SCEC Award Number 20074 View PDF
Proposal Category Collaborative Proposal (Data Gathering and Products)
Proposal Title NASA Collaborative Proposal: Crustal Deformation Time Series from InSAR and GPS
Investigator(s)
Name Organization
David Sandwell University of California, San Diego Xiaohua Xu University of California, San Diego Zhen Liu National Aeronautics and Space Administration Alejandro Gonzalez-Ortega Centro de Investigacion Cientifica y de Educacion Superior de Ensenada (Mexico)
Other Participants Javier Gonzalez
SCEC Priorities 1a, 1b, 2a SCEC Groups Geodesy, CXM
Report Due Date 03/15/2021 Date Report Submitted 03/19/2021
Project Abstract
 Two of the top priorities of SCEC5 are (1) to better understand how faults are loaded across temporal and spatial scales and (2) to establish the role of off-fault inelastic deformation on strain accumulation, dynamic rupture, and radiated seismic energy. Surface crustal velocities and deformation time series are one of the key boundary conditions needed for addressing these problems. Several recent studies have shown that most damaging earthquakes occur in areas where the crustal strain rate exceeds about 50-100 nanostrain/yr. Therefore, accurate strain rate measurements are needed to improve earthquake forecasts. Our 2020 research was focused in two areas: The first part was to continue to contribute to the SCEC CGM. This work was done in collaboration with NASA investigator Zhen Liu. The second aspect of our proposed research was to perform and analyze campaign GPS measurements of the Imperial and Cerro Prieto Faults in northern Baja California, MX. The final report describes what we achieved in these two areas.
Intellectual Merit Two of the top priorities of SCEC5 are (1) to better understand how faults are loaded across temporal and spatial scales and (2) to establish the role of off-fault inelastic deformation on strain accumulation, dynamic rupture, and radiated seismic energy. Surface crustal velocities and deformation time series are one of the key boundary conditions needed for addressing these problems. Several recent studies have shown that most damaging earthquakes occur in areas where the crustal strain rate exceeds about 50-100 nanostrain/yr. Therefore, accurate strain rate measurements are needed to improve earthquake forecasts. Our 2020 research was focused in two areas: The first part was to continue to contribute to the SCEC CGM. This work was done in collaboration with NASA investigator Zhen Liu. The second aspect of our proposed research was to perform and analyze campaign GPS measurements of the Imperial and Cerro Prieto Faults in northern Baja California, MX. The final report describes what we achieved in these two areas.
Broader Impacts Our research involved three field trips where students and postdocs were exposed to GNSS field work. The first was a joint survey of the rupture zone of the Ridgecrest earthquakes (see: https://www.scec.org/article/671 ) The second was a campaign GNSS survey in Northern Baja Mexico. This work was done in collaboration with researchers and students from CICESE, Ensenada. The this field survey was performed days before the COVID lockdown. This involved researchers and students from SIO who performed a campaign GNSS survey across the San Andreas Fault in North Shore CA.
Exemplary Figure Figure 3: Survey results from the 2020 field work Mexicali, Mexico. (left) GNSS velocity in northern Baja California in SNARF. Black arrows are continuous GNSS data. Blue arrows are GNSS survey mode data. GNSS measurements across Indiviso and Tulecheck faults are new sites recently survey during this time project. (right) Fault-parallel velocity profile for the northern extended monuments across Imperial and Tulecheck/Michoacan fault.