9316160 Booker This is a project involving the collection of a continuous tensor electromagnetic profile (EMAP) across the San Andreas Fault in central California. The experiment has the potential to resolve targets of direct relevance to the earthquake process including high conductivity and presumably high pore pressure regions within the fault zone, resistive and hence impermeable membranes between the fault zone and the country rock and enhanced crustal conductivity below the brittle-ductile transition. However, detailed investigation of electrical structure within the fault zone at seismogenic depths is likely to require a controlled electromagnetic source deployed in conjunction with a deep drill hole. Detailed knowledge of the background electrical structure is a key requirement for design of such an experiment and providing this information is as important as the potential for direct insight from the EMAP data. ***
