Investigating Active Crustal Deformation along the San Andreas Plate Boundary from 7+ Years of Combined Sentinel-1 InSAR + GNSS Time Series

Katherine A. Guns, Xiaohua Xu, David T. Sandwell, & Yehuda Bock

Published September 11, 2022, SCEC Contribution #12154, 2022 SCEC Annual Meeting Poster #070 (PDF)

Poster Image: 
Interferometric Synthetic Aperture Radar (InSAR) datasets have come to revolutionize how we monitor, explore, and characterize crustal processes through surface observations. With the recent rise of increased temporal and spatial resolution satellite images, as well as the increased access to data, we are able to measure crustal-scale processes with improved precision, over longer timescales and with increased noise control. Here, we present insights from our updated processing of ascending/descending Sentinel-1 InSAR time series data, over the years 2014 – 2021, spanning the San Andreas plate boundary in California. To correct for long-wavelength atmospheric effects and to apply an underlying ITRF 2014 reference frame, we integrate this InSAR time series with continuous GNSS coordinate time series datasets from the NASA MEaSUREs ESESES project to produce a combined InSAR/GNSS time series. We present updated time series for Sentinel-1 tracks 166, 173, 071, 144, 042, and 115, while additional ascending track processing is ongoing. This 7+ years of data allows us to observe and explore a variety of ongoing crustal processes in both northern and southern California, including earthquake cycle deformation (inter-, co-, and post-seismic motions), fault creep along multiple California faults, hydrological effects, and the effects of anthropogenic fluid extraction and influence. We estimate updated interseismic velocities with uncertainties estimated from a combination of white+flicker noise. In addition, we measure the ongoing effects of postseismic deformation around the 2019 Ridgecrest earthquake sequence.

Key Words
San Andreas Fault, Sentinel-1 InSAR Time Series, GNSS Time Series, Crustal Deformation

Citation
Guns, K. A., Xu, X., Sandwell, D. T., & Bock, Y. (2022, 09). Investigating Active Crustal Deformation along the San Andreas Plate Boundary from 7+ Years of Combined Sentinel-1 InSAR + GNSS Time Series. Poster Presentation at 2022 SCEC Annual Meeting.


Related Projects & Working Groups
Tectonic Geodesy