A Critical Evaluation of Hypotheses for Fluid Overpressure Along the San Andreas Fault, California: Implications for the Stress-Heat Flow Paradox

Fluids play an important role in the mechanics of earthquake generation. As the pressure of subterranean fluids increase, the stress required to trigger an earthquake decreases. Recent work along the San Andreas Fault indicates a fundamental paradox in that the apparent stress along the fault is insufficient, according to theory, to generate earthquakes. One possible solution is that the fluid pressures are sufficiently high that the low stress that is present is still sufficient to trigger earthquakes. The proposed work will model several sources and mechanisms for developing and maintaining elevated fluid pressures in the San Andreas Fault region. The quantitative constraints provided by this research will aid in a more thorough understanding of factors which may relate to earthquakes in California and elsewhere in the world.