P-Wave Study of the San Andreas Fault Near Parkfield, CA, from Ambient Noise Interferometry of Borehole Seismic Data

Abstract

In this thesis, we investigate and develop the optimal data processing procedures necessary to recover Green’s functions for body waves propagating among a network of borehole seismometers near Parkfield, CA. Applying these procedures, we detect P-waves propagating among these stations, which allows us to produce a first-order crustal velocity model for the San Andreas Fault in the Parkfield region. We also discuss under what conditions body wave phenomena such as reflections and mode conversions (P to S) may be observed, as further observing these would provide a dramatic improvement in our ability to characterize seismic velocity structures. Finally, we discuss the potential of seismic interferometry to produce time-lapse body wave characterizations of the San Andreas Fault, in which properties of the fault can be seen to change in time.