Probabilistic Liquefaction Hazard Maps for Memphis, Tennessee

Abstract

Until recently most regional maps of liquefaction hazard have been based primarily on geology, following the methodology of Youd and Perkins (1978). These maps predict the triggering of liquefaction and not its consequences. More than 50 of these maps, showing different areas of the United States, have been published since the methodology was first proposed (Power and Holzer 1996). Maps range in scale from 1:24,000 to 1:390,000. One shortcoming to these maps is that they usually depict the liquefaction hazard with a qualitative ranking, e.g. , low, moderate, or high. Without specifying the hazard, these maps are not useful for risk-based studies. Recently, Holzer et al. (2003), Holzer, Bennett, Noce et al. (2006), and Romero-Hudock and Rix (2005) have applied the liquefaction potential index (LPI) proposed by Iwasaki et al. (1978, 1982) to estimate and map liquefaction probability. Maps of the surficial geology were initially produced for generating seismic hazard maps for Memphis, Tennessee (see references in Cramer et al. 2006). Additionally, the liquefaction potential or probability curve for different soil columns in Memphis also has been developed along with scenario liquefaction potential maps (Romero-Hudock and Rix 2005). Specifically, scenario liquefaction potential maps for moment magnitude (M) 7.7 and 6.2 earthquakes in the southern New Madrid seismic zone were generated by Romero-Hudock and Rix (2005) prior to this study. In this paper we describe the methodology, procedure, and data used in generating probabilistic liquefaction hazard maps for Memphis, and we present the resulting maps. The Memphis liquefaction hazard maps present information in a format similar to the scenario liquefaction potential maps for Memphis by Romero-Hudock and Rix (2005). As proposed by Holzer, Bennett, Noce et al. (2006), Holzer, Blair, Noce et al. (2006), and Holzer et al. (2003), cumulative distributions of LPI for a specified earthquake magnitude and …