The Impact of Plate Motions on Long-Wavelength InSAR-Derived Velocity Fields
Abstract
Interferometric Synthetic Aperture Radar (InSAR) measurements are increasingly being used to measure small amplitude tectonic deformations over large spatial scales. Residual signals are often present at these scales, and are interpreted to be noise of indeterminate origin, limiting studies of long-wavelength deformation. Here, we demonstrate the impact of bulk motion by the Earth's tectonic plates on InSAR-derived velocity fields. The range-dependent incidence angle of the InSAR observations, coupled with plate velocities of centimeters per year, can induce long-wavelength spatial gradients of millimeters per year over hundreds of kilometers in InSAR-derived velocity fields. We show that, after applying corrections, including for the ionosphere and troposphere, plate motion represents the dominant source of long-wavelength secular velocity gradients in multi-year time series for several study areas. This signal can be accounted for using plate motion models, allowing improved detection of regional tectonic strain at continental scales.
Additional Information
Thanks to Xiaohua Xu, Piyush Agram and Howard Zebker for useful conversations. A portion of the work was performed at Jet Propulsion Laboratory, California Institute of Technology under contract with NASA. Open Research. The Sentinel-1 data were provided by the European Space Agency and downloaded from the Alaska Satellite Facility. InSAR data were processed using the InSAR Scientific Computing Environment (ISCE) (Rosen et al., 2012), available at: https://github.com/isce-framework/isce2. Time series analysis was performed using the MintPy software (Yunjun et al., 2019), available at: https://github.com/insarlab/MintPy. Our plate motion correction method is implemented in MintPy as bulk_plate_motion.py (for review purposes this is available at: https://github.com/yuankailiu/MintPy/blob/GRL/mintpy/bulkplatemotion.py). Other data processing was performed using Python. Plots were produced using Matplotlib and Cartopy in Jupyter Notebooks, available at https://zenodo.org/record/6606282.Attached Files
Submitted - essoar.10511538.1.pdf
Supplemental Material - supp_info_plate_motion_insar_signal_grl_submitted.pdf
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Additional details
- Eprint ID
- 115153
- Resolver ID
- CaltechAUTHORS:20220614-222283000
- NASA/JPL/Caltech
- Created
-
2022-06-15Created from EPrint's datestamp field
- Updated
-
2022-06-15Created from EPrint's last_modified field
- Caltech groups
- Seismological Laboratory, Division of Geological and Planetary Sciences (GPS)