On August 31, 1886, Charleston, South Carolina experienced the most damaging earthquake recorded in the Eastern United States. The earthquake had an estimated magnitude of 6.9 to 7.3 and was felt over 2.5 million square miles. Earthquake events have been documented in South Carolina since 1698. Seventy percent of these are located in the Middleton Place–Summerville Seismic Zone (MPSSZ), 30 kilometers northwest of downtown Charleston. 137 earthquakes were recorded in the MPSSZ from 1996 through 2003. The amount of damage that could occur from a reoccurrence of an earthquake of magnitude 6.0 or higher within the region is greater now due to changes in land use and population growth. Major hazards are due to ground shaking and liquefaction.

HAZUS-MH is a natural hazard loss estimation methodology developed by FEMA in partnership with the National Institute of Building Sciences. HAZUS-MH provides state and local decision makers with a better understanding of the types and magnitude of damage caused by natural hazards. It is dependent on and sensitive to the quality of information that is used to determine the degree of hazard. The Earthquake module in HAZUS-MH requires information derived from the NEHRP (National Earthquake Hazards Reduction Program) soil maps in order to determine the extent of damage due to ground shaking and liquefaction. Small changes in the NEHRP soil maps can lead to major differences in the final HAZUS-MH determination. This research looks at the sensitivity of the HAZUS methodology related to the resolution and accuracy of the NEHRP Soil Maps, and how better soil maps can lead to better damage estimates for emergency managers and planners.

Supplemental information generated by this research is contained in an electronic format addendum. There are two file types. The first is a combined PDF of the HAZUS generated damage estimate reports for all scenarios mentioned in the body of the text. The second file type is that of the data tables used to develop the models. There are three data table files. There is one each of the USGS Geology, SSURGO Soils and STATSGO Soils data sets. Due to the extremely large size of the PDF and length of the tables, it was not feasible to include them as figures and tables in the text.