9316733 Roecker This project involves a collaborative investigation of the structure of the crust along the San Andreas fault zone in the Northern Gabilan Range, California. A principal focus of the investigation will be the collection and analysis of seismic data from linear and 2-D arrays of PASSCAL stations deployed across the San Andreas fault. Specific objectives are to use the data collected by the arrays to 1) resolve details of the fault zone structure through forward modeling of travel times and waveforms and tomographic imaging of travel times of various phases (P,S, converted, etc.) from both active and passive sources, 2) use the improved velocity structures to relocate hypocenters to improve the definition of fault complexity at depth, 3) examine anisotropy in the fault zone through shear wave splitting, and 4) determine if and where trapped modes propagate efficiently within the fault zone. ***
