Dynamics and anisotropy of the Earth's inner core - Importance of the magnetic coupling with the outer core

Macroscopic processes which may be responsible for the anisotropic structur e in the Earth's inner core are examined. It is concluded that the magnetic interaction with the outer core plays the most important role in the dynam ics of the inner core. Deformation due to the magnetic interaction causes c umulative strain at least for a period of one magnetic polarity (similar to 0.1-10 my), and can result in a large strain (similar to 1-10(-3)) leading to the formation of anisotropic structures. The flow caused by the magneti c field results in continuing melting and solidification at the inner-outer core boundary which gives rise to a large energy release (or absorption). The present model shows that the pattern of energy release (or absorption) due to this mechanism is consistent with that of dynamo models, indicating that the energy release (or absorption) caused by this mechanism enhances c onvection in the outer core and hence stabilizes the magnetic field which i s otherwise highly unstable.