The Significant Earthquake Database is a global listing of over 5,700 earthquakes from 2150 BC to the present. A significant earthquake is classified as one that meets at least one of the following criteria: caused deaths, caused moderate damage (approximately $1 million or more), magnitude 7.5 or greater, Modified Mercalli Intensity (MMI) X or greater, or the earthquake generated a tsunami. The database provides information on the date and time of occurrence, latitude and longitude, focal depth, magnitude, maximum MMI intensity, and socio-economic data such as the total number of casualties, injuries, houses destroyed, and houses damaged, and $ dollage damage estimates. References, political geography, and additional comments are also provided for each earthquake. If the earthquake was associated with a tsunami or volcanic eruption, it is flagged and linked to the related tsunami event or significant volcanic eruption.

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, Arizona, Montana, Wyoming, Colorado, New Mexico and Texas. Datasets containing fault information for Alaska and the Central and Eastern United States will be the subject of future efforts. These databases are provided as geospatial data (e.g., .SHP and .GeoJSON file formats) and tables (.CSV or .TXT format). Please note: these databases are updated as of February 2022 (version 2), which supersede the databases release in January 2021 (version 1).

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, Arizona, Montana, Wyoming, Colorado, New Mexico and Texas. Datasets containing fault information for Alaska and the Central and Eastern United States will be the subject of future efforts. These databases are provided as geospatial data (e.g., .SHP and .GeoJSON file formats) and tables (.CSV or .TXT format). Please note: these databases are updated as of February 2022 (version 2), which supersede the databases release in January 2021 (version 1).

The NOAA National Centers for Environmental Information ceased providing support for this product in April 2025 in response to an initiative to implement reductions within the U.S. federal government. The U.S. Earthquake Intensity Database (1638–1985) is a collection of damage and felt reports for more than 23,000 U.S. earthquakes. The database contains information regarding epicentral coordinates, magnitudes, focal depths, names, and coordinates of reporting cities/ localities, reported intensities, and the distances to the epicenter. Earthquakes listed in the file date from 1638 to 1985. The majority of the felt reports are in the U.S. States and Territories (155,301). Other reporting countries include: Antigua and Barbuda (2), Canada (1,364), Mexico (54), Panama (285), and the Philippines (9).

Location: Central California, 20.8 kilometers from Coalinga. Affected area: 205,000 square kilometers. Damage: $31 million. The most serious damage occurred in the eight-block downtown commercial district, but residents were also heavily damaged. More then 800 single-family houses were destroyed or incurred major damage. The majority of the 94 injuries occurred in residential sections of the city.

This Data Release contains version 3.0 of two related earthquake geology databases for use in the 2023 U.S. National Seismic Hazard Model. The databases are: 1) A fault sections database (“NSHM23_FSD_v3”), which depicts the geometry of faults capable of hosting independent earthquakes, and 2) an earthquake geology site information database (“NSHM23_EQGeoDB_v3”), which contains fault slip rate constraints at points. These databases cover the 12 western U.S. states: Washington, Oregon, California, Idaho, Nevada, Arizona, Montana, Wyoming, Colorado, New Mexico and Texas. Datasets containing crustal fault information for Alaska and the central and eastern United States were prepared by Bender and others, 2021 and Thompson Jobe and others, 2023 in separate efforts. The two databases are broken into separate child items from this landing page. The databases are provided as geospatial data (.SHP, .KML, and GeoJSON file formats) and tables (.CSV format). Reference information, including change log, version notes, and a README, are included as "Attached Files" below this Summary. Versioning These databases are updated as of December 2023 (version 3.0), which supersede the databases release in February 2022 (version 2.0) and the January 2021 (version 1.0) preliminary datasets. After significant testing by many user groups, this version 3.0 data release contains minor changes. The specific changes made in the fault sections database (FSD) from version 2.0 (2022) to version 3.0 (2023; this release) are outlined in "NSHM23_FSD_v2-v3_VersionChanges.txt." The changes to the EQGeoDB involve fixing typos and further populating the reference list to include UCERF3 references; the authors acknowledge Scott Marshall (Appalachian State University) for uncovering these additional references. Note on the Cheraw fault: At the time of original compilation (2020-2021), the Cheraw fault of Colorado was included in the western U.S. fault sections database. During model implementation, the Cheraw fault was instead treated as a central and eastern U.S. fault. To maintain consistency with earlier releases, we retain the Cheraw fault geometry and attributes in this table. For more information, please review Shumway and others., in press manuscript about CEUS fault implementation. For more information on how these datasets were compiled, please refer to our manuscript publication, Hatem and others, 2022. References Cited Bender, A.M., Haeussler, P.J. and Powers, P.M., 2021, Geologic inputs for the 2023 Alaska update to the U.S. National Seismic Hazard Model (NSHM) (ver. 2.0, February 2023): U.S. Geological Survey data release, https://doi.org/10.5066/P97NRR0F Hatem, A.E., Collett, C.M., Briggs, R.W., Gold, R.D., Angster, S.J., Field, E.H., Powers, P.M. and the Earthquake Geology Working Group, 2022, Simplifying complex fault data for systems-level analysis: Earthquake geology inputs for US NSHM 2023. Scientific data, 9(1), 506. https://doi.org/10.1038/s41597-022-01609-7 Shumway, A.M., Petersen, M.D., Powers, P.M., Toro, G., Altekruse, J. M., Herrick, J.A., Rukstales, K.S., Thompson Jobe, J.A., Hatem, A.E., and Girot, D.L., in press, Earthquake Rupture Forecast Model Construction for the 2023 U.S. 50-State National Seismic Hazard Model Update: Central and Eastern U.S. Fault-Based Source Model. Seismological Research Letters. Thompson Jobe, J.A., Hatem, A.E., Gold, R.D., DuRoss, C., Reitman, N.G., Briggs, R.W., and Collett, C.M., 2022, Earthquake geology inputs for the National Seismic Hazard Model (NSHM) 2023 (central and eastern United States), version 1.0: U.S. Geological Survey data release, https://doi.org/10.5066/P94HLE5G

This Data Release contains version 3.0 of two related earthquake geology databases for use in the 2023 U.S. National Seismic Hazard Model. The databases are: 1) A fault sections database (“NSHM23_FSD_v3”), which depicts the geometry of faults capable of hosting independent earthquakes, and 2) an earthquake geology site information database (“NSHM23_EQGeoDB_v3”), which contains fault slip rate constraints at points. These databases cover the 12 western U.S. states: Washington, Oregon, California, Idaho, Nevada, Arizona, Montana, Wyoming, Colorado, New Mexico and Texas. Datasets containing crustal fault information for Alaska and the central and eastern United States were prepared by Bender and others, 2021 and Thompson Jobe and others, 2023 in separate efforts. The two databases are broken into separate child items from this landing page. The databases are provided as geospatial data (.SHP, .KML, and GeoJSON file formats) and tables (.CSV format). Reference information, including change log, version notes, and a README, are included as "Attached Files" below this Summary. Versioning These databases are updated as of December 2023 (version 3.0), which supersede the databases release in February 2022 (version 2.0) and the January 2021 (version 1.0) preliminary datasets. After significant testing by many user groups, this version 3.0 data release contains minor changes. The specific changes made in the fault sections database (FSD) from version 2.0 (2022) to version 3.0 (2023; this release) are outlined in "NSHM23_FSD_v2-v3_VersionChanges.txt." The changes to the EQGeoDB involve fixing typos and further populating the reference list to include UCERF3 references; the authors acknowledge Scott Marshall (Appalachian State University) for uncovering these additional references. Note on the Cheraw fault: At the time of original compilation (2020-2021), the Cheraw fault of Colorado was included in the western U.S. fault sections database. During model implementation, the Cheraw fault was instead treated as a central and eastern U.S. fault. To maintain consistency with earlier releases, we retain the Cheraw fault geometry and attributes in this table. For more information, please review Shumway and others., in press manuscript about CEUS fault implementation. For more information on how these datasets were compiled, please refer to our manuscript publication, Hatem and others, 2022. References Cited Bender, A.M., Haeussler, P.J. and Powers, P.M., 2021, Geologic inputs for the 2023 Alaska update to the U.S. National Seismic Hazard Model (NSHM) (ver. 2.0, February 2023): U.S. Geological Survey data release, https://doi.org/10.5066/P97NRR0F Hatem, A.E., Collett, C.M., Briggs, R.W., Gold, R.D., Angster, S.J., Field, E.H., Powers, P.M. and the Earthquake Geology Working Group, 2022, Simplifying complex fault data for systems-level analysis: Earthquake geology inputs for US NSHM 2023. Scientific data, 9(1), 506. https://doi.org/10.1038/s41597-022-01609-7 Shumway, A.M., Petersen, M.D., Powers, P.M., Toro, G., Altekruse, J. M., Herrick, J.A., Rukstales, K.S., Thompson Jobe, J.A., Hatem, A.E., and Girot, D.L., in press, Earthquake Rupture Forecast Model Construction for the 2023 U.S. 50-State National Seismic Hazard Model Update: Central and Eastern U.S. Fault-Based Source Model. Seismological Research Letters. Thompson Jobe, J.A., Hatem, A.E., Gold, R.D., DuRoss, C., Reitman, N.G., Briggs, R.W., and Collett, C.M., 2022, Earthquake geology inputs for the National Seismic Hazard Model (NSHM) 2023 (central and eastern United States), version 1.0: U.S. Geological Survey data release, https://doi.org/10.5066/P94HLE5G

Generally referred to as August 31, 1886, as the earthquake occurred at 9:51 pm local time. Eight minutes later there was a severe aftershock. This was the most damaging earthquake to occur in the southeastern U.S. and one of the largest historic shocks in eastern North America. Structural damage was reported within several hundred kilometers from Charleston, and long-period effects were observed at distances exceeding 1,000 kilometers.

Epicenter: 34.0 degrees N, 118.1 degrees W. Magnitude: 5.9. Damage: $358 million. Eight deaths. The fault which ruptured was located about 11 kilometers below the surface, and 20 kilometers east of downtown Los Angeles. The fault was an extension of the previously identified Whittier Fault. Severe damage was confined mainly to communities of Los Angeles and near the epicenter.

The updated 2018 National Seismic Hazard Model includes new ground motion models, aleatory uncertainty, and soil amplification factors for the central and eastern U.S. and incorporates basin depths from local seismic velocity models in four western U.S. (WUS) urban areas. These additions allow us, for the first time, to calculate probabilistic seismic hazard curves for an expanded set of spectral periods (0.01 s to 10 s) and site classes (VS30 = 150 m/s to 1,500 m/s) for the conterminous U.S. (CONUS), as well as account for amplification of long-period ground motions in deep sedimentary basins in the Los Angeles, San Francisco Bay, Salt Lake City, and Seattle regions. Ground motion data for 2, 5, and 10 percent probability of exceedance in 50 years have been derived from these hazard curves.Two sets of data are available: (1) 0.05 by 0.05 degree gridded hazard data for the CONUS and (2) 0.01 by 0.01 degree gridded hazard data for WUS basins. Note that both sets of data contain basin amplification in deep sedimentary basins in the WUS. The 0.01 degree by 0.01 degree data simply provides a higher resolution dataset than then 0.05 degree by 0.05 degree dataset. This dataset is discussed in the journal article titled: "The 2018 update of the US National Seismic Hazard Model: Additional period and site class data" by Shumway et al. (2021) located at https://doi.org/10.1177/8755293020970979. First Posted - October 7, 2019 Revised - February 2020 (ver 1.1) Revised - May 2021 (ver 1.2)