9418942 Wiens This research is to test hypotheses about the faulting mechanism of deep earthquakes involving the spatial distribution and source parameters of the events. These models will be tested using hypocenter and source mechanism inversion methods and 3-D visualization techniques. In March 9, 1994, the largest deep earthquake, M=7.6, in over 20 years occurred beneath Tonga where a temporary deployment of PASSCAL broadband seismographs had been installed by the Principal Investigator. This data set offers a unique opportunity to obtain detailed constraints on the rupture dynamics and aftershock pattern of a large deep earthquake. The results are applicable to seismic hazard estimation in regions of plate tectonic subduction such as Alaska and the Pacific Northwest. This research is a component of the National Earthquake Hazard Reduction Program. *** ??
