UC Berkeley

Laboratory studies of acoustic emission events with seismic signatures have used the point source assumption. Given the millimeter-scale size and clustering of the asperities and the centimeter-scale distances to the sensors, the records can convey information about the source complexity that is not fully revealed in a point source inversion. We develop a finite source inversion technique following Hartzell and Heaton, 1983 to compute the spatiotemporal distribution of slip during rupture of asperities and asperity clusters. First inversions of purely synthetic signals reveal some of the applicability and limitations of the algorithm. A preliminary inversion of one recorded event is included for demonstration. With much further sensitivity analysis and modeling improvements, the resulting slip profiles will provide a new tool for understanding the frictional strength and rupture behaviors of self-similar rough-rough interfaces at any scale.