9405533 Ruff This research will systematically study the seismic events that may precede a large earthquake: multiplets, foreshocks, and rupture precursors. In parallel with the earthquake studies, the work will involve the development of simple mechanical models of interaction between stick-slip and creeping portions of the plate interface. The goal of these models is to provide an explanation of observations such as variability in recurrence times, rupture modes, and earthquake size form one earthquake cycle to the next. The overall goal is a systematic study of multiplets, foreshocks, and rupture precursors and how these seismicity features relate to other geologic characteristics in their tectonic setting. This research is a component of the National Earthquake Hazard Reduction Program. ***
