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The 2002 U.S. Geological Survey (USGS) National Seismic Hazard Maps display earthquake ground motions for various probability levels across the United States and are applied in seismic provisions of building codes, insurance rate structures, risk assessments, and other public policy. This update of the maps incorporates new findings on earthquake ground shaking, faults, seismicity, and geodesy. The resulting maps are derived from seismic hazard curves calculated on a grid of sites across the United States that describe the frequency of exceeding a set of ground motions.
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We generated digital elevation models (DEMs) using pre- and post-event in-track stereo 0.5 m resolution panchromatic Worldview 1 and 2 images (©2019, DigitalGlobe) using the Surface Extraction from TIN-based Searchspace Minimization (SETSM) software [Noh and Howat, 2015] running on the University of Iowa Argon supercomputer (Table S1). The post-event DEMs exhibit along-track striping artifacts common to the Worldview 2 sensor. While de-striping tools, for example within NASAs Ames Stereo Pipeline [Shean et al., 2016], are commonly applied to resolve this issue, a de-striping correction has not been developed for this latitude. Noh, M.-J., and I. M. Howat (2015), Automated stereo-photogrammetric DEM generation...
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The “Database of Central and Eastern North American Seismic Velocity Structure” involves the compilation of one-dimensional (1D) seismic velocity-depth functions for central and eastern North America (CENA). The present database is an update of the report by Chulick and Mooney (2002) who present a compilation and statistical analysis of 1D seismic velocity-depth functions for North America and its margins. All seismic velocity-depth functions are extracted from peer-reviewed journal articles, with 86% derived from active-source seismic refraction profiles and the remaining 14% from receiver functions or local earthquake tomography models. No reanalysis of the original seismic field data was undertaken. The database...
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The Global Vs30 Server allows a user to select from a map or input a rectangular region of interest. It then provides (optionally) a Vs30 grid in ASCII or GMT grid format, and a JPEG Vs30 map. Wald et al. (2004) first, and Wald and Allen (BSSA, 2007, in press), more fully, describe a methodology for deriving maps of seismic site conditions using topographic slope as a proxy. Vs30 measurements (the average shear-velocity down to 30 m) are correlated against topographic slope to develop two sets of coefficients for deriving Vs30: one for active tectonic regions that possess dynamic topographic relief, and one for stable continental regions where changes in topography are more subdued.
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The significant rise in seismicity rates in Oklahoma and Kansas (OK–KS) in the last decade has led to an increased interest in studying induced earthquakes. Although additional instruments have been deployed in the region, there are still relatively few recordings at the distances (<20 km) and magnitudes (M4+) most relevant to earthquake hazard. In contrast, the USGS Did You Feel It? (DYFI) system has collected more than 200,000 observations during this period with 22,000+ observations at distances less than 20 km. This dataset has already been used to study the unique characteristics of induced earthquakes, to evaluate the extent of felt area, shaking, and damage, to compare intensity and ground motion metrics,...
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The 2018 Update of the U.S. National Seismic Hazard Model defines the potential for earthquake ground shaking for various probability levels across the conterminous United States and is applied in seismic provisions of building codes, insurance rate structures, risk assessments, and other public policy. The updated model represents an assessment of the best available science in earthquake hazards and incorporates new findings on earthquake ground shaking, seismicity, and long-period amplification over deep sedimentary basins. The new model represents an update of the seismic hazard model; previous versions were developed in 1996, 2002, 2008, and 2014. The output from the National Seismic Hazard Model is a suite...
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The 2014 U.S. Geological Survey (USGS) National Seismic Hazard Maps display earthquake ground motions for various probability levels across the United States and are applied in seismic provisions of building codes, insurance rate structures, risk assessments, and other public policy. The updated maps represent an assessment of the best available science in earthquake hazards and incorporate new findings on earthquake ground shaking, faults, seismicity, and geodesy. The USGS National Seismic Hazard Mapping Project developed these maps by incorporating information on potential earthquakes and associated ground shaking obtained from interaction in science and engineering workshops involving hundreds of participants,...
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OpenSHA is an effort to develop object-oriented, web- & GUI-enabled, open-source, and freely available code for conducting Seismic Hazard Analyses (SHA). Our goal is to provide a framework where any arbitrarily complex (e.g., physics based) earthquake-rupture forecast, ground-motion, or engineering-response model can “plug in” for analysis without having to change what’s being plugged into.
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The ANSS Comprehensive Catalog (ComCat) contains earthquake source parameters and other products produced by contributing seismic networks. Important digital catalogs of earthquake source parameters (e.g. Centennial Catalog, Global Centroid Moment Tensor Catalog) are loaded into ComCat. New and updated data are added to the catalog dynamically as sources publish or update products. Access to the ComCat is via the online search page, on which a user can select a wide variety of criteria to locate earthquake events of interest. Source Parameters: -amplitude - hypocenter - magnitude - phase data - finite fault - focal mechanism - moment tensor - tectonic summary - regional information Products: - Did You Feel It? -...
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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 datasets for this investigation consist of microtremor array data collected at sites in San Jose, California, Pleasanton, California, and synthetic microtremor array data created as part of a blind shear-wave velocity modeling study as part of the Third International Symposium on the Effects of Surface Geology on Seismic Motion (ESG2006), Grenoble, France, 30 August - 1 September 2006. The data from site STGA in San Jose, consisting of seven sensors used in the paper, are available from the Incorporated Research Institutions for Seismology (IRIS) through a request form at http://ds.iris.edu/ds/nodes/dmc/forms/assembled-data/?dataset_report_number=04-016. An associated report for these data available at http://ds.iris.edu/data/reports/2004/04-016/04-016.pdf....
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The dataset for this investigation consists of microtremor array data collected at 11 sites in the Seattle basin, Washington State. Ten of the arrays consisted of seven Nanometrics Trillium Compact broadband sensors deployed in asymmetric nested triangles (sites ST01, BA02, SP04, LF05, UW06, SN07, RD08, EL09, CH10, and KG11) that recorded for up to six hours. The eleventh array, at site NW03, was supplemented with a smaller triangular array that recorded for about 1 hour before redeployment to a larger array. The inter-sensor distances varied from about 173 m to 2000 m. The data were recorded on Reftek RT-130 data loggers and converted to SAC binary format for archival. All three components were recorded from each...
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The 2008 U.S. Geological Survey (USGS) National Seismic Hazard Maps display earthquake ground motions for various probability levels across the United States and are applied in seismic provisions of building codes, insurance rate structures, risk assessments, and other public policy. This update of the maps incorporates new findings on earthquake ground shaking, faults, seismicity, and geodesy. The resulting maps are derived from seismic hazard curves calculated on a grid of sites across the United States that describe the frequency of exceeding a set of ground motions. The USGS National Seismic Hazard Mapping Project developed these maps by incorporating information on potential earthquakes and associated ground...
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We produce the USGS 2018 one-year probabilistic seismic hazard forecast for the central and eastern United States from induced and natural earthquakes. For consistency, the updated 2018 forecast is developed using the same probabilistic seismicity-based methodology as applied in the two previous forecasts for 2016 and 2017. Rates of earthquakes across the U.S. (M ≥ 3.0) grew rapidly between 2008 and 2015 but have steadily declined over the past three years, especially in areas of Oklahoma and southern Kansas where fluid injection has decreased. The seismicity pattern in 2017 was complex with earthquakes more spatially dispersed than in previous years. Some areas of west-central Oklahoma experienced increased activity...
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The 2021 update of the U.S. National Seismic Hazard Model for Hawaii succeeds the twenty-year-old former model by incorporating new data and modeling techniques to improve the ground shaking forecasts. Output from the model includes probabilistic seismic hazard curves calculated for a 0.02° x 0.02° grid of latitude/longitude locations across Hawaii. The new model provides an expanded suite of hazard curves for twenty-three different ground motion intensity measures, including PGA, PGV, and spectral accelerations between 0.01 and 10 second, and for eight separate soil site classes (VS30 = 1500 m/sec to 150 m/sec), representing NEHRP site classes A/B to E. In addition, gridded uniform- hazard data are provided...
For designing buildings and other structures, the 2020 NEHRP Recommended Seismic Provisions and the 2022 ASCE/SEI 7 Standard provide Risk-Targeted Maximum Considered Earthquake (MCER) spectral response accelerations and Maximum Considered Earthquake Geometric Mean (MCEG) peak ground accelerations. The MCER ground motions are also expected to be in the 2023 ASCE/SEI 41 Standard and the 2024 and 2027 editions of the International Building Code. Both sets of ground motions are derived from USGS National Seismic Hazard Models via the gridded values of this data release. The files in the "Child Items" below also underlie corresponding USGS Seismic Design Web Services. See the "Related External Resources" below for...


    map background search result map search result map Quaternary Fault and Fold Database of the United States Data Release for 2018 One-Year Seismic Hazard Forecast for the Central and Eastern United States from Induced and Natural Earthquakes Shear-wave velocity in the Seattle basin to 2 km depth characterized with the krSPAC microtremor array method: insights for urban basin-scale imaging - Data Release Spatially averaged coherencies (krSPAC) and Rayleigh effective-mode modeling of microtremor data from asymmetric arrays Data Release for the 2018 Update of the U.S. National Seismic Hazard Model 2016 Mw 6.0 Petermann Ranges earthquake, Australia: Pre- and post-earthquake digital elevation models Data Release for the 2021 Update of the U.S. National Seismic Hazard Model for Hawaii Database of Central and Eastern North American Seismic Velocity Structure Spatially averaged coherencies (krSPAC) and Rayleigh effective-mode modeling of microtremor data from asymmetric arrays Shear-wave velocity in the Seattle basin to 2 km depth characterized with the krSPAC microtremor array method: insights for urban basin-scale imaging - Data Release Data Release for the 2021 Update of the U.S. National Seismic Hazard Model for Hawaii 2016 Mw 6.0 Petermann Ranges earthquake, Australia: Pre- and post-earthquake digital elevation models Data Release for the 2018 Update of the U.S. National Seismic Hazard Model Data Release for 2018 One-Year Seismic Hazard Forecast for the Central and Eastern United States from Induced and Natural Earthquakes Database of Central and Eastern North American Seismic Velocity Structure Quaternary Fault and Fold Database of the United States