "Bulletin of the Seismological Society of America", "volume": "74", "number": "4", "publisher": "Seismological Society of America", "pagerange": "1361-1380", "id_number": "CaltechAUTHORS:20140903-082817079", "issn": "0037-1106", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140903-082817079", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR82-08387" }, { "agency": "Lamont Postdoctoral Fellowship" } ] }, "primary_object": { "basename": "1361.full.pdf", "url": "https://authors.library.caltech.edu/records/nm8qy-pma80/files/1361.full.pdf" }, "resource_type": "article", "pub_year": "1984", "author_list": "Jones, Lucile M." } ]