Joint Inversion of Magnetotelluric Impedance and Tipper Data in 3D Axial Anisotropic Media

Abstract

Magnetotelluric (MT) impedance and tipper data can be utilized to reflect underground structural information. However, when the axial anisotropic property of an abnormal body is marked, it will seriously influence MT measuring data. This study divides the MT field into primary and secondary components and replaces the conductivity parameter in a three-dimensional (3D) governing equation with axial anisotropic conductivity. Analysis of the influence of axial anisotropy on MT tipper data is presented, and a limited-memory Broyden-Fletcher-Goldfarb-Shanno method is then utilized to realize a 3D MT axial anisotropic inversion with impedance and tipper data. The tests presented in this paper show that the resolution of the inverting axial anisotropic model with impedance and tipper data is better than that of only using impedance data.