9418643 Lay This research involves the use of broadband seismic data to address fundamental questions about earth structure and earthquake rupture processes. The areas to be studied include short-period analysis of layering near subduction zones, deep slab energy focusing effects and associated slab structure, tectonic analysis of new aspherical global shear-wave models, development of unified seismic source models from body wave and surface wave data. The results apply to convection in the mantle which is the driving force of plate tectonics, and to details of the generation of seismic waves in a multiple rupture earthquake process. This research is a component of the National Earthquake Hazard Reduction Program. *** ??
