9416756 Lettis This study will produce a detailed map of liquefaction susceptibility in the Simi Valley, Ventura County, California, an area of rapid urban development. Limited liquefaction and lateral spreading occurred in the region during the January 17, 1994 Northridge earthquake, which presents an hitherto unassessed hazard in this and other alluviated valleys of the Los Angeles area. Liquefaction is generally restricted to areas within a narrow range of identifiable geologic and hydrogeologic characteristics in Quaternary deposits. The distribution of Quaternary deposits will be mapped at surface and in shallow subsurface, and liquefaction susceptibility determined using the criteria set forth by the California Division of Mines and Geology Seismic Hazards Mapping group. Primary areas of concern are historically-deposited sediments and areas of saturated, poorly engineered artificial fill. Methodology will include field mapping at 1:24,000 and collection of borehole data. The final products will include a digitized 1:24,000-scale Quaternary geology map, a 1:24,000-scale liquefaction susceptibility map and a final report, all of which will be freely available to earth scientists, engineers, planners and government agencies, including the USGS. An easy-to-read version of the final report will be made available for a lay audience. ***
