Three‐Dimensional Magnetotelluric Inversion for Arbitrarily Anisotropic Earth Using Unstructured Tetrahedral Discretization

Abstract

Electrical anisotropy, manifested as varying resistivities of a medium with the direction of current flow, exists widely in nature. The electrical anisotropy can be divided into microanisotropy and macroanisotropy. The microanisotropy belongs to the attribute characteristics of media that shows anisotropic characteristics in very small scale. The anisotropy studied in geophysics is generally macroanisotropy, which is caused by the tiny isotropic structures that have same orientations, such as layering. Due to the limited resolution of electromagnetic (EM) methods, these tiny structures are generally treated as a whole and replaced by the parameter of anisotropy. These are typical macroanisotropy in EM geophysics. In the past decades, more and more long-period magnetotelluric (MT) signal shows that the electrical anisotropy exists widely in the deep crust and mantle (

Crustal Electrical Anisotropic Structure of the Altyn Tagh Fault in the Subei Area, NW China: Implications for Fault Zone Architecture

“…Therefore, the presence of electrical anisotropy may indicate damage zones (Chesley et al., 2019) and provide useful information about the architecture and deformations associated with major strike‐slip faults. At present, applications of magnetotelluric (MT) anisotropic inversion to real data have been reported worldwide (Baba et al., 2006; Comeau et al., 2020; Kong et al., 2021; Le Pape et al., 2012; Pek et al., 2011; Rong et al., 2022; Xiao et al., 2022; Yu et al., 2022).…”