SCEC Award Number 16072 View PDF
Proposal Category Collaborative Proposal (Data Gathering and Products)
Proposal Title Assembly of the Community Geodetic Model and GPS Survey of the Cerro Prieto Fault
Name Organization
David Sandwell University of California, San Diego Alejandro Gonzalez-Ortega University of California, San Diego Jose Javier Gonzàlez-Garcìa Centro de Investigacion Cientifica y de Educacion Superior de Ensenada (Mexico) Wayne Thatcher United States Geological Survey
Other Participants Xiaohua Xu
Daniel Drugman
SCEC Priorities 1d SCEC Groups Geodesy, Geology
Report Due Date 03/15/2017 Date Report Submitted 06/25/2017
Project Abstract
One of the priorities of SCEC4 is to investigate stress transfer from plate motion to crustal faults. Surface crustal velocities are one of the key boundary conditions needed for developing 3-D stress rate models. The quality and quantity of GPS and InSAR data are increasing rapidly. In collaboration with other SCEC scientists, we have assembled a uniform-velocity, high spatial resolution CGM using layers of contributions from the community and make these layers available on the SCEC web site. The main science driver for this assembly/analysis is to examine the strain partitioning between elastic strain buildup in the near field of the main faults and off-fault inelastic deformation. The second aspect of our research was to perform and analyze campaign GPS measurements of the Imperial and Cerro Prieto Faults in northern Baja California, MX. In addition, we have recently used InSAR time series from the Sentinel 1-A and B satellites to corroborate and refine the GPS observations. This new analysis provides refined estimates of three important crustal deformation signals: 1) The analysis provides the first complete map of the Cerro Prieto Geothermal Field (CPGF), the area of high subsidence rate at the step-over between the Imperial and Cerro Prieto faults. 2) The Imperial fault does not accommodate the full 40 mm/yr of strike slip motion across the region and there is significant deformation across unmapped faults in the western Mexicali valley and further to the west. 3) Currently the Cerro Prieto fault accommodates less than half of the full plate motion.
Intellectual Merit see technical report
Broader Impacts see technical report
Exemplary Figure Figure 1. (left) Mean velocity is the average of 10 models. Colors show velocity magnitude and arrows show direction. (right) Standard deviation of the GGM velocity. Note the deviations are small in the locations of the GPS constraints, especially in areas where the velocity model is smooth. The blue lines outline areas of higher standard deviation.