by Mark D. Zoback, Stephen Hoyt Hickman, William L. Ellsworth

Phase 1 of the SAFOD (San Andreas Fault Zone Observatory at Depth) project will commence drilling around June 1, 2004. All direct expenses associated with this project are covered by the National SAcience Foundation as part of the EarthScope program or provided through direct and “in kind” support by the U.S. Geological Survey. ICDP has had a long involvement with SAFOD. Most notably, ICDP financial support paid for drilling and Downhole measurements in the highly successful pilot hole drillied in 2002. In this proposal we seek funding ($83,950) to enable members of the ICDP Operational Support to participate in Phase 1 of the SAFOD project. Three individuals will provide support. Lothar Wohlgemuth will serve as Drilling Manager during the ~120 day campaign. Jochem Kück will provide occasional expertise and assistance with respect to planned Downhole measurements and deployment of monitoring instrumentation. Ronald Conze will assist the project in the utilization of the ICDP Drilling Information System. The DIS was extremely valuable during the drilling of the SAFOD pilot hole in 2002. Finally, ICDP personnel will be used to staff the real-time collection and analysis of gases in the drilling fluid. These measurements proved to be quite successful in the SAFOD pilot hole. Subsequent proposals will be submitted for the Phase 2 drilling in the summer of 2005 and Phase 3 coring activities in the summer 2007. As these campaigns will be similar in duration to Phase 1, these proposals will be of similar financial scope.

• The central scientific objective of the San Andreas Fault Observatory at Depth (SAFOD) is to study directly the physical and chemical processes that control deformation and earthquake generation within an active plate-bounding fault zone. SAFOD will enable a broad spectrum of earth science community to address multiple scientific objectives: The results of the proposed experiment are critical to development of more realistic models for the seismic cycle and assessment of the practicability of short-term earthquake prediction. As the weakness of plate boundary (relative to plate interiors) is a fundamental aspect of plate tectonics, how and why plate boundary faults lose their strength is of first-order importance for understanding where plate boundaries form, how they evolve with time and how deformation is partitioned along them.

Active Faulting, California, Directional Drilling, Downhole Monitoring, Earthquakes, ICDP-2004/04, Parkfield, SAFOD, San Andreas Fault, U.s.a.

Latitude: 35.9742579, Longitude: -120.5521071