9614525 Cormier This research is to investigate the heterogeneity, anisotropy, and anelasticity of the earth's lowermost mantle and core by means of observed and predicted seismic waveforms interacting with those structures. PKIKP precursors will be modeled in statistically described structures of the lowermost mantle and compared with observations. In this comparison, a unified model will be determined, consistent with both PKIKP precursor data as well as with all other broadband waveforms interacting with the core-mantle boundary. A study will also be made of the scatter typically found in the measurements of the anelasticity of the inner core. The results of these studies will be important to geodynamic models of slab cycling, plume formation, and chemical heterogeneity of the earth's deep mantle and to the search for constraints on the high pressure mineral phase of iron in the earth's inner core. ***