Decomposition for the Impedance Tensor Distortion of Magnetotelluric Data from the West Sichuan‐East Xizang Profile

A regional structure close to the 3D/2D model and the distortion factors obtained from the Swift and Bahr's decomposition are used in analysis to the magnetotelluric data from West Sichuan-East Xizang sounding profile. The result shows that the structure of the region along this profile is simpler in the shallow part and relatively complex in the deep part. Taking the Ya'an line as a boundary, we find that the structure is simpler and more stable in the eastern part than that in the western part. The orientation of major structural axis is basically in nearly S-N direction and its deviation is less 30°. The decomposed parameters can well express several major faults. The sounding line 1 runs across three major tectonic units, which are cut by several major faults, so the structure is most complex. The structure along the sounding line 2 is close to 3D/2D model. And the sounding line 3 exhibits stronger static shift distortion.