Details of the Abstract
| Title of paper | 3D magnetotelluric inversion with structurally guided regularization constraint |
| List of authors | Diba, D., Song, H., Uyeshima, M., Usui, Y. |
| Affiliation(s) |
Diba, D. : Earthquake Research Institute, the University of Tokyo Song, H. : (1) Earthquake Research Institute, the University of Tokyo, (2) State Key Laboratory of Marine Geology, Tongji University Uyeshima, M. : Earthquake Research Institute, the University of Tokyo Usui, Y. : Earthquake Research Institute, the University of Tokyo |
| Summary | We propose a technique for the structurally regularized three-dimensional magnetotelluric inversion scheme. In the proposed method, the structural resemblance between the inverted electrical resistivity model and the independently derived guiding model is enforced by controlling weights of the roughness operator for regularization. Using a simple method, we forced the weights to be small across presumed discontinuities in the guiding model, allowing for sharp changes in resistivity values across the discontinuity. We forced the weights to be large along blocks with similar values in guiding physical parameters, enforcing smooth changes of resistivity along the blocks. Numerical inversion tests suggest that our guided regularization inversion results can perform better than conventional smooth inversion, and even the cross-gradient inversion. In the field data application, the guided inversion model is more consistent with the geophysical and geological inferences, while fitting the data as well as the smooth inversion model. We suggest that the guided regularization inversion method can serve as an alternative to the commonly used cross-gradient method, especially in the absence of objective schemes for the simultaneous selection of multiple trade-off parameters in the objective function. |
| Session Keyword | 2.0 EM theory, modelling and Inversion |
| File upload |
2.0_3d_magnetotelluric_invers_diba_03.pdf
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