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These data are from a 3-month long deployment of nodal seismometers that ran from December 22th, 2022 until March 1st, 2023 as part of a Distributed Acoustic Sensing (DAS) experiment above the Gorda plate. The deployment was done in response to the 2022/12/20 M6.4 Ferndale earthquake. The sensors were deployed at 46 locations along Old Arcata Rd between Arcata and Eureka California (Figure 1); these locations track the approximate location of the fiber optic cable used as part of the DAS experiment. The instruments have a battery recording life of approximately one month and were swapped out in the same locations in Mid-to-late January, and late February-Early march. Exceptions are that only 29 were deployed for...
Earthquake-triggered ground-failure, such as landsliding and liquefaction, can contribute significantly to losses, but our current ability to accurately include them in earthquake hazard analyses is limited. The development of robust and transportable models requires access to numerous inventories of ground failure triggered by earthquakes that span a broad range of terrains, shaking characteristics, and climates. We present an openly accessible, centralized earthquake-triggered ground-failure inventory repository in the form of a ScienceBase Community to provide open access to these data, and help accelerate progress. The Community hosts digital inventories created by both USGS and non-USGS authors. We present...
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Peak ground acceleration ground motion values for 50, 10, and 2 percent probability of exceedance in 50 years are converted to equivalent modified Mercalli intensity using the relationships of Worden and others (2012). Values are for NEHRP site class B/C with a VS30 = 760 m/s.
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This data set contains maps and shapefiles of uniform-hazard ground motion values calculated for a grid of points with a spacing of 0.2° in latitude and longitude over the conterminous U.S and Alaska, and 0.02° over Hawaii, using the 2023 National Seismic Hazard Model. 2%, 5% and 10% in 50-year probability of exceedance values are shown for peak ground acceleration (PGA), and 0.2, 1, and 5 second spectral acceleration for VS30 = 760 and 260 m/s, representing the National Earthquake Hazards Reduction Program site conditions B/C and D, respectively.
Between October 12, 2019 and December 13, 2019, the U.S. Geological Survey deployed 30 nodal seismometers in Humboldt county CA for the purpose of recording seismicity in the subducting Gorda plate. 20 instruments were deployed at the McBride ranch, around NCSN station KCT, and 10 were deployed at the Bureau of Land Management’s Lost Coast Headlands property. The nodes were replaced in mid-November after one month of recording due to battery life.
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Earthquake stress drop is a critical parameter for estimating seismic hazard. This parameter can have a strong effect on ground motion amplitudes above ~1Hz and is especially important in Oklahoma and Kansas where earthquake rates have increased sharply since 2008. We estimate stress drops for 1121 earthquakes greater than ~M3 in and near the conterminous United States using spectral ratios between collocated events at given stations. We find that the average stress drop for the few eastern United States (EUS, 26–340 Bars) tectonic main shocks studied, which tend to be deeper thrusting events with few foreshocks and aftershocks, is about three times greater than tectonic main shocks in the western United States...
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The boundaries (polygons and their tables) of the zones of induced seismicity are provided as documentation for the 50-state update of the National Seismic Hazard Model (NSHM) of 2023. These zones are within the conterminous United States and have assigned durations to represent seismicity that is considered induced. Previous NSHMs also considered the role of induced seismicity (Petersen and others, 2018 and Petersen and others, 2017) which is a separate category from other anthropogenic sources considered in the seismicity catalogs used in the hazard models. For expanded explanations, see Llenos and others (2023) and the metadata which also contains documented references used in this study.
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This inventory was originally created by Okuyama and others (2013) describing the landslides triggered by the M 9.1 Tohoku-Oki, Japan earthquake that occurred on 2011-03-11 at 05:46:24 UTC. Care should be taken when comparing with other inventories because different authors use different mapping techniques. This inventory also could be associated with other earthquakes such as aftershocks or triggered events. Please check the author methods summary and the original data source for more information on these details and to confirm the viability of this inventory for your specific use. With the exception of the data from USGS sources, the inventory data and associated metadata were not acquired by the U.S. Geological...
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The Quaternary Fault and Fold Database contains the results of thousands of scientific assessments of faults and associated folds in the United States that demonstrate geologic evidence for coseismic surface deformation in the Quaternary (the past 1,600,000 years). The Quaternary Fault and Fold Database includes information on the age of the most recent coseismic surface deformation, relative rates of activity, fault geometry, sense of movement, and citations of pertinent literature. Much of the information in the database is based on paleoseismology, which is the geologic study of prehistoric earthquakes. Paleoseismology combines well-established geologic practices such as trenching with archeological-style analysis...
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The USGS Powell Center Cascadia earthquake hazards working group compiled published onshore and offshore paleoseismic data along the Cascadia subduction zone, spanning sites from Vancouver Island to the Mendocino triple junction. Evidence for megathrust rupture includes coastal land-level change, tsunami inundation, onshore shaking proxies such as landslides or liquefaction, and offshore shaking proxies such as marine turbidites. The quality of paleoseismic data for megathrust rupture along the Cascadia subduction zone collected over the past three decades varies because analytical capabilities and data collection methodologies have evolved. Thus, as part of the compilation, we also present a ranking scheme to assess...
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This data release contains data sets associated with the 2023 50-State National Seismic Hazard Model Update. The 2023 50-State National Seimsic Hazard Model (NSHM) Update includes an update to the NSHMs for the conterminous U.S (CONUS, last updated in 2018), Alaska (AK, last updated in 2007), and Hawaii (last updated in 2001). Data sets include inputs like seismicity catalogs used as input to the smoothed seismicity model and updated induced seismicity zone polygons in the central and eastern U.S., as well as outputs like hazard curves and uniform-hazard ground motion values. Plots of selected data sets are also included. The data sets provided here are primarily for the 2023 CONUS NHSM and 2023 AK NSHM. Additional...
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The 2023 National Seismic Hazard Model for the conterminous United States considers the full catalog and several declustered catalogs in calculating earthquake rates and seismic hazard. These catalogs were declustered using the Reasenberg and nearest neighbor methods. All of these catalogs are included here and are described in more detail in the paper by Llenos and others (2023).
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This data set represents probabilisitic seismic hazard curves and uniform-hazard ground motion values calculated for a grid of points with a spacing of 0.2 degrees in latitude and longitude over the conterminous U.S. (CONUS) and Alaska (AK) using the 2023 National Seismic Hazard Model. CONUS The data sets includes (1) probabilistic seismic hazard curves (full and truncated) for two peak parameters, peak ground velocity (PGV) and peak ground acceleration (PGA), and pseudo-spectral accelerations at 21 oscillator periods between 0.01 and 10s, and (2) uniform-hazard ground motion values for 2, 5, and 10% in 50 years probability of exceedance (PE) (corresponding to 2,475, 975, and 475-year return periods, respectively)...
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Version 3.0 is now available. Please see new data release here: https://doi.org/10.5066/P9AWINWZ. This Data Release contains preliminary versions of two related databases: 1) A fault sections database (“NSHM23_FSD_v2”), which depicts the geometry of faults capable of hosting independent earthquakes, and 2) An earthquake geology site information database (“NSHM23_EQGeoDB_v2”), which contains fault slip-rate constraints at points. These databases were prepared in anticipation of updates to the National Seismic Hazard Model (NSHM) 2023. Fault-specific geologic parameters for the NSHM have not been updated since the 2014 NSHM release. The datasets include the states of Washington, Oregon, California, Idaho, Nevada,...
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This page houses model results used in the U.S. National Seismic Hazard Model, 2023. We include results from four geodetic deformation models (Pollitz, Zeng, Shen, Evans), post-seismic relaxation ("ghost transient") calculation (Hearn), and creep calculation (Johnson/Murray). Geologic deformation model results are available in Hatem et al. (2022a). An overview of all model procedures and comparisons is available at: Pollitz, F.F., E. L. Evans, E. H. Field, A. E. Hatem, E. H. Hearn, K. M. Johnson, J. R. Murray, P. M. Powers, Z.-K. Shen, C. Wespestad, and Y. Zeng (2022). Western U.S. Deformation models for the 2023 update to the U.S. National Seismic Hazard Model, Seismol. Res. Lett. doi: 10.1785/0220220143 Individual,...
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These data are from a 3-month long deployment of nodal seismometers that ran from December 22th, 2022 until March 1st, 2023 as part of a Distributed Acoustic Sensing (DAS) experiment above the Gorda plate. The deployment was done in response to the 2022/12/20 M6.4 Ferndale earthquake. The sensors were deployed at 46 locations along Old Arcata Rd between Arcata and Eureka California (Figure 1); these locations track the approximate location of the fiber optic cable used as part of the DAS experiment. The instruments have a battery recording life of approximately one month and were swapped out in the same locations in Mid-to-late January, and late February-Early march. Exceptions are that only 29 were deployed for...
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We performed laboratory time-dependent creep and stress-oscillation earthquake simulations in uniaxial loading in compression and tension on four blocks of porphyritic dacite collected from pyroclastic deposits of Mt. Fugen, of the Unzen-dake volcanic complex in Japan (referred to as ‘Unzen volcano’). Experiments were carried out in the Experimental Volcanology and Geothermal Research Laboratory at the University of Liverpool. Loading experiments were carried out in a 100 kN Instron 8800 uniaxial press at room temperature using both compression tests, and Brazilian disk tests to provide the indirect tensile strength (hereafter referred to as tensile strength/tension tests). Load was recorded by an Instron Dynacell...
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This data set represents multiple period response spectra (MPRS) results for 160 test sites for the conterminous U.S (CONUS) using the 2023 National Seismic Hazard Model. The data sets includes (1) probabilistic seismic hazard curves (full and truncated) for peak ground velocity (PGV), peak ground acceleration (PGA), and 21 spectra periods from 0.01 to 10 seconds spectra acceleration and (2) uniform-hazard ground motion values for 2, 5, and 10% in 50 years probability of exceedance (PE) (corresponding to 2,475, 975, and 475-year return periods, respectively) and 1% in 100 year PE (corresponding to a 10,000-year return period) for each of the 160 test sites. Results are provided for VS30 = 1500, 1080, 760, 530, 365,...
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The November 30, 2018, magnitude (Mw) 7.1 Anchorage, Alaska earthquake triggered substantial ground failure throughout Anchorage and surrounding areas (Grant and others, 2020; Jibson and others, 2020). The earthquake was an intraslab event with a focal depth of about 47 km and an epicenter about 16 km north of the city of Anchorage. Peak ground accelerations reached ∼30% g. Despite the relatively low severity of most of the ground failure occurrences, geotechnical damage to buildings and structures was widespread (Franke and others, 2019). Here, we present an inventory of the earthquake-triggered ground failure based on information compiled from numerous data sources. The inventory is comprised of 886 points that...
map background search result map search result map Influence of Lithostatic Stress on Earthquake Stress Drops in North America Quaternary Fault and Fold Database of the United States Nodal Seismic Deployment at KCT and Lost Coast Headlands Earthquake geology inputs for the U.S. National Seismic Hazard Model (NSHM) 2023 (western US) (ver. 2.0, February 2022) Earthquake triggered ground failure associated with the M7.1 2018 southcentral Alaska Earthquake (ver. 2.0, December 2023) Okuyama and others (2013) Geodetic deformation model results and corrections for use in U.S. National Seismic Hazard Model 2023 Compiled onshore and offshore paleoseismic data along the Cascadia Subduction zone Data for Laboratory simulation of earthquake-induced damage in lava dome rocks Data Release for the 2023 U.S. 50-State National Seismic Hazard Model - Overview February-March 2023 Arcata to Eureka, California, Deployment of Nodal Seismometers December 2022- January 2023 Arcata to Eureka, California, Deployment of Nodal Seismometers 03. Hazard curves and uniform-hazard ground motion data for the conterminous U.S. and Alaska 04. Uniform-hazard ground motion maps for the conterminous U.S., Alaska, and Hawaii 01. Seismicity catalogs for the conterminous U.S. 05. Multiple period response spectra for 160 conterminous U.S. test sites 02. Central and eastern U.S. induced seismicity zones 07. Modified Mercalli Intensity maps for the conterminous U.S., Alaska, and Hawaii Data for Laboratory simulation of earthquake-induced damage in lava dome rocks Nodal Seismic Deployment at KCT and Lost Coast Headlands Okuyama and others (2013) Earthquake triggered ground failure associated with the M7.1 2018 southcentral Alaska Earthquake (ver. 2.0, December 2023) Compiled onshore and offshore paleoseismic data along the Cascadia Subduction zone 02. Central and eastern U.S. induced seismicity zones Earthquake geology inputs for the U.S. National Seismic Hazard Model (NSHM) 2023 (western US) (ver. 2.0, February 2022) Geodetic deformation model results and corrections for use in U.S. National Seismic Hazard Model 2023 05. Multiple period response spectra for 160 conterminous U.S. test sites 01. Seismicity catalogs for the conterminous U.S. Quaternary Fault and Fold Database of the United States 03. Hazard curves and uniform-hazard ground motion data for the conterminous U.S. and Alaska Data Release for the 2023 U.S. 50-State National Seismic Hazard Model - Overview 04. Uniform-hazard ground motion maps for the conterminous U.S., Alaska, and Hawaii 07. Modified Mercalli Intensity maps for the conterminous U.S., Alaska, and Hawaii Influence of Lithostatic Stress on Earthquake Stress Drops in North America