Rapid inversion of two‐ and three‐dimensional magnetotelluric data

TLDR

An efficient iterative inversion method for both 2‑D and 3‑D magnetotelluric data was developed. The algorithm decouples horizontal coordinates by using previous‑iteration field values, performs independent site‑wise inversions, and interpolates the results to update the multidimensional conductivity model. The method converges rapidly, with 2‑D tests showing promising results.

Abstract

We have developed an efficient iterative inversion method applicable to both two‐dimensional (2D) and three‐dimensional magnetotelluric data. The method approximates horizontal derivative terms with their values calculated from the fields of the previous iteration. The equations at each horizontal coordinate then become uncoupled. At each iteration this allows separate inversions for the improved conductivity profile beneath each measurement site. Resultant profiles are interpolated to form a new multidimensional model for which the fields for the next iteration are calculated. The method is extremely fast, and tests with 2D data show very promising results.