GLOBAL EARTH DYNAMICS AND INDUCED GRAVITY CHANGES

We consider the elastogravitational deformation of an Earth model with a liquid outer core and a surficial fluid layer modeling the oceans or the atmosphere. The surface gravity changes caused by planetary-scale dynamical phenomena can be expressed in terms of generalized gravimetric factors. Each of these factors is related to a specific boundary condition (in normal or transverse traction, in potential and derivative) which has to be considered at the different interfaces (inner core-outer core, outer core-mantle, surface) according to the problem. We apply this formalism to express in a self-consistent and uniform manner the gravity disturbances due to various sources: tides, Earth rotation, loading process, inner and outer core dynamics, with special attention paid to possible resonance effects.