3D modelling of controlled-source electromagnetic fields in applied Geophysics

Michael Weiss
Department of Geosciences
Uppsala University


Abstract:

Unstructured tetrahedral meshes with local refinement facilitate the use of total-field solution approaches to solve geophysical electromagnetic (EM) forward problems. Combining them with the vector finite-element method as well as refinement near the transmitters and receivers can yield accurate solutions and can handle realistic models with complex geometry and topography.

However, the fine mesh refinement comes at the cost of high number of unknowns. In order to avoid this, a spectral element method, which is known for its high degree of accuracy with a minimal number of unknowns, is proposed. Starting from the vector Maxwell's equations, the spectral element method is applied to establish the discrete form of the curl-curl equation for the electric field.