Teleseismic imaging with wave equation migration

Charles K. Wilson, Jeff Shragge, and Brad Artman

wilsonck@sep.stanford, brad@sep.stanford.edu, jeff@sep.stanford.edu

ABSTRACT

Images of the lithosphere from three-component seismic arrays recording wavefields generated by teleseismic earthquakes (30- 90 epicentral distance) reveal important aspects of lithospheric structure. Unfortunately, interpretation of these images remains ambiguous due to improper reflector mapping and amplitude restoration. We introduce the shot-profile representation of wave equation migration as a novel way to cast the teleseismic imaging problem. We show results from two synthetic datasets using both forward- and backscattered modes to demonstrate the strength of this imaging scheme. To demonstrate the techniques effictiveness with real data, we present preliminary images from the forward-scattered P-to-S mode from data collected across the Proterozoic Cheyenne suture near Laramie, Wyoming.