Different Strategies Applied to 3D Inversion of MT Data from Los Humeros Superhot Geothermal Resource in Mexico

Abstract

Within the framework of the European-Mexican project GEMex, 122 Magnetotelluric (MT) and 120 Transient electromagnetic (TEM) soundings were acquired in Los Humeros volcanic complex (Mexico), which is considered a superhot geothermal system. Both datasets were collected at the same location, and the TEM data were used for static-shift correction of the MT data. Transient responses were measured from 0.1 to 90ms with a TerraTEM device and using a 100x100m2 single-loop configuration. Whereas MT signals were recorded with Metronix systems in the period range from 0.001 to 1000s. The dimensionality analysis of MT data suggests a 1D and 3D subsurface structure. Three-dimensional inversion of MT data was performed with ModEM software. We applied different 3D inversion schemes to the MT data, and their results were appraised. Sensitivity studies were carried out to analyze whether or not the structures derived from the 3D MT inversion are reliable. This conference paper presents results of the GEMex Project, funded by the European Union’s Horizon 2020 research and innovation programme under grant agreement No. 727550, and by the Mexican Energy Sustainability Fund CONACYT-SENER, Project 2015-04-268074. More information can be found on the GEMex Website: http://www.gemex-h2020.eu