IEEE Transactions on Geoscience and Remote Sensing

Xiaojua Xu, David T. Sandwell, Ekaterina Tymofyeyeva, Alejandro Gonzalez-Ortega, & Xiaopeng Tong

Published June 15, 2017, SCEC Contribution #7285

The Cerro Prieto Geothermal Field (CPGF) lies at the step-over between the Imperial and the Cerro Prieto Faults in northern Baja California, Mexico. While tectonically this is the most active section of the southern San Andreas Fault system, the spatial and temporal deformation in the area is poorly resolved by the sparse Global Positioning System (GPS) network coverage. Moreover, interferograms from satellite observations spanning more than a few months are de-correlated due to the extensive agricultural activity in this region. Here we investigate the use of frequent, short temporal baseline interferograms offered by the new Sentinel-1A satellite to recover two components of deformation time series across these faults. Following previous studies, we developed a purely geometric approach for image alignment that achieves better than 1/200 pixel alignment needed for accurate phase recovery. We construct InSAR time series using a coherence-based SBAS method with atmospheric corrections by means of common-point stacking. We did not apply Enhanced Spectral Diversity (ESD) because the burst discontinuities are generally small (< 1.4 mm). They can be effectively captured and removed during the atmospheric corrections. With these algorithms, the subsidence at CPGF is clearly resolved. The maximum subsidence rate of 160 mm/yr, due to extraction of geothermal fluids and heat, dominates the ~40 mm/yr deformation across the proximal ends of the Imperial and the Cerro Prieto Faults.

Xu, X., Sandwell, D. T., Tymofyeyeva, E., Gonzalez-Ortega, A., & Tong, X. (2017). IEEE Transactions on Geoscience and Remote Sensing. Tectonic and Anthropogenic Deformation at the Cerro Prieto Geothermal Step-Over Revealed by Sentinel-1A InSAR, 1-9. doi: 10.1109/TGRS.2017.2704593.

Related Projects & Working Groups
Tectonic Geodesy