SCEC Project Details
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) |
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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. |
Linked Publications
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