Two-Dimensional Inversion of Magnetotelluric Data when Studying Three-Dimensional Media

Abstract—A three-dimensional geoelectric model of the tectonosphere has been constructed, containing typical geoelectric heterogeneities at three structural levels: uplift and subsidence of the roof of the basement, conductive prisms in the consolidated crust, and asthenospheric uplift in the upper mantle. Synthetic magnetotelluric data were calculated, and their sensitivity to geoelectric structures was analyzed. A two-dimensional smoothing inversion of synthetic data was performed along two perpendicular profiles. Despite significant three-dimensional effects, the obtained sections quite accurately reconstruct the position of the roof of the basement, obtain rough images of crustal structures, and poorly resolve the structure of the mantle. The influence of random noise of different levels on the inversion results is assessed. In the future, it is planned to perform three-dimensional inversion of synthetic data.