9507994 HEDLIN This research is to analyze global network recordings of short- period precursors to the inner-core seismic phase PKP(DF) in order to test the feasibility of directly imaging small scatterers at or near the core-mantle boundary (CMB). The expectation is that migration techniques developed for crustal scattering problems can be used to back-project precursor energy from the free-surface to the CMB. A goal is to identify areas in which we have sufficient resolution to image small-scale CMB scatterers and to discriminate between core entry and exit point structure. Following synthetic experiments, a comprehensive analysis will be done of PKP(DF) precursors in all available short-period and broadband data from the global seismic networks. This research is a component of the Cooperative Studies of the Earth's Deep Interior program. ***
