The Los Humeros Superhot Geothermal Resource in Mexico: Resistivity Survey (TEM and MT); Data Acquisition, Processing and Inversion - Geological Significance

A joint geothermal project of a European and Mexican consortium began in late 2016 with the purpose to develop geothermal energy in the easternmost region of the Trans-Mexican Volcanic Belt. Two sites that belong to the Comisión Federal de Electricidad (CFE) have been investigated. One of the them, Los Humeros, is the subject of our study. In order to further explore the Los Humeros superhot geothermal resource, extensive geological, geochemical and geophysical studies were carried out. Previously existing regional gravity and magnetic maps were studied, and gravity was measured on a dense grid. Some 23 broadband and 22 short period seismic stations were set up which collected data for one year. Finally, 122 co-located MT and TEM soundings were made in 2017 and 2018 through a joint effort by the European and Mexican partners. Their location was based on the interpretation of already existing resistivity data. The TEM and MT data were acquired with a TerraTEM equipment and Metronix equipment, respectively. The bounded influence remote reference processing method was used for processing of the MT timeseries. Each TEM/MT pair was jointly inverted in 1D, where the TEM data were used to static shift correct the MT data. A 3D inversion was performed on the full impedance tensor of the MT data using different initial models. Two codes were applied for comparison, the WSINV3DMT code was run in Europe and ModEM in Mexico. Finally, the resistivity models were compared with and interpreted together with other geoscientific results from the GEMex project, gravity, seismics and the geological mapping. This abstract 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