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)