Scale and Mechanism of Lateral Heterogeneity in the Oceanic Upper Mantle

This research is to study the extent and mechanism of lateral heterogeneity in the oceanic upper mantle. The method of analysis will be joint inversion of seismic wave travel times, geoid, and bathymetry anomalies to determine upper mantle temperature and/or compositional variations. It is intended to attempt to distinguish between the competing models of thermal and compositional mechanisms for lateral heterogeneity on a regional (500-5000 km) scale in the vicinity of mid-ocean ridges and mid-plate swells. The initial effort will be to incorporate surface wave data into the joint inversion and apply the technique to the East Pacific Rise region.