EPP

地球与行星物理

ISSN  2096-3955

CN  10-1502/P

Two-dimensional regularized inversion of AMT data based on rotation invariant of Central impedance tensor
XiaoZhong Tong, JianXin Liu, AiYong Li
doi: 10.26464/epp2018040
Considering the uncertainty of the electrical axis for two-dimensional audo-magnetotelluric (AMT) data processing, an AMT inversion method with the Central impedance tensor was presented. First, we present a calculation expression of the Central impedance tensor in AMT, which can be considered as the arithmetic mean of TE-polarization mode and TM-polarization mode in the two-dimensional geo-electrical model. Second, a least-squares iterative inversion algorithm is established, based on a smoothness-constrained model, and an improved L-curve method is adopted to determine the best regularization parameters. We then test the above inversion method with synthetic data and field data. The test results show that this two-dimensional AMT inversion scheme for the responses of Central impedance is effective and can reconstruct reasonable two-dimensional subsurface resistivity structures. We conclude that the Central impedance tensor is a useful tool for two-dimensional inversion of AMT data.
Keywords: audio-magnetotelluric/AMT, impedance tensor, rotation invariants, two-dimensional geo-electrical model, regularized inversion

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