HMC Physics Colloquium

Tuesdays at 16:30 in Shanahan Center for Teaching and Learning, Room B460

Wendy Panero (’97)

Ohio State University

The New Mineralogy and Chemistry of the Earth’s Inner Core

Oct. 26, 2010

Understanding the evolution of the Earth’s interior requires knowledge of the mineralogy, temperature, and viscosity of the Earth’s inner core. Recent seismic results showing significant yet heterogeneous seismic anisotropy for the inner core suggest that it is undergoing a dynamic process of unknown origin.

This talk presents new methods for measuring transport properties under the high-pressure, high-temperature conditions of the Earth’s core, combining synchrotron-based X-ray experiments at high pressure and temperature with post-run focused-ion beam milling and transmission electron microscopy. Combined with models for texture evolution in metals, the mechanism by which the inner core develops and maintains anisotropy appears to be a combination of preferential growth in equatorial regions combined with solid-state deformation in response to mass variations in the Earth’s mantle.