Present‐Day Tectonic and Non‐Tectonic Crustal Deformation of and Around the Indian Plate From GNSS and GRACE Measurements

Abstract We use continuous Global Navigation Satellite System (GNSS) measurements from >1600 sites on and around the Indian subcontinent, including 64 sites in the Indian plate interior, to estimate site motions and their seasonal variations. Stations in the Himalayan and Indo‐Burmese plate boundary zones exhibit rapid velocities (15–20 mm/year with respect to the Indian plate) and correspondingly higher strain rates (70–100 ηstrain/year). We find that the southern part of the plate interior is more stable, with residual motions <1 mm/year. Although the northern part of the plate interior appears more deformable (∼2 mm/year), there is no clear fragmentation of the Indian plate. The southern part exhibits a low shear strain of ∼1 ηstrain/year, while the northwestern India region, referred to as the Rajputana block lying west of the Aravalli Delhi Fold Belt (ADFB), consistently shows a higher shear strain rate of >2 ηstrain/year and higher southward motion with respect to the region to the east. Such a motion is consistent with sinistral shear along the ADFB and ∼north‐south contraction across the Kachchh failed rift in the south, explaining the higher earthquake productivity in Gujarat. Long‐term vertical rates on the Indian plate are low except in the northwestern region where Gravity Recovery and Climate Experiment (GRACE) measurements show negative equivalent water height changes and GNSS measurements record uplift, caused by the depletion of groundwater storage. Seasonal variations in the GNSS and GRACE data distinctly show the influence of hydrological loading on land movement. After the monsoon, the entire hydrological load seems to be centered in the Indo‐Gangetic plains and the central‐east India region.