In this section I would like to provide a short summary of my interests in Earth and planetary magnetism.

The interior structure of the Earth is layered.The distinction of these layers can be done  either  by  their chemical  or  rheological properties. The Earth has a silicate solid crust, a highly viscous mantle, a liquid outer core that is much less viscous than the mantle, and  a  solid  inner  core. The  Earth’s  core plays an important role in the evolution of the Earth. On one hand, the core is the origin of the Earth’s magnetic field that protects us largely from cosmic radiation, and on the other hand, because of the stored heat in the  core that is released to the  mantle, the core is the engine of plate tectonics. Our knowledge about the Earth’s core is strongly limited because it isn’t immediate accessible.

There are several evidence from wave propagation and normal mode splitting for an inner core anisotropy. Poupinet et al. (1983)  first observed that PKIKP body waves travelling  parallel  to the  Earth's rotation axis  arrive faster than waves travelling in the equatorial plane. They explained this  observation in terms of a prolate inner core. The  concept  of  inner-core  anisotropy  was introduced in back-to-back papers by Morelli et al. (1986) and Woodhouse et al. (1986) as an explanation for bouth anomalous PKIKP traveltimes and anomalously split modes. Cylindrical anisotropy at the level  of  a  few  percent with a fast axis roughly parallel to the Earth’s rotation axis and a slow axis in  the equatorial plane was  still the preferred explanation  for both sets of observations.

Figure reference

Geologists at the University of Illinois have confirmed the discovery of Earth’s inner, innermost  core, and  have  created  a three-dimensional  model that describes the seismic anisotropy and texturing of iron crystals within the inner core (see figure above).