Deep scientific drilling in the San Andreas Fault Zone

A deep scientific drilling experiment in San Andreas fault zone would provide data essential to understanding the structure, composition, mechanical behavior, and physical state of an active, major plate‐boundary fault. Toward this end, we are working with an international team of scientists and engineers to propose a long‐term, integrated program of surface‐based geological and geophysical investigations and deep drilling along the San Andreas fault system. Prior to drilling, a suite of comparative geodynamic models will be developed incorporating detailed investigations of geology, crustal structure, geophysical environment, hydrology, seismotectonics, and fault‐movement history at each of the candidate sites. These studies will have a major impact on our understanding of the structure and physical properties of the San Andreas fault system and will form a critical framework for applying the knowledge gained in a deep San Andreas borehole to other segments of the fault and other tectonic environments.