Heterogeneity and Anisotropy of Earth's Inner Core

  title={Heterogeneity and Anisotropy of Earth's Inner Core},
  author={Arwen Deuss},
  journal={Annual Review of Earth and Planetary Sciences},
  • A. Deuss
  • Published 5 June 2014
  • Geology
  • Annual Review of Earth and Planetary Sciences
Seismic observations provide strong evidence that Earth's inner core is anisotropic, with larger velocity in the polar than in the equatorial direction. The top 60–80 km of the inner core is isotropic; evidence for an innermost inner core is less compelling. The anisotropy is most likely due to alignment of hcp (hexagonal close-packed) iron crystals, aligned either during solidification or by deformation afterward. The existence of hemispherical variations used to be controversial, but there is… 

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