The anisotropy of properties of the Earth's inner core

The anisotropy of properties of the Earth's inner core can be seen from the fact that the time a seismic wave takes to traverse the core along the rotation axis is 1 % less than the time taken in the equator plane. Another piece of evidence comes from the splitting of the Earth's eigen oscillation spectra. In addition to the velocity difference between traversing the core along and normal to the rotation axis, a lateral core anisotropy has been discovered both from function splitting and travel time data. This phenomenon is discussed.