Determination of density contrasts for a three-dimensional sub-surface intermediate layer

Abstract

The quantitative determination of the variable density contrasts for an intermediate horizontal layer has been demonstrated. In particular a sub-surface dipping dike with a priori depth-dependent density contrasts was adopted as a forward model to project gravity anomaly effect above the Earth surface. The sub-surface location and density contrasts in a series of intermediate horizontal layers in the causative dipping dike structure have been recovered by means of inversion analysis. Density contrasts recovery errors of less than 8.0 percent were realized to a depth of 2.00 km on a maximum synthetic gravity anomaly effect of 10.0 mGals that is better in comparison to constant density models. Finally to demonstrate the efficacy of the inverse analysis in the study, the entire process was successfully applied to real field data, i.e., residual gravity anomaly for a micro-gravimetry site and/or localized structures in Matsumoto Basin, Chubu District - Japan. Copyright © The Society of Geomagnetism and Earth, Planetary and Space Sciences (SGEPSS); The Seismological Society of Japan; The Volcanological Society of Japan; The Geodetic Society of Japan; The Japanese Society for Planetary Sciences.