CSEDI: Cooperative Studies of Electrochemistry at the Core-Mantle Boundary

Kavner

0112448

The investigators plan to provide an examination of the Earth's core-mantle boundary as an electrochemical system. They will undertake a series of piston-cylinder experiments designed to investigate the effect of an electric field on the physical and chemical behavior at metal-silicate interfaces. Both DC resistance measurements and AC impedance spectroscopy will be employed to examine the electrical behavior of a metal-silicate interface, and electron microprobe analysis will record changes in chemistry for a series of anodic and cathodic electrical loadings of the interface. These results will be used, in turn, to show how differences in chemistry and physical properties overlying local areas of the core-mantle boundary may translate into geophysical and geochemical observables such as length of day variations, the behavior of the magnetic field dynamo, and creation of physical and chemical structure in the outer core and lower mantle. The goal is to extend our understanding of the core-mantle boundary to encompass electrical and electrochemical behavior at high pressures and temperatures, examining both electrically-induced chemical partitioning and resultant core-mantle dynamic coupling.