SCEC Award Number 14190 View PDF
Proposal Category Individual Proposal (Data Gathering and Products)
Proposal Title High-resolution geodetic imaging of damage zones of major seismogenic faults in Southern California
Investigator(s)
Name Organization
Yuri Fialko University of California, San Diego
Other Participants
SCEC Priorities 4c, 4b, 1d SCEC Groups Geodesy, FARM, Transient Detection
Report Due Date 03/15/2015 Date Report Submitted N/A
Project Abstract
 We developed a method for estimating radar phase delays due to
propagation through the troposphere and the ionosphere based on the
averaging of redundant interferograms that share a common scene.
Estimated atmospheric contributions can then be subtracted from the
radar interferograms to improve measurements of surface deformation.
Inversions using synthetic data demonstrate that this procedure can
considerably reduce scatter in the timeseries of the line-of-sight
displacements. We applied this method to investigate interseismic
deformation due to the Blackwater Fault and the Hunter Mountain Fault
in the Eastern California Shear Zone where anomalous localized
deformation has been reported by previous studies.
Intellectual Merit We investigated deformation across the Blackwater and the Hunter Mountain faults, where previous studies have suggested anomalously large slip rates and shallow locking depths (Gourmelen et al., 2011; Peltzer et al., 2001). The deformation
across the Blackwater Fault occurred at a nearly constant rate of 1.5
mm/year in the satellite LOS between 1992 and 2000, consistent with
the study by Peltzer et al. (2001), but stopped, or perhaps even
reversed in 2000-2010. We do not observe a resolvable deformation
signal across the Hunter Mountain Fault, where a study by
Gourmelen et al. (2011) suggested higher than geologic slip rates and an
anomalously shallow locking depth of 2km. We speculate that the mean
LOS velocity estimates by Gourmelen et al. (2011) might be biased by
large seasonal variations in the LOS velocities at small (few km)
spatial scales around the fault.
Broader Impacts This project provided training and support for a female graduate
student (Tymofyeyeva). The PI (Fialko) used results of this study in a
graduate-level seminar taught at SIO. Results of this work were
presented at several major conferences.
Exemplary Figure Figure 1: Average line-of-sight velocity from ERS and ENVISAT tracks 170, 399, and 442, computed using atmospheric corrections. The locations of the GPS stations used for comparison with InSAR time series are marked by black circles, and the reference station is marked by a black star. The outlined areas C and D correspond to our focus areas in the Eastern California Shear Zone: Blackwater Fault, and Hunter Mountain Fault, respectively. Positive LOS velocity indicates motion toward the satellite.