Research Interests

I am a geophysicist interested in the composition, dynamics, and evolution of the solid Earth. Some of the major issues that have driven my research are the nature of the plate-tectonic return flow, the formation of a thickened tectosphere beneath the ancient continental cratons, and the question of mantle stratification. I have been involved in developing seismological techniques for elucidating features in the Earth's interior that bear on these and other problems. The results have included demonstrations that lithospheric slabs penetrate into the lower mantle, that large-scale mantle heterogeneities correlate with the low-degree features of the geoid, and that the cratons are stabilized by a thickened chemical boundary layer generated early in the Earth's history. I have also worked on modeling plate motions and using them to constrain neotectonic deformations in plate-boundary zones, on quantifying various aspects of seafloor morphology, and on characterizing what happens during large earthquakes. The latter studies have yielded observations of infraseismic slip episodes that precede some earthquakes on the oceanic ridge-transform system.

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Primary Section

Section 15: Geology

Secondary Section

Section 16: Geophysics