Tectonic Deformation and Surface Processes of the Tibetan Plateau Constrained by Time Series Analysis of ARIA Sentinel-1 InSAR Products

We quantify surface deformation patterns resulting from tectonic motions and surface processes across the central Tibetan Plateau since late 2014 using more than 20,000 interferograms from ascending and descending passes of the Sentinel-1 satellites. Our data set comprises up to 10 frames per track, with more than 100 epochs and 300 interferograms per frame. To access and prepare such an extensive data set for time series analysis, we leverage the Advanced Rapid Imaging and Analysis (ARIA) standardized interferometric synthetic aperture radar (InSAR) products and toolbox. We then construct time series of surface deformation measured from our Sentinel-1 interferograms in the satellite lines of sight using the small baseline subset approach implemented by the Miami InSAR time series software in Python (MintPy). Differential phase corrections for tropospheric delay are made using ECMWF ERA-5 weather models and PyAPS. The broad spatial extent of these data (> 10⁶ km²), fine spatial resolution (originally processed at 90 m pixels, resampled to 270 m pixels), and high rate of temporal sampling (12-24-day orbit repeat time) offer unprecedented resolution of surface deformation in space and time. Time series of the surface displacements helps characterize the signal associated with hydrology and groundwater freeze/thaw cycles, and separate this signal from the secular tectonic loading. The resulting velocity fields will provide a more complete and accurate picture of interseismic strain accumulation rates across active faults in the region. The 2014 to present strain rate maps reveal surface movements associated with post-seismic relaxation following the 1997 M_W 7.6 Manyi and 2001 M_W 7.8 Kokoxili earthquakes. These observations and physical modeling will place strong constraints on the rheological properties of the lower crust and upper mantle.