Research Interests

I am a geophysicist and a student of the inner workings of Earth-like planets and their manifestations at planetary surfaces. For the Earth itself my principal investigative tool has been seismology, with which I have pursued the nature of the processes that form new crust at mid-ocean ridges, the evolution and state of stress of the lithosphere, and the seismic-velocity signatures of mantle convective flow beneath sites of sustained surface volcanism. For the other inner planets I have used spacecraft observations of surface deformation, volcanism, topography, and gravity to address parallel questions, guided by the goal--far from yet realized--of achieving a general understanding of how Earth-like planets form and evolve. I am presently wrestling to fit new observations of Mars' internal structure, crustal magnetization, and volcanic and fluvial histories into a coherent description of interior differentiation and cooling. I am also leading the planning and design of the first mission to make orbital geochemical, geological, and geophysical observations of Mercury.

Membership Type


Election Year


Primary Section

Section 16: Geophysics

Secondary Section

Section 15: Geology