Joint inversion of gravity, magnetotelluric and surface wave dispersion data for geothermal exploration

    The key to geothermal resource exploration lies in accurately determining the spatial distribution characteristics of geothermal reservoirs, including their depth, size, and geometric structure. However, due to the limited resolution of single geophysical datasets and the inherent non-uniqueness in geophysical inversion, inversion models independently derived from different datasets are difficult to accurately reveal the characteristics of subsurface structures. To reduce the uncertainty of inversion results and improve their reliability, We employed a 3-D approach to jointly invert gravity, magnetotelluric, and seismic surface wave dispersion data in the Huangshadong, Huizhou, based on the cross-gradient structural consistency constraints. The results indicated that the physical property structure obtained by the joint inversion was more comprehensive, with density, resistivity, and shear wave velocity models exhibiting good structural consistency, and provided a clearer characterization of the relief shape of the thermal reservoir interface, the thickness of the sedimentary, and the spatial distribution of hidden faults. Finally, we proposed a geothermal geological model for the region based on the geological information and joint inversion results, which will provide a scientific basis for effective geothermal exploration in the future.