oa Three-dimensional Joint Inversion of Gravity and Magnetic Anomalies Based on Density-Magnetization Relationship

We present a three-dimensional (3D) joint inversion method to estimate two physical parameters, density and magnetization of subsurface materials using surface potential measurements (gravity and magnetic anomalies). In the method, we assume a linear relationship between the density and magnetization to relate gravity with magnetic data. In the approach, the subsurface structure is discretized to a set of rectangular prisms. For estimating the density and magnetization of each prism, we minimize the quadratic norm of the residuals between the observed and the forward-modeled potentials. Two regularization terms are used in our joint inversion. We also minimize the roughness and the similarity of the two physical parameters. The regularization parameters controlling the degree of roughness and similarity are determined in the L-curve criterion scheme. We apply our method to a numerical model which represents submarine massive sulphides (SMS). The joint inversion results, which have the advantages of both gravity and magnetic inversion, show better accuracy and resolution than the individual inversion results.