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Southern California crustal deformation map and long-term transient from InSAR time series analysis

Zhen Liu, Paul Lundgren, & Zheng-Kang Shen

Published September 2013, SCEC Contribution #2051

Differential interferometric synthetic aperture radar (InSAR) provides capability to image surface deformation of plate boundary zones at fine spatial resolution with coarse temporal sampling along the satellite line-of-sight (LOS) direction. More than 18 years of extensive SAR data collection over southern California makes it now possible to generate a long time interval InSAR-based LOS velocity map to examine the resolution of both steady-state and transient deformation processes. We present InSAR time series analysis results of crustal deformation in southern California using the extensive catalog of ERS-1/2 and Envisat data since 1992. We apply a variant of the Small Baseline Subset (SBAS) time series analysis approach to derive InSAR LOS velocity map and time series. When applicable, a GPS derived crustal model is used to constrain long wavelength deformation signals while estimating and removing orbital ramp error. The spatiotemporal details of deformation signals provided by InSAR measurements, when combined with in-situ continuous GPS, enable the separation of tectonic and nontectonic sources. Following the observation of long-term transient across Eastern California Shear Zone from our preliminary analysis, we extend our analysis to other descending and ascending tracks in the region. We characterize spatial variation of tectonic and transient deformation and examine the time dependency of resulting deformation patterns.

Liu, Z., Lundgren, P., & Shen, Z. (2013, 9). Southern California crustal deformation map and long-term transient from InSAR time series analysis. Poster Presentation at SCEC Annual Meeting 2013.