[ { "id": "https://authors.library.caltech.edu/records/9gy4y-y4921", "eprint_id": 114801, "eprint_status": "archive", "datestamp": "2023-08-20 01:45:39", "lastmod": "2023-10-24 15:11:52", "type": "conference_item", "metadata_visibility": "show", "creators": { "items": [ { "id": "Kohler-M-D", "name": { "family": "Kohler", "given": "Monica D." }, "orcid": "0000-0002-4703-190X" }, { "id": "Filippitzis-Filippos", "name": { "family": "Filippitzis", "given": "Filippos" }, "orcid": "0000-0001-8377-4914" }, { "id": "Graves-Robert-W", "name": { "family": "Graves", "given": "Robert" }, "orcid": "0000-0001-9758-453X" }, { "id": "Massari-Anthony", "name": { "family": "Massari", "given": "Anthony" }, "orcid": "0000-0002-6561-4674" }, { "id": "Heaton-T-H", "name": { "family": "Heaton", "given": "Thomas" }, "orcid": "0000-0003-3363-2197" }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert" }, "orcid": "0000-0003-3323-3508" }, { "id": "Bunn-Julian-J", "name": { "family": "Bunn", "given": "Julian" }, "orcid": "0000-0002-3798-298X" }, { "id": "Guy-Richard-G", "name": { "family": "Guy", "given": "Richard" }, "orcid": "0000-0002-8651-5608" }, { "id": "Chandy-K-M", "name": { "family": "Chandy", "given": "K. Mani" }, "orcid": "0000-0001-9190-1290" } ] }, "title": "Variations in Ground Motion Amplification in the Los Angeles Basin due to the 2019 M7.1 Ridgecrest Earthquake: Implications for the Long-Period Response of Infrastructure", "ispublished": "unpub", "full_text_status": "public", "note": "We are grateful to Caltech, the Betty and Gordon Moore Foundation, the Conrad N. Hilton Foundation, and Computers & Structures, Inc., for providing support for the Community Seismic Network and for this study.\n\n
Accepted Version - Kohler_etal_ASCE_Lifelines_2021_2022.pdf
", "abstract": "Coherent patterns and large variations in ground shaking amplification were observed in the Los Angeles basin during the 2019 M7.1 Ridgecrest earthquake. In particular, 3 s to 6 s responses showed variations due to shallow basin geological structure that have implications for the response to large earthquakes of mid-rises, high-rises, long-span bridges, and fuel storage tanks, even if epicentral distances are several hundred kilometers. The Ridgecrest strong-motion data were recorded by seismic stations from the spatially dense Community Seismic Network, the Southern California Seismic Network, and the California Strong Motion Instrumentation Program. The mainshock observations are compared at the same locations with ground motion simulations to examine the regions that experienced the largest shaking, and to investigate the geological sources of large-amplitude shaking. The simulations were computed for the two most commonly-used regional community seismic velocity models, CVM-S4.26.M01 ('CVM-S') and CVM-H 15.1.0 ('CVM-H'). Both observations and simulations are used in dynamic analysis with a finite-element model of an existing high-rise with ~6-second fundamental horizontal periods, located in downtown Los Angeles. The geographical variation in maximum story drift, story-level shear force, and story-level moment values suggest that the excitation of a hypothetical high-rise located in an area characterized by the largest 6-s PSA values could be significantly larger than in a downtown Los Angeles location. Ground motion simulations using the CVM-H velocity model more closely predict the long-period site amplifications in greater Los Angeles, particularly in the south-central San Fernando Valley, than simulations using CVM-S.", "date": "2022-05-19", "date_type": "published", "publisher": "Caltech Library", "id_number": "CaltechAUTHORS:20220518-205134775", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20220518-205134775", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Caltech" }, { "agency": "Gordon and Betty Moore Foundation" }, { "agency": "Conrad N. Hilton Foundation" }, { "agency": "Computers & Structures, Inc" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "primary_object": { "basename": "Kohler_etal_ASCE_Lifelines_2021_2022.pdf", "url": "https://authors.library.caltech.edu/records/9gy4y-y4921/files/Kohler_etal_ASCE_Lifelines_2021_2022.pdf" }, "pub_year": "2022", "author_list": "Kohler, Monica D.; Filippitzis, Filippos; et el." }, { "id": "https://authors.library.caltech.edu/records/4e37a-ew431", "eprint_id": 112375, "eprint_status": "archive", "datestamp": "2023-08-20 06:14:31", "lastmod": "2023-10-23 22:30:58", "type": "conference_item", "metadata_visibility": "show", "creators": { "items": [ { "id": "Brissaud-Quentin", "name": { "family": "Brissaud", "given": "Quentin" }, "orcid": "0000-0001-8189-4699" }, { "id": "Krishnamoorthy-Siddharth", "name": { "family": "Krishnamoorthy", "given": "Siddharth" }, "orcid": "0000-0002-0379-1616" }, { "id": "Jackson-J-M", "name": { "family": "Jackson", "given": "Jennifer M." }, "orcid": "0000-0002-8256-6336" }, { "id": "Bowman-Daniel-C", "name": { "family": "Bowman", "given": "Daniel C." }, "orcid": "0000-0002-9341-520X" }, { "id": "Komjathy-Attila", "name": { "family": "Komjathy", "given": "Attila" }, "orcid": "0000-0002-5975-438X" }, { "id": "Cutts-James-A", "name": { "family": "Cutts", "given": "James" }, "orcid": "0000-0002-1765-8322" }, { "id": "Zhan-Zhongwen", "name": { "family": "Zhan", "given": "Zhongwen" }, "orcid": "0000-0002-5586-2607" }, { "id": "Pauken-Michael-T", "name": { "family": "Pauken", "given": "Michael T." }, "orcid": "0000-0002-3993-675X" }, { "id": "Izraelevitz-Jacob-S", "name": { "family": "Izraelevitz", "given": "Jacob S." } }, { "id": "Walsh-Gerald-J", "name": { "family": "Walsh", "given": "Gerald J." } } ] }, "title": "What can the sound of earthquakes tell us about a planet's interior structure?", "ispublished": "unpub", "full_text_status": "public", "note": "CC_BY_NC_ND_4.0\n\nAccepted Version - essoar.10509367.1.pdf
", "abstract": "Deploying seismic or infrasound arrays on the ground to probe a planet's interior structure remains challenging in remote regions facing harsh surface conditions such as Venus with a surface temperature of 464\u00b0C. Fortunately, a fraction of the seismic energy transmits in the upper atmosphere as infrasound waves, i.e. low-frequency pressure perturbations (< 20Hz). On July 22, 2019, a heliotrope balloon, equipped with pressure sensors, was launched from the Johnson Valley, CA with the objective of capturing infrasound signals from the aftershock sequence of the 2019 Ridgecrest earthquake. At 16:27:36 UTC, the sound of a natural earthquake of Mw 4.2 was detected for the first time by a balloon platform. This observation offered the opportunity to attempt the first inversion of seismic velocities from the atmosphere. Shear velocities extracted by our analytical inversion method fell within a reasonable range from the values provided by regional tomographic models. While our analysis was limited by the observation's low signal-to-noise ratio, future observations of seismic events from a network of balloons carrying multiple pressure sensors could provide excellent constraints on crustal properties. However, to build robust estimates of seismic properties, inversion procedures will have to account for uncertainties in terms of velocity models, source locations, and instrumental errors. In this contribution, we will discuss the current state of balloon-based observations, the sensitivity of the acoustic wavefield on subsurface properties, and perspectives on future inversions of seismically-induced acoustic data.", "date": "2021-12-14", "date_type": "published", "publisher": "Wiley", "id_number": "CaltechAUTHORS:20211213-518517000", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20211213-518517000", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1002/essoar.10509367.1", "primary_object": { "basename": "essoar.10509367.1.pdf", "url": "https://authors.library.caltech.edu/records/4e37a-ew431/files/essoar.10509367.1.pdf" }, "pub_year": "2021", "author_list": "Brissaud, Quentin; Krishnamoorthy, Siddharth; et el." }, { "id": "https://authors.library.caltech.edu/records/eyaa6-hf002", "eprint_id": 87838, "eprint_status": "archive", "datestamp": "2023-08-19 09:32:22", "lastmod": "2023-10-18 21:28:44", "type": "conference_item", "metadata_visibility": "show", "creators": { "items": [ { "id": "Kohler-M-D", "name": { "family": "Kohler", "given": "M. D." } }, { "id": "Guy-R", "name": { "family": "Guy", "given": "R." } }, { "id": "Bunn-J", "name": { "family": "Bunn", "given": "J." }, "orcid": "0000-0002-3798-298X" }, { "id": "Massari-A", "name": { "family": "Massari", "given": "A." }, "orcid": "0000-0002-6561-4674" }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "R." }, "orcid": "0000-0003-3323-3508" }, { "id": "Heaton-T-H", "name": { "family": "Heaton", "given": "T." }, "orcid": "0000-0003-3363-2197" }, { "id": "Chandy-K-M", "name": { "family": "Chandy", "given": "K. M." } }, { "id": "Ebrahimian-H", "name": { "family": "Ebrahimian", "given": "H." } }, { "id": "Dorn-C", "name": { "family": "Dorn", "given": "C." }, "orcid": "0000-0001-6516-2586" } ] }, "title": "Community seismic network and localized earthquake situational awareness", "ispublished": "unpub", "full_text_status": "public", "note": "This study was partially funded by a Caltech-JPL Research and Technology Development Fund grant. We also thank the Betty and Gordon Moore Foundation, the Terrestrial Hazard Observation and Reporting Center at Caltech, and the Divisions of Geological and Planetary Science, and Engineering and Applied Science at Caltech for funding the development of the Community Seismic Network.\n\nPublished - Kohler_etal_11ncee_1675.pdf
", "abstract": "Community-hosted seismic networks are a solution to the need for large numbers of sensors to operate over a seismically active region in order to accurately measure the size and location of an earthquake, assess resulting damage, and provide alerts. The Community Seismic Network is one such strong-motion network, currently comprising hundreds of elements located in California. It consists of low-cost, three-component, MEMS accelerometers capable of recording accelerations up to twice the level of gravity. The primary product of the network is to produce measurements of shaking of the ground and multiple locations of every upper floor in buildings, in the seconds during and following a major earthquake. Each sensor uses a small, dedicated ARM processor computer running Linux, and analyzes time series data in real time at hundreds of samples per second. The network reports on shaking parameters that indicate intensity of the structural response levels such as maximum floor acceleration and velocity, displacement of a floor in a building, as well as data products that depend on the response time histories. To do this, Cloud computing has been expanded through the use of statically defined subsets of sensors called cloudlets. These are smaller subsets of similar sensors that carry out customized calculations for those locations. The measurements are reported as rapidly as possible following an earthquake so that they may be incorporated into structural diagnosis and prognosis applications that can be used by first responders to prioritize their initial disaster management efforts. The cloudlet displays are customized for specific buildings and they show in real time: instantaneous displacement, inter-story drift, and resonant frequency and mode shapes using system identification software tools. The real-time display products are useful for decision-making about whether the potential for damage exists, what level of damage may have occurred and where, and whether total business disruption is necessary. City-wide dense monitoring makes it possible for emergency response managers to prioritize the target locations requiring first response on a block-by-block scale based on reports of shaking intensity.", "date": "2018-06", "date_type": "published", "publisher": "Caltech Library", "id_number": "CaltechAUTHORS:20180713-133233514", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180713-133233514", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Caltech-JPL Research and Technology Development Fund" }, { "agency": "Gordon and Betty Moore Foundation" }, { "agency": "Terrestrial Hazard Observation and Reporting Center" }, { "agency": "Caltech Division of Geological and Planetary Science" }, { "agency": "Caltech Division of Engineering and Applied Science" } ] }, "other_numbering_system": { "items": [ { "id": "2018-04", "name": "EERL Report" } ] }, "local_group": { "items": [ { "id": "Earthquake-Engineering-Research-Laboratory" }, { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "primary_object": { "basename": "Kohler_etal_11ncee_1675.pdf", "url": "https://authors.library.caltech.edu/records/eyaa6-hf002/files/Kohler_etal_11ncee_1675.pdf" }, "pub_year": "2018", "author_list": "Kohler, M. D.; Guy, R.; et el." }, { "id": "https://authors.library.caltech.edu/records/kmdpr-3pb02", "eprint_id": 73802, "eprint_status": "archive", "datestamp": "2023-08-19 01:01:50", "lastmod": "2023-10-24 16:28:01", "type": "conference_item", "metadata_visibility": "show", "creators": { "items": [ { "id": "Massari-A", "name": { "family": "Massari", "given": "A." }, "orcid": "0000-0002-6561-4674" }, { "id": "Kohler-M-D", "name": { "family": "Kohler", "given": "M." } }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "R." }, "orcid": "0000-0003-3323-3508" }, { "id": "Guy-R", "name": { "family": "Guy", "given": "R." } }, { "id": "Heaton-T-H", "name": { "family": "Heaton", "given": "T." }, "orcid": "0000-0003-3363-2197" }, { "id": "Bunn-J", "name": { "family": "Bunn", "given": "J." }, "orcid": "0000-0002-3798-298X" }, { "id": "Chandy-K-M", "name": { "family": "Chandy", "given": "K. M." } }, { "id": "Demetri-D", "name": { "family": "Demetri", "given": "D." } } ] }, "title": "Dense Building Instrumentation Application for City-Wide Structural Health Monitoring", "ispublished": "unpub", "full_text_status": "public", "keywords": "damage detection, structural health monitoring, seismic instrumentation, earthquake engineering, resilient cities", "note": "We thank Christopher Janover for his work developing the automation tools used in our study. This study was partially funded by a Caltech-JPL Research and Technology Development Fund grant. We also thank the Betty and Gordon Moore Foundation, the Terrestrial Hazard Observation and Reporting Center at Caltech, and the Divisions of Geological and Planetary Science, and Engineering and Applied Science at Caltech for funding the development of the Community Seismic Network.\n\nAccepted Version - Massari_etal_Paper_N\u00b0_3735.pdf
", "abstract": "The Community Seismic Network (CSN) has partnered with the NASA Jet Propulsion Laboratory (JPL) to initiate a campus-wide structural monitoring program of all buildings on the premises. The JPL campus serves as a proxy for a densely instrumented urban city with localized vibration measurements collected throughout the free-field and built environment. Instrumenting the entire campus provides dense measurements in a horizontal geospatial sense for soil response; in addition five buildings have been instrumented on every floor of the structure. Each building has a unique structural system as well as varied amounts of structural information via structural drawings, making several levels of assessment and evaluation possible. Computational studies with focus on damage detection applied to the campus structural network are demonstrated for a collection of buildings. For campus-wide real-time and post-event evaluation, ground and building response products using CSN data are illustrating the usefulness of higher spatial resolution compared to what was previously typical with sparser instrumentation.", "date": "2017-01-28", "date_type": "published", "publisher": "Caltech Library", "id_number": "CaltechAUTHORS:20170127-163202195", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170127-163202195", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "JPL Research and Technology Development Fund" }, { "agency": "Gordon and Betty Moore Foundation" }, { "agency": "Caltech Terrestrial Hazards Observations and Reporting center (THOR)" }, { "agency": "Caltech Division of Geological and Planetary Sciences" }, { "agency": "Caltech Division of Engineering and Applied Science" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "primary_object": { "basename": "Massari_etal_Paper_N\u00b0_3735.pdf", "url": "https://authors.library.caltech.edu/records/kmdpr-3pb02/files/Massari_etal_Paper_N\u00b0_3735.pdf" }, "pub_year": "2017", "author_list": "Massari, A.; Kohler, M.; et el." }, { "id": "https://authors.library.caltech.edu/records/xenfy-g6t33", "eprint_id": 73804, "eprint_status": "archive", "datestamp": "2023-08-19 01:01:55", "lastmod": "2023-10-24 16:28:06", "type": "conference_item", "metadata_visibility": "show", "creators": { "items": [ { "id": "Shi-Jian-CIVILENG", "name": { "family": "Shi", "given": "J." } }, { "id": "Kohler-M-D", "name": { "family": "Kohler", "given": "M. D." } }, { "id": "Sutton-J-N", "name": { "family": "Sutton", "given": "J. N." } }, { "id": "Ampuero-J-P", "name": { "family": "Ampuero", "given": "J.-P." }, "orcid": "0000-0002-4827-7987" } ] }, "title": "Mapping Coherent, Time-Varying Wavefronts from the Tohoku Tsunami into Enhanced, Time-Dependent Warning Messages", "ispublished": "unpub", "full_text_status": "public", "keywords": "tsunami, beamforming technique, coherence stacking, back projection, tsunami warning", "note": "Support for this work was provided by the NSF Hazard-SEES (award #1331600) and OCE-MG&G (award #0825254) programs. The OBS deployment was made possible with instruments and logistical support of the IRIS U.S. National Ocean Bottom Seismic Instrumentation Pool (OBSIP) and Scripps Institution of Oceanography. The deployment and recovery cruises were made possible with the equipment and logistical support of the UNOLS vessel fleet and staff support, and Scripps Institution of Oceanography\n\nAccepted Version - Shi_et_al__2017__16WCEE.pdf
", "abstract": "Recent results are presented to illustrate how predictions of tsunami wave impact and tsunami warning mes-sages can be improved by including information about multiple, large-amplitude wave arrivals over longer time durations and at refined spatial resolution. A deployment of ocean bottom seismometers off the coast of southern California recorded the March 2011 Tohoku tsunami on 22 differential pressure gauges. The pressure gauge tsu-nami records across the entire array show multiple large-amplitude, coherent phases arriving one hour to more than 36 hours after the initial tsunami phase. Analysis of the pressure gauge recordings reveals possible locations of the geographical sources that contributed to secondary tsunami arrivals in southern California. A beamform-ing technique is applied to the pressure gauge data to determine the azimuths and arrival times of scattered wave energy. In addition, a backward ray-tracing procedure is applied to a wide range of back azimuth starting values from the pressure gauge array to map possible scattering source locations. The results show several possible candidates of secondary tsunami source structures. These include: (1) southeastern Alaska producing a tsunami arrival 1\u20132 hours after the first arrival; and elongated bathymetry structures near: (2) the northern Hawaiian Is-land chain producing an arrival 1\u20132 hours, (3) Papua New Guinea producing an arrival 8\u20139 hours, and (4) French Polynesia producing an arrival 10\u201311 hours, all after the first arrival. These results are then incorporated into tsunami warning messages to improve clarity of the hazard threat and protective action guidance, and the specificity of impact location over time. Revised tsunami messages have been tested through online experiments with the public in order to determine how changes in message clarity and specificity affects message receiver understanding, believing, and personalizing, all of which are pre-decisional sense-making activities. The geo-physical results are mapped into modified tsunami warning messages to show how a time-varying hazard could be communicated with more effective message format and content. The results are demonstrating the effects of including clearly described locations, time of impact, and hazard impact consequences on message perception among the public.", "date": "2017-01-28", "date_type": "published", "publisher": "Caltech Library", "id_number": "CaltechAUTHORS:20170127-163908004", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170127-163908004", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "OCE-1331600" }, { "agency": "NSF", "grant_number": "OCE-0825254" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" } ] }, "primary_object": { "basename": "Shi_et_al__2017__16WCEE.pdf", "url": "https://authors.library.caltech.edu/records/xenfy-g6t33/files/Shi_et_al__2017__16WCEE.pdf" }, "pub_year": "2017", "author_list": "Shi, J.; Kohler, M. D.; et el." }, { "id": "https://authors.library.caltech.edu/records/9cteg-twn93", "eprint_id": 34666, "eprint_status": "archive", "datestamp": "2023-08-19 10:31:46", "lastmod": "2023-10-19 21:21:58", "type": "conference_item", "metadata_visibility": "show", "creators": { "items": [ { "id": "Lin-Fan-Chi", "name": { "family": "Lin", "given": "Fan-Chi" }, "orcid": "0000-0003-0394-6830" }, { "id": "Li-Dunzhu", "name": { "family": "Li", "given": "Dunzhu" }, "orcid": "0000-0003-3149-0236" }, { "id": "Clayton-R-W", "name": { "family": "Clayton", "given": "Robert W." }, "orcid": "0000-0003-3323-3508" } ] }, "title": "Interferometry with a dense 3D dataset", "ispublished": "unpub", "full_text_status": "public", "note": "The authors gratefully acknowledge NodalSeismic LLC\nand Signal Hill Petroleum Inc for permitting us to use the\nLong Beach data. We also thank Victor Tsai and Christof\nStork for helpful discussions.\n\nPublished - Lin-SEG2012.pdf
", "abstract": "In this paper we report on progress using ambient noise\ncorrelation with a dense 3D survey conducted in Long\nBeach, California, to estimate subsurface velocity. We\nshow that both Rayleigh wave and body wave signals can\nbe clearly observed between 0.2-10 Hz frequency range in\nthe noise cross-correlations. The observed signals also\ncompare well with an active source gather. We apply\neikonal tomography to invert for the Rayleigh wave phase\nvelocity maps at several different frequencies. The phase\nvelocity maps, which are most sensitive to structure in the\ntop 600 meters, show clear correlation with known surface\nfeatures such as the slow anomaly adjacent to the coast in\nthe south and a fast anomaly associated with the Newport-\nInglewood fault zone. The results presented in this study\nshow the potential of using ambient noise interferometry\nmethod to complement active source techniques in studying\nhigh-resolution shallow crustal structure.", "date": "2012-10-03", "date_type": "published", "publisher": "Caltech Library", "id_number": "CaltechAUTHORS:20121003-112803929", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121003-112803929", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "primary_object": { "basename": "Lin-SEG2012.pdf", "url": "https://authors.library.caltech.edu/records/9cteg-twn93/files/Lin-SEG2012.pdf" }, "pub_year": "2012", "author_list": "Lin, Fan-Chi; Li, Dunzhu; et el." }, { "id": "https://authors.library.caltech.edu/records/bzrd3-c7668", "eprint_id": 104901, "eprint_status": "archive", "datestamp": "2023-09-15 06:48:19", "lastmod": "2023-10-23 21:31:43", "type": "conference_item", "metadata_visibility": "show", "creators": { "items": [ { "id": "Hollingsworth-J", "name": { "family": "Hollingsworth", "given": "James" }, "orcid": "0000-0003-0122-296X" }, { "id": "Leprince-S", "name": { "family": "Leprince", "given": "S\u00e9bastien" }, "orcid": "0000-0003-4555-8975" }, { "id": "Ayoub-F", "name": { "family": "Ayoub", "given": "Fran\u00e7ois" }, "orcid": "0000-0002-7389-8400" }, { "id": "Avouac-J-P", "name": { "family": "Avouac", "given": "Jean-Philippe" }, "orcid": "0000-0002-3060-8442" } ] }, "title": "Revisiting Past Earthquakes and Seismo-Volcanic Crises Using Declassified Optical Satellite Imagery", "ispublished": "unpub", "full_text_status": "public", "note": "Published - f98321205eb88aefcd952b6c9ba99501b21f.pdf
", "abstract": "Recent development of the user-friendly software package \"Co-registration of Optically Sensed Images and Correlation\"\n(COSI-Corr), which allows for automatic and precise ortho-rectification, co-registration, and sub-pixel correlation of pushbroom satellite and aerial images, has enabled Earth's surface dynamics to be accurately monitored using optical imagery [1]. This technique compares two images of the Earth's surface that were acquired at different times, and estimates any potential pixel shifts between them with an accuracy typically better than 1/10 of the pixel size. Correlation of both satellite and aerial images has been successfully used to identify coseismic ground ruptures and quantify fault offsets during large earthquakes [2]\u2013[4], as well as monitoring sand dune migration, landsliding, ice flow [5] [6], and volcanic activity [7] [8]. In this study, we demonstrate that recently declassified US spy satellite images can be used to measure ground deformation resulting from seismotectonic and volcanic events using optical sub-pixel correlation. KH-9 Hexagon satellite images, with a swath size of 250\u00d7125 km, were acquired by the US government between 1971 and 1980, and are available for purchase from the United States Geological Survey (USGS) at small cost ($30 per image). During this period, around 29,000 images were acquired globally [9], providing a comprehensive record of the Earth's surface at 6\u20139m resolution.", "date": "2009-12", "date_type": "published", "publisher": "Caltech Library", "id_number": "CaltechAUTHORS:20200810-153624897", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200810-153624897", "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": "f98321205eb88aefcd952b6c9ba99501b21f.pdf", "url": "https://authors.library.caltech.edu/records/bzrd3-c7668/files/f98321205eb88aefcd952b6c9ba99501b21f.pdf" }, "pub_year": "2009", "author_list": "Hollingsworth, James; Leprince, S\u00e9bastien; et el." } ]