Details of the Abstract
| Title of paper | Influence of Anisotropy and Development of 3-D Anisotropic Resistivity Inversion for Magnetotelluric Data based on WSINV3DMT |
| List of authors | Amatayakul, P., Thongyoy, W., Rung-Arunwan, T., Siripunvaraporn, W. |
| Affiliation(s) |
Department of Physics, Faculty of Science, Mahidol University, 272 Rama 6 Road, Rachatawee, Bangkok 10400, Thailand Thailand Center of Excellence in Physics, Ministry of Higher Education, Science, Research and Innovation, 328 Si Ayutthaya Road, Bangkok 10400, Thailand Curl-E Geophysics Co., Ltd., 85/87 Nantawan Village, Uttayan-Aksa Road, Salaya, Phuthamonthon District, Nakhon Pathom 73170, Thailand |
| Summary | We investigated the influence of anisotropic resistivity elements on magnetotelluric (MT) surface responses, focusing on 3-D axial, dipping, and azimuthal anisotropy. Using influence indices for impedance components and edge effect indices for tipper components, we found that for decoupled modes, ρxx strongly influences Zxy, Zyy, and Ty, while ρyy affects Zyx, Zxx, and Tx. The elements ρzz, ρxz, and ρyz show a weak influence on all responses. For coupled modes, ρxx, ρyy, and ρxy significantly affect all responses. Based on these findings, we have developed two axial anisotropic inversion codes for MT data: full axial inversion and decoupled axial inversion, based on the data space inversion method of WSINV3DMT and implemented with OpenMP. Using the influence study, we split the inversion into ρxx and ρyy modes, reducing the data parameters by half for each mode, allowing independent execution. Testing against synthetic models and real MT data demonstrated that decoupled inversion reduces computational time and memory usage significantly. It also confirmed anisotropy at a depth of 60 to 160 km beneath the ocean floor, as suspected in the Northwestern Pacific Ocean data. |
| Session Keyword | 2.0 EM theory, modelling and Inversion |
| File upload |
2.0_influence_of_anisotropy_a_amatyakul.pdf
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