Forward modeling and inversion of tensor CSAMT in 3D anisotropic media
Wang Tao1, Wang Kun-Peng2,3, and Tan Han-Dong3,4
1. Key Laboratory of Electromagnetic Radiation and Sensing Technology, Chinese Academy of Sciences, Beijing 100190, China.
2. College of Geophysics, Chengdu University of Technology, Chengdu 610059, China.
3. School of Geophysics and information Technology, China University of Geosciences (Beijing), Beijing 100083, China.
4. Key Laboratory of Geo-detection (China University of Geosciences), Ministry of Education, Beijing 100083, China.
Abstract:
Tensor controlled-source audio-frequency magnetotellurics (CSAMT) can yield information about electric and magnetic fields owing to its multi-transmitter configuration compared with the common scalar CSAMT. The most current theories, numerical simulations, and inversion of tensor CSAMT are based on far-field measurements and the assumption that underground media have isotropic resistivity. We adopt a three-dimensional (3D) staggered-grid finite difference numerical simulation method to analyze the resistivity in axial anisotropic and isotropic media. We further adopt the limited-memory Broyden–Fletcher–Goldfarb–Shanno (LBFGS) method to perform 3D tensor CSAMT axial anisotropic inversion. The inversion results suggest that when the underground structure is anisotropic, the isotropic inversion will introduce errors to the interpretation.
. Forward modeling and inversion of tensor CSAMT in 3D anisotropic media[J]. APPLIED GEOPHYSICS, 2017, 14(4): 590-605.
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