Publication Date:
2023-06-20
Description:
Magnetotellurics (MT) is widely used to image volcanic regions' three-dimensional (3-D) electrical conductivity structures. This requires a robust modeling solver which can deal with models with large conductivity contrast between melts and solid rock as well as topography. To this end, we developed a parallel 3-D MT forward modeling tool using the adaptive finite element method based on the open-source and scalar C++ library called the modular finite element method (MFEM). Tetrahedral grids were adopted to discretize the whole modeling domain, which can deal with complex underground structures with arbitrary topography. The flexible generalized minimum residual solver (FGMRES) with an auxiliary Maxwell solver pre-conditioner was applied to solve the final large-scale system of linear equations. We performed several experiments on synthetic models to verify the accuracy and efficiency of the developed tool. Then, we applied the tool to calculate the MT responses (impedance and tipper) at Mount St. Helens taking into account topography in the modeling to demonstrate the capability of the developed tool for dealing with complex models. The tool will be incorporated into the inversion tool JIF3D and substantially open-access.
Language:
English
Type:
info:eu-repo/semantics/conferenceObject
Permalink
