Determination of Gravity and Topography from Seismic Velocities, Accounting for Dynamic Behavior of the Earth's Mantle

摘要

Determination of density distribution in the Earth's mantle using geophysical and geodetic techniques is considered. The results of the computation of the geoid (degree 2 to 6), just by propagating the gravity effect of tomographic density observations, shows a negative correlation with the observed geoid (except degree 4). Using dynamic response functions (including the flow effects) as defined by Ricard et al (1984) results in relatively high positive correlations (except degree 4), but the differences between various models are not small, especially concerning amplitude. However, models can result in a very good resemblance with the observed geoid and can explain (with help of dynamic response theory) features of the observed geoid which were unexplained. The computed topography (degree 2 to 6) resulting from the flow seems to be very likely in general, but could not be verified by observations.