Abstract
Three-dimensional forward modeling is a challenge for geometrically complex magnetotellurics (MT) problems. We present a new edge-based finite-element algorithm using an unstructured mesh for accurately and efficiently simulating 3D MT responses. The electric field curl-curl equation in the frequency domain was used to deduce the H (curl) variation weak form of the MT forward problem, the Galerkin rule was used to derive a linear finite-element equation on the linear-edge tetrahedroid space, and, finally, a BI-CGSTAB solver was used to estimate the unknown electric fields. A local mesh refinement technique in the neighbor of the measuring MT stations was used to greatly improve the accuracies of the numerical solutions. Four synthetic models validated the powerful performance of our algorithms. We believe that our method will effectively contribute to processing more complex MT studies.
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This work was financially supported by National High Technology Research and Development Program (863 Program) (No. 2006AA06Z105, 2007AA06Z134).
Liu Changsheng graduated with a Masters degree from the Institute of Computer and Technologies, Central South University. He is now a Doctoral student for EM modeling at the Institute of Applied Geophysics, Central South University.
Tang Jingtian graduated with a PhD from the Institute of Applied Geophysics, Central South University, in 1992. He was a research Professor at the U.S. Lawrence Berkeley National Laboratory in 1998–1999. He is currently a full Professor at the Institute of Applied Geophysics, Central South University.
Ren Zhengyong (Corresponding author), graduated with a Masters degree from the Institute of Applied Geophysics, Central South University, in 2007. He is now a PhD candidate at the Institute of Geophysics, Department of Earth Science, ETH Zurich-Swiss Federal Institute of Technology. His research interest is mainly MT inversion.
Yan Yan graduated with a Masters degree from the Institute of Higher Education, Central South University, in 2008. Her research interest is natural resources evaluation.
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Liu, C., Ren, Z., Tang, J. et al. Three-dimensional magnetotellurics modeling using edgebased finite-element unstructured meshes. Appl. Geophys. 5, 170–180 (2008). https://doi.org/10.1007/s11770-008-0024-4
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DOI: https://doi.org/10.1007/s11770-008-0024-4