9725175 Ruff This research is a continuation of the routine cataloging of large-earthquake source time functions, and the investigation into the application of this catalog to study of tectonic regions of the earth. The cataloging of source time functions is an addition to traditional on-going cataloging of earthquake parameters including the time, location, magnitude, first-motion focal mechanism, and the moment tensor. The source time function is the history of the moment release during the earthquake that, depending on the frequency-content of the energy, is spatially averaged over the faulted region. Shorter-period energy gives more detail of the earthquake rupture process. Further investigation involves the search for systematics of parameters of the source time function that can give insight into earthquakes as a function of their tectonic setting. This research is a component of the National Earthquake Hazard Reduction Program. ***
