3D Volumetric Strain Distribution of the Cerro Prieto Geothermal Field Inferred From Inverse Modeling of InSAR and Leveling Data

Advanced Interferometric Synthetic Aperture Radar (InSAR) data has led to an extensive observation of Earth's surface displacements. Whereas the combined use of high-resolution InSAR, leveling and GPS data may enable highly detailed three-dimensional deformation models, publicly available modeling and inversion algorithms either seek a single homogeneously deformed source or involve a few thousand modeling elements. We present and release a conjugate-gradient inversion code that searches for the three-dimensional distribution of the volumetric strain that predicts simultaneously any observed InSAR, leveling and GPS surface displacement. By applying our algorithm on to leveling and InSAR data of the Cerro Prieto Geothermal area in Mexico for the 2012–2015 period, we find that the volume loss matches the extent and depth of the known geothermal reservoir or recharging aquifer and corresponds to 13% of the reported geothermal fluid extraction volume. We also identify non-volumetric deformation near the tectonic faults, possibly associated with creep displacement.