Study on the deep conductive geologic structure by magnetovariational method

Abstract

In the magnetotelluric method, along with the magnetotelluric response functions originating from linear relations between components of the electric and magnetic fields we can determine the magnetovariational response functions derived from linear relations between components of the magnetic field Hx, Hy, Hz. This consideration may significantly enhance the capabilities of the magnetotellurics, since at low frequencies the magnetic field becomes free of nearsurface distortions and shines a nondeceptive light on the deep geoelectric structures. The components of the magnetic field are represented by Wiese–Parkinson matrix 𝑊 . From the matrix, we use the transformations to construct Vozoff tipper 𝑉 , tipper phase ψ, and tipper ellipticity of magnetic field H   to study the electrical heterogeneity. We obtain more information than previous methods because V gives two parameters: direction and amplitude, |V| > |ReW| and |V| > |ImW|; therefore data interpretation has many advantages over previous methods. The results allow us to give meaningful conclusions about the geology, such as mapping some deep conductive geologic structures of the crust.