A STUDY OF PARAMETER COUPLING IN MT AND GRAVITY JOINT INVERSION FOR GEOTHERMAL EXPLORATION

Abstract

Joint inversion techniques may be used to refine the geological model derived from the analysis of different geophysical techniques. In geothermal exploration, magnetotellurics and gravity data are among the most common data acquired to characterize the geothermal resources. The problem of non-uniqueness of magneto-tellurics and gravity inversion can be addressed through joint inversion of both data with a proper choice of parameter coupling techniques between density and resistivity. While there is no obvious reason to correlate one to one electrical resistivity and density values, there may be geological clues to expect similar resistivity and density features. We test a series of stochastic correlation techniques between the parameters and their spatial gradients to provide the required constraints to obtain a distribution of density and resistivity values. The approach is tested on field data from different geological settings.