This research will develop a new global three-dimensional S- wave velocity model for the upper mantle with lateral resolution of on the order of 1000 km or less. The new aspect of this project is that it will depart fundamentally from the approach of using little or no a priori information which underlies all recent seismological tomographic studies. To better account for the overwhelming influence of shallow lithospheric velocity heterogeneity, a regionalized initial model, including topographic, crustal and lithosphere variations will be used in some of the inversion. The inversions will include simultaneous determination of source locations and structure using Love and Rayleigh wave spectral data. This project will promote multi-disciplinary advances in the study of plate tectonics, mantle dynamics and the geoid, and petrology and geochemistry of the lithosphere.
