Subsidence at Cerro Prieto Geothermal Field and postseismic slip along the Indiviso fault from 2011 to 2016 RADARSAT‐2 DInSAR time series analysis

Abstract

We present RADARSAT‐2 Differential Interferometric Synthetic Aperture Radar (DInSAR) observations of deformation due to fluid extraction at the Cerro Prieto Geothermal Field (CPGF) and afterslip on the 2010 M7.2 El Mayor‐Cucapah (EMC) earthquake rupture during 2011–2016. Advanced multidimensional time series analysis reveals subsidence at the CPGF with the maximum rate greater than 100 mm/yr accompanied by horizontal motion (radial contraction) at a rate greater than 30 mm/yr. During the same time period, more than 30 mm of surface creep occurred on the Indiviso fault ruptured by the EMC earthquake. We performed inversions of DInSAR data to estimate the rate of volume changes at depth due to the geothermal production at the CPGF and the distribution of afterslip on the Indiviso fault. The maximum coseismic slip due to the EMC earthquake correlates with the Coulomb stress changes on the Indiviso fault due to fluid extraction at the CPGF. Afterslip occurs on the periphery of maximum coseismic slip areas. Time series analysis indicates that afterslip still occurs 6 years after the earthquake.

Cumulative and Coseismic (During the 2016 Mw6.6 Aketao Earthquake) Deformation of the Dextral‐Slip Muji Fault, Northeastern Pamir Orogen

“…Additionally, clearly displaced landforms along the Muji Fault contrast with the negligible surface-faulting deformation observed during the Aketao earthquake ( Figure 6), therefore, cumulative deformation along the fault cannot be formed coseismically by repetitions of the Aketao earthquake. One explanation for this mismatch is that the coseismic unbroken shallow zone (0-3 km at depth) and the slip gap are dominated by aseismic (postseismic and/o interseismic) creeping, which can produce clear surface-faulting deformation as observed in previous earthquakes (e.g., Fialko et al, 2005;Lienkaemper et al, 2016;Lyons & Sandwell, 2003;Samsonov et al, 2017). The other possibility is that the Aketao earthquake is not a characteristic event of the Muji Fault.…”

Production-Induced Subsidence at the Los Humeros Geothermal Field Inferred from PS-InSAR

“…This ratio is much larger than the corresponding ratio of many other geothermal fields. For Cerro Pietro, for instance, the produced volume is only about 3 times larger than the modeled subsurface volume change [4]. Of course, the extracted volume cannot be directly associated with the volume change within the reservoir: the reservoir compressibility, in combination with the pressure reduction of the reservoir, results in a smaller subsurface volume change than the extracted volume.…”

“…These models most commonly relate surface deformation to subsurface extraction or injection processes through so-called influence functions that are based on analytical solutions for different nuclei of strain. For instance, Trugman et al [3] and Samsonov et al [4] used inflation point sources to model subsidence due to production at the world's second largest geothermal field, Cerro Pietro. Surface subsidence at the Reykjanes geothermal field was modeled with point and ellipsoidal pressure sources [5].…”

Wide-Area InSAR Survey of Surface Deformation in Urban Areas and Geothermal Fields in the Eastern Trans-Mexican Volcanic Belt, Mexico

“…ERS-1/2 SAR imagery acquired in the 1990s over Cerro Prieto was used to model subsidence due to geothermal fluid withdrawal [17]. The same geothermal field was also the geographic focus of an InSAR study based on ENVISAT scenes acquired in 2003-2006 [18], another based on RADARSAT-2 data in 2011-2016 [19] and a more recent investigation exploiting Sentinel-1 imagery [20].…”