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U.S. Geological Survey, Earthquake Hazards Program

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Subduction zones are home to the most seismically active faults on the planet. The shallow megathrust interface of subduction zones host our largest earthquakes, and are the only faults capable of M9+ ruptures. Despite these facts, our knowledge of subduction zone geometry - which likely plays a key role in determining the spatial extent and ultimately the size of subduction zone earthquakes - is incomplete. Here we calculate the three- dimensional geometries of all active global subduction zones. The resulting model - Slab2 - provides for the first time a comprehensive geometrical analysis of all known slabs in unprecedented detail.
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ShakeMap is a product of the USGS Earthquake Hazards Program in conjunction with the regional seismic networks. ShakeMaps provide near-real-time maps of ground motion and shaking intensity following significant earthquakes. These maps are used by federal, state, and local organizations, both public and private, for post-earthquake response and recovery, public and scientific information, as well as for preparedness exercises and disaster planning.
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Subduction zones are home to the most seismically active faults on the planet. The shallow megathrust interface of subduction zones host our largest earthquakes, and are the only faults capable of M9+ ruptures. Despite these facts, our knowledge of subduction zone geometry - which likely plays a key role in determining the spatial extent and ultimately the size of subduction zone earthquakes - is incomplete. Here we calculate the three- dimensional geometries of all active global subduction zones. The resulting model - Slab2 - provides for the first time a comprehensive geometrical analysis of all known slabs in unprecedented detail. ##### This distribution includes models of three-dimensional slab geometry under...
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The NEIC global earthquake bulletin is called the Preliminary Determination of Epicenters or PDE, and is one of many discrete products in the ANSS Comprehensive Catalog (ComCat). We use the word "Preliminary" for our final bulletin because the Bulletin of the International Seismological Centre is considered to be the final global archive of parametric earthquake data, in other words phase arrival (“pick”) times and amplitudes.
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This dataset presents where, why, and how much probabilistic ground motions have changed with the 2018 update of the National Seismic Hazard Model (NSHM) for the conterminous U.S. (CONUS) vs. the 2014 NSHM. In the central and eastern U.S., hazard changes are the result of updated ground motion models (further broken down by median and epistemic uncertainty, aleatory variability, and site effects models) and gridded seismicity models. In the western U.S., hazard changes are the result of updated ground motion models in four urban areas with deep sedimentary basins and gridded seismicity models. Probabilistic ground motion changes (2% in 50 years probability of exceedance for a firm rock site, VS30 = 760 m/s, NEHRP...
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