SEISMIC AND LIQUEFACTION HAZARD MAPS FOR LAUDERDALE COUNTY, WESTERN TENNESSEE

A five-year seismic and liquefaction hazard mapping project for five western Tennessee counties began in 2017 under a Disaster Resilience Competition grant from the U.S. Department of Housing and Urban Development to the State of Tennessee. The project supports natural hazard mitigation efforts in the counties of Lake, Dyer, Lauderdale, Tipton, and Madison. The county seismic hazard maps for Lake County in northwestern most Tennessee were completed in early 2018. Similar maps for Dyer County were completed in 2019. And now maps for Lauderdale County are being completed in early 2020. Additional geological, geotechnical, and geophysical information has been gathered in Lake, Dyer, and Lauderdale Counties to improve the base northern Mississippi Embayment hazard maps of Dhar and Cramer (2017). Information gathered includes additional geological and geotechnical subsurface exploration logs, water table level data collection and measurements, new measurements of shallow and deep shear-wave velocity (Vs) profiles, and the compilation of existing Vs profiles in and around the counties. Improvements are being made in the 3D geological model, water table model, the geotechnical liquefaction probability curves, and the Vs correlation with lithology model for these counties. Resulting improved soil response amplification distributions on a 0.5 km grid will be combined with the 2014 U.S. Geological Survey seismic hazard model (Petersen et al., 2014) earthquake sources and attenuation models to add the effect of local geology for Lake, Dyer, and Lauderdale Counties. Resulting products will be similar to the Memphis and Shelby County urban seismic hazard maps recently updated by Cramer et al. (2018).