P wave velocity variations in the Coso region, California, derived from local earthquake travel times ( USA).

Abstract

Inversion of 4036 P-wave travel time residuals from 429 local earthquakes using a tomographic scheme provides information about 3-D upper crustal velocity variations in the Indian Wells Valley-Coso region of SE California. Slowness variations in the surface layer reflect local geology, including slow velocities for the sedimentary basins of Indian Wells and Rose valleys and relatively fast velocities for the Sierra Nevada and Argus Mountains. In the depth range of 3-5 km the inversion images an area of reduced compressional velocity in W and N Indian Wells Valley but finds no major velocity variations beneath the Coso volcanic field to the N.-from Authors