Large‐Scale Interseismic Strain Mapping of the NE Tibetan Plateau From Sentinel‐1 Interferometry

The launches of the Sentinel‐1 synthetic aperture radar satellites in 2014 and 2016 started a new era of high‐resolution velocity and strain rate mapping for the continents. However, multiple challenges exist in tying independently processed velocity data sets to a common reference frame and producing high‐resolution strain rate fields. We analyze Sentinel‐1 data acquired between 2014 and 2019 over the northeast Tibetan Plateau, and develop new methods to derive east and vertical velocities with ∼100 m resolution and ∼1 mm/yr accuracy across an area of 440,000 km2. By implementing a new method of combining horizontal gradients of filtered east and interpolated north velocities, we derive the first ∼1 km resolution strain rate field for this tectonically active region. The strain rate fields show concentrated shear strain along the Haiyuan and East Kunlun Faults, and local contractional strain on fault junctions, within the Qilianshan thrusts, and around the Longyangxia Reservoir. The Laohushan‐Jingtai creeping section of the Haiyuan Fault is highlighted in our data set by extremely rapid strain rates. Strain across unknown portions of the Haiyuan Fault system, including shear on the eastern extension of the Dabanshan Fault and contraction at the western flank of the Quwushan, highlight unmapped tectonic structures. In addition to the uplift across most of the lowlands, the vertical velocities also contain climatic, hydrological or anthropogenic‐related deformation signals. We demonstrate the enhanced view of large‐scale active tectonic processes provided by high‐resolution velocities and strain rates derived from Sentinel‐1 data and highlight associated wide‐ranging research applications. The new‐generation radar satellites permit the derivation of crustal velocities in fine resolution over continental scales. With the technical advancements developed in this study, we reveal unseen details of the crustal deformation over the earthquake‐prone Hexi Corridor in the northeast corner of the Tibetan Plateau. In particular, we observe concentrated elastic loading along, and at branch points of, major earthquake‐generating faults. The ability to monitor such phenomena is important for understanding future seismic hazard as such geometrical complexities along faults are often associated with earthquake triggering and termination. We also draw attention to previously unknown structures that are rapidly deforming. This new and enhanced view of the local tectonic setting could improve local seismic hazard assessment. Last but not least, we observe climatic, hydrological and anthropogenic signals in the vertical velocity field, which are related to permafrost thawing, blocked river drainage, mining, damming and the extraction of groundwater for farming. Overall, we demonstrate the wealth of information that can be derived from the rapidly growing space‐born Earth observation data, which are destined to play an important role in shaping a more resilient world for the future. We present new methods to mosaic line‐of‐sight velocity frames, derive Cartesian velocities, and produce high‐resolution strain‐rate mapsWe construct 440,000 km2maps of east‐west, vertical velocities, and strain rates over NE Tibet from Sentinel‐1 interferometryWe quantify strain partitioning, measure creep rate, identify unmapped structures and climatic, hydrological and anthropogenic signals We present new methods to mosaic line‐of‐sight velocity frames, derive Cartesian velocities, and produce high‐resolution strain‐rate maps We construct 440,000 km2maps of east‐west, vertical velocities, and strain rates over NE Tibet from Sentinel‐1 interferometry We quantify strain partitioning, measure creep rate, identify unmapped structures and climatic, hydrological and anthropogenic signals