Kirchhoff Coda Migration of Regional Network Data

9614874 Revenaugh This research involves the mapping of crustal scatterers by means of the application of Kirchhoff migration inversion techniques to local earthquake data. Current research has successfully emonstrated the effectiveness of the methodology using three different scattering modes. 1) P scattered into Rg due to topography and scattered Rg due to shear-wave heterogeneity; 2) P to P scattering due to a subducting slab; and 3) P to S scattering due to fault zone heterogeneity, presumably temporal in nature related to the timing of earthquake occurrence. This work will involve modification of the migration technique to better model high-frequency wave propagation, include azimuthally varying scattering intensity and site responses and use the latest tomographic models in the travel time calculations. Data from seismic arrays in California, Hawaii, and western Washington will be used. The results are related to earthquake hazard mapping, volcanic hazard mapping and crustal and upper mantle structure. This research is a component of the National Earthquake Hazard Reduction Program. ***