High-Pressure Elasticity of Iron and Anisotropy of Earth's Inner Core
Abstract
A first principles theoretical approach shows that, at the density of the inner core, both hexagonal [hexagonal close-packed (hcp)] and cubic [face-centered-cubic (fcc)] phases of iron are substantially elastically anisotropic. A forward model of the inner core based on the predicted elastic constants and the assumption that the inner core consists of a nearly perfectly aligned aggregate of hcp crystals shows good agreement with seismic travel time anomalies that have been attributed to inner core anisotropy. A cylindrically averaged aggregate of fcc crystals disagrees with the seismic observations.
- Publication:
-
Science
- Pub Date:
- March 1995
- DOI:
- Bibcode:
- 1995Sci...267.1972S