Regularized joint inversion of magnetotelluric and gravity data based on inequality and Gramian constraints
CHEN Xiao1,2(), ZENG Zhi-Wen3(), DENG Ju-Zhi1,2, ZHANG Zhi-Yong1,2, CHEN Hui1,2, YU Hui1,2, WANG Yan-Guo1,2
1. State Key Laboratory of Nuclear Resources and Environment, East China University of Technology, Nanchang 330013, China 2. School of Geophysics and Measurement-control Technology, East China University of Technology, Nanchang 330013, China 3. College of Geoexploration Science and Technology, Jilin University, Changchun 130026, China
Regularized joint inversion based on Gramian constraints is a hot research topic in the field of geophysical joint inversion. Given the difficulty in selecting weighted factors of the regularization and constraint items, it is necessary to introduce inequality constraints into the regularized joint inversion. To investigate the regularized joint inversion of magnetotelluric (MT) and gravity data based on Gramian constraints, this study compared the application effects of the penalty function method and the transform function method in the joint inversion and processed the measured data of a survey line in Xiangshan, Jiangxi Province. According to the results from model experiments, both methods can effectively constrain petrophysical parameters, and the penalty function method has higher flexibility but requires the artificial setting of the weighted factors. Moreover, the processing of the measured data shows that the joint inversion based on inequality and Gramian constraints is highly practical and can improve the precision of geophysical interpretation.
Fig.6 3D MT反演结果和联合反演的密度结果对比 a—3D MT反演结果;b—联合反演的剩余密度结果
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