This research will study the detailed source processes of the Loma Prieta earthquake using a combined teleseismic data set including teleseismic broad-band and short-period body waves and strong motion data near the source. To simulate the highest frequency energy radiated by the mainshock, the research will include the analysis of aftershocks used as empirical Green's functions. By means of this technique, details of the main shock rupture surface will be mapped. This research is a component of the National Earthquake Hazard Reduction Program.