Three-dimensional unstructured adaptive finite element forward modeling simulation of magnetotellurics based on magnetic vector potential-electric scalar potential.

Song, Huadong; Xue, Yunfeng; Yan, Chaoxu

The prerequisite of inversion is the forward modeling study. In recent years, structured electromagnetic method for forward modeling has become mature. However, it has low computing efficiency and difficulty in simulating complex geological bodies. The electromagnetic field equations are represented by the coupled equations of magnetic vector potential and electric scalar potential. The node-based finite element method can efficiently calculate the electromagnetic field. The linear equations obtained are solved using a symmetric successive overrelaxation preconditioned conjugate gradient solver. This iterative method provides a faster solution speed. Unstructured grids used in numerical simulation can effectively simulate complex geological bodies. The use of adaptive finite elements optimizes the grid and improves calculation accuracy. The accuracy of the forward modeling code is verified through the establishment of layered models and three-dimensional models; the significant advantage of unstructured grids in simulating complex geological bodies is confirmed by the forward modeling simulation of complex ellipsoidal anomaly bodies; the effectiveness of the adaptive finite element method is verified by the forward modeling simulation of the prism model.

ELECTROMAGNETIC fields; THREE-dimensional modeling; LINEAR equations; MAGNETOTELLURICS; COMPUTER simulation

Environmental Earth Sciences, 2024, Vol 83, Issue 17, p1

1866-6280

Academic Journal

10.1007/s12665-024-11802-z