Improving the Community Geodetic Model with GPS and InSAR

Principal Investigator: 
Proposal 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

and many groups are developing detailed crustal velocity models. We have identified two areas

of weakness in these models - the southernmost SAF system in the Mexicali Valley and the

small-scale deformation near faults having shallow interseismic slip. Our proposed tasks are:

(1) Collaborate with other SCEC and PBO scientists to develop a time-dependent Community

Geodetic Model (CGM) at variable spatial resolution. Work with SCEC community on optimal

integration of InSAR and GPS. Under this SCEC proposal we will begin the InSAR time series

analysis and integration of two new data streams (Sentinel-1 and ALOS-2) with the CGPS data.

(2) Work with CICESE scientists to acquire spatially dense GPS velocities across the Imperial

and Cerro Prieto Faults. Over the past four years we (SIO and CICESE) have installed GPS

arrays across the Imperial and Cerro Prieto Faults to better characterize their moment

accumulation rates and thus their seismic potential. We propose to re-survey these two arrays

using the rapid-static approach with two 60-90 minute occupations at each monument. As in the

past three years, all surveys will be performed in collaboration with scientists and students from

CICESE (e.g. Javier and Alejandro Gonzales).

(3) Participate in SCEC workshops related to the development of the Community Geodetic

Model as well as the Community Stress Model. Our research group (Sandwell, Tong, Gonzalez,

Smith-Konter, and Zeng) have been active participants in SCEC-sponsored workshops. Under

this proposal we hope to participate in the InSAR time series comparisons planned for the

Community Geodetic Model. Zeng plans to collaborate with the GPS investigators to continue

to compile campaign and continuous GPS datasets for the Western US with a focus on Southern

California. In addition, if invited, we will participate in the activities of the Community Stress

Model. We will develop and compare deformation and stress models that incorporate available

CGM, in particular the high resolution component CGM data from this research, to better

understand regional and local tectonic loading processes and fault structures.

Start and End Date: 
February 2012 to January 2014