A python package for magnetotelluric data visualization, analysis, modeling and inversion

Abstract

Magnetotellurics (MT) is a geophysical technique that can be used for various subsurface studies including groundwater, geothermal, volcanology, and tectonics. Despite the popularity of this method, there are few MT programs for data handling, analysis, and modeling. Commercial software packages are expensive, particularly for students doing MT research, and the MT community is mostly reliant on open source/freeware programs, often written using Fortran programing language, however, compiling, preparing input files, and running these codes can be challenging. In this paper, we present a new, open-source, easy-to-use python package as an alternative for students and researchers working on MT projects. This python package assists in data format handling, plotting MT observations, dimensionality, and directionality analysis, as well as in modeling and inversion for a 1D case. The source codes were written in Python programming language (version 3) and was designed to work with the standard MT EDI file format. The program is designed to be used at different stages of the MT workflow, e.g. for data analysis in dimensionality and directionality estimation, plotting MT observations such as visualizing sounding curves of apparent resistivity or phase curves and to generate resistivity maps and pseudo-sections at different frequencies. The package can also be used in MT 1D modeling and inversion; the inversion is based on the Marquardt-Levenberg algorithm and the forward modeling calculates the Wait's recursion formula. In addition, postprocessing and visualization tools are also included; these are python scripts developed for generating input files (data and model files) and visualizing inversion results for various academically available inversion programs (e.g., 3DMT ModEM and 1D & 2D OCCAM programs).