This dataset contains earthquake catalogs compiled for Alaska from U.S. Geolgical Survey (USGS) Advanced National Seismic System (ANSS) Comprehensive Earthquake Catalog (ComCat) (USGS, 2017) and Natural Resources Canada (NRCan) Canadian National Earthquake Database (NRCan, 1985) catalog searches and processed following the methods of Mueller (2019) and Llenos et al. (2024). Catalogs are deculstered using multiple methods and segregated into crustal, subduction interface, and subduction intraslab catalogs using Slab2 (Hayes, 2018).

The U.S. National Seismic Hazard Model (NSHM) for the state of Alaska was updated in 2023 as part of the 50-state NSHM update. The new model incorporates more than 15 years of additional science since the release of the previous model in 2007 and has been reviewed by a six-member review panel and a supplementary eight-member team of ground motion model developers. This time-independent probabilistic seismic hazard model applies new earthquake catalogs, declustering algorithms, gridded seismicity models, magnitude-scaling relations, geologic and geodetic deformation models, and ground motion models. This data release supports the 2023 Alaska NSHM and includes the seismicity catalogs used to develop the model, hazard curves and uniform-hazard ground motions for the state of Alaska, and multiple period response spectra for the Alaska test sites.

The U.S. National Seismic Hazard Model (NSHM) for the state of Alaska was updated in 2023 as part of the 50-state NSHM update. The new model incorporates more than 15 years of additional science since the release of the previous model in 2007 and has been reviewed by a six-member review panel and a supplementary eight-member team of ground motion model developers. This time-independent probabilistic seismic hazard model applies new earthquake catalogs, declustering algorithms, gridded seismicity models, magnitude-scaling relations, geologic and geodetic deformation models, and ground motion models. This data release supports the 2023 Alaska NSHM and includes the seismicity catalogs used to develop the model, hazard curves and uniform-hazard ground motions for the state of Alaska, and multiple period response spectra for the Alaska test sites.

The U.S. National Seismic Hazard Model (NSHM) for the state of Alaska was updated in 2023 as part of the 50-state NSHM update. The new model incorporates more than 15 years of additional science since the release of the previous model in 2007 and has been reviewed by a six-member review panel and a supplementary eight-member team of ground motion model developers. This time-independent probabilistic seismic hazard model applies new earthquake catalogs, declustering algorithms, gridded seismicity models, magnitude-scaling relations, geologic and geodetic deformation models, and ground motion models. This data release supports the 2023 Alaska NSHM and includes the seismicity catalogs used to develop the model, hazard curves and uniform-hazard ground motions for the state of Alaska, and multiple period response spectra for the Alaska test sites.

Gridded seismic hazard curve data, gridded ground motion data, and mapped gridded ground motion values are available for the 2007 Alaska Seismic Hazard Model. Time-independent probabilistic seismic hazard data and maps of Alaska and the Aleutians for peak ground acceleration (PGA) and 0.1, 0.2, 0.3, 0.5, 1.0 and 2.0 second spectral acceleration at probability levels of 2 percent in 50 years (annual probability of 0.000404), 5 percent in 50 years (annual probability of 0.001026), and 10 percent in 50 years (annual probability of 0.0021) assuming firm rock soil conditions at 760 m/s are available. Development of the 2007 Alaska Seismic Hazard Model is documented in the USGS Open-File Report 2007-1043 (https://pubs.usgs.gov/of/2007/1043/). This dataset is considered a legacy dataset. The original dataset was uploaded to the USGS website at the time of publication of the seismic hazard model (2007) but was later moved over the the USGS ScienceBase Catalog (2019). The original dataset was assumed to be complete and accurate, but may contain inconsistencies when compared to more recent, actively maintained datasets.

Gridded seismic hazard curve data, gridded ground motion data, and mapped gridded ground motion values are available for the 2007 Alaska Seismic Hazard Model. Time-independent probabilistic seismic hazard data and maps of Alaska and the Aleutians for peak ground acceleration (PGA) and 0.1, 0.2, 0.3, 0.5, 1.0 and 2.0 second spectral acceleration at probability levels of 2 percent in 50 years (annual probability of 0.000404), 5 percent in 50 years (annual probability of 0.001026), and 10 percent in 50 years (annual probability of 0.0021) assuming firm rock soil conditions at 760 m/s are available. Development of the 2007 Alaska Seismic Hazard Model is documented in the USGS Open-File Report 2007-1043 (https://pubs.usgs.gov/of/2007/1043/). This dataset is considered a legacy dataset. The original dataset was uploaded to the USGS website at the time of publication of the seismic hazard model (2007) but was later moved over the the USGS ScienceBase Catalog (2019). The original dataset was assumed to be complete and accurate, but may contain inconsistencies when compared to more recent, actively maintained datasets.

Gridded ground motion data and mapped gridded ground motion values are available for the 1999 Alaska Seismic Hazard Model. Probabilistic seismic hazard data and maps of Alaska and the Aleutians for peak ground acceleration (PGA) and 0.2, 0.3, and 1.0 second spectral acceleration at probability levels of 2 percent in 50 years (annual probability of 0.000404) and 10 percent in 50 years (annual probably of 0.0021), assuming firm rock soil conditions at 760 m/s, are available. Development of the 1999 Alaska Seismic Hazard Model is documented in the USGS Open-File Report 99-36 (https://doi.org/10.3133/ofr9936). This dataset is considered a legacy dataset. The original dataset was uploaded to the USGS website at the time of publication of the seismic hazard model (1999) but was later moved over the the USGS ScienceBase Catalog (2019). The original dataset was assumed to be complete and accurate, but may contain inconsistencies when compared to more recent, actively maintained datasets.

Gridded ground motion data and mapped gridded ground motion values are available for the 1999 Alaska Seismic Hazard Model. Probabilistic seismic hazard data and maps of Alaska and the Aleutians for peak ground acceleration (PGA) and 0.2, 0.3, and 1.0 second spectral acceleration at probability levels of 2 percent in 50 years (annual probability of 0.000404) and 10 percent in 50 years (annual probably of 0.0021), assuming firm rock soil conditions at 760 m/s, are available. Development of the 1999 Alaska Seismic Hazard Model is documented in the USGS Open-File Report 99-36 (https://doi.org/10.3133/ofr9936). This dataset is considered a legacy dataset. The original dataset was uploaded to the USGS website at the time of publication of the seismic hazard model (1999) but was later moved over the the USGS ScienceBase Catalog (2019). The original dataset was assumed to be complete and accurate, but may contain inconsistencies when compared to more recent, actively maintained datasets.

This data set represents multi-period response spectra (MPRS) results for 36 Alaska test sites using the 2023 National Seismic Hazard Model for the state of Alaska. The data sets includes (1) probabilistic seismic hazard curves (full and truncated) for peak ground velocity (PGV), peak ground acceleration (PGA), and spectral accelerations at 21 spectral periods from 0.01 to 10 seconds 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). Results are provided for Vs30s (time-averaged shear-wave velocity [VS] in the upper 30 m) of 1500, 1080, 760, 530, 365, 260, 185, and 150 m/s, representing the National Earthquake Hazards Reduction Program site conditions A, B, BC, C, CD, D, DE and E, respectively. Two different sets of hazard curves are available, full (curves.csv) and truncated (curves-truncated.csv). The full gridded hazard curves data include ground motions at long return periods, whereas the truncated curves only span return periods of 10,000 years (annual frequency of exceedance of 1.0E-04) and less. The National Seismic Hazard Models are not intended to provide ground motions at return periods longer than 10,000 years.

This data set represents multi-period response spectra (MPRS) results for 36 Alaska test sites using the 2023 National Seismic Hazard Model for the state of Alaska. The data sets includes (1) probabilistic seismic hazard curves (full and truncated) for peak ground velocity (PGV), peak ground acceleration (PGA), and spectral accelerations at 21 spectral periods from 0.01 to 10 seconds 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). Results are provided for Vs30s (time-averaged shear-wave velocity [VS] in the upper 30 m) of 1500, 1080, 760, 530, 365, 260, 185, and 150 m/s, representing the National Earthquake Hazards Reduction Program site conditions A, B, BC, C, CD, D, DE and E, respectively. Two different sets of hazard curves are available, full (curves.csv) and truncated (curves-truncated.csv). The full gridded hazard curves data include ground motions at long return periods, whereas the truncated curves only span return periods of 10,000 years (annual frequency of exceedance of 1.0E-04) and less. The National Seismic Hazard Models are not intended to provide ground motions at return periods longer than 10,000 years.