[ { "id": "https://authors.library.caltech.edu/records/13cbg-a4n57", "eprint_id": 104568, "eprint_status": "archive", "datestamp": "2023-08-19 22:49:03", "lastmod": "2023-10-20 20:37:27", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Zimmaro-P", "name": { "family": "Zimmaro", "given": "Paolo" }, "orcid": "0000-0002-3544-5961" }, { "id": "Nweke-C-C", "name": { "family": "Nweke", "given": "Chukwuebuka C." }, "orcid": "0000-0002-8939-571X" }, { "id": "Hernandez-J-L", "name": { "family": "Hernandez", "given": "Janis L." }, "orcid": "0000-0001-8603-5500" }, { "id": "Hudson-K-S", "name": { "family": "Hudson", "given": "Kenneth S." } }, { "id": "Hudson-M-B", "name": { "family": "Hudson", "given": "Martin B." } }, { "id": "Ahdi-S-K", "name": { "family": "Ahdi", "given": "Sean K." }, "orcid": "0000-0003-0274-5180" }, { "id": "Boggs-M-L", "name": { "family": "Boggs", "given": "Matthew L." } }, { "id": "Davis-C-A", "name": { "family": "Davis", "given": "Craig A." } }, { "id": "Goulet-C-A", "name": { "family": "Goulet", "given": "Christine A." }, "orcid": "0000-0002-7643-357X" }, { "id": "Brandenberg-S-J", "name": { "family": "Brandenberg", "given": "Scott J." }, "orcid": "0000-0003-2493-592X" }, { "id": "Hudnut-K-W", "name": { "family": "Hudnut", "given": "Kenneth W." }, "orcid": "0000-0002-3168-4797" }, { "id": "Stewart-J-P", "name": { "family": "Stewart", "given": "Jonathan P." }, "orcid": "0000-0003-3602-3629" } ] }, "title": "Liquefaction and Related Ground Failure from July 2019 Ridgecrest Earthquake Sequence", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 2020 Seismological Society of America. \n\nManuscript received 17 January 2020; Published online 21 July 2020. \n\nThe Geotechnical Extreme Events Reconnaissance (GEER) association is supported by the National Science Foundation (NSF) through the Geotechnical Engineering Program under Grant Number CMMI\u20101266418. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the NSF. The GEER association is made possible by the vision and support of the NSF Geotechnical Engineering Program Directors Richard Fragaszy and the late Cliff Astill. GEER members also donate their time, talent, and resources to collect time\u2010sensitive field observations of the effects of extreme events. Part of the research was sponsored by the NASA Earth Science Disasters Program (Grant Number 18\u2010DISASTER18\u20100034) and performed in collaboration with the Jet Propulsion Laboratory and California Institute of Technology. Additional research support was provided by the Southern California Earthquake Center (SCEC), funded by the National Science Foundation (NSF) and U.S. Geological Survey (USGS), and by NSF RAPID Award Number EAR\u20101945781. We would like to thank Camille Anderson, Steven Kourakos, Adam Bingham, Dipti Barari, Devin Katzenstein at Searles Valley Minerals and Jade Zimmerman at Naval Air Weapons Station China Lake for assisting with the preparation and deployment of reconnaissance activities at Searles Lake in November 2019. We also thank Kate Allstadt, Eric Thompson, Alex Grant, Katherine J. Kendrick, Mike Diggles, Shane T. Detweiler, Timothy Dawson (Guest Editor) at USGS and one anonymous reviewer, whose constructive comments helped improving this paper. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government. \n\nData and Resources: Seismic moments and resulting moment magnitudes were taken from the Global Centroid\u2010Moment\u2010Tensor (GCMT) project (Ekstr\u00f6m et al., 2012), available at https://www.globalcmt.org (last accessed June 2020). We prefer these magnitudes because they are well constrained from data derived from global seismic networks. The use of GCMT magnitudes conforms with Next Generation Attenuation procedures as described by Contreras et al. (2020). Fault traces from the Uniform California Earthquake Rupture Forecast, version 3 (UCERF3) model were retrieved from the California Geological Survey (CGS) open data portal at https://data.ca.gov/dataset/cgs-map-sheet-48-fault-based-seismic-sources-used-in-the-uniform-california-earthquake-rupture (last accessed May 2020). The damage proxy map used was retrieved from the National Aeronautics and Space Administration (NASA) Advanced Rapid Imaging and Analysis (ARIA) Jet Propulsion Laboratory (JPL) event page at https://aria-share.jpl.nasa.gov/20190704-0705-Searles_Valley_CA_EQs/DPM/ (last accessed January 2020). The USGS liquefaction hazard map produced following the MM 7.1 mainshock was retrieved from the USGS event page at https://earthquake.usgs.gov/earthquakes/eventpage/ci38457511/ground-failure/summary (last accessed May 2020). The theoretical background of the USGS liquefaction hazard map used in this study is available at https://earthquake.usgs.gov/data/ground-failure/background.php (last accessed May 2020). The HydroSHEDS database is available at https://www.hydrosheds.org/ (last accessed June 2020). The distance from the coast dataset from the NASA Ocean Color Group is available at https://oceancolor.gsfc.nasa.gov/docs/distfromcoast/ (last accessed May 2020). Observation wells data were retrieved from the California Department of Water Resources (DWR) database at http://wdl.water.ca.gov/waterdatalibrary/groundwater/hydrographs/brr_hydro.cfm?CFGRIDKEY=23361 (last accessed May 2020). The USGS topographic map was retrieved from the USGS National Geospatial Program\u2014US Topo at https://www.usgs.gov/core-science-systems/national-geospatial-program/us-topo-maps-america?qt-science_support_page_related_con=0# (last accessed May 2020). Elevation data were retrieved from Google Earth Pro (https://www.google.com/earth/versions/#earth-pro, last accessed May 2020). All maps were produced using QGIS (Open Source Geospatial Foundation Project, available at http://qgis.osgeo.org, last accessed January 2020). The unpublished manuscript by T. Dawson et al., \"Field\u2010based observations of surface ruptures associated with the 2019 Ridgecrest earthquake sequence,\" submitted to Bull. Seimol. Soc. Am. A summary table of observations at the Naval Air Weapons Station (NAWS), China Lake, 19 figures showing liquefaction features at the at the NAWS, China Lake and Argus, and three maps are available in the supplemental material to this article.\n\n
Supplemental Material - bssa-2020025_supplement.pdf
", "abstract": "The 2019 Ridgecrest earthquake sequence produced a 4 July M 6.5 foreshock and a 5 July M 7.1 mainshock, along with 23 events with magnitudes greater than 4.5 in the 24 hr period following the mainshock. The epicenters of the two principal events were located in the Indian Wells Valley, northwest of Searles Valley near the towns of Ridgecrest, Trona, and Argus. We describe observed liquefaction manifestations including sand boils, fissures, and lateral spreading features, as well as proximate non\u2010ground failure zones that resulted from the sequence. Expanding upon results initially presented in a report of the Geotechnical Extreme Events Reconnaissance Association, we synthesize results of field mapping, aerial imagery, and inferences of ground deformations from Synthetic Aperture Radar\u2010based damage proxy maps (DPMs). We document incidents of liquefaction, settlement, and lateral spreading in the Naval Air Weapons Station China Lake US military base and compare locations of these observations to pre\u2010 and postevent mapping of liquefaction hazards. We describe liquefaction and ground\u2010failure features in Trona and Argus, which produced lateral deformations and impacts on several single\u2010story masonry and wood frame buildings. Detailed maps showing zones with and without ground failure are provided for these towns, along with mapped ground deformations along transects. Finally, we describe incidents of massive liquefaction with related ground failures and proximate areas of similar geologic origin without ground failure in the Searles Lakebed. Observations in this region are consistent with surface change predicted by the DPM. In the same region, geospatial liquefaction hazard maps are effective at identifying broad percentages of land with liquefaction\u2010related damage. We anticipate that data presented in this article will be useful for future liquefaction susceptibility, triggering, and consequence studies being undertaken as part of the Next Generation Liquefaction project.", "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": "1549-1566", "id_number": "CaltechAUTHORS:20200724-121439432", "issn": "0037-1106", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200724-121439432", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "CMMI\u20101266418" }, { "agency": "NASA", "grant_number": "18\u2010DISASTER18\u20100034" }, { "agency": "Southern California Earthquake Center (SCEC)" }, { "agency": "USGS" }, { "agency": "NSF", "grant_number": "EAR\u20101945781" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" } ] }, "doi": "10.1785/0120200025", "primary_object": { "basename": "bssa-2020025_supplement.pdf", "url": "https://authors.library.caltech.edu/records/13cbg-a4n57/files/bssa-2020025_supplement.pdf" }, "resource_type": "article", "pub_year": "2020", "author_list": "Zimmaro, Paolo; Nweke, Chukwuebuka C.; et el." }, { "id": "https://authors.library.caltech.edu/records/zg9n3-f9349", "eprint_id": 103039, "eprint_status": "archive", "datestamp": "2023-08-19 22:15:52", "lastmod": "2023-10-20 00:43:34", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Hudnut-K-W", "name": { "family": "Hudnut", "given": "Kenneth W." }, "orcid": "0000-0002-3168-4797" }, { "id": "Brooks-B-A", "name": { "family": "Brooks", "given": "Benjamin A." } }, { "id": "Scharer-K", "name": { "family": "Scharer", "given": "Katherine" }, "orcid": "0000-0003-2811-2496" }, { "id": "Hernandez-Janis-L", "name": { "family": "Hernandez", "given": "Janis L." }, "orcid": "0000-0001-8603-5500" }, { "id": "Dawson-T-E", "name": { "family": "Dawson", "given": "Timothy E." } }, { "id": "Oskin-M-E", "name": { "family": "Oskin", "given": "Michael E." }, "orcid": "0000-0002-6631-5326" }, { "id": "Arrowsmith-J-R", "name": { "family": "Arrowsmith", "given": "J. Ramon" }, "orcid": "0000-0003-1756-3697" }, { "id": "Goulet-C-A", "name": { "family": "Goulet", "given": "Christine A." }, "orcid": "0000-0002-7643-357X" }, { "id": "Blake-Kelly", "name": { "family": "Blake", "given": "Kelly" } }, { "id": "Boggs-M-L", "name": { "family": "Boggs", "given": "Matthew L." } }, { "id": "Bork-S", "name": { "family": "Bork", "given": "Stephan" } }, { "id": "Glennie-C-L", "name": { "family": "Glennie", "given": "Craig L." }, "orcid": "0000-0003-1570-0889" }, { "id": "Fernandez-Diaz-J-C", "name": { "family": "Fernandez-Diaz", "given": "Juan Carlos" }, "orcid": "0000-0003-3703-7555" }, { "id": "Singhania-A", "name": { "family": "Singhania", "given": "Abhinav" } }, { "id": "Hauser-D-L", "name": { "family": "Hauser", "given": "Darren" } }, { "id": "Sorhus-S", "name": { "family": "Sorhus", "given": "Sven" } } ] }, "title": "Airborne Lidar and Electro-Optical Imagery along Surface Ruptures of the 2019 Ridgecrest Earthquake Sequence, Southern California", "ispublished": "pub", "full_text_status": "restricted", "note": "\u00a9 2020 Seismological Society of America. \n\nManuscript received 28 October 2019; Published online 22 April 2020. \n\nThe coauthors thank the U.S. Geological Survey and National Science Foundation (NSF) for providing the funding to National Center for Airborne Laser Mapping (NCALM) for this project and the authors especially also thank our pilots Robert Chalender and Greg McDonald and the aircraft vendor. Misty Ellingson and Andria Bullock, with support of Ole Hendon of Naval Air Warfare Center Weapons Division (NAWCWD) provided them with airspace access within the NAWSCL. The authors also benefitted greatly from the generosity of the Inyokern airport manager, Scott Seymour, and his staff who helped to locate parts and facilitate repair of the aircraft in their hangar. Mayor Peggy Breeden and Chief of Police Jed McLaughlin of the City of Ridgecrest opened their arms to our whole team while the authors worked in their city. Margo Allen, Helen Haase, Jeff Mayberry, Rob Gallagher, and Renee Hatcher, the team of Naval Air Weapons Station China Lake and NAWCWD Public Affairs Officers, tirelessly provided operational security review support to our whole team, as did the entire unexploded ordnance team. LT Angela Roush, U.S. Navy, and the R\u20102508 Joshua airspace controllers are also greatly thanked, as are California Highway Patrol and National Guard for helicopter support for the field work that allowed our flight line planning. The effective reconnaissance and geodata response resulted from several years of conference calls, e\u2010mails, meetings, exercises, and planning. It took advanced planning, strategic thought, and coordination with other agencies. The important coordination role of the California Air Coordination Group, led by Derek Kantar of Caltrans, and of the California Earthquake Clearinghouse, co\u2010led by Anne Rosinski and recently by Cindy Pridmore who co\u2010led it, along with Heidi Tremayne, Maggie Ortiz\u2010Millan, and others from Earthquake Engineering Research Institute, during the 2019 Ridgecrest sequence, and of its Overflight committee in particular, cannot be overstated. In addition, U.S. Department of the Interior's Office of Aircraft Services had established memoranda of understanding so that U.S. Geological Survey (USGS) personnel were able to safely conduct multiple aerial reconnaissance and geodata missions. Thanks to the NCALM processing team and the OpenTopography team for making these data available rapidly. Many thanks to the Southern California Earthquake Center (SCEC) headquarters who helped support the Rapid Response Research (RAPID) award from the U.S. NSF. OpenTopography is supported by the U.S. NSF under Award Numbers 1833703, 1833643, and 1833632. Important Global Navigation Satellite Systems (GNSS) data from stations CCCC, P594, and P595 were provided by the Geodetic Facility for the Advancement of GEoscience (GAGE), operated by UNAVCO, Inc., with support from the NSF and the National Aeronautics and Space Administration under NSF Cooperative Agreement EAR\u20101724794. The authors also thank the reviewers of this article, Andrew Meigs, James Hollingsworth, Beth Haddon, and Dan Opstal for improving the article. \n\nAny use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. \n\nData and Resources: The data will all be made available at the following OpenTopography URL: Hudnut, K. W., B. Brooks, K. Scharer, J. L. Hernandez, T. E. Dawson, M. E. Oskin, R. Arrowsmith, C. A. Goulet, K. Blake, M. L. Boggs, S. Bork, C. L. Glennie, J. C. Fernandez\u2010Diaz, A. Singhania, D. Hauser, S. Sorhus (2020). 2019 Ridgecrest, CA postearthquake light detection and ranging (lidar) collection, National Center for Airborne Laser Mapping (NCALM), distributed by OpenTopography, available at doi: 10.5069/G97W69C0, 10.5069/G9W0942Z. Additional portions of the data set will be released pending additional review. Additional raw files may be accessed from the NCALM long\u2010term archive, contact ncalm@egr.uh.edu; further information available at http://ncalm.cive.uh.edu/. Capture one image processing software is available at https://www.captureone.com/en/. The B4 lidar data are available in https://u.osu.edu/b4lidar/, https://doi.org/10.5066/F7TQ5ZQ6, and http://opentopo.sdsc.edu/lidarDataset?opentopoID=OTLAS.032018.32611.1. Documentation from NCALM is available at http://ncalm.cive.uh. For further information on Online Positioning User Service (OPUS), see https://www.ngs.noaa.gov/OPUS/ and for more information on the CORS network, see https://www.ngs.noaa.gov/CORS/. GrafNet Overview is available at https://docs.novatel.com/Waypoint/Content/GrafNet/GrafNet_Overview.htm. Current version of TerraScan v.19.019 is available at www.terrasolid.com/products/terrascanpage.php. A detailed discussion on the causes of data artifacts is available at ncalm.berkeley.edu/reports/GEM_Rep_2005_01_002.pdf and a discussion of NCALM procedures is available at ncalm.berkeley.edu/reports/NCALM_WhitePaper_v1.2.pdf. LASer (LAS) format description is available at https://www.loc.gov/preservation/digital/formats/fdd/fdd000418.shtml. American Society for Photogrammetry and Remote Sensing (ASPRS) and LAS formats are available at www.asprs.org/Committee-General/LASer-LAS-File-Format-Exchange-Activities.html. All websites were last accessed in March 2020.", "abstract": "Surface rupture from the 2019 Ridgecrest earthquake sequence, initially associated with the M_w 6.4 foreshock, occurred on 4 July on a \u223c17\u2009\u2009km long, northeast\u2013southwest\u2010oriented, left\u2010lateral zone of faulting. Following the M_w 7.1 mainshock on 5 July (local time), extensive northwest\u2013southeast\u2010oriented, right\u2010lateral faulting was then also mapped along a \u223c50\u2009\u2009km long zone of faults, including subparallel splays in several areas. The largest slip was observed in the epicentral area and crossing the dry lakebed of China Lake to the southeast. Surface fault rupture mapping by a large team, reported elsewhere, was used to guide the airborne data acquisition reported here. Rapid rupture mapping allowed for accurate and efficient flight line planning for the high\u2010resolution light detection and ranging (lidar) and aerial photography. Flight line planning trade\u2010offs were considered to allocate the medium (25 pulses per square meter [ppsm]) and high\u2010resolution (80 ppsm) lidar data collection polygons. The National Center for Airborne Laser Mapping acquired the airborne imagery with a Titan multispectral lidar system and Digital Modular Aerial Camera (DiMAC) aerial digital camera, and U.S. Geological Survey acquired Global Positioning System ground control data. This effort required extensive coordination with the Navy as much of the airborne data acquisition occurred within their restricted airspace at the China Lake ranges.", "date": "2020-07-01", "date_type": "published", "publication": "Seismological Research Letters", "volume": "91", "number": "4", "publisher": "Seismological Society of America", "pagerange": "2096-2107", "id_number": "CaltechAUTHORS:20200506-130633278", "issn": "0895-0695", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200506-130633278", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "USGS" }, { "agency": "NSF", "grant_number": "EAR-1833703" }, { "agency": "NSF", "grant_number": "EAR-1833643" }, { "agency": "NSF", "grant_number": "EAR-1833632" }, { "agency": "NASA" }, { "agency": "NSF", "grant_number": "EAR-1724794" } ] }, "doi": "10.1785/0220190338", "resource_type": "article", "pub_year": "2020", "author_list": "Hudnut, Kenneth W.; Brooks, Benjamin A.; et el." }, { "id": "https://authors.library.caltech.edu/records/4kewb-pzb98", "eprint_id": 103035, "eprint_status": "archive", "datestamp": "2023-08-19 21:20:15", "lastmod": "2023-10-20 00:43:16", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Hough-S-E", "name": { "family": "Hough", "given": "Susan E." }, "orcid": "0000-0002-5980-2986" }, { "id": "Thompson-E-M", "name": { "family": "Thompson", "given": "Eric" } }, { "id": "Parker-G-A", "name": { "family": "Parker", "given": "Grace A." } }, { "id": "Graves-R-W", "name": { "family": "Graves", "given": "Robert W." } }, { "id": "Hudnut-K-W", "name": { "family": "Hudnut", "given": "Kenneth W." }, "orcid": "0000-0002-3168-4797" }, { "id": "Patton-Jason", "name": { "family": "Patton", "given": "Jason" } }, { "id": "Dawson-T-E", "name": { "family": "Dawson", "given": "Timothy" } }, { "id": "Ladinsky-T", "name": { "family": "Ladinsky", "given": "Tyler" } }, { "id": "Oskin-M-E", "name": { "family": "Oskin", "given": "Michael" }, "orcid": "0000-0002-6631-5326" }, { "id": "Sirorattanakul-K", "name": { "family": "Sirorattanakul", "given": "Krittanon" } }, { "id": "Blake-Kelly", "name": { "family": "Blake", "given": "Kelly" } }, { "id": "Baltay-A-S", "name": { "family": "Baltay", "given": "Annemarie" } }, { "id": "Cochran-E-S", "name": { "family": "Cochran", "given": "Elizabeth" }, "orcid": "0000-0003-2485-4484" } ] }, "title": "Near-Field Ground Motions from the July 2019 Ridgecrest, California, Earthquake Sequence", "ispublished": "pub", "full_text_status": "restricted", "note": "\u00a9 2020 Seismological Society of America. \n\nManuscript received 27 September 2019; Published online 26 February 2020. \n\nThe authors thank Paul Friberg for supplying an ah2sac code to help us resuscitate data from the 1995 Ridgecrest sequence, and the many residents of Ridgecrest who provided information about earthquake effects. Assistance from Ken Sanger and Skip Graff, and the staffs of the Maturango Museum, Ridgecrest Animal Shelter, and Ridgecrest Independent are acknowledged with appreciation. The general cooperation of the Naval Air Weapons stations is acknowledged with appreciation. The authors thank Nicholas van der Elst, Brad Aagaard, Shane Detweiller, and two anonymous reviewers for their constructive reviews of this article, and Alison Bent for her stewardship of the journal. \n\nData and Resources: Ground\u2010motion recordings of the foreshock and mainshock, peak acceleration values for both events, and site characterization information for the stations listed in Table 1 can be downloaded from https://strongmotioncenter.org (last accessed July 2019). \"Did You Feel It?\" (DYFI) intensity data can be downloaded from https://earthquake.usgs.gov/earthquakes/eventpage/ci38443183/dyfi/intensity and https://earthquake.usgs.gov/earthquakes/eventpage/ci38457511/dyfi/intensity (both last accessed July 2019) for the foreshock and mainshock, respectively. News reports about damage on the China Lake Naval Air Weapons Station were downloaded from https://www.navytimes.com/news/your-navy/2019/08/12/china-lake-repair-costs-might-top-2-billion/ (last accessed September 2019). Evaluating damage at China Lake base school is available at https://www.bakersfield.com/multimedia/photo-galleries/photo-gallery-evaluating-damage-at-china-lake-base-school/collection_91115390-a2a5-11e9-944f-977e60c2b209.html (last accessed September 2019). The information about the Navy facing a billion dollar tab is available at https://news.usni.org/2019/08/21/navy-facing-billion-dollar-tab-years-to-get-china-lake-fully-operational-after-quake (last accessed September 2019).", "abstract": "The 2019 Ridgecrest, California, earthquake sequence, including an M_w 6.4 event on 4 July and an M_w 7.1 approximately 34 hr later, was recorded by 15 instruments within 55 km nearest\u2010fault distance. To characterize and explore near\u2010field ground motions from the M_w 6.4 foreshock and M_w 7.1 mainshock, we augment these records with available macroseismic information, including conventional intensities and displaced rocks. We conclude that near\u2010field shaking intensities were generally below modified Mercalli intensity 9, with concentrations of locally high values toward the northern and southern termini of the mainshock rupture. We further show that, relative to near\u2010field ground motions at hard\u2010rock sites, instrumental ground motions at alluvial near\u2010field sites for both the M_w 6.4 foreshock and M_w 7.1 mainshock were depleted in energy at frequencies higher than 2\u20133 Hz, as expected from ground\u2010motion models. Both the macroseismic and instrumental observations suggest that sediments in the Indian Wells Valley experienced a pervasively nonlinear response, which helps explain why shaking intensities and damage in the closest population center, Ridgecrest, were relatively modest given its proximity to the earthquakes.", "date": "2020-05-01", "date_type": "published", "publication": "Seismological Research Letters", "volume": "91", "number": "3", "publisher": "Seismological Society of America", "pagerange": "1542-1555", "id_number": "CaltechAUTHORS:20200506-123528173", "issn": "0895-0695", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200506-123528173", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "doi": "10.1785/0220190279", "resource_type": "article", "pub_year": "2020", "author_list": "Hough, Susan E.; Thompson, Eric; et el." }, { "id": "https://authors.library.caltech.edu/records/na4ma-37d69", "eprint_id": 72779, "eprint_status": "archive", "datestamp": "2023-08-19 01:14:30", "lastmod": "2023-10-23 22:56:17", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Veeraraghavan-Swetha", "name": { "family": "Veeraraghavan", "given": "Swetha" }, "orcid": "0000-0002-8667-6022" }, { "id": "Hudnut-K-W", "name": { "family": "Hudnut", "given": "Kenneth W." }, "orcid": "0000-0002-3168-4797" }, { "id": "Krishnan-Swaminathan", "name": { "family": "Krishnan", "given": "Swaminathan" }, "orcid": "0000-0002-2594-1523" } ] }, "title": "Toppling Analysis of the Echo Cliffs Precariously Balanced Rock", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 2016 Seismological Society of America. \n\nManuscript received 29 May 2016; Published Online 13 December 2016. \n\nWe thank James Brune, Richard Brune, Glenn Biasi, and Matthew Purvance for the results from the shake-table experiments and for sharing their insights and experiences with precariously balanced rocks (PBRs). We would also like to thank David Phillips of UNAVCO for supporting laser scanning of the Echo Cliffs PBR, as well as the field crew that included D. Haddad, D. Rood, A. Limaye, W. Amidon, D. Lynch, and E. Pounders, and also G. Bawden and S. Bond who helped process the data. In addition, we thank Robert Graves, Thomas Hanks, and Patricia McCrory of U.S. Geological Survey (USGS), Jack Baker, and an anonymous reviewer for providing reviews of earlier versions of this article. This research project has been supported by the National Science Foundation (NSF Award EAR-1247029), the USGS, and the Southern California Earthquake Center (SCEC). Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government.\n\nPublished - 72.full.pdf
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Supplemental Material - 2016169_esupp_Figure_S3.jpg
Supplemental Material - 2016169_esupp_Figure_S4.jpg
", "abstract": "Toppling analysis of a precariously balanced rock (PBR) can provide insight into the nature of ground motion that has not occurred at that location in the past and, by extension, can constrain peak ground motions for use in engineering design. Earlier approaches have targeted 2D models of the rock or modeled the rock\u2013pedestal contact using spring\u2010damper assemblies that require recalibration for each rock. Here, a method to model PBRs in 3D is presented through a case study of the Echo Cliffs PBR. The 3D model is created from a point cloud of the rock, the pedestal, and their interface, obtained using terrestrial laser scanning. The dynamic response of the model under earthquake excitation is simulated using a rigid\u2010body dynamics algorithm. The veracity of this approach is demonstrated through comparisons against data from shake\u2010table experiments. Fragility maps for toppling probability of the Echo Cliffs PBR as a function of various ground\u2010motion parameters, rock\u2013pedestal interface friction coefficient, and excitation direction are presented. These fragility maps indicate that the toppling probability of this rock is low (less than 0.2) for peak ground acceleration (PGA) and peak ground velocity (PGV) lower than 3\u2009\u2009m/s^2 and 0.75\u2009\u2009m/s, respectively, suggesting that the ground\u2010motion intensities at this location from earthquakes on nearby faults have most probably not exceeded the above\u2010mentioned PGA and PGV during the age of the PBR. Additionally, the fragility maps generated from this methodology can also be directly coupled with existing probabilistic frameworks to obtain direct constraints on unexceeded ground motion at a PBR's location.", "date": "2017-02", "date_type": "published", "publication": "Bulletin of the Seismological Society of America", "volume": "107", "number": "1", "publisher": "Seismological Society of America", "pagerange": "72-84", "id_number": "CaltechAUTHORS:20161213-141035303", "issn": "0037-1106", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161213-141035303", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR-1247029" }, { "agency": "USGS" }, { "agency": "Southern California Earthquake Center (SCEC)" } ] }, "collection": "CaltechAUTHORS", "doi": "10.1785/0120160169", "primary_object": { "basename": "2016169_esupp_Figure_S3.jpg", "url": "https://authors.library.caltech.edu/records/na4ma-37d69/files/2016169_esupp_Figure_S3.jpg" }, "related_objects": [ { "basename": "2016169_esupp_Figure_S2.png", "url": "https://authors.library.caltech.edu/records/na4ma-37d69/files/2016169_esupp_Figure_S2.png" }, { "basename": "72.full.pdf", "url": "https://authors.library.caltech.edu/records/na4ma-37d69/files/72.full.pdf" }, { "basename": "2016169_esupp_Figure_S1.png", "url": "https://authors.library.caltech.edu/records/na4ma-37d69/files/2016169_esupp_Figure_S1.png" }, { "basename": "2016169_esupp_Figure_S4.jpg", "url": "https://authors.library.caltech.edu/records/na4ma-37d69/files/2016169_esupp_Figure_S4.jpg" } ], "resource_type": "article", "pub_year": "2017", "author_list": "Veeraraghavan, Swetha; Hudnut, Kenneth W.; et el." }, { "id": "https://authors.library.caltech.edu/records/r9wb9-bds66", "eprint_id": 63100, "eprint_status": "archive", "datestamp": "2023-08-20 09:52:56", "lastmod": "2023-10-25 23:30:54", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Kargel-J-S", "name": { "family": "Kargel", "given": "J. S." } }, { "id": "Hudnut-K-W", "name": { "family": "Hudnut", "given": "K." }, "orcid": "0000-0002-3168-4797" } ] }, "title": "Geomorphic and geologic controls of geohazards induced by Nepal's 2015 Gorkha earthquake", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 2015 American Association for the Advancement of Science. \n\n\nReceived 20 June 2015; accepted 27 November 2015; Published Online December 16 2015. \n\nJSK, GJL, and UKH thank the NASA SERVIR Applied Science Team and NASA Cryosphere Program for support. DHS thanks the Hakai Institute for support. Part of this research was sponsored by the NASA Earth Surface and Interior focus area and performed at the Jet Propulsion Laboratory, California Institute of Technology. We gratefully acknowledge support from several \"citizen scientists\" who provided key observations and reports from various locations in Nepal: Deep Rai, JB Rai, Nabaraj Sapkota, Mauli Dhan Rai, and Mukhya Gotame, who made on-site inspections and photo documentation of Thulagi (Dona) Lake, Rolpa Lake, Kali Gandaki, and 'Lower Pisang' landslide dammed lake. ASTER data courtesy of NASA/GSFC/METI/Japan Space Systems, the U.S./Japan ASTER Science Team, and GLIMS. We especially laud DigitalGlobe's decision to acquire and make available a vast volume of data for analysis related to Gorkha earthquake response. We thank Cunren Liang for processing the ALOS-2 wide-swath interferogram. Original ALOS-2 data are \u00a9 2015 JAXA. This study was partially supported by core funds of ICIMOD contributed by the governments of Afghanistan, Australia, Austria, Bangladesh, Bhutan, China, India, Myanmar, Nepal, Norway, Pakistan, Switzerland, and the United Kingdom. The two chief databases produced by this work are available at ICIMOD (landslides - http://rds.icimod.org/Home/DataDetail?metadataId=24055 ; and glacial lakes - http://rds.icimod.org/Home/DataDetail?metadataId=24065).\n\nSupplemental Material - Kargel-SM.pdf
", "abstract": "The Gorkha earthquake (M 7.8) on 25 April 2015 and later aftershocks struck South Asia, killing ~9,000 and damaging a large region. Supported by a large campaign of responsive satellite data acquisitions over the earthquake disaster zone, our team undertook a satellite image survey of the earthquakes' induced geohazards in Nepal and China and an assessment of the geomorphic, tectonic, and lithologic controls on quake-induced landslides. Timely analysis and communication aided response and recovery and informed decision makers. We mapped 4,312 co-seismic and post-seismic landslides. We also surveyed 491 glacier lakes for earthquake damage, but found only 9 landslide-impacted lakes and no visible satellite evidence of outbursts. Landslide densities correlate with slope, peak ground acceleration, surface downdrop, and specific metamorphic lithologies and large plutonic intrusions.", "date": "2016-01-08", "date_type": "published", "publication": "Science", "volume": "351", "number": "6269", "publisher": "American Association for the Advancement of Science", "pagerange": "Art. No. aac8353", "id_number": "CaltechAUTHORS:20151221-091632888", "issn": "0036-8075", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20151221-091632888", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA" }, { "agency": "Hakai Institute" }, { "agency": "NASA/JPL/Caltech" }, { "agency": "Government of Afghanistan" }, { "agency": "Government of Australia" }, { "agency": "Government of Austria" }, { "agency": "Government of Bangladesh" }, { "agency": "Government of Bhutan" }, { "agency": "Government of China" }, { "agency": "Government of India" }, { "agency": "Government of Myanmar" }, { "agency": "Government of Nepal" }, { "agency": "Government of Norway" }, { "agency": "Government of Pakistan" }, { "agency": "Government of Switzerland" }, { "agency": "Government of United Kingdom" } ] }, "doi": "10.1126/science.aac8353", "primary_object": { "basename": "Kargel-SM.pdf", "url": "https://authors.library.caltech.edu/records/r9wb9-bds66/files/Kargel-SM.pdf" }, "resource_type": "article", "pub_year": "2016", "author_list": "Kargel, J. S. and Hudnut, K." }, { "id": "https://authors.library.caltech.edu/records/wmk83-bve93", "eprint_id": 62605, "eprint_status": "archive", "datestamp": "2023-08-20 08:53:42", "lastmod": "2023-10-25 17:16:27", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Yun-Sang-Ho", "name": { "family": "Yun", "given": "Sang-Ho" }, "orcid": "0000-0001-6952-6156" }, { "id": "Hudnut-K-W", "name": { "family": "Hudnut", "given": "Kenneth" }, "orcid": "0000-0002-3168-4797" }, { "id": "Owen-S-E", "name": { "family": "Owen", "given": "Susan" } }, { "id": "Webb-F-H", "name": { "family": "Webb", "given": "Frank" } }, { "id": "Simons-M", "name": { "family": "Simons", "given": "Mark" }, "orcid": "0000-0003-1412-6395" }, { "id": "Sacco-P", "name": { "family": "Sacco", "given": "Patrizia" } }, { "id": "Gurrola-E", "name": { "family": "Gurrola", "given": "Eric" } }, { "id": "Manipon-G", "name": { "family": "Manipon", "given": "Gerald" } }, { "id": "Liang-Cunren", "name": { "family": "Liang", "given": "Cunren" }, "orcid": "0000-0003-3938-426X" }, { "id": "Fielding-E-J", "name": { "family": "Fielding", "given": "Eric" }, "orcid": "0000-0002-6648-8067" }, { "id": "Milillo-P", "name": { "family": "Milillo", "given": "Pietro" }, "orcid": "0000-0002-1171-3976" }, { "id": "Hua-Hook", "name": { "family": "Hua", "given": "Hook" } }, { "id": "Coletta-A", "name": { "family": "Coletta", "given": "Alessandro" } } ] }, "title": "Rapid Damage Mapping for the 2015 M_w 7.8 Gorkha Earthquake Using Synthetic Aperture Radar Data from COSMO\u2013SkyMed and ALOS-2 Satellites", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 2015 Seismological Society of America. \n\nThe COSMO\u2013SkyMed data were made available for disaster response\nby the Italian Space Agency (ASI). The Advanced Land Observing Satellite-2 (ALOS-2) radar data were made available by the Japan Aerospace Exploration Agency (JAXA) through the Committee on Earth Observation Satellite (CEOS) in support of the response effort. The Global Urban Footprint was provided by German Aerospace Center (DLR) for disaster response. We thank Matthew Gamm and his team with the National Geospatial-Intelligence Agency (NGA), Thomas Esch with DLR, Keiko Saito with the World Bank, Shay Har-Noy, and Andrew Steele with Digital Globe, David Saeger with Office of Foreign Disaster Assistance (OFDA)/United States Agency for International Development (USAID), Mir Matin, and Deo Raj Gurung with the International Centre for Integrated Mountain Development (ICIMOD), Jon Pedder with Esri, and Mike Rubel with Planet Labs for supportive coordination and analysis for response. Constructive comments from Susan Hough, Gerald Bawden, and two anonymous reviewers improved the article. This research was supported by the National Aeronautics and Space Administration Applied Sciences/Disasters Program and Advanced Information Systems Technology (AIST) Program, and performed at the Jet Propulsion Laboratory (JPL), California Institute of Technology.\n\nPublished - 1549.full.pdf
", "abstract": "The 25 April 2015 M_w 7.8 Gorkha earthquake caused more than 8000 fatalities and widespread building damage in central Nepal. The Italian Space Agency's COSMO\u2013SkyMed Synthetic Aperture Radar (SAR) satellite acquired data over Kathmandu area four days after the earthquake and the Japan Aerospace Exploration Agency's Advanced Land Observing Satellite-2 SAR satellite for larger area nine days after the mainshock. We used these radar observations and rapidly produced damage proxy maps (DPMs) derived from temporal changes in Interferometric SAR coherence. Our DPMs were qualitatively validated through comparison with independent damage analyses by the National Geospatial-Intelligence Agency and the United Nations Institute for Training and Research's United Nations Operational Satellite Applications Programme, and based on our own visual inspection of DigitalGlobe's WorldView optical pre- versus postevent imagery. Our maps were quickly released to responding agencies and the public, and used for damage assessment, determining inspection/imaging priorities, and reconnaissance fieldwork.", "date": "2015-11", "date_type": "published", "publication": "Seismological Research Letters", "volume": "86", "number": "6", "publisher": "Seismological Society of America", "pagerange": "1549-1556", "id_number": "CaltechAUTHORS:20151204-093621926", "issn": "0895-0695", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20151204-093621926", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1785/0220150152", "primary_object": { "basename": "1549.full.pdf", "url": "https://authors.library.caltech.edu/records/wmk83-bve93/files/1549.full.pdf" }, "resource_type": "article", "pub_year": "2015", "author_list": "Yun, Sang-Ho; Hudnut, Kenneth; et el." }, { "id": "https://authors.library.caltech.edu/records/qhk0h-nz521", "eprint_id": 58975, "eprint_status": "archive", "datestamp": "2023-10-25 17:32:00", "lastmod": "2023-10-25 17:32:00", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Galetzka-J", "name": { "family": "Galetzka", "given": "J." } }, { "id": "Genrich-J-F", "name": { "family": "Genrich", "given": "J. F." } }, { "id": "Avouac-J-P", "name": { "family": "Avouac", "given": "J.-P." }, "orcid": "0000-0002-3060-8442" }, { "id": "Hudnut-K-W", "name": { "family": "Hudnut", "given": "K. W." }, "orcid": "0000-0002-3168-4797" } ] }, "title": "Slip pulse and resonance of the Kathmandu basin during the 2015 Gorkha earthquake, Nepal", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 2015 American Association for the Advancement of Science. \n\nReceived for publication 25 May 2015. Accepted for publication 29 July 2015. \n\nPublished online 6 August 2015.\n\nThe GPS data are available from the UNAVCO website. The InSAR\ndata are available at http://topex.ucsd.edu/nepal/. The Nepal\nGeodetic Array was funded by Caltech and DASE (to J.-P.A.) and\nby the Gordon and Betty Moore Foundation, through grant GBMF\n423.01 to the Caltech Tectonics Observatory; support was\nmaintained by NSF grant EAR-1345136. A. Miner and the Pacific\nNorthwest Geodetic Array (PANGA) at CWU are thanked for\ntechnical assistance with the construction and operation of the\nTribhuvan University (TU)\u2013CWU network. Additional funding for the\nTU-CWU network came from the United Nations Development\nProgramme and the Nepal Academy for Science and Technology.\nThe high-rate data were recovered thanks to (i) a rapid\nintervention funded by NASA (USA) and the Department of Foreign\nInternational Development (UK) and (ii) engineering services\nprovided by UNAVCO via the GAGE (Geodesy Advancing\nGeosciences and EarthScope) Facility, with support from NSF and\nNASA under NSF Cooperative Agreement no. EAR-1261833. We\nalso thank Trimble Navigation and the Vaidya family for supporting\nthe rapid response. The accelerometer record at KATNP was\nprovided by USGS. We thank A. Nathan (U.S. Embassy in\nKathmandu), S. Hough, D. Given, I. Flores, and J. Luetgert for\ncontributions to the installation of this station. Research at\nUC\u2013Berkeley was funded by the Gordon and Betty Moore\nFoundation through grant GBMF 3024. A portion of this work\nwas carried out at JPL under a contract with the NASA.\nThe GPS data were processed by the Advanced Rapid Imaging and\nAnalysis Center for Natural Hazards (JPL) and the Scripps Orbit\nand Permanent Array Center. The effort at the Scripps Institution\nof Oceanography was funded by NASA grants NNX14AQ53G and\nNNX14AT33G. Advanced Land Observing Satellite\u20132 data were\nprovided by the Japan Aerospace Exploration Agency under\ninvestigations 1148 and 1413. J.-P.A. thanks the Royal Society for\nsupport. We thank D. Dreger for discussion and W. Mooney for\ncomments. J.-P.A led the study and wrote the article. D.M.\nperformed the kinematic modeling and wrote the article. Y.B.\nsupervised the high-rate data processing and wrote the article.\nJ.Ga. led the field operations. J.Ge. conducted the high-rate data\nprocessing. S.O., A.M., W.S., and J.F.G. conducted the low-rate\ndata analysis to estimate coseismic offsets. E.O.L. and X.X.\nconducted the InSAR data processing. L.B. helped to organize the\nfield operations. All other authors contributed to building and\nservicing the GPS stations and to the post-earthquake data\nrecovery. All authors edited the article.\n\nSupplemental Material - aac6383-Galetzka-SM-movie-S1.mp4
Supplemental Material - aac6383-Galetzka-SM.pdf
", "abstract": "Detailed geodetic imaging of earthquake ruptures enhances our understanding of earthquake physics and associated ground shaking. The 25 April 2015 moment magnitude 7.8 earthquake in Gorkha, Nepal was the first large continental megathrust rupture to have occurred beneath a high-rate (5-hertz) Global Positioning System (GPS) network. We used GPS and interferometric synthetic aperture radar data to model the earthquake rupture as a slip pulse ~20 kilometers in width, ~6 seconds in duration, and with a peak sliding velocity of 1.1 meters per second, which propagated toward the Kathmandu basin at ~3.3 kilometers per second over ~140 kilometers. The smooth slip onset, indicating a large (~5-meter) slip-weakening distance, caused moderate ground shaking at high frequencies (>1 hertz; peak ground acceleration, ~16% of Earth's gravity) and minimized damage to vernacular dwellings. Whole-basin resonance at a period of 4 to 5 seconds caused the collapse of tall structures, including cultural artifacts.", "date": "2015-09-04", "date_type": "published", "publication": "Science", "volume": "349", "number": "6252", "publisher": "American Association for the Advancement of Science", "pagerange": "1091-1095", "id_number": "CaltechAUTHORS:20150721-170858547", "issn": "0036-8075", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150721-170858547", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Caltech" }, { "agency": "DASE" }, { "agency": "Gordon and Betty Moore Foundation", "grant_number": "GBMF 423.01" }, { "agency": "NSF", "grant_number": "EAR-1345136" }, { "agency": "United Nations Development Programme" }, { "agency": "Nepal Academy for Science and Technology" }, { "agency": "Department of Foreign International Development (UK)" }, { "agency": "NSF", "grant_number": "EAR-1261833" }, { "agency": "Gordon and Betty Moore Foundation", "grant_number": "GBMF 3024" }, { "agency": "NASA/JPL/Caltech" }, { "agency": "NASA", "grant_number": "NNX14AQ53G" }, { "agency": "NASA", "grant_number": "NNX14AT33G" }, { "agency": "Japan Aerospace Exploration Agency (JAXA)", "grant_number": "1148" }, { "agency": "Japan Aerospace Exploration Agency (JAXA)", "grant_number": "1413" }, { "agency": "Royal Society" } ] }, "collection": "CaltechAUTHORS", "local_group": { "items": [ { "id": "Seismological-Laboratory", "value": "Seismological Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences", "value": "Division of Geological and Planetary Sciences" } ] }, "doi": "10.1126/science.aac6383", "primary_object": { "basename": "42339125.pdf", "url": "https://authors.library.caltech.edu/records/qhk0h-nz521/files/42339125.pdf" }, "related_objects": [ { "basename": "aac6383-Galetzka-SM-movie-S1.mp4", "url": "https://authors.library.caltech.edu/records/qhk0h-nz521/files/aac6383-Galetzka-SM-movie-S1.mp4" }, { "basename": "aac6383-Galetzka-SM.pdf", "url": "https://authors.library.caltech.edu/records/qhk0h-nz521/files/aac6383-Galetzka-SM.pdf" } ], "resource_type": "article", "pub_year": "2015", "author_list": "Galetzka, J.; Genrich, J. F.; et el." }, { "id": "https://authors.library.caltech.edu/records/qt3cj-11b27", "eprint_id": 57087, "eprint_status": "archive", "datestamp": "2023-08-22 15:56:49", "lastmod": "2023-10-23 17:02:34", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Wei-Shengji", "name": { "family": "Wei", "given": "Shengji" } }, { "id": "Avouac-J-P", "name": { "family": "Avouac", "given": "Jean-Philippe" }, "orcid": "0000-0002-3060-8442" }, { "id": "Hudnut-K-W", "name": { "family": "Hudnut", "given": "Kenneth W." }, "orcid": "0000-0002-3168-4797" }, { "id": "Donnellan-A", "name": { "family": "Donnellan", "given": "Andrea" } }, { "id": "Parker-J-W", "name": { "family": "Parker", "given": "Jay W." } }, { "id": "Graves-R-W", "name": { "family": "Graves", "given": "Robert W." } }, { "id": "Helmberger-D-V", "name": { "family": "Helmberger", "given": "Don" } }, { "id": "Fielding-E-J", "name": { "family": "Fielding", "given": "Eric" }, "orcid": "0000-0002-6648-8067" }, { "id": "Liu-Zhen", "name": { "family": "Liu", "given": "Zhen" }, "orcid": "0000-0002-6313-823X" }, { "id": "Cappa-F", "name": { "family": "Cappa", "given": "Frederic" }, "orcid": "0000-0003-4859-8024" }, { "id": "Eneva-M", "name": { "family": "Eneva", "given": "Mariana" } } ] }, "title": "The 2012 Brawley swarm triggered by injection-induced aseismic slip", "ispublished": "pub", "full_text_status": "public", "keywords": "fluid injection; aseismic slip; high frequency waveform modeling; UAVSAR and InSAR; geothermal; finite fault model", "note": "\u00a9 2015 Elsevier B.V.\n\nReceived 21 November 2014; Received in revised form 26 March 2015; Accepted 31 March 2015.\n\nThe seismic data were downloaded from Southern California Seismic Data Center and strong motion data center (strongmotioncenter.org). We thank the Omar Company for providing the leveling data used in this study. We are grateful to Elizabeth Cochran and two anonymous reviewers for their insightful and constructive comments. Suzanne Donovan helped editing the manuscript. Part of the research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration. Part of this research was supported by NASA's Earth Surface and Interior and Geodetic Imaging programs (grant number 102443-281945.02.47.02.89). We thank the UAVSAR team and in particular Scott Hensley, Yunling Lou, Brian Hawkins, Naiara Pinto, and Yang Zheng for collection and processing of the UAVSAR data.\n\nSupplemental Material - mmc1.docx
Supplemental Material - mmc2.pdf
Supplemental Material - mmc3.pdf
Supplemental Material - mmc4.pdf
Supplemental Material - mmc5.pdf
Supplemental Material - mmc6.pdf
Supplemental Material - mmc7.pdf
Supplemental Material - mmc8.pdf
", "abstract": "It has long been known that fluid injection or withdrawal can induce earthquakes, but the underlying mechanisms remain elusive. For example, the 2012 Brawley swarm, which produced two strike-slip shocks with magnitudes larger than 5.3 and surface ruptures in the close vicinity of a geothermal field, started with earthquakes about 5 km deeper than the injection depth (\u223c1.5 km). This makes the causality between the injection and seismicity unclear. Here, we jointly analyze broadband and strong motion waveforms, UAVSAR, leveling measurements and field observations to reveal the detailed seismic and aseismic faulting behaviors associated with the 2012 Brawley swarm. In particular, path calibration established from smaller events in the swarm allows waveform inversion to be conducted up to 3 Hz to resolve finite rupture process of the Mw 4.7 normal event. Our results show that the 2012 earthquake sequence was preceded by aseismic slip on a shallow normal fault beneath the geothermal field. Aseismic slip initiated in 2010 when injection rate rapidly increased and triggered the following earthquakes subsequently, including unusually shallow and relatively high frequency seismic excitations on the normal fault. In this example, seismicity is induced indirectly by fluid injection, a result of mediation by aseismic creep, rather than directly by a pore pressure increase at the location of the earthquakes.", "date": "2015-07-15", "date_type": "published", "publication": "Earth and Planetary Science Letters", "volume": "422", "publisher": "Elsevier", "pagerange": "115-125", "id_number": "CaltechAUTHORS:20150429-104726958", "issn": "0012-821X", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150429-104726958", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA/JPL/Caltech" }, { "agency": "NASA", "grant_number": "102443-281945.02.47.02.89" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/j.epsl.2015.03.054", "primary_object": { "basename": "mmc2.pdf", "url": "https://authors.library.caltech.edu/records/qt3cj-11b27/files/mmc2.pdf" }, "related_objects": [ { "basename": "mmc3.pdf", "url": "https://authors.library.caltech.edu/records/qt3cj-11b27/files/mmc3.pdf" }, { "basename": "mmc4.pdf", "url": "https://authors.library.caltech.edu/records/qt3cj-11b27/files/mmc4.pdf" }, { "basename": "mmc5.pdf", "url": "https://authors.library.caltech.edu/records/qt3cj-11b27/files/mmc5.pdf" }, { "basename": "mmc6.pdf", "url": "https://authors.library.caltech.edu/records/qt3cj-11b27/files/mmc6.pdf" }, { "basename": "mmc7.pdf", "url": "https://authors.library.caltech.edu/records/qt3cj-11b27/files/mmc7.pdf" }, { "basename": "mmc8.pdf", "url": "https://authors.library.caltech.edu/records/qt3cj-11b27/files/mmc8.pdf" }, { "basename": "mmc1.docx", "url": "https://authors.library.caltech.edu/records/qt3cj-11b27/files/mmc1.docx" } ], "resource_type": "article", "pub_year": "2015", "author_list": "Wei, Shengji; Avouac, Jean-Philippe; et el." }, { "id": "https://authors.library.caltech.edu/records/97cr7-vre81", "eprint_id": 57110, "eprint_status": "archive", "datestamp": "2023-08-20 05:37:05", "lastmod": "2023-10-23 17:04:42", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Chen-Tao", "name": { "family": "Chen", "given": "T." } }, { "id": "Akciz-Sinan-O", "name": { "family": "Akciz", "given": "S. O." } }, { "id": "Hudnut-K-W", "name": { "family": "Hudnut", "given": "K. W." }, "orcid": "0000-0002-3168-4797" }, { "id": "Zhang-D-Z", "name": { "family": "Zhang", "given": "D. Z." } }, { "id": "Stock-J-M", "name": { "family": "Stock", "given": "J. M." }, "orcid": "0000-0003-4816-7865" } ] }, "title": "Fault\u2010Slip Distribution of the 1999 M_w 7.1 Hector Mine Earthquake, California, Estimated from Postearthquake Airborne LiDAR Data", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 2015 Seismological Society of America.\n\nManuscript received 2 May 2013; Published Online 3 February 2015.\n\nThis research was supported by Public Service Funds for earthquake studies (201308012) and Fundamental Research Funds in the Institute of Geology (IGCEA1125). Tao Chen was sponsored as a visiting scholar to the U.S. Geological Survey (USGS) by the China Scholarship Council (Grant Number 2010419008). Work by D. Z. Zhang was supported, in part, by the Multi-Hazards Demonstration Project of the USGS. Jing Liu-Zeng and Kate Scharer helped us to improve the manuscript. We thank Katherine Kendrick for providing the database of field measurements from the original postearthquake observations of Treiman et al. (2002). We also thank an anonymous reviewer and Mike Oskin for their advice. Original LiDAR data acquisition was funded by the USGS and the Southern California Earthquake Center (SCEC). SCEC is funded by National Science Foundation Cooperative Agreement EAR-1033462 and USGS Cooperative AgreementG12AC20038. The SCEC contribution number for this article is 1973.\n\nPublished - 0120130108.full.pdf
", "abstract": "The 16 October 1999 Hector Mine earthquake (M_w 7.1) was the first large earthquake for which postearthquake airborne Light Detection and Ranging (LiDAR) data were collected to image the fault surface rupture. In this work, we present measurements of both vertical and horizontal slip along the entire surface rupture of this earthquake based on airborne LiDAR data acquired in April 2000. We examine the details of the along\u2010fault slip distribution of this earthquake based on 255 horizontal and 85 vertical displacements using a 0.5 m digital elevation model derived from the LiDAR imagery. The slip measurements based on the LiDAR dataset are highest in the epicentral region, and taper in both directions, consistent with earlier findings by other works. The maximum dextral displacement measured from LiDAR imagery is 6.60\u00b11.10\u2009\u2009m, located about 700 m south of the highest field measurement (5.25\u00b10.85\u2009\u2009m). Our results also illustrate the difficulty in resolving displacements smaller than 1 m using LiDAR imagery alone. We analyze slip variation to see if it is affected by rock type and whether variations are statistically significant. This study demonstrates that a postearthquake airborne LiDAR survey can produce an along\u2010fault horizontal and vertical offset distribution plot of a quality comparable to a reconnaissance field survey. Although LiDAR data can provide a higher sampling density and enable rapid data analysis for documenting slip distributions, we find that, relative to field methods, it has a limited ability to resolve slip that is distributed over several fault strands across a zone. We recommend a combined approach that merges field observation with LiDAR analysis, so that the best attributes of both quantitative topographic and geological insight are utilized in concert to make best estimates of offsets and their uncertainties.", "date": "2015-04", "date_type": "published", "publication": "Bulletin of the Seismological Society of America", "volume": "105", "number": "2A", "publisher": "Seismological Society of America", "pagerange": "776-790", "id_number": "CaltechAUTHORS:20150430-094007973", "issn": "0037-1106", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150430-094007973", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Public Service Funds for Earthquake Studies", "grant_number": "201308012" }, { "agency": "Institute of Geology Fundamental Research Funds", "grant_number": "IGCEA1125" }, { "agency": "China Scholarship Council", "grant_number": "2010419008" }, { "agency": "Southern California Earthquake Center (SCEC)" }, { "agency": "NSF", "grant_number": "EAR-1033462" }, { "agency": "USGS", "grant_number": "G12AC20038" } ] }, "other_numbering_system": { "items": [ { "id": "1973", "name": "Southern California Earthquake Center" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1785/0120130108", "primary_object": { "basename": "0120130108.full.pdf", "url": "https://authors.library.caltech.edu/records/97cr7-vre81/files/0120130108.full.pdf" }, "resource_type": "article", "pub_year": "2015", "author_list": "Chen, T.; Akciz, S. O.; et el." }, { "id": "https://authors.library.caltech.edu/records/zctks-m3t13", "eprint_id": 56744, "eprint_status": "archive", "datestamp": "2023-08-20 05:10:05", "lastmod": "2023-10-23 15:47:06", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Wei-Shengji", "name": { "family": "Wei", "given": "Shengji" } }, { "id": "Barbot-S", "name": { "family": "Barbot", "given": "Sylvain" }, "orcid": "0000-0003-4257-7409" }, { "id": "Graves-R-W", "name": { "family": "Graves", "given": "Robert" } }, { "id": "Lienkaemper-J-J", "name": { "family": "Lienkaemper", "given": "James J." } }, { "id": "Wang-Teng", "name": { "family": "Wang", "given": "Teng" } }, { "id": "Hudnut-K-W", "name": { "family": "Hudnut", "given": "Kenneth" }, "orcid": "0000-0002-3168-4797" }, { "id": "Fu-Yuning", "name": { "family": "Fu", "given": "Yuning" } }, { "id": "Helmberger-D-V", "name": { "family": "Helmberger", "given": "Don" } } ] }, "title": "The 2014 M_w 6.1 South Napa Earthquake: A Unilateral Rupture with Shallow Asperity and Rapid Afterslip", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 2015 by the Seismological Society of America. \n\nStrong-motion waveform data was downloaded from the Northern California Data Center, California Geological Survey, and U.S. Geological Survey (USGS) (strongmotioncenter.org; last accessed September 2014). Interferometric Synthetic Aperture Radar data were obtained from the Jet Propulsion Laboratory (JPL), static GPS data were made available by Tom Herring from the Massachusetts Institute of Technology. Constructive reviews by Annemarie Baltay, Art Frankel, and an anonymous reviewer led to improvements in the manuscript. Figures were made using Generic Mapping Tool (Wessel and Smith, 1991). Part of this research was carried out at JPL (California Institute of Technology), sponsored by the National Aeronautics and Space Administration.\n\nPublished - 344.full.pdf
", "abstract": "The Mw 6.1 South Napa earthquake occurred near Napa, California, on 24 August 2014 at 10:20:44.03 (UTC) and was the largest inland earthquake in northern California since the 1989 Mw 6.9 Loma Prieta earthquake. The first report of the earthquake from the Northern California Earthquake Data Center (NCEDC) indicates a hypocentral depth of 11.0 km with longitude and latitude of (122.3105\u00b0 W, 38.217\u00b0 N). Surface rupture was documented by field observations and Light Detection and Ranging (LiDAR) imaging (Brooks et al., 2014; Hudnut et al., 2014; Brocher et al., 2015), with about 12 km of continuous rupture starting near the epicenter and extending to the northwest. The southern part of the rupture is relatively straight, but the strike changes by about 15\u00b0 at the northern end over a 6 km segment. The peak dextral offset was observed near the Buhman residence with right\u2010lateral motion of 46 cm, near the location where the strike of fault begins to rotate clockwise (Hudnut et al., 2014). The earthquake was well recorded by the strong\u2010motion network operated by the NCEDC, the California Geological Survey and the U.S. Geological Survey (USGS). There are about 12 sites within an epicentral distance of 15 km that had relatively good azimuthal coverage (Fig. 1). The largest peak ground velocity (PGV) of nearly 100\u2009\u2009cm/s was observed on station 1765, which is the closest station to the rupture and lies about 3 km east of the northern segment (Fig. 1). The ground deformation associated with the earthquake was also well recorded by the high resolution COSMO\u2013SkyMed (CSK) satellite and Sentinel-1A satellite, providing independent static observations.", "date": "2015-03", "date_type": "published", "publication": "Seismological Research Letters", "volume": "86", "number": "2A", "publisher": "Seismological Society of America", "pagerange": "344-354", "id_number": "CaltechAUTHORS:20150417-120038001", "issn": "0895-0695", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150417-120038001", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA/JPL/Caltech" } ] }, "doi": "10.1785/0220140249", "primary_object": { "basename": "344.full.pdf", "url": "https://authors.library.caltech.edu/records/zctks-m3t13/files/344.full.pdf" }, "resource_type": "article", "pub_year": "2015", "author_list": "Wei, Shengji; Barbot, Sylvain; et el." }, { "id": "https://authors.library.caltech.edu/records/q1mnd-03c05", "eprint_id": 49226, "eprint_status": "archive", "datestamp": "2023-08-20 02:16:59", "lastmod": "2023-10-17 21:13:58", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Fletcher-J-M", "name": { "family": "Fletcher", "given": "John M." } }, { "id": "Teran-O-J", "name": { "family": "Teran", "given": "Orlando J." } }, { "id": "Rockwell-T-K", "name": { "family": "Rockwell", "given": "Thomas K." } }, { "id": "Oskin-M-E", "name": { "family": "Oskin", "given": "Michael" }, "orcid": "0000-0002-6631-5326" }, { "id": "Hudnut-K-W", "name": { "family": "Hudnut", "given": "Kenneth W." }, "orcid": "0000-0002-3168-4797" }, { "id": "Mueller-K-J", "name": { "family": "Mueller", "given": "Karl J." } }, { "id": "Spelz-R-M", "name": { "family": "Spelz", "given": "Ronald M." } }, { "id": "Akciz-S-O", "name": { "family": "Akciz", "given": "Sinan O." } }, { "id": "Masana-E", "name": { "family": "Masana", "given": "Eulalia" } }, { "id": "Faneros-G", "name": { "family": "Faneros", "given": "Geoff" } }, { "id": "Fielding-E-J", "name": { "family": "Fielding", "given": "Eric J." }, "orcid": "0000-0002-6648-8067" }, { "id": "Leprince-S", "name": { "family": "Leprince", "given": "S\u00e9bastien" }, "orcid": "0000-0003-4555-8975" }, { "id": "Morelan-A-E", "name": { "family": "Morelan", "given": "Alexander E." } }, { "id": "Stock-J-M", "name": { "family": "Stock", "given": "Joann" }, "orcid": "0000-0003-4816-7865" }, { "id": "Lynch-D-K", "name": { "family": "Lynch", "given": "David K." } }, { "id": "Elliott-A-J", "name": { "family": "Elliott", "given": "Austin J." } }, { "id": "Gold-Peter", "name": { "family": "Gold", "given": "Peter" } }, { "id": "Liu-Zeng-Jing", "name": { "family": "Liu-Zeng", "given": "Jing" } }, { "id": "Gonz\u00e1lez-Ortega-A", "name": { "family": "Gonz\u00e1lez-Ortega", "given": "Alejandro" } }, { "id": "Hinojosa-Corona-A", "name": { "family": "Hinojosa-Corona", "given": "Alejandro" } }, { "id": "Gonz\u00e1lez-Garc\u00eda-J", "name": { "family": "Gonz\u00e1lez-Garc\u00eda", "given": "Javier" } } ] }, "title": "Assembly of a large earthquake from a complex fault system: Surface rupture kinematics of the 4 April 2010 El Mayor\u2013Cucapah (Mexico) M_w 7.2 earthquake", "ispublished": "pub", "full_text_status": "restricted", "note": "\u00a9 2014 Geological Society of America. Received 25 March 2013. Revision received 18 March 2014. Accepted 25 April 2014. Published online 24 June 2014. This work was fi nanced by CONACYT (Consejo Nacional de Ciencia y Tecnolog\u00eda) grant 81463, SCEC (Southern California Earthquake Center) grant 1697, and National Science Foundation grant EAR-0529922; the GEER (Geotechnical Extreme Events Reconnaissance) Foundation provided funding for initial field work. S. Leprince was supported in part by the Keck Institute for Space Studies and by the Gordon\nand Betty Moore Foundation. Part of this study\nwas sponsored by the National Aeronautics and Space\nAdministration (NASA) Earth Surface and Interior\nfocus area and performed at the Jet Propulsion Laboratory,\nCalifornia Institute of Technology, under contract\nwith NASA. Enlightening discussions with Paul Wetmore\nand Francisco Suarez helped refine ideas about\ntectonics of the Big Bend domain and the kinematics\nof faulting in the Colorado River delta, respectively.\nWe thank John Galetzka, Kate Scharer, David Bowman,\nRoman Manjarrez, and Maria Oturno for help\nwith field work. We also thank Jose Mojarro, Sergio\nArregui, and Luis Gradilla for technical support.", "abstract": "The 4 April 2010 moment magnitude (M_w) 7.2 El Mayor\u2013Cucapah earthquake revealed the existence of a previously unidentified fault system in Mexico that extends \u223c120 km from the northern tip of the Gulf of California to the U.S.\u2013Mexico border. The system strikes northwest and is composed of at least seven major faults linked by numerous smaller faults, making this one of the most complex surface ruptures ever documented along the Pacific\u2013North America plate boundary. Rupture propagated bilaterally through three distinct kinematic and geomorphic domains. Southeast of the epicenter, a broad region of distributed fracturing, liquefaction, and discontinuous fault rupture was controlled by a buried, southwest-dipping, dextral-normal fault system that extends \u223c53 km across the southern Colorado River delta. Northwest of the epicenter, the sense of vertical slip reverses as rupture propagated through multiple strands of an imbricate stack of east-dipping dextral-normal faults that extend \u223c55 km through the Sierra Cucapah. However, some coseismic slip (10\u201330 cm) was partitioned onto the west-dipping Laguna Salada fault, which extends parallel to the main rupture and defines the western margin of the Sierra Cucapah. In the northernmost domain, rupture terminates on a series of several north-northeast\u2013striking cross-faults with minor offset (<8 cm) that cut uplifted and folded sediments of the northern Colorado River delta in the Yuha Desert.\n\nIn the Sierra Cucapah, primary rupture occurred on four major faults separated by one fault branch and two accommodation zones. The accommodation zones are distributed in a left-stepping en echelon geometry, such that rupture passed systematically to structurally lower faults. The structurally lowest fault that ruptured in this event is inclined as shallowly as \u223c20\u00b0. Net surface offsets in the Sierra Cucapah average \u223c200 cm, with some reaching 300\u2013400 cm, and rupture kinematics vary greatly along strike. Nonetheless, instantaneous extension directions are consistently oriented \u223c085\u00b0 and the dominant slip direction is \u223c310\u00b0, which is slightly (\u223c10\u00b0) more westerly than the expected azimuth of relative plate motion, but considerably more oblique to other nearby historical ruptures such as the 1992 Landers earthquake. Complex multifault ruptures are common in the central portion of the Pacific North American plate margin, which is affected by restraining bend tectonics, gravitational potential energy gradients, and the inherently three-dimensional strain of the transtensional and transpressional shear regimes that operate in this region.", "date": "2014-08", "date_type": "published", "publication": "Geosphere", "volume": "10", "number": "4", "publisher": "Geological Society of America", "pagerange": "797-827", "id_number": "CaltechAUTHORS:20140904-090345033", "issn": "1553-040X", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140904-090345033", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Consejo Nacional de Ciencia y Tecnolog\u00eda (CONACYT)", "grant_number": "81463" }, { "agency": "Southern California Earthquake Center (SCEC)", "grant_number": "1697" }, { "agency": "NSF", "grant_number": "EAR-0529922" }, { "agency": "Geotechnical Extreme Events Reconnaissance Foundation (GEER)" }, { "agency": "Keck Institute for Space Studies (KISS)" }, { "agency": "Gordon and Betty Moore Foundation" }, { "agency": "NASA/JPL/Caltech" } ] }, "local_group": { "items": [ { "id": "Keck-Institute-for-Space-Studies" }, { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1130/GES00933.1", "resource_type": "article", "pub_year": "2014", "author_list": "Fletcher, John M.; Teran, Orlando J.; et el." }, { "id": "https://authors.library.caltech.edu/records/tbh64-cx393", "eprint_id": 42865, "eprint_status": "archive", "datestamp": "2023-08-22 08:56:09", "lastmod": "2023-10-25 23:06:36", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Wei-Shengji", "name": { "family": "Wei", "given": "Shengji" } }, { "id": "Helmberger-D-V", "name": { "family": "Helmberger", "given": "Don" } }, { "id": "Owen-S-E", "name": { "family": "Owen", "given": "Susan" } }, { "id": "Graves-R-W", "name": { "family": "Graves", "given": "Robert W." } }, { "id": "Hudnut-K-W", "name": { "family": "Hudnut", "given": "Kenneth W." }, "orcid": "0000-0002-3168-4797" }, { "id": "Fielding-E-J", "name": { "family": "Fielding", "given": "Eric J." }, "orcid": "0000-0002-6648-8067" } ] }, "title": "Complementary slip distributions of the largest earthquakes in the 2012 Brawley swarm, Imperial Valley, California", "ispublished": "pub", "full_text_status": "public", "keywords": "Brawley Earthquake Swarm Imperial Valley; high-rate GPS; geothermal; strong motion", "note": "\u00a9 2013 American Geophysical Union. Received 20 December 2012; revised 12 February 2013; accepted 14 February 2013; published 14 March 2013. The strong motion data were downloaded from the Southern California Seismic Network and USGS. The original TerraSAR-X data is copyright 2012 by the German space agency DLR, provided under the Group on Earth Observation Geohazard Supersite project. Part of this research was supported by the USGS grant G12AP20072,\nCaltech Tectonics Observatory, NASA Earth Surface and Interior focus area and performed at the JPL, Caltech. The high-rate GPS data were provided by the NSF PBO and archived at UNAVCO. Static offset GPS processing\nwas performed by Jerry Svarc (USGS) and Tom Herring (MIT). The manuscript was improved by the constructive input of Karen Felzer, Gavin Hayes and two anonymous reviewers.\n\nPublished - grl50259.pdf
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Supplemental Material - fig_S7.pdf
", "abstract": "We investigate the finite rupture processes of two M\u2009>\u20095 earthquakes in the 2012 Brawley swarm by joint inversion of nearby strong motion and high-rate GPS data. Waveform inversions up to 3 Hz were made possible by using a small event (M_w3.9) for path calibration of the velocity structure. Our results indicate that the first (M_w5.3) event ruptured a strong, concentrated asperity with offsets of ~20 cm centered at a depth of 5 km. The subsequent M_w5.4 event occurred 1.5 h later with a shallower slip distribution that surrounds and is complementary to that of the earlier event. The second event has a longer rise time and weaker high-frequency energy release compared to the M_w5.3 event. Both events display strong rupture directivity toward the southwest and lack of very shallow (<2 km) coseismic slip. The hypocenters for these events appear to be near or in the bedrock, but most of the slip is distributed at shallower depths (<6 km) and can explain a large part of the GPS offsets for the swarm. The complementary slip distributions of the two events suggest a triggering relationship between them with no significant creep needed to explain the various data sets.", "date": "2013-03-16", "date_type": "published", "publication": "Geophysical Research Letters", "volume": "40", "number": "5", "publisher": "American Geophysical Union", "pagerange": "847-852", "id_number": "CaltechAUTHORS:20131205-145703895", "issn": "0094-8276", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20131205-145703895", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "USGS", "grant_number": "G12AP20072" }, { "agency": "Caltech Tectonics Observatory" }, { "agency": "NASA/JPL/Caltech" } ] }, "local_group": { "items": [ { "id": "Caltech-Tectonics-Observatory" } ] }, "doi": "10.1002/grl.50259", "primary_object": { "basename": "55999Rreadme.txt", "url": "https://authors.library.caltech.edu/records/tbh64-cx393/files/55999Rreadme.txt" }, "related_objects": [ { "basename": "fig_S1.pdf", "url": "https://authors.library.caltech.edu/records/tbh64-cx393/files/fig_S1.pdf" }, { "basename": "fig_S2.pdf", "url": "https://authors.library.caltech.edu/records/tbh64-cx393/files/fig_S2.pdf" }, { "basename": "fig_S3.pdf", "url": "https://authors.library.caltech.edu/records/tbh64-cx393/files/fig_S3.pdf" }, { "basename": "fig_S4.pdf", "url": "https://authors.library.caltech.edu/records/tbh64-cx393/files/fig_S4.pdf" }, { "basename": "fig_S5.pdf", "url": "https://authors.library.caltech.edu/records/tbh64-cx393/files/fig_S5.pdf" }, { "basename": "fig_S6.pdf", "url": "https://authors.library.caltech.edu/records/tbh64-cx393/files/fig_S6.pdf" }, { "basename": "fig_S7.pdf", "url": "https://authors.library.caltech.edu/records/tbh64-cx393/files/fig_S7.pdf" }, { "basename": "grl50259.pdf", "url": "https://authors.library.caltech.edu/records/tbh64-cx393/files/grl50259.pdf" } ], "resource_type": "article", "pub_year": "2013", "author_list": "Wei, Shengji; Helmberger, Don; et el." }, { "id": "https://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.edu/records/r6pn8-vbx09", "eprint_id": 35997, "eprint_status": "archive", "datestamp": "2023-08-22 07:42:05", "lastmod": "2023-10-20 22:06:30", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Zhan-Zhongwen", "name": { "family": "Zhan", "given": "Zhongwen" }, "orcid": "0000-0002-5586-2607" }, { "id": "Helmberger-D-V", "name": { "family": "Helmberger", "given": "Don" } }, { "id": "Simons-M", "name": { "family": "Simons", "given": "Mark" }, "orcid": "0000-0003-1412-6395" }, { "id": "Kanamori-H", "name": { "family": "Kanamori", "given": "Hiroo" }, "orcid": "0000-0001-8219-9428" }, { "id": "Wu-Wenbo", "name": { "family": "Wu", "given": "Wenbo" }, "orcid": "0000-0002-6249-8065" }, { "id": "Cubas-Nadaya", "name": { "family": "Cubas", "given": "Nadaya" } }, { "id": "Duputel-Zacharie", "name": { "family": "Duputel", "given": "Zacharie" } }, { "id": "Chu-Risheng", "name": { "family": "Chu", "given": "Risheng" } }, { "id": "Tsai-V-C", "name": { "family": "Tsai", "given": "Victor C." }, "orcid": "0000-0003-1809-6672" }, { "id": "Avouac-J-P", "name": { "family": "Avouac", "given": "Jean-Philippe" }, "orcid": "0000-0002-3060-8442" }, { "id": "Hudnut-K-W", "name": { "family": "Hudnut", "given": "Kenneth W." }, "orcid": "0000-0002-3168-4797" }, { "id": "Ni-Sidao", "name": { "family": "Ni", "given": "Sidao" }, "orcid": "0000-0003-2988-4850" }, { "id": "Hetland-E-A", "name": { "family": "Hetland", "given": "Eric" } }, { "id": "Ortega-Culaciati-F-H", "name": { "family": "Ortega Culaciati", "given": "Francisco H." } } ] }, "title": "Anomalously steep dips of earthquakes in the 2011 Tohoku-Oki source region and possible explanations", "ispublished": "pub", "full_text_status": "public", "keywords": "subduction zone; the 2011 Tohoku-Oki earthquake; focal mechanism; fault geometry; seamount; fault zone structure", "note": "\u00a9 2012 Elsevier B.V. \n\nReceived 19 May 2012. Received in revised form 26 July 2012. Accepted 27 July 2012. Editor: P.Shearer. Available online 7 September 2012. \n\nWe thank Seiichi Miura, Narumi Takahashi, Aki Ito and Ryota Hino for providing their velocity models or earthquake catalog. We thank Robert Graves, another anonymous USGS internal reviewer and two anonymous reviewers for their comments that improved the manuscript. The Incorporated Research Institutions for Seismology (IRIS) provided the seismic data. All figures are made with GMT. This work is supported by the National Science Foundation through grant number EAR-1142020. Contribution #10080 of the Tectonic Observatory, California Institute of Technology.\n\nSupplemental Material - mmc1.pdf
", "abstract": "The 2011 M_w 9.1 Tohoku-Oki earthquake had unusually large slip (over 50 m) concentrated in a relatively small region, with local stress drop inferred to be 5\u201310 times larger than that found for typical megathrust earthquakes. Here we conduct a detailed analysis of foreshocks and aftershocks (M_w 5.5\u20137.5) sampling this megathrust zone for possible clues regarding such differences in seismic excitation. We find that events occurring in the region that experienced large slip during the M_w 9.1 event had steeper dip angles (by 5\u201310\u00b0) than the surrounding plate interface. This discrepancy cannot be explained by a single smooth plate interface. We provide three possible explanations. In Model I, the oceanic plate undergoes two sharp breaks in slope, which were not imaged well in previous seismic surveys. These break-points may have acted as strong seismic barriers in previous seismic ruptures, but may have failed in and contributed to the complex rupture pattern of the Tohoku-Oki earthquake. In Model II, the discrepancy of dip angles is caused by a rough plate interface, which in turn may be the underlying cause for the overall strong coupling and concentrated energy-release. In Model III, the earthquakes with steeper dip angles did not occur on the plate interface, but on nearby steeper subfaults. Since the differences in dip angle are only 5\u201310\u00b0, this last explanation would imply that the main fault has about the same strength as the nearby subfaults, rather than much weaker. A relatively uniform fault zone with both the main fault and the subfaults inside is consistent with Model III. Higher resolution source locations and improved models of the velocity structure of the megathrust fault zone are necessary to resolve these issues.", "date": "2012-11-01", "date_type": "published", "publication": "Earth and Planetary Science Letters", "volume": "353-35", "publisher": "Elsevier", "pagerange": "121-133", "id_number": "CaltechAUTHORS:20121214-153612362", "issn": "0012-821X", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121214-153612362", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR-1142020" } ] }, "other_numbering_system": { "items": [ { "id": "10080", "name": "Caltech Tectonics Observatory" } ] }, "local_group": { "items": [ { "id": "Caltech-Tectonics-Observatory" }, { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1016/j.epsl.2012.07.038", "primary_object": { "basename": "mmc1.pdf", "url": "https://authors.library.caltech.edu/records/r6pn8-vbx09/files/mmc1.pdf" }, "resource_type": "article", "pub_year": "2012", "author_list": "Zhan, Zhongwen; Helmberger, Don; et el." }, { "id": "https://authors.library.caltech.edu/records/mmpk9-h3m26", "eprint_id": 27115, "eprint_status": "archive", "datestamp": "2023-08-22 03:32:23", "lastmod": "2023-10-24 16:52:50", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Wei-Shengji", "name": { "family": "Wei", "given": "Shengji" } }, { "id": "Fielding-E-J", "name": { "family": "Fielding", "given": "Eric" }, "orcid": "0000-0002-6648-8067" }, { "id": "Leprince-S", "name": { "family": "Leprince", "given": "S\u00e9bastien" }, "orcid": "0000-0003-4555-8975" }, { "id": "Sladen-A", "name": { "family": "Sladen", "given": "Anthony" }, "orcid": "0000-0003-4126-0020" }, { "id": "Avouac-J-P", "name": { "family": "Avouac", "given": "Jean-Philippe" }, "orcid": "0000-0002-3060-8442" }, { "id": "Helmberger-D-V", "name": { "family": "Helmberger", "given": "Don" } }, { "id": "Hauksson-E", "name": { "family": "Hauksson", "given": "Egill" }, "orcid": "0000-0002-6834-5051" }, { "id": "Chu-Risheng", "name": { "family": "Chu", "given": "Risheng" } }, { "id": "Simons-M", "name": { "family": "Simons", "given": "Mark" }, "orcid": "0000-0003-1412-6395" }, { "id": "Hudnut-K-W", "name": { "family": "Hudnut", "given": "Kenneth" }, "orcid": "0000-0002-3168-4797" }, { "id": "Herring-T", "name": { "family": "Herring", "given": "Thomas" } }, { "id": "Briggs-R-W", "name": { "family": "Briggs", "given": "Richard" } } ] }, "title": "Superficial simplicity of the 2010 El Mayor\u2013Cucapah earthquake of Baja California in Mexico", "ispublished": "pub", "full_text_status": "public", "keywords": "Structural geology; tectonics and geodynamics; Seismology", "note": "\u00a9 2011 Macmillan Publishers Limited. \n\nReceived 8 August 2010; accepted 23 June 2011; published online 31 July 2011. \n\nThis work was financially supported by NSF, USGS, the Gordon and Betty Moore Foundation, NASA and SCEC. Regional seismic data were provided by SCSN and RESNOM. The Incorporated Research Institutions for Seismology (IRIS) Data Management System (DMS) was used to access the Global Seismographic Network data. The GPS analyses were obtained from the Earthscope PBO data products system and UNAVCO. Optical data were provided by USGS. Envisat data are copyright 2009, 2010 ESA and were obtained from the WInSAR archive and the Group on Earth Observation Geohazards Supersite virtual archive. ALOS data are copyright METI, JAXA and were obtained from the Alaska Satellite Facility Level 1 Data Pool. Part of this research was carried out at the Jet Propulsion Laboratory, California Institute of Technology under contract with the National Aeronautics and Space Administration. We thank CICESE colleagues J. Gonzalez and J. Fletcher for their support and interest, and we thank J. Hollingsworth for his suggestions to improve the figures. This is Tectonics Observatory contribution #172. SCEC is funded by NSF Cooperative Agreement EAR-0529922 and USGS Cooperative Agreement 07HQAG0008. \n\nContributions\nS.W. carried out the modelling and edited the paper; E.F. carried out the InSAR and SAR processing and edited the paper; S.L. carried out the optical image and SAR cross-correlation processing; A.S. helped with the modelling and downsampled the InSAR and SAR data; J-P.A. conceived and supervised the research and editing of the paper; D.H. supervised the research and edited the paper; E.H. carried out relocation of aftershocks and foreshocks; R.C. carried out modelling of teleseismic data; M.S. provided InSAR data; K.H. edited the paper and provided geological interpretation; T.H. carried out the processing of GPS data; R.B. contributed to the tectonic interpretation. \n\nThe authors declare no competing financial interests.\n\nSubmitted - Wei_etal_EMC_20101208.pdf
Supplemental Material - ngeo1213-s1.pdf
", "abstract": "The geometry of faults is usually thought to be more complicated at the surface than at depth and to control the initiation, propagation and arrest of seismic ruptures. The fault system that runs from southern California into Mexico is a simple strike-slip boundary: the west side of California and Mexico moves northwards with respect to the east. However, the M_w 7.2 2010 El Mayor\u2013Cucapah earthquake on this fault system produced a pattern of seismic waves that indicates a far more complex source than slip on a planar strike-slip fault. Here we use geodetic, remote-sensing and seismological data to reconstruct the fault geometry and history of slip during this earthquake. We find that the earthquake produced a straight 120-km-long fault trace that cut through the Cucapah mountain range and across the Colorado River delta. However, at depth, the fault is made up of two different segments connected by a small extensional fault. Both segments strike N130\u00b0\u2009E, but dip in opposite directions. The earthquake was initiated on the connecting extensional fault and 15\u2009s later ruptured the two main segments with dominantly strike-slip motion. We show that complexities in the fault geometry at depth explain well the complex pattern of radiated seismic waves. We conclude that the location and detailed characteristics of the earthquake could not have been anticipated on the basis of observations of surface geology alone.", "date": "2011-09", "date_type": "published", "publication": "Nature Geoscience", "volume": "4", "number": "9", "publisher": "Nature Publishing Group", "pagerange": "615-618", "id_number": "CaltechAUTHORS:20111006-084146589", "issn": "1752-0894", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20111006-084146589", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Gordon and Betty Moore Foundation" }, { "agency": "NASA" }, { "agency": "Southern California Earthquake Center (SCEC)" }, { "agency": "NSF", "grant_number": "EAR-0529922" }, { "agency": "USGS", "grant_number": "07HQAG0008" } ] }, "other_numbering_system": { "items": [ { "id": "172", "name": "Caltech Tectonics Observatory" } ] }, "local_group": { "items": [ { "id": "Caltech-Tectonics-Observatory" }, { "id": "Seismological-Laboratory" }, { "id": "Keck-Institute-for-Space-Studies" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1038/ngeo1213", "primary_object": { "basename": "ngeo1213-s1.pdf", "url": "https://authors.library.caltech.edu/records/mmpk9-h3m26/files/ngeo1213-s1.pdf" }, "related_objects": [ { "basename": "Wei_etal_EMC_20101208.pdf", "url": "https://authors.library.caltech.edu/records/mmpk9-h3m26/files/Wei_etal_EMC_20101208.pdf" } ], "resource_type": "article", "pub_year": "2011", "author_list": "Wei, Shengji; Fielding, Eric; et el." }, { "id": "https://authors.library.caltech.edu/records/b482b-ta834", "eprint_id": 21200, "eprint_status": "archive", "datestamp": "2023-08-22 01:14:01", "lastmod": "2023-10-20 23:50:23", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Hayes-G-P", "name": { "family": "Hayes", "given": "G. P." } }, { "id": "Briggs-R-W", "name": { "family": "Briggs", "given": "R. W." } }, { "id": "Sladen-A", "name": { "family": "Sladen", "given": "A." }, "orcid": "0000-0003-4126-0020" }, { "id": "Fielding-E-J", "name": { "family": "Fielding", "given": "E. J." }, "orcid": "0000-0002-6648-8067" }, { "id": "Prentice-C", "name": { "family": "Prentice", "given": "C." } }, { "id": "Hudnut-K-W", "name": { "family": "Hudnut", "given": "K." }, "orcid": "0000-0002-3168-4797" }, { "id": "Mann-P", "name": { "family": "Mann", "given": "P." } }, { "id": "Taylor-F-W", "name": { "family": "Taylor", "given": "F. W." } }, { "id": "Crone-A-J", "name": { "family": "Crone", "given": "A. J." } }, { "id": "Gold-R-E", "name": { "family": "Gold", "given": "R." } }, { "id": "Ito-Takeo", "name": { "family": "Ito", "given": "T." }, "orcid": "0000-0003-1661-9943" }, { "id": "Simons-M", "name": { "family": "Simons", "given": "M." }, "orcid": "0000-0003-1412-6395" } ] }, "title": "Complex rupture during the 12 January 2010 Haiti earthquake", "ispublished": "pub", "full_text_status": "public", "keywords": "Structural geology; tectonics and geodynamics", "note": "\u00a9 2010 Macmillan Publishers Limited.\n\nReceived 24 May 2010; Accepted 09 September 2010; Published online 10 October 2010.\n\nWe thank V. Tsai, H. Benz, J. McCarthy, R. Bilham and three anonymous reviewers for their comments in improving this manuscript. The study benefited greatly from the assistance of P. Jean of Le Bureau des Mines et de l'Energie d'Haiti, and from the logistical aid of R. Boyer. We thank K. Ludwig and J. Kindinger of USGS and the captain and crew of the RV Endeavor for use and transport of the rigid-hulled inflatable boat. We thank G. Choy for the first-motion focal mechanism. We thank R. Bilham and R. Koehler for early field observations of coastal deformation. Fieldwork studies were sponsored by the US Agency for International Development, USGS and the National Science Foundation. PALSAR level 1.0 data are shared among PIXEL (PALSAR Interferometry Consortium to Study our Evolving Land Surface), and provided from the Japanese Aerospace Exploration Agency under a cooperative research contract with the Earthquake Research Institute, University of Tokyo. Early PALSAR data were provided under the Group on Earth Observation Geohazards Supersite programme and other scenes through the Alaska Satellite Facility. The ownership of PALSAR data belongs to METI (Ministry of Economy, Trade and Industry) and the Japanese Aerospace Exploration Agency. G.P.H. is contracted to work for the USGS by Synergetics Inc., Fort Collins, Colorado. A.S. and M.S. are partially supported under funds provided by the Gordon and Betty Moore Foundation through the Tectonics Observatory. This paper is Caltech Tectonic Observatory contribution 138. Part of the research described in this publication was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration. Figures have been made using the Generic Mapping Tools of Wessel and Smith23. Fieldwork partially supported by NSF-EAR RAPID grant 1024990. UTIG contribution no. 2285.\n\nSupplemental Material - ngeo977-s1.pdf
", "abstract": "Initially, the devastating M_w 7.0, 12 January 2010 Haiti earthquake seemed to involve straightforward accommodation of oblique relative motion between the Caribbean and North American plates along the Enriquillo\u2013Plantain Garden fault zone. Here, we combine seismological observations, geologic field data and space geodetic measurements to show that, instead, the rupture process involved slip on multiple faults. Primary surface deformation was driven by rupture on blind thrust faults with only minor, deep, lateral slip along or near the main Enriquillo\u2013Plantain Garden fault zone; thus the event only partially relieved centuries of accumulated left-lateral strain on a small part of the plate-boundary system. Together with the predominance of shallow off-fault thrusting, the lack of surface deformation implies that remaining shallowshear strain will be released in future surface-rupturing earthquakes on the Enriquillo\u2013Plantain Garden fault zone, as occurred in inferred Holocene and probable historic events. We suggest that the geological signature of this earthquake\u2014broad warping and coastal deformation rather than surface rupture along the main fault zone\u2014will not be easily recognized by standard palaeoseismic studies. We conclude that similarly complex earthquakes in tectonic environments that accommodate both translation and convergence\u2014such as the San Andreas fault through the Transverse Ranges of California\u2014may be missing from the prehistoric earthquake record.", "date": "2010-11", "date_type": "published", "publication": "Nature Geoscience", "volume": "3", "number": "11", "publisher": "Nature Publishing Group", "pagerange": "800-805", "id_number": "CaltechAUTHORS:20101206-152908508", "issn": "1752-0894", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20101206-152908508", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "United States Agency for International Development (USAID)" }, { "agency": "USGS" }, { "agency": "Gordon and Betty Moore Foundation" }, { "agency": "NASA/JPL/Caltech" }, { "agency": "NSF", "grant_number": "EAR-1024990" } ] }, "other_numbering_system": { "items": [ { "id": "2285", "name": "UTIG" } ] }, "local_group": { "items": [ { "id": "Caltech-Tectonics-Observatory" }, { "id": "Keck-Institute-for-Space-Studies" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1038/NGEO977", "primary_object": { "basename": "ngeo977-s1.pdf", "url": "https://authors.library.caltech.edu/records/b482b-ta834/files/ngeo977-s1.pdf" }, "resource_type": "article", "pub_year": "2010", "author_list": "Hayes, G. P.; Briggs, R. W.; et el." }, { "id": "https://authors.library.caltech.edu/records/p99pj-a7308", "eprint_id": 21274, "eprint_status": "archive", "datestamp": "2023-08-22 01:11:02", "lastmod": "2023-10-20 23:54:08", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Holzer-T-L", "name": { "family": "Holzer", "given": "Thomas L." } }, { "id": "Jayko-A-S", "name": { "family": "Jayko", "given": "Angela S." } }, { "id": "Hauksson-E", "name": { "family": "Hauksson", "given": "Egill" }, "orcid": "0000-0002-6834-5051" }, { "id": "Fletcher-J-P-B", "name": { "family": "Fletcher", "given": "Jon P. B." } }, { "id": "Noce-T-E", "name": { "family": "Noce", "given": "Thomas E." } }, { "id": "Bennett-M-J", "name": { "family": "Bennett", "given": "Michael J." } }, { "id": "Dietel-C-M", "name": { "family": "Dietel", "given": "Christopher M." } }, { "id": "Hudnut-K-W", "name": { "family": "Hudnut", "given": "Kenneth W." }, "orcid": "0000-0002-3168-4797" } ] }, "title": "Liquefaction caused by the 2009 Olancha, California (USA), M5.2 earthquake", "ispublished": "pub", "full_text_status": "restricted", "keywords": "Liquefaction; Earthquake; Simplified procedure; Paleoliquefaction", "note": "\u00a9 2010 Elsevier B.V. \n\nReceived 16 January 2010; revised 8 July 2010; accepted 14 July 2010. Available online 29 July 2010. \n\nWe thank Grace A. McCarley-Holder and Earl Wilson of the Great Basin Unified Air Pollution Control District for help with logistics and sampling; Ross W. Boulanger, Wayne R. Thatcher, and John C. Tinsley, III, for constructive reviews; Coyn C. Criley for the grain-size analyses; and Hamid Haddadi and Christopher D. Stephens for help in retrieving the permanent accelerograph records.", "abstract": "The October 3, 2009 (01:16:00 UTC), Olancha M5.2 earthquake caused extensive liquefaction as well as permanent horizontal ground deformation within a 1.2 km^2 area earthquake in Owens Valley in eastern California (USA). Such liquefaction is rarely observed during earthquakes of M \u2264 5.2. We conclude that subsurface conditions, not unusual ground motion, were the primary factors contributing to the liquefaction. The liquefaction occurred in very liquefiable sands at shallow depth (< 2 m) in an area where the water table was near the land surface. Our investigation is relevant to both geotechnical engineering and geology. The standard engineering method for assessing liquefaction potential, the Seed\u2013Idriss simplified procedure, successfully predicted the liquefaction despite the small earthquake magnitude. The field observations of liquefaction effects highlight a need for caution by earthquake geologists when inferring prehistoric earthquake magnitudes from paleoliquefaction features because small magnitude events may cause such features.", "date": "2010-10-27", "date_type": "published", "publication": "Engineering Geology", "volume": "116", "number": "1-2", "publisher": "Elsevier", "pagerange": "184-188", "id_number": "CaltechAUTHORS:20101209-121641326", "issn": "0013-7952", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20101209-121641326", "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": "10.1016/j.enggeo.2010.07.009", "resource_type": "article", "pub_year": "2010", "author_list": "Holzer, Thomas L.; Jayko, Angela S.; et el." }, { "id": "https://authors.library.caltech.edu/records/gvn2m-xhz72", "eprint_id": 21287, "eprint_status": "archive", "datestamp": "2023-08-19 01:50:19", "lastmod": "2023-10-20 23:54:48", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Hudnut-K-W", "name": { "family": "Hudnut", "given": "Kenneth W." }, "orcid": "0000-0002-3168-4797" } ] }, "title": "ShakeOut, California Style", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 2010 International Anesthesia Research Society. \n\nAccepted for publication November 30, 2009.", "abstract": "The M 7.8 ShakeOut Scenario earthquake would result in thousands of physical injuries both directly from the ground motion and the resulting damage as well as from secondary hazards [e.g., fire-following-earthquake] . . . Overall, the earthquake is expected to result in almost 50,000 injuries requiring treatment, 750 injuries requiring specialized trauma or burn care, and almost 1800 deaths.\"", "date": "2010-03", "date_type": "published", "publication": "Anesthesia and Analgesia", "volume": "110", "number": "3", "publisher": "Lippincott, Williams & Wilkins", "pagerange": "655-656", "id_number": "CaltechAUTHORS:20101209-154222003", "issn": "0003-2999", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20101209-154222003", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "collection": "CaltechAUTHORS", "doi": "10.1213/ANE.0b013e3181cd443d", "resource_type": "article", "pub_year": "2010", "author_list": "Hudnut, Kenneth W." }, { "id": "https://authors.library.caltech.edu/records/8r35d-v7x79", "eprint_id": 14480, "eprint_status": "archive", "datestamp": "2023-08-19 23:58:11", "lastmod": "2023-10-18 18:02:05", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Graves-R-W", "name": { "family": "Graves", "given": "Robert W." } }, { "id": "Aagaard-B-T", "name": { "family": "Aagaard", "given": "Brad T." } }, { "id": "Hudnut-K-W", "name": { "family": "Hudnut", "given": "Kenneth W." }, "orcid": "0000-0002-3168-4797" }, { "id": "Star-L-M", "name": { "family": "Star", "given": "Lisa M." } }, { "id": "Stewart-J-P", "name": { "family": "Stewart", "given": "Jonathan P." } }, { "id": "Jordan-T-H", "name": { "family": "Jordan", "given": "Thomas H." } } ] }, "title": "Broadband simulations for M_w 7.8 southern San Andreas earthquakes: Ground motion sensitivity to rupture speed", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 2008 by the American Geophysical Union.\n\nReceived 20 August 2008; accepted 9 October 2008; published 20 November 2008. \nWe thank members of the SCEC CME\ncollaboration for their efforts on the ShakeOut simulation project. We\nappreciate the constructive comments by Art Frankel, Paul Spudich and two\nanonymous reviewers. Funding for this work was provided by SCEC under\nNSF grants EAR-0623704 and OCI-0749313 and by the USGS. The large-scale\nsimulations were run at USC's Center for High Performance Computing\nand Communications (http://www.usc.edu/hpcc) under an agreement\nwith the SCEC CME project. This is SCEC contribution 1238.\n\nPublished - Graves2008p2909Geophys_Res_Lett.pdf
", "abstract": "Using the high-performance computing resources of the Southern California Earthquake Center, we simulate broadband (0\u201310 Hz) ground motions for three M_w 7.8 rupture scenarios of the southern San Andreas fault. The scenarios incorporate a kinematic rupture description with the average rupture speed along the large slip portions of the fault set at 0.96, 0.89, and 0.84 times the local shear wave velocity. Consistent with previous simulations, a southern hypocenter efficiently channels energy into the Los Angeles region along the string of basins south of the San Gabriel Mountains. However, we find the basin ground motion levels are quite sensitive to the prescribed rupture speed, with peak ground velocities at some sites varying by over a factor of two for variations in average rupture speed of about 15%. These results have important implications for estimating seismic hazards in Southern California and emphasize the need for improved understanding of earthquake rupture processes.", "date": "2008-11-20", "date_type": "published", "publication": "Geophysical Research Letters", "volume": "35", "number": "22", "publisher": "American Geophysical Union", "pagerange": "L22302", "id_number": "CaltechAUTHORS:20090701-151932462", "issn": "0094-8276", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20090701-151932462", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "EAR-0623704" }, { "agency": "NSF", "grant_number": "OCI-0749313" }, { "agency": "USGS" }, { "agency": "Southern California Earthquake Center (SCEC)" } ] }, "other_numbering_system": { "items": [ { "id": "1238", "name": "Southern California Earthquake Center Contribution" } ] }, "doi": "10.1029/2008GL035750", "primary_object": { "basename": "Graves2008p2909Geophys_Res_Lett.pdf", "url": "https://authors.library.caltech.edu/records/8r35d-v7x79/files/Graves2008p2909Geophys_Res_Lett.pdf" }, "resource_type": "article", "pub_year": "2008", "author_list": "Graves, Robert W.; Aagaard, Brad T.; et el." }, { "id": "https://authors.library.caltech.edu/records/f3c4e-aax34", "eprint_id": 12061, "eprint_status": "archive", "datestamp": "2023-08-22 12:35:30", "lastmod": "2023-10-17 16:30:16", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Lynch-D-K", "name": { "family": "Lynch", "given": "David K." } }, { "id": "Hudnut-K-W", "name": { "family": "Hudnut", "given": "Kenneth W." }, "orcid": "0000-0002-3168-4797" } ] }, "title": "The Wister Mud Pot Lineament: Southeastward Extension or Abandoned Strand of the San Andreas Fault?", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 2008 Seismological Society of America. \n\nManuscript received 10 October 2007. \n\nWe would like to thank the Adolfo Hernandez and Randy VonNordheim of the California Department of Fish and Game, Wister Unit of the Imperial Wildlife Refuge, for help in locating many of the mud pots. We gratefully acknowledge Hobart King, Carl L. Strand, Karen Felzer, and Nancy King for comments on early drafts of this article. Mike Rymer and Don Nicholson provided useful discussions on tectonics of the Salton Trough. We are indebted to Christian Schoneman, Jason Wilson, and Daniel Gomez of the U.S. Fish and Wildlife Service for help in surveying the vents near Mullet Island. Bob Dollar of the USGS helped with the seismisity KMZ files, and Greg Anderson and Duncan Agnew digitized the Clark fault map and put it into KML for us.\n\nPublished - LYNbssa08.pdf
", "abstract": "We present the results of a survey of mud pots in the Wister Unit of the Imperial Wildlife Area. Thirty-three mud pots, pot clusters, or related geothermal vents (hundreds of pots in all) were identified, and most were found to cluster along a northwest-trending line that is more or less coincident with the postulated Sand Hills fault. An extrapolation of the trace of the San Andreas fault southeastward from its accepted terminus north of Bombay Beach very nearly coincides with the mud pot lineament and may represent a surface manifestation of the San Andreas fault southeast of the Salton Sea. Additionally, a recent survey of vents near Mullet Island in the Salton Sea revealed eight areas along a northwest-striking line where gas was bubbling up through the water and in two cases hot mud and water were being violently ejected.", "date": "2008-08", "date_type": "published", "publication": "Bulletin of the Seismological Society of America", "volume": "98", "number": "4", "publisher": "Seismological Society of America", "pagerange": "1720-1729", "id_number": "CaltechAUTHORS:LYNbssa08", "issn": "0037-1106", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:LYNbssa08", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "doi": "10.1785/0120070252", "primary_object": { "basename": "LYNbssa08.pdf", "url": "https://authors.library.caltech.edu/records/f3c4e-aax34/files/LYNbssa08.pdf" }, "resource_type": "article", "pub_year": "2008", "author_list": "Lynch, David K. and Hudnut, Kenneth W." }, { "id": "https://authors.library.caltech.edu/records/0dye0-ek952", "eprint_id": 20861, "eprint_status": "archive", "datestamp": "2023-08-22 05:09:42", "lastmod": "2023-10-20 23:31:48", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Meltzner-A-J", "name": { "family": "Meltzner", "given": "Aron J." }, "orcid": "0000-0002-2955-0896" }, { "id": "Sieh-K-E", "name": { "family": "Sieh", "given": "Kerry" }, "orcid": "0000-0002-7311-2447" }, { "id": "Abrams-M-J", "name": { "family": "Abrams", "given": "Michael" } }, { "id": "Agnew-D-C", "name": { "family": "Agnew", "given": "Duncan C." } }, { "id": "Hudnut-K-W", "name": { "family": "Hudnut", "given": "Kenneth W." }, "orcid": "0000-0002-3168-4797" }, { "id": "Avouac-J-P", "name": { "family": "Avouac", "given": "Jean-Philippe" }, "orcid": "0000-0002-3060-8442" }, { "id": "Natawidjaja-D-H", "name": { "family": "Natawidjaja", "given": "Danny H." } } ] }, "title": "Uplift and subsidence associated with the great Aceh-Andaman earthquake of 2004", "ispublished": "pub", "full_text_status": "public", "keywords": "satellite imagery; coral reef; Sumatra", "note": "\u00a9 2006 American Geophysical Union. \n\nReceived 20 June 2005; revised 5 October 2005; accepted 22 November 2005; published 15 February 2006. \n\nWe thank Mohamed Chlieh, Chen Ji, Rich Briggs, and Rob McCaffrey for assistance and many insightful discussions. We are grateful to John Galetzka, Imam Suprihanto, and Bambang Suwargadi for data collection and invaluable field support in Indonesia and to Hidayat and Samsir of Derazona Air Services, our helicopter pilot and mechanic. We are very appreciative of Chris Goldfinger for collecting and sharing satellite imagery and of Roger Bilham for sharing data and making his manuscripts available to us, which benefited us tremendously. We thank JoAnne Giberson and Shaun Healy for ongoing GIS support. We\nalso thank Vineet Gahalaut, Roger Bilham, and an anonymous reviewer for helpful reviews that led to substantial improvements in the paper. We acknowledge the use of QuickBird imagery made freely available by DigitalGlobe, and the use of IKONOS and SPOT 5 images acquired, processed, and made freely available by CRISP, National University of Singapore. This research was supported in part by the Gordon and Betty Moore Foundation and by NASA grant NAG5-10406. This is Caltech Tectonic Observatory contribution 23.\n\nPublished - Meltzner_JGR2006.pdf
", "abstract": "Rupture of the Sunda megathrust on 26 December 2004 produced broad regions of uplift and subsidence. We define the pivot line separating these regions as a first step in defining the lateral extent and the downdip limit of rupture during that great M_w \u2248 9.2 earthquake. In the region of the Andaman and Nicobar islands we rely exclusively on the interpretation of satellite imagery and a tidal model. At the southern limit of the great rupture we rely principally on field measurements of emerged coral microatolls. Uplift extends from the middle of Simeulue Island, Sumatra, at ~2.5\u00b0N, to Preparis Island, Myanmar (Burma), at ~14.9\u00b0N. Thus the rupture is ~1600 km long. The distance from the pivot line to the trench varies appreciably. The northern and western Andaman Islands rose, whereas the southern and eastern portion of the islands subsided. The Nicobar Islands and the west coast of Aceh province, Sumatra, subsided. Tilt at the southern end of the rupture is steep; the distance from 1.5 m of uplift to the pivot line is just 60 km. Our method of using satellite imagery to recognize changes in elevation relative to sea surface height and of using a tidal model to place quantitative bounds on coseismic uplift or subsidence is a novel approach that can be adapted to other forms of remote sensing and can be applied to other subduction zones in tropical regions.", "date": "2006-02-15", "date_type": "published", "publication": "Journal of Geophysical Research B", "volume": "111", "number": "B2", "publisher": "American Geophysical Union", "pagerange": "Art. No. B02407", "id_number": "CaltechAUTHORS:20101117-114453223", "issn": "0148-0227", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20101117-114453223", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Gordon and Betty Moore Foundation" }, { "agency": "NASA", "grant_number": "NAG5-10406" } ] }, "other_numbering_system": { "items": [ { "id": "23", "name": "Caltech Tectonics Observatory" } ] }, "local_group": { "items": [ { "id": "Caltech-Tectonics-Observatory" }, { "id": "Caltech-Tectonics-Observatory.-Sumatran-Plate-Boundary" }, { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1029/2005JB003891", "primary_object": { "basename": "Meltzner_JGR2006.pdf", "url": "https://authors.library.caltech.edu/records/0dye0-ek952/files/Meltzner_JGR2006.pdf" }, "resource_type": "article", "pub_year": "2006", "author_list": "Meltzner, Aron J.; Sieh, Kerry; et el." }, { "id": "https://authors.library.caltech.edu/records/wjaz9-78r67", "eprint_id": 47962, "eprint_status": "archive", "datestamp": "2023-08-19 14:45:32", "lastmod": "2023-10-26 21:26:12", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Aagaard-B-T", "name": { "family": "Aagaard", "given": "Brad T." } }, { "id": "Anderson-G-W", "name": { "family": "Anderson", "given": "Greg" } }, { "id": "Hudnut-K-W", "name": { "family": "Hudnut", "given": "Ken W." }, "orcid": "0000-0002-3168-4797" } ] }, "title": "Dynamic Rupture Modeling of the Transition from Thrust to Strike-Slip Motion in the 2002 Denali Fault Earthquake, Alaska", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 2004 Seismological Society of America.\n\nManuscript received 3 February 2004.\n\nWe thank Jeanne Hardebeck for guidance in interpreting stress orientations\nfrom focal mechanism inversions and analyzing our preferred\nstress orientations with the focal mechanism data. We also benefited from\nhelpful discussions with Chen Ji and Douglas Dreger regarding their kinematic\nsource inversions for this earthquake and thank Peter Hauessler for\nproviding the locations of the surface rupture. We appreciated helpful reviews\nfrom Ruth Harris, David Oglesby, Paul Spudich, and an anonymous\nreviewer. The simulations were run on the Hewlett-Packard V-Class computer,\nlocated at the California Institute of Technology, with access provided\nby the Center for Advanced Computing Research. Some of the plots\nwere created using the Generic Mapping Tools (GMT) (Wessel and Smith,\n1998).\n\nPublished - S190.full.pdf
", "abstract": "We use three-dimensional dynamic (spontaneous) rupture models to investigate the nearly simultaneous ruptures of the Susitna Glacier thrust fault and the Denali strike-slip fault. With the 1957 M_w 8.3 Gobi-Altay, Mongolia, earthquake as the only other well-documented case of significant, nearly simultaneous rupture of both thrust and strike-slip faults, this feature of the 2002 Denali fault earthquake provides a unique opportunity to investigate the mechanisms responsible for development of these large, complex events. We find that the geometry of the faults and the orientation of the regional stress field caused slip on the Susitna Glacier fault to load the Denali fault. Several different stress orientations with oblique right-lateral motion on the Susitna Glacier fault replicate the triggering of rupture on the Denali fault about 10 sec after the rupture nucleates on the Susitna Glacier fault. However, generating slip directions compatible with measured surface offsets and kinematic source inversions requires perturbing the stress orientation from that determined with focal mechanisms of regional events. Adjusting the vertical component of the principal stress tensor for the regional stress field so that it is more consistent with a mixture of strike-slip and reverse faulting significantly improves the fit of the slip-rake angles to the data. Rotating the maximum horizontal compressive stress direction westward appears to improve the fit even further.", "date": "2004-12", "date_type": "published", "publication": "Bulletin of the Seismological Society of America", "volume": "94", "number": "6", "publisher": "Seismological Society of America", "pagerange": "S190-S201", "id_number": "CaltechAUTHORS:20140805-091335567", "issn": "0037-1106", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140805-091335567", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "doi": "10.1785/0120040614", "primary_object": { "basename": "S190.full.pdf", "url": "https://authors.library.caltech.edu/records/wjaz9-78r67/files/S190.full.pdf" }, "resource_type": "article", "pub_year": "2004", "author_list": "Aagaard, Brad T.; Anderson, Greg; et el." }, { "id": "https://authors.library.caltech.edu/records/rrbs4-2zt12", "eprint_id": 20960, "eprint_status": "archive", "datestamp": "2023-08-22 02:26:55", "lastmod": "2023-10-20 23:37:26", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Ji-Chen", "name": { "family": "Ji", "given": "Chen" }, "orcid": "0000-0002-0350-5704" }, { "id": "Larson-Kristine-M", "name": { "family": "Larson", "given": "Kristine M." } }, { "id": "Tan-Ying", "name": { "family": "Tan", "given": "Ying" } }, { "id": "Hudnut-K-W", "name": { "family": "Hudnut", "given": "Kenneth W." }, "orcid": "0000-0002-3168-4797" }, { "id": "Choi-Kyuhong", "name": { "family": "Choi", "given": "Kyuhong" } } ] }, "title": "Slip history of the 2003 San Simeon earthquake constrained by combining 1-Hz GPS, strong motion, and teleseismic data", "ispublished": "pub", "full_text_status": "public", "keywords": "Geodesy and Gravity: Seismic deformations; Seismology: Earthquake ground motions and engineering; Tectonophysics: Dynamics, seismotectonics", "note": "\u00a9 2004 American Geophysical Union.\n\nReceived 6 May 2004; revised 4 June 2004; accepted 20 August 2004; published 15 September 2004.\nWe thank Lupei Zhu for deconvolution\nscripts and Jeanne Hardebeck for fault plane information. Discussions with\nEgill Hauksson were very constructive. Reviews by Don Helmberger, John\nLangbein, Nancy King, and an anonymous reviewer improved the manuscript.\nSeismic data were provided by CISN and IRIS DMC. We acknowledge\nSCIGN and its funders (W. M. Keck Foundation, NASA, NSF, USGS,\nSCEC) as the source of the GPS data. We especially thank Yehuda\nBock and John Langbein for their efforts in updating the Parkfield GPS\nArray to record at 1-Hz. UCSD, SCIGN, USGS, and UCB all contributed to\nthe development of the array. Assistance with GPS data, archiving, and\nanalysis software was provided by SOPAC, UNAVCO, and JPL-Caltech.\nThis paper is supported by USGS grant #04HQGR0048, NSF grant\n#EAR-0337206, and the Gordon and Betty Moore Foundation. This is\nCaltech Seismological Laboratory contribution 9077 and Caltech Tectonic\nObservatory contribution #6.\n\nPublished - ji_GRL2004.pdf
Supplemental Material - 2004GL020448-FigureS1.tif
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Supplemental Material - 2004GL020448-FigureS5.tif
Supplemental Material - 2004GL020448-README.txt
", "abstract": "The slip history of the 2003 San Simeon earthquake is constrained by combining strong motion and teleseismic data, along with GPS static offsets and 1-Hz GPS observations. Comparisons of a 1-Hz GPS time series and a co-located strong motion data are in very good agreement, demonstrating a new application of GPS. The inversion results for this event indicate that the rupture initiated at a depth of 8.5 km and propagated southeastwards with a speed ~3.0 km/sec, with rake vectors forming a fan structure around the hypocenter. We obtained a peak slip of 2.8 m and total seismic moment of 6.2 \u00d7 10^(18) Nm. We interpret the slip distribution as indicating that the hanging wall rotates relative to the footwall around the hypocenter, in a sense that appears consistent with the shape of the mapped fault trace.", "date": "2004-09-15", "date_type": "published", "publication": "Geophysical Research Letters", "volume": "31", "number": "17", "publisher": "American Geophysical Union", "pagerange": "Art. No. L17608", "id_number": "CaltechAUTHORS:20101122-154926765", "issn": "0094-8276", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20101122-154926765", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "USGS" }, { "agency": "NSF", "grant_number": "EAR-0337206" }, { "agency": "Gordon and Betty Moore Foundation" } ] }, "other_numbering_system": { "items": [ { "id": "9077", "name": "Caltech Seismological Laboratory" } ] }, "local_group": { "items": [ { "id": "Caltech-Tectonics-Observatory" }, { "id": "Seismological-Laboratory" } ] }, "doi": "10.1029/2004GL020448", "primary_object": { "basename": "2004GL020448-README.txt", "url": "https://authors.library.caltech.edu/records/rrbs4-2zt12/files/2004GL020448-README.txt" }, "related_objects": [ { "basename": "ji_GRL2004.pdf", "url": "https://authors.library.caltech.edu/records/rrbs4-2zt12/files/ji_GRL2004.pdf" }, { "basename": "2004GL020448-FigureS1.tif", "url": "https://authors.library.caltech.edu/records/rrbs4-2zt12/files/2004GL020448-FigureS1.tif" }, { "basename": "2004GL020448-FigureS2.tif", "url": "https://authors.library.caltech.edu/records/rrbs4-2zt12/files/2004GL020448-FigureS2.tif" }, { "basename": "2004GL020448-FigureS3.tif", "url": "https://authors.library.caltech.edu/records/rrbs4-2zt12/files/2004GL020448-FigureS3.tif" }, { "basename": "2004GL020448-FigureS4.tif", "url": "https://authors.library.caltech.edu/records/rrbs4-2zt12/files/2004GL020448-FigureS4.tif" }, { "basename": "2004GL020448-FigureS5.tif", "url": "https://authors.library.caltech.edu/records/rrbs4-2zt12/files/2004GL020448-FigureS5.tif" } ], "resource_type": "article", "pub_year": "2004", "author_list": "Ji, Chen; Larson, Kristine M.; et el." }, { "id": "https://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.edu/records/kyzna-xxj73", "eprint_id": 47844, "eprint_status": "archive", "datestamp": "2023-08-19 09:24:37", "lastmod": "2023-10-26 21:18:05", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Hudnut-K-W", "name": { "family": "Hudnut", "given": "K. W." }, "orcid": "0000-0002-3168-4797" }, { "id": "King-N-E", "name": { "family": "King", "given": "N. E." } }, { "id": "Galetzka-J-E", "name": { "family": "Galetzka", "given": "J. E." } }, { "id": "Stark-K-F", "name": { "family": "Stark", "given": "K. F." } }, { "id": "Behr-J-A", "name": { "family": "Behr", "given": "J. A." } }, { "id": "Aspiotes-A", "name": { "family": "Aspiotes", "given": "A." } }, { "id": "van-Wyk-S", "name": { "family": "van Wyk", "given": "S." } }, { "id": "Moffitt-R", "name": { "family": "Moffitt", "given": "R." } }, { "id": "Dockter-S", "name": { "family": "Dockter", "given": "S." } }, { "id": "Wyatt-F", "name": { "family": "Wyatt", "given": "F." } } ] }, "title": "Continuous GPS Observations of Postseismic Deformation Following the 16 October 1999 Hector Mine, California, Earthquake (M_w 7.1)", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 2002 Seismological Society of America. Manuscript received 22 October 2000. Without the permission and support of the U.S. Marine Corps Air Ground Combat Center (MCAGCC) in Twentynine Palms, California, we would not have been able to conduct this study. In particular, we thank Lt.\nCol. James J. Tabak for his support. We also thank Captain Teitzel, Mr. Paul \"Kip\" Otis-Deihl, the Explosive Ordinance Disposal Section, the Range Operations Section, Range Control, and the command and personnel of MCAGCC for their tremendous assistance and cooperation in facilitating\nfield investigations. We thank W. Karl Gross of the U.S. Geological Survey for exemplary service as scientific operations liaison with MCAGCC, providing tremendous help and insight with all logistical matters in the field,\nand for arranging aircraft support. We thank CWO4 T. Murphy, 1st Lt. J. Ochwatt, and SPC4 B. V. Cabanban Jr. of the Los Alamitos Army Aviation Support Facility, California Army National Guard, and Landells' Aviation for providing aircraft support. We also thank Duncan Agnew, Don Elliot,\nand Greg Anderson of Scripps Institution of Oceanography for field logistics and support, Ed Arnitz, Fred Nissen, Chris Mora, John Taylor, and Ryan Densmore of Gradient Engineers, as well as Mike Capriano of GPS Drilling, for their fieldwork. We thank Sue Hough, Mike Bevis, and Mike\nRymer for their helpful reviews. We acknowledge the Southern California Integrated GPS Network (SCIGN) and its sponsors, the W. M. Keck Foundation, NASA, NSF, and USGS, for providing funding and support. Southern California Earthquake Center Publication Number 634.\n\nPublished - 1403.full.pdf
", "abstract": "Rapid field deployment of a new type of continuously operating Global Positioning System (GPS) network and data from Southern California Integrated GPS Network (SCIGN) stations that had recently begun operating in the area allow unique observations of the postseismic deformation associated with the 1999 Hector Mine earthquake. Innovative solutions in fieldcraft, devised for the 11 new GPS stations, provide high-quality observations with 1-year time histories on stable monuments at remote sites. We report on our results from processing the postseismic GPS data available from these sites, as well as 8 other SCIGN stations within 80 km of the event (a total of 19 sites). From these data, we analyze the temporal character and spatial pattern of the postseismic transients. Data from some sites display statistically significant time variation in their velocities. Although this is less certain, the spatial pattern of change in the postseismic velocity field also appears to have changed. The pattern now is similar to the pre-Landers (pre-1992) secular field, but laterally shifted and locally at twice the rate. We speculate that a 30 km \u00d7 50 km portion of crust (near Twentynine Palms), which was moving at nearly the North American plate rate (to within 3.5 mm/yr of that rate) prior to the 1992 Landers sequence, now is moving along with the crust to the west of it, as though it has been entrained in flow along with the Pacific Plate as a result of the Landers and Hector Mine earthquake sequence. The inboard axis of right-lateral shear deformation (at lower crustal to upper mantle depth) may have jumped 30 km farther into the continental crust at this fault junction that comprises the southern end of the eastern California shear zone.", "date": "2002-05", "date_type": "published", "publication": "Bulletin of the Seismological Society of America", "volume": "92", "number": "4", "publisher": "Seismological Society of America", "pagerange": "1403-1422", "id_number": "CaltechAUTHORS:20140801-153058779", "issn": "0037-1106", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140801-153058779", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "W. M. Keck Foundation" }, { "agency": "NASA" }, { "agency": "NSF" }, { "agency": "USGS" } ] }, "other_numbering_system": { "items": [ { "id": "634", "name": "Southern California Earthquake Center (SCEC)" } ] }, "doi": "10.1785/0120000912", "primary_object": { "basename": "1403.full.pdf", "url": "https://authors.library.caltech.edu/records/kyzna-xxj73/files/1403.full.pdf" }, "resource_type": "article", "pub_year": "2002", "author_list": "Hudnut, K. W.; King, N. E.; et el." }, { "id": "https://authors.library.caltech.edu/records/1yx32-7jx66", "eprint_id": 47864, "eprint_status": "archive", "datestamp": "2023-08-19 09:24:42", "lastmod": "2023-10-26 21:18:47", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Hudnut-K-W", "name": { "family": "Hudnut", "given": "K. W." }, "orcid": "0000-0002-3168-4797" }, { "id": "Borsa-A", "name": { "family": "Borsa", "given": "A." } }, { "id": "Glennie-C-L", "name": { "family": "Glennie", "given": "C." } }, { "id": "Minster-J-B", "name": { "family": "Minster", "given": "J.-B." } } ] }, "title": "High-Resolution Topography along Surface Rupture of the 16 October 1999 Hector Mine, California, Earthquake (M_w 7.1) from Airborne Laser Swath Mapping", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 2002 Seismological Society of America. Manuscript received 5 March 2002. Without the permission and support of the U.S. Marine Corps Air Ground Combat Center in Twentynine Palms, California, we would not have been able to conduct this study. In particular, we thank Lt. Col. James J. Tabak for his support. Also, W. Karl Gross of the USGS, as liaison with the Marine Corps, provided invaluable assistance with field and aircraft logistics. Bill Krabill provided advice on methods and calibration experiments\nand has since collected additional data along these flight lines for use in future comparative analyses. We also appreciate the support of Analytical Photogrammetric Services for providing the digital photogrammetric map of the Rheox Hector Mine area, along with the raw data for the\ngridded elevation data that we used in evaluating the accuracy of this method. Rheox, Inc., allowed us access to their mine to conduct control surveys and carry out other GPS surveys for our calibrations. The SCIGN and its sponsors, the W. M. Keck Foundation, National Aeronautics and Space Administration, National Science Foundation (NSF), and USGS, provided support in the collection of high-sampling-rate GPS data from the nearby SCIGN stations. For these SCIGN data that we used in aircraft positioning, we especially thank John Galetzka, Aris Aspiotes, Keith Stark, and Shannon van Wyk, all at the USGS\u2013SCIGN group in Pasadena. We are also grateful to Jim Dow and others from Aerotec, LLC, for ensuring the success of this project. Reviews by Katherine Kendrick, Greg Anderson, Mark Simons, and Michael Rymer improved this manuscript. This research was funded by the USGS, the Institute of Geophysics and\nPlanetary Physics of the University of California, and the Southern California Earthquake Center (SCEC). SCEC is funded by NSF Cooperative Agreement EAR-8920136 and USGS Cooperative Agreements 14-08-0001-A0899 and 1434-HQ-97AG01718. The SCEC contribution number for this article is 637.\n\nPublished - 1570.full.pdf
", "abstract": "In order to document surface rupture associated with the Hector Mine earthquake, in particular, the area of maximum slip and the deformed surface of Lavic Lake playa, we acquired high-resolution data using relatively new topographic-mapping methods. We performed a raster-laser scan of the main surface breaks along the entire rupture zone, as well as along an unruptured portion of the Bullion fault. The image of the ground surface produced by this method is highly detailed, comparable to that obtained when geologists make particularly detailed site maps for geomorphic or paleoseismic studies. In this case, however, for the first time after a surface-rupturing earthquake, the detailed mapping is along the entire fault zone rather than being confined to selected sites. These data are geodetically referenced, using the Global Positioning System, thus enabling more accurate mapping of the rupture traces. In addition, digital photographs taken along the same flight lines can be overlaid onto the precise topographic data, improving terrain visualization. We demonstrate the potential of these techniques for measuring fault-slip vectors.", "date": "2002-05", "date_type": "published", "publication": "Bulletin of the Seismological Society of America", "volume": "92", "number": "4", "publisher": "Seismological Society of America", "pagerange": "1570-1576", "id_number": "CaltechAUTHORS:20140804-073023391", "issn": "0037-1106", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140804-073023391", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "University of California Institute of Geophysics and Planetary Physics" }, { "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": "637", "name": "Southern California Earthquake Center (SCEC)" } ] }, "doi": "10.1785/0120000934", "primary_object": { "basename": "1570.full.pdf", "url": "https://authors.library.caltech.edu/records/1yx32-7jx66/files/1570.full.pdf" }, "resource_type": "article", "pub_year": "2002", "author_list": "Hudnut, K. W.; Borsa, A.; et el." }, { "id": "https://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.edu/records/4dyyx-28n61", "eprint_id": 36863, "eprint_status": "archive", "datestamp": "2023-08-19 04:51:35", "lastmod": "2023-10-23 15:52:12", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Deng-Jishu", "name": { "family": "Deng", "given": "Jishu" } }, { "id": "Hudnut-K-W", "name": { "family": "Hudnut", "given": "Kenneth" }, "orcid": "0000-0002-3168-4797" }, { "id": "Gurnis-M", "name": { "family": "Gurnis", "given": "Michael" }, "orcid": "0000-0003-1704-597X" }, { "id": "Hauksson-E", "name": { "family": "Hauksson", "given": "Egill" }, "orcid": "0000-0002-6834-5051" } ] }, "title": "Stress loading from viscous flow in the lower crust and triggering of aftershocks following the 1994 Northridge California, earthquake", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 1999 by the American Geophysical Union. \n\nReceived April 14, 1999; revised June 14, 1999; accepted June 17, 1999. \n\nThis research was supported by the Southern California Earthquake Center. SCEC contribution 465. This also represents contribution number 8622 of the Division of Geological and Planetary Sciences, California Institute of Technology.\n\nPublished - 1999_Deng_etal_GRL.pdf
", "abstract": "Following the M_w 6.7 Northridge earthquake, significant postseismic displacements were resolved with GPS. Using a three-dimensional viscoelastic model, we suggest that this deformation is mainly driven by viscous flow in the lower crust. Such flow can transfer stress to the upper crust and load the rupture zone of the main shock at a decaying rate. Most aftershocks within the rupture zone, especially those that occurred after the first several weeks of the main shock, may have been triggered by continuous stress loading from viscous flow. The long-term decay time of aftershocks (about 2 years) approximately matches the decay of viscoelastic loading, and thus is controlled by the viscosity of the lower crust. Our model provides a physical interpretation of the observed correlation between aftershock decay rate and surface heat flow.", "date": "1999-11-01", "date_type": "published", "publication": "Geophysical Research Letters", "volume": "26", "number": "21", "publisher": "American Geophysical Union", "pagerange": "3209-3212", "id_number": "CaltechAUTHORS:20130212-082104331", "issn": "0094-8276", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130212-082104331", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Southern California Earthquake Center (SCEC)" } ] }, "other_numbering_system": { "items": [ { "id": "8622", "name": "Caltech Division of Geological and Planetary Sciences" } ] }, "local_group": { "items": [ { "id": "Seismological-Laboratory" }, { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "doi": "10.1029/1999GL010496", "primary_object": { "basename": "1999_Deng_etal_GRL.pdf", "url": "https://authors.library.caltech.edu/records/4dyyx-28n61/files/1999_Deng_etal_GRL.pdf" }, "resource_type": "article", "pub_year": "1999", "author_list": "Deng, Jishu; Hudnut, Kenneth; et el." }, { "id": "https://authors.library.caltech.edu/records/6z5hb-kpg67", "eprint_id": 44955, "eprint_status": "archive", "datestamp": "2023-08-19 00:15:30", "lastmod": "2023-10-26 17:27:03", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Peltzer-G", "name": { "family": "Peltzer", "given": "Gilles" } }, { "id": "Rosen-P-A", "name": { "family": "Rosen", "given": "Paul" } }, { "id": "Rogez-F", "name": { "family": "Rogez", "given": "Francois" } }, { "id": "Hudnut-K-W", "name": { "family": "Hudnut", "given": "Ken" }, "orcid": "0000-0002-3168-4797" } ] }, "title": "Postseismic Rebound in Fault Step-Overs Caused by Pore Fluid Flow", "ispublished": "pub", "full_text_status": "restricted", "note": "\u00a9 1996 American Association for the Advancement of Science. 4 June 1996; accepted 17 July 1996. We thank E. Ivins and P. Segall for discussions on postseismic deformation processes, A. Sylvester for sharing unpublished results of leveling across the Homestead Valley fault, and two anonymous reviewers\nfor constructive suggestions. The ERS-1 radar data were provided by the European Space Agency. The research described in this paper was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under contract with NASA, and at the U.S. Geological Survey.", "abstract": "Near-field strain induced by large crustal earthquakes results in changes in pore fluid pressure that dissipate with time and produce surface deformation. Synthetic aperture radar (SAR) interferometry revealed several centimeters of postseismic uplift in pull-apart structures and subsidence in a compressive jog along the Landers, California, 1992 earthquake surface rupture, with a relaxation time of 270 \u00b1 45 days. Such a postseismic rebound may be explained by the transition of the Poisson's ratio of the deformed volumes of rock from undrained to drained conditions as pore fluid flow allows pore pressure to return to hydrostatic equilibrium.", "date": "1996-08-30", "date_type": "published", "publication": "Science", "volume": "273", "number": "5279", "publisher": "American Association for the Advancement of Science", "pagerange": "1202-1204", "id_number": "CaltechAUTHORS:20140415-112853279", "issn": "0036-8075", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140415-112853279", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NASA/JPL/Caltech" }, { "agency": "USGS" } ] }, "collection": "CaltechAUTHORS", "doi": "10.1126/science.273.5279.1202", "resource_type": "article", "pub_year": "1996", "author_list": "Peltzer, Gilles; Rosen, Paul; et el." }, { "id": "https://authors.library.caltech.edu/records/43w2e-vwv80", "eprint_id": 48016, "eprint_status": "archive", "datestamp": "2023-08-20 07:13:24", "lastmod": "2023-10-26 21:28:32", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Hudnut-K-W", "name": { "family": "Hudnut", "given": "K. W." }, "orcid": "0000-0002-3168-4797" }, { "id": "Shen-Z", "name": { "family": "Shen", "given": "Z." } }, { "id": "Murray-M", "name": { "family": "Murray", "given": "M." } }, { "id": "McClusky-S", "name": { "family": "McClusky", "given": "S." } }, { "id": "King-R", "name": { "family": "King", "given": "R." } }, { "id": "Herring-T", "name": { "family": "Herring", "given": "T." } }, { "id": "Hager-B-H", "name": { "family": "Hager", "given": "B. H." }, "orcid": "0000-0002-5643-1374" }, { "id": "Feng-Y", "name": { "family": "Feng", "given": "Y." } }, { "id": "Fang-P", "name": { "family": "Fang", "given": "P." } }, { "id": "Donnellan-A", "name": { "family": "Donnellan", "given": "A." } }, { "id": "Bock-Y", "name": { "family": "Bock", "given": "Y." } } ] }, "title": "Co-Seismic Displacements of the 1994 Northridge, California, Earthquake", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 1996 Seismological Society of America.\n\nManuscript received 17 January 1995.\n\nThe GPS data used in this study were, in large part, collected through the cooperative efforts of several agencies and institutions. The National Geodetic\nSurvey, Caltrans District 7 and Headquarters, Los Angeles County, and City of Los Angeles were the main surveying agencies that provided us with crucial assistance in GPS surveys conducted both prior to and following the Northridge earthquake. Without the work of these surveying\nagencies, only a portion of the results obtained in this study would have been possible. Of particular importance were the help of D. D'Onofrio, L. Fenske, R. Packard, R. Reader, and J. Satalich. The leveling results we discuss resulted from work by these agencies, in part supported by a FEMA mission assignment to the USGS under the direction of R. Stein. Also, the various field, logistical, and other efforts of many of our colleagues after the earthquake were greatly appreciated. We thank the following in particular:\nD. Agnew, J. Behr, E. Calais, K. Clark, M. Cline, G. Franklin, X. Ge, W. K. Gross, G. Hamilton, K. Hurst, D. Jackson, H. Johnson, S. Larsen, G. Lyzenga, D. Potter, M. Smith, J. Sutton, K. Stark, C. Stiffler, F. Webb,\nJ. Zhang, and J. Zumberge. Much of the software used in producing, modeling, and displaying our results is freely available, and we particularly thank the developers of DISL, FONDA, GINV, GAMIT, GIPSY, GLOBK, and GMT who happen not to be co-authors of the present article: G. Blewitt, D.\nDong, K. Feigl, K. Hurst, D. Jefferson, S. Larsen, W. Smith, F. Webb, P. Wessel, and J. Zumberge among many others. Though our published results were obtained using the GAMIT/GLOBK software, earlier analyses using\nFONDA and GIPSY/OASIS-II contributed significantly to the results. M. Murakami kindly provided a preprint of his article on the SAR interferometry results. We thank reviewers R. Stein, J. Mori, T. Heaton, and an anonymous\nreviewer for their suggestions. The National Earthquake Hazard Reduction Program (NEHRP) supported much of this work, both through the direct support of the USGS, NSF, and FEMA and indirectly through SCEC contracts with M/T, UCLA, and UCSD; portions of the research described in this work\nwere carded out at the Jet Propulsion Laboratory, California Institute of Technology, under contract with NASA; research at UCSD is funded by Grants NASA NAG 5-1917, USGS 1434-92-G2196, NSF EAR 92 08447, and NSF EAR-9416338, as well as through SCEC. SCEC Contribution Number\n153.\n\nPublished - S19.full.pdf
", "abstract": "The 17 January 1994 Northridge, California, earthquake significantly deformed the Earth's crust in the epicentral region. Displacements of 66 survey stations determined from Global Positioning System (GPS) observations collected before and after the earthquake show that individual stations were uplifted by up to 417 \u00b1 5 mm and displaced horizontally by up to 216 \u00b1 3 mm. Using these displacements, we estimate parameters of a uniform-slip model. Fault geometry and slip are estimated independent of seismological information, using Monte Carlo optimization techniques that minimize the model residuals. The plane that best fits the geodetic data lies 1 to 2 km above the plane indicated by aftershock seismicity. Modeling for distributed slip on a coplanar, yet larger model fault indicates that a high-slip patch occurred up-dip and northwest of the mainshock hypocenter and that less than 1 m of slip occurred in the uppermost 5 km of the crust. This finding is consistent with the lack of clear surface rupture and with the notion that the intersection with the fault that ruptured in 1971 formed the up-dip terminus of slip in the Northridge earthquake. Displacements predicted by either of these simple models explain most of the variance in the data within 50 km of the epicenter. On average, however, the scatter of the residuals is twice the data uncertainties, and in some areas, there is significant systematic misfit to either model. The co-seismic contributions of aftershocks are insufficient to explain this mismatch, indicating that the source geometry is more complicated than a single rectangular plane.", "date": "1996-02", "date_type": "published", "publication": "Bulletin of the Seismological Society of America", "volume": "86", "number": "1B", "publisher": "Seismological Society of America", "pagerange": "S19-S36", "id_number": "CaltechAUTHORS:20140805-154226754", "issn": "0037-1106", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140805-154226754", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "National Earthquake Hazard Reduction Program (NEHRP)" }, { "agency": "USGS" }, { "agency": "FEMA" }, { "agency": "NASA", "grant_number": "NAG 5-1917" }, { "agency": "USGS", "grant_number": "1434-92-G2196" }, { "agency": "NSF", "grant_number": "92 08447" }, { "agency": "NSF", "grant_number": "EAR-9416338" }, { "agency": "Southern California Earthquake Center (SCEC)" } ] }, "other_numbering_system": { "items": [ { "id": "153", "name": "Southern California Earthquake Center (SCEC)" } ] }, "primary_object": { "basename": "S19.full.pdf", "url": "https://authors.library.caltech.edu/records/43w2e-vwv80/files/S19.full.pdf" }, "resource_type": "article", "pub_year": "1996", "author_list": "Hudnut, K. W.; Shen, Z.; et el." }, { "id": "https://authors.library.caltech.edu/records/hxpag-mb516", "eprint_id": 37296, "eprint_status": "archive", "datestamp": "2023-08-22 10:50:40", "lastmod": "2023-10-23 17:20:31", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Wald-D-J", "name": { "family": "Wald", "given": "David J." } }, { "id": "Heaton-T-H", "name": { "family": "Heaton", "given": "Thomas H." }, "orcid": "0000-0003-3363-2197" }, { "id": "Hudnut-K-W", "name": { "family": "Hudnut", "given": "K. W." }, "orcid": "0000-0002-3168-4797" } ] }, "title": "The slip history of the 1994 Northridge, California, earthquake determined from strong-motion, teleseismic, GPS, and leveling data", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 1996 Seismological Society of America. \n\nManuscript received 20 January 1995. G. Hawkins of Southern California Edison, M. Trifunac of the University of Southern California, J. Steidl of the University of California at Santa Barbara, and R. Tognazinni, C. Davis, and P. Lahr of the Los Angeles Department of Power and Water generously provided in formation and data from their strong-motion stations. R. Stein of the USGS graciously allowed use of the postearthquake leveling data collected under his direction, with funding support from FEMA. J. Satalich of Caltrans provided all of the preliminary leveling data we required for this analysis. Figure 3 was provided by N. Blaise and Kevin Miller of FEMA. Discussions with D. Dreger, R. Graves, N. Smith, and H. Thio were helpful. Reviews by P. Spudich and D. Jackson improved the original manuscript.\n\nPublished - Wald_pS49.pdf
", "abstract": "We present a rupture model of the Northridge earthquake, determined from the joint inversion of near-source strong ground motion recordings, P and SH teleseismic body waves, Global Positioning System (GPS) displacement vectors, and permanent uplift measured along leveling lines. The fault is defined to strike 122\u00b0 and dip 40\u00b0 to the south-southwest. The average rake vector is determined to be 101\u00b0, and average slip is 1.3 m; the peak slip reaches about 3 m. Our estimate of the seismic moment is 1.3 \u00b1 0.2 \u00d7 10^(26) dyne-cm (potency of 0.4 km3). The rupture area is small relative to the overall aftershock dimensions and is approximately 15 km along strike, nearly 20 km in the dip direction, and there is no indication of slip shallower than about 5 to 6 km. The up-dip, strong-motion velocity waveforms are dominated by large S-wave pulses attributed to source directivity and are comprised of at least 2 to 3 distinct arrivals (a few seconds apart). Stations at southern azimuths indicate two main S-wave arrivals separated longer in time (about 4 to 5 sec). These observations are best modeled with a complex distribution of subevents: The initial S-wave arrival comes from an asperity that begins at the hypocenter and extends up-dip and to the north where a second, larger subevent is centered (about 12 km away). The secondary S arrivals at southern azimuths are best fit with additional energy radiation from another high slip region at a depth of 19 km, 8 km west of the hypocenter. The resolving power of the individual data sets is examined by predicting the geodetic (GPS and leveling) displacements with the dislocation model determined from the waveform data, and vice versa, and also by analyzing how well the teleseismic solution predicts the recorded strong motions. The general features of the geodetic displacements are not well predicted from the model determined independently from the strong-motion data; likewise, the slip model determined from geodetic data does not adequately reproduce the strong-motion characteristics. Whereas a particularly smooth slip pattern is sufficient to satisfy the geodetic data, the strong-motion and teleseismic data require a more heterogeneous slip distribution in order to reproduce the velocity amplitudes and frequency content. Although the teleseismic model can adequately reproduce the overall amplitude and frequency content of the strong-motion velocity recordings, it does a poor job of predicting the geodetic data. Consequently, a robust representation of the slip history and heterogeneity requires a combined analysis of these data sets.", "date": "1996-02", "date_type": "published", "publication": "Bulletin of the Seismological Society of America", "volume": "86", "number": "1B", "publisher": "Seismological Society of America", "pagerange": "S49-S70", "id_number": "CaltechAUTHORS:20130305-093406967", "issn": "0037-1106", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130305-093406967", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Federal Emergency Management Agency (FEMA)" } ] }, "local_group": { "items": [ { "id": "Division-of-Geological-and-Planetary-Sciences" } ] }, "primary_object": { "basename": "Wald_pS49.pdf", "url": "https://authors.library.caltech.edu/records/hxpag-mb516/files/Wald_pS49.pdf" }, "resource_type": "article", "pub_year": "1996", "author_list": "Wald, David J.; Heaton, Thomas H.; et el." }, { "id": "https://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.edu/records/yt1w5-0y450", "eprint_id": 48056, "eprint_status": "archive", "datestamp": "2023-08-20 04:18:42", "lastmod": "2023-10-17 15:25:05", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Hudnut-K-W", "name": { "family": "Hudnut", "given": "K. W." }, "orcid": "0000-0002-3168-4797" }, { "id": "Bock-Y", "name": { "family": "Bock", "given": "Y." } }, { "id": "Cline-M", "name": { "family": "Cline", "given": "M." } }, { "id": "Fang-P", "name": { "family": "Fang", "given": "P." } }, { "id": "Freymueller-J", "name": { "family": "Freymueller", "given": "J." } }, { "id": "Ge-X", "name": { "family": "Ge", "given": "X." } }, { "id": "Gross-W-K", "name": { "family": "Gross", "given": "W. K." } }, { "id": "Jackson-D", "name": { "family": "Jackson", "given": "D." } }, { "id": "Kim-M", "name": { "family": "Kim", "given": "M." } }, { "id": "King-N-E", "name": { "family": "King", "given": "N. E." } }, { "id": "Langbein-J", "name": { "family": "Langbein", "given": "J." } }, { "id": "Larsen-S-C", "name": { "family": "Larsen", "given": "S. C." } }, { "id": "Lisowski-M", "name": { "family": "Lisowski", "given": "M." } }, { "id": "Shen-Z-K", "name": { "family": "Shen", "given": "Z.-K." } }, { "id": "Svarc-J", "name": { "family": "Svarc", "given": "J." } }, { "id": "Zhang-J", "name": { "family": "Zhang", "given": "J." } } ] }, "title": "Co-Seismic Displacements of the 1992 Landers Earthquake Sequence", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 1994, by the Seismological Society of America. Manuscript received 29 July 1993. This study benefited from the field efforts of many people, including SCEC staff and UCLA and UCSD students, the staff of the USGS, engineers from the University Navstar Consortium (UNAVCO), and surveyors from state and county agencies. Bill Young of Riverside Co. Flood Control District and Jerry Stayner (County Surveyor, Riverside Co.), and also Larry Cotton (County Surveyor, San Bernardino Co.), gave much support in conducting the pre- and post-Landers field GPS surveys, and providing us with GPS data they collected prior to the Landers sequence for their own projects. Many GPS stations were provided by the Caltrans and NGS's HPGN project; these agencies also conducted extensive postearthquake field work and provided their data to the SCEC archive for use in this study. We would like to thank Larry Fenske, Bob Nelson, and John Fundus at Caltrans for access to the HPGN data. Some of the GPS stations used here were established in the STRC surveys led by Rob Reilinger at MIT. Reviews by D. Eberhart-Phillips, M. Murray, and J. Sauber helped to improve this\nmanuscript. We especially thank M. Murray and D. Agnew for their efforts and their helpful and thorough commentaries. Funding for this work was from the USGS and NSF through the internal and external NEHRP programs and the SCEC. In part, this work was performed under the auspices of the Department of Energy by the Lawrence Livermore\nNational Laboratory under contract W-7405-ENG-48. The work\nat Scripps is supported by NASA (NAGW-2641 and NAG 5-1917), NSF (EAR 92 08447), the Southern California Earthquake Center USGS cooperative agreement (14-08-00001-A0899), the USGS (1434-92-G2196), and Caltrans (53N195). SCEC Contribution Number 94.\n\nPublished - 625.full.pdf
", "abstract": "We present co-seismic displacement vectors derived from Global Positioning System (GPS) measurements of 92 stations in southern California. These GPS results are combined with five well-determined GPS displacement vectors from continuously tracking stations of the Permanent GPS Geodetic Array, as well as line-length changes from USGS Geodolite and two-color laser trilateration observations, to determine a self-consistent set of geodetic data for the earthquake. These combined displacements are modeled by an elastic dislocation representation of the primary fault rupture planes. On average, the model residuals are about twice the estimated measurement errors.", "date": "1994-06", "date_type": "published", "publication": "Bulletin of the Seismological Society of America", "volume": "84", "number": "3", "publisher": "Seismological Society of America", "pagerange": "625-645", "id_number": "CaltechAUTHORS:20140806-092949944", "issn": "0037-1106", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140806-092949944", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "USGS" }, { "agency": "NSF NEHRP programs" }, { "agency": "Southern California Earthquake Center (SCEC)" }, { "agency": "Department of Energy (DOE)", "grant_number": "W-7405-ENG-48" }, { "agency": "NASA", "grant_number": "NAGW-2641" }, { "agency": "NASA", "grant_number": "NAG 5-1917" }, { "agency": "NSF", "grant_number": "EAR 92 08447" }, { "agency": "Southern California Earthquake Center" }, { "agency": "USGS", "grant_number": "14-08-00001-A0899" }, { "agency": "USGS", "grant_number": "1434-92-G2196" }, { "agency": "Caltrans", "grant_number": "53N195" } ] }, "other_numbering_system": { "items": [ { "id": "94", "name": "Southern California Earthquake Center (SCEC)" } ] }, "primary_object": { "basename": "625.full.pdf", "url": "https://authors.library.caltech.edu/records/yt1w5-0y450/files/625.full.pdf" }, "resource_type": "article", "pub_year": "1994", "author_list": "Hudnut, K. W.; Bock, Y.; et el." }, { "id": "https://authors.library.caltech.edu/records/7nzg6-qgm37", "eprint_id": 48057, "eprint_status": "archive", "datestamp": "2023-08-20 04:18:46", "lastmod": "2023-10-17 15:49:25", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Johnson-H-O", "name": { "family": "Johnson", "given": "Hadley O." } }, { "id": "Agnew-D-C", "name": { "family": "Agnew", "given": "Duncan Carr" } }, { "id": "Hudnut-K-W", "name": { "family": "Hudnut", "given": "Ken" }, "orcid": "0000-0002-3168-4797" } ] }, "title": "Extremal Bounds on Earthquake Movement from Geodetic Data: Application to the Landers Earthquake", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 1994, by the Seismological Society of America. Manuscript received 29 July 1993. The authors would like to thank P. Stark and R. Parker for sharing their computer code to simulate linear programming with one-norm misfits using BVLS. This work was supported by the Southern California\nEarthquake Center and the National Science Foundation.\n\nPublished - 660.full.pdf
", "abstract": "We present a technique to place quantifiable bounds on the moment of an earthquake from geodetic data, assuming known fault geometry. Application of this technique to the 1992 Landers earthquake shows that the moment must have been between 0.84 and 1.15 \u00d7 10^(20) Nm with 90% confidence (M 7.25 to 7.34). We also find that to satisfy the data to this same level of confidence, the slip on the fault must have exceeded 7 m in at least one location, in good agreement with field mapping of the surface rupture.", "date": "1994-06", "date_type": "published", "publication": "Bulletin of the Seismological Society of America", "volume": "84", "number": "3", "publisher": "Seismological Society of America", "pagerange": "660-667", "id_number": "CaltechAUTHORS:20140806-094944484", "issn": "0037-1106", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140806-094944484", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Southern California Earthquake Center (SCEC)" }, { "agency": "NSF" } ] }, "primary_object": { "basename": "660.full.pdf", "url": "https://authors.library.caltech.edu/records/7nzg6-qgm37/files/660.full.pdf" }, "resource_type": "article", "pub_year": "1994", "author_list": "Johnson, Hadley O.; Agnew, Duncan Carr; et el." }, { "id": "https://authors.library.caltech.edu/records/gk9kv-3h610", "eprint_id": 48061, "eprint_status": "archive", "datestamp": "2023-08-20 04:18:55", "lastmod": "2023-10-17 15:49:35", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Bodin-P", "name": { "family": "Bodin", "given": "Paul" } }, { "id": "Bilham-R", "name": { "family": "Bilham", "given": "Roger" } }, { "id": "Behr-J", "name": { "family": "Behr", "given": "Jeff" } }, { "id": "Gomberg-J-S", "name": { "family": "Gomberg", "given": "Joan" } }, { "id": "Hudnut-K-W", "name": { "family": "Hudnut", "given": "Kenneth W." }, "orcid": "0000-0002-3168-4797" } ] }, "title": "Slip Triggered on Southern California Faults by the 1992 Joshua Tree, Landers, and Big Bear Earthquakes", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 1994, by the Seismological Society of America. Manuscript received 2 August 1993. The digital creepmeters are maintained by USGS grant 14-08-001-G1876, and the Caltech analog creepmeters by USGS 14-08-0001-G1666 and USGS 14-08-0001-G1990. This work was supported in part by USGS 1434-93-G-2356. We thank Kerry Sieh, Clarence Allen, David Johnson, and Wayne Miller for data from the Caltech creepmeters.\n\nPublished - 806.full.pdf
", "abstract": "Five out of six functioning creepmeters on southern California faults recorded slip triggered at the time of some or all of the three largest events of the 1992 Landers earthquake sequence. Digital creep data indicate that dextral slip was triggered within 1 min of each mainshock and that maximum slip velocities occurred 2 to 3 min later. The duration of triggered slip events ranged from a few hours to several weeks. We note that triggered slip occurs commonly on faults that exhibit fault creep. To account for the observation that slip can be triggered repeatedly on a fault, we propose that the amplitude of triggered slip may be proportional to the depth of slip in the creep event and to the available near-surface tectonic strain that would otherwise eventually be released as fault creep. We advance the notion that seismic surface waves, perhaps amplified by sediments, generate transient local conditions that favor the release of tectonic strain to varying depths. Synthetic strain seismograms are presented that suggest increased pore pressure during periods of fault-normal contraction may be responsible for triggered slip, since maximum dextral shear strain transients correspond to times of maximum fault-normal contraction.", "date": "1994-06", "date_type": "published", "publication": "Bulletin of the Seismological Society of America", "volume": "84", "number": "3", "publisher": "Seismological Society of America", "pagerange": "806-816", "id_number": "CaltechAUTHORS:20140806-100558839", "issn": "0037-1106", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140806-100558839", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "USGS", "grant_number": "14-08-001-G1876" }, { "agency": "USGS", "grant_number": "14-08-0001-G1666" }, { "agency": "USGS", "grant_number": "14-08-0001-G1990" }, { "agency": "USGS", "grant_number": "1434-93-G-2356" } ] }, "primary_object": { "basename": "806.full.pdf", "url": "https://authors.library.caltech.edu/records/gk9kv-3h610/files/806.full.pdf" }, "resource_type": "article", "pub_year": "1994", "author_list": "Bodin, Paul; Bilham, Roger; et el." }, { "id": "https://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.edu/records/akn6w-tqg11", "eprint_id": 44942, "eprint_status": "archive", "datestamp": "2023-08-20 01:05:29", "lastmod": "2023-10-26 17:26:16", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Hudnut-K-W", "name": { "family": "Hudnut", "given": "Kenneth W." }, "orcid": "0000-0002-3168-4797" } ] }, "title": "Geodesy tracks plate motion", "ispublished": "pub", "full_text_status": "restricted", "note": "\u00a9 1992 Nature Publishing Group.", "abstract": "Our current understanding of the large scale movements of the Earth's great crustal plates is based mainly upon offsets of old geological features on land as well as on the ocean floor.", "date": "1992-02-20", "date_type": "published", "publication": "Nature", "volume": "355", "number": "6362", "publisher": "Nature Publishing Group", "pagerange": "681-682", "id_number": "CaltechAUTHORS:20140415-075621930", "issn": "0028-0836", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140415-075621930", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "doi": "10.1038/355681a0", "resource_type": "article", "pub_year": "1992", "author_list": "Hudnut, Kenneth W." }, { "id": "https://authors.library.caltech.edu/records/jjphy-k1965", "eprint_id": 46595, "eprint_status": "archive", "datestamp": "2023-08-20 00:36:25", "lastmod": "2023-10-26 19:51:49", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Petersen-M-D", "name": { "family": "Petersen", "given": "Mark D." } }, { "id": "Seeber-L", "name": { "family": "Seeber", "given": "Leonardo" } }, { "id": "Sykes-L-R", "name": { "family": "Sykes", "given": "Lynn R." } }, { "id": "N\u00e1b\u011blek-J-L", "name": { "family": "N\u00e1b\u011blek", "given": "John L." } }, { "id": "Armbruster-J-G", "name": { "family": "Armbruster", "given": "John G." } }, { "id": "Pacheco-J-F", "name": { "family": "Pacheco", "given": "Javier" } }, { "id": "Hudnut-K-W", "name": { "family": "Hudnut", "given": "Kenneth W." }, "orcid": "0000-0002-3168-4797" } ] }, "title": "Seismicity and fault interaction, Southern San Jacinto Fault Zone and adjacent faults, southern California: Implications for seismic hazard", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 1991 American Geophysical Union.\n\nManuscript Accepted: 6 May 1991; Manuscript Received: 28 November 1990.\n\nPaper number 91TC01240.\n\nThis paper benefitted greatly by discussions with John Taber, John Beavan, Paul Huang, Cliff Thurber, Micky Van Fossen and Ken Howard. We also thank Diane Doser for her preprint and K. Nagao for drafting a figure. Critical reviews by Diane Doser, Allison Bent, C.H. Scholz and G.\nBond improved the manuscript substantially. The staff of the Caltech Seismology Laboratory and USGS (Pasadena) are also thanked for providing the microearthquake data. This work was funded by USGS grant 14-08-001-G948. Lamont-Doherty Geological Observatory contribution 4829.\n\nPublished - tect619.pdf
", "abstract": "The southern San Jacinto fault zone is characterized by high seismicity and a complex fault pattern that offers an excellent setting for investigating interactions between distinct faults. This fault zone is roughly outlined by two subparallel master fault strands, the Coyote Creek and Clark-San Felipe Hills faults, that are located 2 to 10 km apart and are intersected by a series of secondary cross faults. Seismicity is intense on both master faults and secondary cross faults in the southern San Jacinto fault zone. The seismicity on the two master strands occurs primarily below 10 km; the upper 10 km of the master faults are now mostly quiescent and appear to rupture mainly or solely in large earthquakes. Our results also indicate that a considerable portion of recent background activity near the April 9, 1968, Borrego Mountain rupture zone (M_L=6.4) is located on secondary faults outside the fault zone. We name and describe the Palm Wash fault, a very active secondary structure located about 25 km northeast of Borrego Mountain that is oriented subparallel to the San Jacinto fault system, dips approximately 70\u00b0 to the northeast, and accommodates right-lateral shear motion. The Vallecito Mountain cluster is another secondary feature delineated by the recent seismicity and is characterized by swarming activity prior to nearby large events on the master strand. The 1968 Borrego Mountain and the April 28, 1969, Coyote Mountain (M_L=5.8) events are examples of earthquakes with aftershocks and subevents on these secondary and master faults. Mechanisms from those earthquakes and recent seismic data for the period 1981 to 1986 are not simply restricted to strike-slip motion; dipslip motion is also indicated. Teleseismic body waves (long-period P and SH) of the 1968 and 1969 earthquakes were inverted simultaneously for source mechanism, seismic moment, rupture history, and centroid depth. The complicated waveforms of the 1968 event (M_o=1.2 \u00d7 10^(19) Nm) are interpreted in terms of two subevents; the first caused by right-lateral strike-slip motion in the mainshock along the Coyote Creek fault and the second by a rupture located about 25 km away from the master fault. Our waveform inversion of the 1969 event indicates that strike-slip motion predominated, releasing a seismic moment of 2.5 \u00d7 10^(17) Nm. Nevertheless, the right-lateral nodal plane of the focal mechanism is significantly misoriented (20\u00b0) with respect to the master fault, and hence the event is not likely to be associated with a rupture on that fault. From this and other examples in southern California, we conclude that cross faults may contribute significantly to seismic hazard and that interaction between faults has important implications for earthquake prediction.", "date": "1991-12", "date_type": "published", "publication": "Tectonics", "volume": "10", "number": "6", "publisher": "American Geophysical Union", "pagerange": "1187-1203", "id_number": "CaltechAUTHORS:20140701-102612873", "issn": "0278-7407", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140701-102612873", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "USGS", "grant_number": "14-08-001-G948" } ] }, "other_numbering_system": { "items": [ { "id": "4829", "name": "Lamont-Doherty Geological Observatory" } ] }, "doi": "10.1029/91TC01240", "primary_object": { "basename": "tect619.pdf", "url": "https://authors.library.caltech.edu/records/jjphy-k1965/files/tect619.pdf" }, "resource_type": "article", "pub_year": "1991", "author_list": "Petersen, Mark D.; Seeber, Leonardo; et el." }, { "id": "https://authors.library.caltech.edu/records/kx5md-87h87", "eprint_id": 44946, "eprint_status": "archive", "datestamp": "2023-08-19 21:31:41", "lastmod": "2023-10-26 17:26:30", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Hudnut-K-W", "name": { "family": "Hudnut", "given": "K. W." }, "orcid": "0000-0002-3168-4797" }, { "id": "Sieh-K-E", "name": { "family": "Sieh", "given": "K. E." }, "orcid": "0000-0002-7311-2447" } ] }, "title": "Behavior of the Superstition Hills fault during the past 330 years", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 1989 Seismological Society of America. Manuscript received 3 October 1988. L. Gilbert, J. Goodmacher, S. F. McGill, T. Rockwell, L. Seeber, C. Sieh, M. Sigmon, A. Thomas, S. Moore, and D. Valentine all helped with the field effort. We also thank P. Williams and S. F. McGill for\nafterslip data and data from the Caltech alignment array, respectively. Carl Stover kindly provided preliminary intensity estimates for the 1987 earthquakes. Detailed and helpful reviews were made by M. Clark, N. Christie-Blick, and L. Seeber. Work at this site was done with permission from the U.S. Bureau of Land Management (BLM) and the U.S. Navy. We thank Pat Welch and Lynda Kastoll of the BLM for their assistance. Research was supported by U.S. Geological Survey grants No. 14-08-0001-G1330 (K.W.H.) and No. 14-08-0001-G1098 (K.E.S.). Lamont-Doherty Geological Observatory contribution No. 4417; Caltech Division of Geological and Planetary Sciences contribution No. 4656.\n\nPublished - 304.full.pdf
", "abstract": "We have investigated the recent prehistoric behavior of the Superstition Hills fault by examining its effect on the beach deposits of ancient Lake Cahuilla. Excavation of these sediments in three dimensions where they are cut by the fault has enabled determination of total offset since the latest highstand of the lake, about 330 years ago. As of 3 March 1988, total dextral offset was 1106 \u00b1 50 mm. About 609 mm of this amount can be attributed to one or more slip events before 1987. The remaining slip occurred during the moderate earthquake of 24 November 1987 and as subsequent aftercreep. Additional aftercreep here might produce a total of 1210 \u00b1 100 mm for that event. Thus, if afterslip continues according to our prediction, slip associated with the penultimate seismic slip event on the Superstition Hills fault was only about half of the co-seismic slip and predicted afterslip associated with the 1987 earthquake. This difference, established at a single site on the fault, may reflect a larger size for the 1987 event than for its predecessor. We calculate that the slip rate of the Superstition Hills fault zone, averaged over the past 330 years, is between about 2 and at least 6 mm/yr at this site. During this time, the average interval between large surface slip events on the Superstition Hills fault has been between about 150 and 300 years. The pre-1987 slip event documented in our excavations could have occurred at any time between A.D. 1660 and about A.D. 1915. These results are significant for understanding earthquake recurrence and patterns of earthquakes in the Imperial and Coachella Valleys.", "date": "1989-04", "date_type": "published", "publication": "Bulletin of the Seismological Society of America", "volume": "79", "number": "2", "publisher": "Seismological Society of America", "pagerange": "304-329", "id_number": "CaltechAUTHORS:20140415-084021853", "issn": "0037-1106", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140415-084021853", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "USGS", "grant_number": "14-08-0001-G1330" }, { "agency": "USGS", "grant_number": "14-08-0001-G1098" } ] }, "other_numbering_system": { "items": [ { "id": "4656", "name": "Division of Geological and Planetary Sciences Contribution" } ] }, "primary_object": { "basename": "304.full.pdf", "url": "https://authors.library.caltech.edu/records/kx5md-87h87/files/304.full.pdf" }, "resource_type": "article", "pub_year": "1989", "author_list": "Hudnut, K. W. and Sieh, K. E." }, { "id": "https://authors.library.caltech.edu/records/fm8en-cte08", "eprint_id": 44945, "eprint_status": "archive", "datestamp": "2023-08-19 21:31:36", "lastmod": "2023-10-26 17:26:28", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Lindvall-S-C", "name": { "family": "Lindvall", "given": "Scott C." } }, { "id": "Rockwell-T-K", "name": { "family": "Rockwell", "given": "Thomas K." } }, { "id": "Hudnut-K-W", "name": { "family": "Hudnut", "given": "Kenneth W." }, "orcid": "0000-0002-3168-4797" } ] }, "title": "Evidence for prehistoric earthquakes on the Superstition Hills fault from offset geomorphic features", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 1989 Seismological Society of America. Manuscript received 4 August 1988. We are grateful to R. Wallace for his initial enthusiasm to pursue this study of the offset features along this fault. We thank D. Valentine at SDSU for helping with the surveying, T. Hanks at the USGS for providing us with new air photos, and P. Williams at L-DGO/C.I.T. for his discussions on afterslip. We especially thank D. Schwartz for his thoughtful review of our manuscript, which led to improvements and clarification of the presentation. This project was partially supported by USGS Grant no. 14-08-\n0001-G1330.\n\nPublished - 342.full.pdf
", "abstract": "Offset geomorphic features along the Superstition Hills fault show evidence for at least one slip event prior to the 1987 surface rupture, and possibly as many as four to five earlier prehistoric earthquakes. We documented several geomorphic features that appeared offset by multiple events by making detailed topographic maps. Offset features were abundant along reaches of the fault with high topographic relief and large displacement. Slip distribution for the penultimate event, as recorded by offset rills, streams, and shrub-coppice dunes, is very similar to the slip distribution from the 1987 earthquake through April 1988. This similarity may prove to be fortuitous if afterslip from the 1987 event continues to increase the total slip for this earthquake. But if afterslip associated with the 1987 event ceases in the near future, then the past two earthquakes were nearly identical in slip, and the Superstition Hills fault may be expected to produce characteristic earthquakes of roughly magnitude 6\u00bd.", "date": "1989-04", "date_type": "published", "publication": "Bulletin of the Seismological Society of America", "volume": "79", "number": "2", "publisher": "Seismological Society of America", "pagerange": "342-361", "id_number": "CaltechAUTHORS:20140415-083018011", "issn": "0037-1106", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140415-083018011", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "USGS", "grant_number": "14-08-0001-G1330" } ] }, "primary_object": { "basename": "342.full.pdf", "url": "https://authors.library.caltech.edu/records/fm8en-cte08/files/342.full.pdf" }, "resource_type": "article", "pub_year": "1989", "author_list": "Lindvall, Scott C.; Rockwell, Thomas K.; et el." }, { "id": "https://authors.library.caltech.edu/records/swkr2-qt158", "eprint_id": 44944, "eprint_status": "archive", "datestamp": "2023-08-19 21:31:32", "lastmod": "2023-10-26 17:26:26", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "McGill-S-F", "name": { "family": "McGill", "given": "Sally F." } }, { "id": "Allen-C-R", "name": { "family": "Allen", "given": "Clarence R." } }, { "id": "Hudnut-K-W", "name": { "family": "Hudnut", "given": "Kenneth W." }, "orcid": "0000-0002-3168-4797" }, { "id": "Johnson-D-C", "name": { "family": "Johnson", "given": "David C." } }, { "id": "Miller-W-F", "name": { "family": "Miller", "given": "Wayne F." } }, { "id": "Sieh-K-E", "name": { "family": "Sieh", "given": "Kerry E." }, "orcid": "0000-0002-7311-2447" } ] }, "title": "Slip on the Superstition Hills fault and on nearby faults associated with the 24 November 1987 Elmore Ranch and Superstition Hills earthquakes, southern California", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 1989 Seismological Society of America. Manuscript received 15 August 1988. This work was supported by USGS Grant 14-08-0001-G1177 and by funds from the Caltech Earthquake\nResearch Associates.\n\nPublished - 362.full.pdf
", "abstract": "Alignment arrays and creepmeters spanning several faults in southern California recorded slip associated with the 24 November 1987 Elmore Ranch and Superstition Hills earthquakes. No precursory slip had occurred on the Superstition Hills fault up to 27 October 1987, when the last measurement before the earthquakes was made. About 23 days before the earthquake, dextral creep events of about 13 mm and 0.5 mm may have occurred simultaneously on the Imperial and southern San Andreas faults, respectively, but the tectonic origin of the smaller event is questionable.\n\nWithin 12 hr after the Superstition Hills earthquake, 20.9 cm of dextral slip occurred on the main fault trace at the Superstition Hills alignment array, and 39.8 cm of dextral slip was recorded over the entire 110-m width of the array. Despite this initial wide distribution of slip, nearly all of the postseismic slip is occurring on the main fault trace. As of 3 August 1988, the alignment array had recorded a total of 80.2 cm of dextral slip. As of 5 days after the earthquakes, 65 to 80 per cent of the total slip measured by the alignment array had occurred on discrete, mappable fractures.\n\nIn addition, the two earthquakes triggered slip on the Coyote Creek fault, the southern San Andreas fault, and on the Imperial fault. Telemetered data from creepmeters on the southern San Andreas and Imperial faults indicate that triggered slip began there within 3 min or less of each of the two earthquakes. Additional triggered slip occurred on the Imperial fault beginning 3.5 hr after the second earthquake.", "date": "1989-04", "date_type": "published", "publication": "Bulletin of the Seismological Society of America", "volume": "79", "number": "2", "publisher": "Seismological Society of America", "pagerange": "362-375", "id_number": "CaltechAUTHORS:20140415-081920776", "issn": "0037-1106", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140415-081920776", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "USGS", "grant_number": "14-08-0001-G1177" }, { "agency": "Caltech Earthquake Research Associates" } ] }, "primary_object": { "basename": "362.full.pdf", "url": "https://authors.library.caltech.edu/records/swkr2-qt158/files/362.full.pdf" }, "resource_type": "article", "pub_year": "1989", "author_list": "McGill, Sally F.; Allen, Clarence R.; et el." }, { "id": "https://authors.library.caltech.edu/records/nxxky-7xb77", "eprint_id": 49133, "eprint_status": "archive", "datestamp": "2023-08-19 21:31:59", "lastmod": "2023-10-17 21:09:46", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Hudnut-K-W", "name": { "family": "Hudnut", "given": "K." }, "orcid": "0000-0002-3168-4797" }, { "id": "Seeber-L", "name": { "family": "Seeber", "given": "L." } }, { "id": "Rockwell-T", "name": { "family": "Rockwell", "given": "T." } }, { "id": "Goodmacher-J", "name": { "family": "Goodmacher", "given": "J." } }, { "id": "Klinger-R", "name": { "family": "Klinger", "given": "R." } }, { "id": "Lindvall-S", "name": { "family": "Lindvall", "given": "S." } }, { "id": "McElwain-R", "name": { "family": "McElwain", "given": "R." } } ] }, "title": "Surface ruptures on cross-faults in the 24 November 1987 Superstition Hills, California, earthquake sequence", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 1989, by the Seismological Society of America. Manuscript received 28 July 1988. We thank H. Kanamori and the staff at the CIT/USGS office in Pasadena, especially L. Jones and\nD. Given, for epicenter locations soon after the earthquakes. We also thank T. Hanks at the USGS for\nproviding us with the new airphotos. We thank R. Sharp, M. Clark, M. Rymer, and J. Lienkaemper at the USGS, J. Kahle at CDMG, P. Williams at L-DGO/CIT, and others for their advice and comments in the field. L. Sykes pointed out the April 1988 seismicity on the Extra fault to us. Reviews by R. Wallace, C. Scholz, and D. Simpson greatly improved this paper. Research was supported by U. S. Geological Survey grant No. 14-08-00001-G1330. Lamont-Doherty Geological Observatory contribution No. 4429.\n\nPublished - 282.full.pdf
", "abstract": "Left-lateral slip occurred on individual surface breaks along northeast-trending faults associated with the 24 November 1987 earthquake sequence in the Superstition Hills, Imperial Valley, California. This sequence included the M_s = 6.2 event on a left-lateral, northeast-trending \"cross-fault\" between the Superstition Hills fault (SHF) and Brawley seismic zone, which was spatially associated with the left-lateral surface breaks. Six distinct subparallel cross-faults broke at the surface, with rupture lengths ranging from about Formula to 10 km and maximum displacements ranging from 30 to 130 mm. About half a day after the M_s = 6.2 event, an M_s = 6.6 earthquake nucleated near the intersection of the cross-faults with the SHF, and rupture propagated southeast along the SHF. Whereas right-lateral slip on the SHF occurred dominantly on a single trace in a narrow zone, the cross-fault surface slip was distributed over several stands across a 10-km-wide zone. Also, whereas afterslip accounted for a large proportion of total slip on the SHF, there is no evidence for afterslip on the cross-faults. We present documentation of these surface ruptures. A simple mechanical model of faulting illustrates how the foreshock sequence may have triggered the main rupture. Displacement on other cross-faults could trigger an event on the southern San Andreas fault by a similar mechanism in the future.", "date": "1989-04", "date_type": "published", "publication": "Bulletin of the Seismological Society of America", "volume": "79", "number": "2", "publisher": "Seismological Society of America", "pagerange": "282-296", "id_number": "CaltechAUTHORS:20140902-140150397", "issn": "0037-1106", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140902-140150397", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "USGS", "grant_number": "14-08-00001-G1330" } ] }, "other_numbering_system": { "items": [ { "id": "4429", "name": "Lamont-Doherty Geological Observatory contribution" } ] }, "primary_object": { "basename": "282.full.pdf", "url": "https://authors.library.caltech.edu/records/nxxky-7xb77/files/282.full.pdf" }, "resource_type": "article", "pub_year": "1989", "author_list": "Hudnut, K.; Seeber, L.; et el." } ]