Ground motion prediction using coda-wave interferometry for the Sounthern San andreas fault

Abstract

Ground motion prediction in urban areas that are under the threat of major earthquakes, such as Los Angeles, is a challenge for seismic hazard analysis. The effect of complex sedimentary basins is a source of particular concern for simulating wave propagation here. Previous works developed a new approach that directly accounts for elastic and anelastic effects, through computing the Green's function using seismic noise. However, this technique is limited because the distribution of the noise sources in southern California is not homogeneous. This project used coda-wave interferometry of the M7.2 El Mayor-Cucapah aftershock to extract the Green’s function for stations along the southern San Andreas fault. By stacking the Green's function, we found that Green’s function can be extracted from coda-wave interferometry and has higher signal to noise ratio than seismic noise Green’s function that implied more accurate Green’s function. Furthermore, the combination of both would greatly enhance the accuracy of the retrieved Green's function. Finally, obtained coda-wave Green’s function can be used to predict ground motion in Los Angeles sedimentary basin as a response to M7+ earthquake on the San Andreas fault.