Skip to main content
Advanced Search

Filters: Contacts: {oldPartyId:8876} (X)

115 results (116ms)   

Filters
Date Range
Extensions
Types
Contacts
Categories
Tag Types
Tag Schemes
View Results as: JSON ATOM CSV
thumbnail
This data set represents the results of calculations of hazard curves for a grid of points with a spacing of 0.05 degrees in latitude and longitude. This particular data set is for horizontal spectral response acceleration for 0.2-second period with a 1 percent probability of exceedance in 1 year. The data are for the Western United States and are based on the long-term 2014 National Seismic Hazard Model.
thumbnail
A comparison of the 2017 USGS South America seismic hazard model with the Global Seismic Hazard Assessment Program (GSHAP) model and the 2010 USGS preliminary model was made to see how the models differ. The comparisons were made as ratios of PGA at 10% probability of exceedance in 50 years. Ratio maps of each comparison are included as a geo-referenced tiff (GeoTIFF).
thumbnail
These data sets are the results of calculations of hazard curves for a grid of points with a spacing of 0.05 degrees in latitude and longitude. They represent the chance of experiencing potentially damaging ground shaking for fixed ground shaking levels that corresponds with MMI = VII. The values are obtained by averaging the probability of experiencing MMI = VII based on a peak ground acceleration value of 0.2152 g for site class D, and the probability of experiencing MMI = VII based on 1.0-second spectral acceleration value of 0.2256 g for site class D. The data are for the Central and Eastern United States.
thumbnail
In processing step 3, declustering is applied to flag aftershocks and foreshocks in catalog wmm.c2. Each earthquake is considered a potential mainshock, and an algorithm searches for events within a specified distance from its epicenter and time after its origin (Gardner and Knopoff, 1974). A smaller earthquake found within a window is an aftershock. If a larger earthquake is found, the first earthquake is a foreshock of the larger one. WUS catalog wmm.c3 is produced by deleting aftershocks and foreshocks from wmm.c2; it consists of statistically independent earthquakes with moment magnitudes greater than or equal to 2.5.
Each of the downloadable files below contains spectral response accelerations at 22 periods on a grid of latitudes and longitudes that cover this geographic region. See the parent item for how Risk-Targeted Maximum Considered Earthquake (MCER) spectral response accelerations are derived from the data in these files.
For background, please see the Parent Item. The Maximum Considered Earthquake Geometric Mean (MCEG) peak ground acceleration (PGA) values of the 2009 NEHRP Recommended Seismic Provisions and the 2010 ASCE/SEI 7 Standard are calculated from the data in the downloadable files below, via the following equations: PGA = min[ PGAUH , max( PGAD84th , 0.6 ) ] for the 2009 NEHRP Recommended Seismic Provisions; PGA = min[ PGAUH , max( PGAD84th , 0.5 ) ] for the 2010 ASCE/SEI 7 Standard; where PGAUH = uniform-hazard peak ground acceleration; PGAD84th = 84th-percentile peak ground acceleration; and 0.6 or 0.5 = deterministic lower limit peak ground acceleration. These peak ground...
Categories: Data
thumbnail
A seismic hazard model for South America, based on a smoothed (gridded) seismicity model, a subduction model, a crustal fault model, and a ground motion model, has been produced by the U.S. Geological Survey. These models are combined to account for ground shaking from earthquakes on known faults as well as earthquakes on un-modeled faults. This data set represents the results of calculations of hazard curves for a grid of points with a spacing of 0.1 degrees in latitude and longitude. This particular data set is for peak ground acceleration with a 10 percent probability of exceedance in 50 years.
thumbnail
A seismic hazard model for South America, based on a smoothed (gridded) seismicity model, a subduction model, a crustal fault model, and a ground motion model, has been produced by the U.S. Geological Survey. These models are combined to account for ground shaking from earthquakes on known faults as well as earthquakes on un-modeled faults. This data set represents the results of calculations of hazard curves for a grid of points with a spacing of 0.1 degrees in latitude and longitude. This particular data set is for horizontal spectral response acceleration for 0.2-second period with a 50 percent probability of exceedance in 50 years.
thumbnail
In processing step 1, preexisting catalogs found online or in the literature are collected and merged. Each entry is reformatted to a standard record that lists basic earthquake information (moment magnitude, hypocenter, origin time), three parameters for modeling seismicity rates, and a comment field that lists the original catalog and size measure. Two distinct WUS catalogs are produced in step 1 to facilitate integrating California seismicity with the rest of the WUS. The Uniform California Earthquake Rupture Forecast (UCERF3) project developed a catalog for a region extending about 100km beyond the California border. Catalog B is constructed for the whole WUS with the intention of using only its part outside...
thumbnail
A seismic hazard model for South America, based on a smoothed (gridded) seismicity model, a subduction model, a crustal fault model, and a ground motion model, has been produced by the U.S. Geological Survey. These models are combined to account for ground shaking from earthquakes on known faults as well as earthquakes on un-modeled faults. This data set represents the results of calculations of hazard curves for a grid of points with a spacing of 0.1 degrees in latitude and longitude. This particular data set is for horizontal spectral response acceleration for 1.0-second period with a 10 percent probability of exceedance in 50 years.
thumbnail
Seismic hazard curves were determined using the USGS seismic hazard model for South America. The curves represent the annual rate of exceedance versus peak horizontal acceleration or horizontal spectral response acceleration for 0.2- or 1.0-second periods, for a grid of points with a spacing of 0.1 degrees in latitude and longitude. The hazard curves were used to prepare maps and gridded data that portray peak horizontal acceleration and horizontal spectral response acceleration for 0.2- and 1.0-second periods with a 2%, 10%, and 50% probability of exceedance in 50 years, and a uniform site condition (Vs30) of 760 m/sec. MMI maps for 2%, 10%, and 50% probability of exceedance in 50 years were derived from PGA...
thumbnail
A comparison of the 2021 and 2001 National Seismic Hazard Models (NSHMs) for Hawaii was performed by creating difference and ratio maps for a uniform-hazard with a 2% probability of excedance in 50 years, for spectral accelerations at 0.2 and 1.0 second periods. The data are for a reference site condition of Vs30 equal to 760 m/s. A similar comparison between the ground-motion models (GMMs) used in 2021 versus 2001 was performed by running the 2021 NSHM with the 2001 GMMs. The maps and gridded data used to make the maps are available here for download.
Categories: Data
thumbnail
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...
Each of the downloadable files below contains spectral response accelerations at 22 periods on a grid of latitudes and longitudes that cover this geographic region. See the parent item for how Risk-Targeted Maximum Considered Earthquake (MCER) spectral response accelerations are derived from the data in these files.
thumbnail
This data set represents the results of calculations of hazard curves for a grid of points with a spacing of 0.05 degrees in latitude and longitude. It represents the average Modified Mercalli Intensity (MMI) with a 1-percent probability of exceedance in 1 year. Using a topographic-based soil classification method, the ground motions are amplified for soil type. The MMI values are the average of the MMI values obtained by converting peak ground acceleration to MMI and 1.0-second spectral response acceleration to MMI. The data are for the Western United States and are based on the long-term 2014 National Seismic Hazard Model.
Categories: Data; Types: Downloadable, GeoTIFF, Map Service, Raster
thumbnail
This data set represents the results of calculations of hazard curves for a grid of points with a spacing of 0.05 degrees in latitude and longitude. This particular data set is for horizontal spectral response acceleration for 1.0-second period with a 1 percent probability of exceedance in 1 year. The data are for the Western United States and are based on the long-term 2014 National Seismic Hazard Model.
thumbnail
An updated, declustered seismicity catalog is assembled from several preexisting catalogs. The methodology developed by Mueller (2019) was used to convert original magnitudes to uniform moment magnitudes, delete duplicate events, delete non-tectonic events, and finally decluster the catalog.
thumbnail
A comparison of the 2017 USGS South America seismic hazard model and the 2010 USGS preliminary model was made to see how the models differ. The comparison was made as the ratio of PGA at 10% probability of exceedance in 50 years. The ratio map is included here as a geo-referenced tiff (GeoTIFF). The gridded data for the 2017 PGA at 10% probability can be found here, while the gridded data for the 2010 PGA at 10% probability can be found in the zip archive that can be downloaded using a link on this page.
thumbnail
Maximum considered earthquake geometric mean peak ground acceleration maps (MCEG) are for assessment of the potential for liquefaction and soil strength loss, as well as for determination of lateral earth pressures in the design of basement and retaining walls. The maps are derived from the USGS seismic hazard maps in accordance with the site-specific ground-motion procedures of the NEHRP Recommended Seismic Provisions for New Building and Other Structures and the ASCE Minimum Design Loads for Buildings and Other Structures (also known as the ASCE 7 Standard; ASCE, 2016). The MCEG ground motions are taken as the lesser of probabilistic and deterministic values, as explained in the Provisions. The gridded probabilistic...
thumbnail
A comparison of the 2017 USGS South America seismic hazard model and the Global Seismic Hazard Assessment Program (GSHAP) model was made to see how the models differ. The comparison was made as the ratio of PGA at 10% probability of exceedance in 50 years. The ratio map is included here as a geo-referenced tiff (GeoTIFF). The gridded data for the 2017 PGA at 10% probability can be found here, while the GSHAP data can be found here. Shedlock, K.M., Giardini, Domenico, Grünthal, Gottfried, and Zhang, Peizhan, 2000, The GSHAP Global Seismic Hazar Map, Sesimological Research Letters, 71, 679-686. https://doi.org/10.1785/gssrl.71.6.679


map background search result map search result map 2) Probabilistic seismic hazard maps and data for South America Peak ground acceleration with a 10% probability of exceedance in 50 years 1.0-second spectral response acceleration (5% of critical damping) with a 10% probability of exceedance in 50 years 3) Comparison with previous models Comparison with the 2010 USGS preliminary model Comparison with the 1999 Global Seismic Hazard Assessment (GSHAP) model 0.2-second spectral response acceleration (5% of critical damping) with a 50% probability of exceedance in 50 years Chance of potentially moderate-damage ground shaking in 2018 based on the average of horizontal spectral response acceleration for 1.0-second period and peak ground acceleration for the Central and Eastern United States Modified Mercalli Intensity based on the average of horizontal spectral response acceleration for 1.0-second period and peak ground acceleration, with 1-percent probability of exceedance in 1 year for the Western United States 0.2-second spectral response acceleration (5% of critical damping) with a 1% probability of exceedance in 1 year for the Western United States 1.0-second spectral response acceleration (5% of critical damping) with a 1% probability of exceedance in 1 year for the Western United States 1.6 : American Samoa 1.5 : Guam & the Northern Mariana Islands Data Release for the 2018 Update of the U.S. National Seismic Hazard Model: Where, Why, and How Much Probabilistic Ground Motion Maps Changed 1.6 : American Samoa 1.5 : Guam & the Northern Mariana Islands Modified Mercalli Intensity based on the average of horizontal spectral response acceleration for 1.0-second period and peak ground acceleration, with 1-percent probability of exceedance in 1 year for the Western United States 0.2-second spectral response acceleration (5% of critical damping) with a 1% probability of exceedance in 1 year for the Western United States 1.0-second spectral response acceleration (5% of critical damping) with a 1% probability of exceedance in 1 year for the Western United States Chance of potentially moderate-damage ground shaking in 2018 based on the average of horizontal spectral response acceleration for 1.0-second period and peak ground acceleration for the Central and Eastern United States Data Release for the 2018 Update of the U.S. National Seismic Hazard Model: Where, Why, and How Much Probabilistic Ground Motion Maps Changed Comparison with the 2010 USGS preliminary model Comparison with the 1999 Global Seismic Hazard Assessment (GSHAP) model 2) Probabilistic seismic hazard maps and data for South America 3) Comparison with previous models 1.0-second spectral response acceleration (5% of critical damping) with a 10% probability of exceedance in 50 years 0.2-second spectral response acceleration (5% of critical damping) with a 50% probability of exceedance in 50 years Peak ground acceleration with a 10% probability of exceedance in 50 years