Abstract
While deformation at the Earth's surface primarily occurs along tectonic plate boundaries, major earthquakes have shaken regions deep within continental interiors. Three of the largest (M > 7.5) historic intraplate earthquakes occurred within the Indian subcontinent, suggesting the possibility of significant intraplate deformation. We consider surface velocities determined from new GPS data collected at 29 continuous GPS stations and 41 survey-mode GPS stations in India between 1995 and 2007 to find a north-south shortening rate of 0.3 ± 0.05 nanostrain yr−1, which may be accommodated by 2 ± 1 mm/yr of more localized convergence across central India. Southward motions at 4–7 mm/yr of sites on the Shillong plateau in northeast India reflect rapid shortening and high earthquake hazard associated with active thrust faults bounding the plateau. The width and magnitude of the elastic strain accumulation field across the Himalaya varies little from ∼76°–90° longitude, but the strain is more broadly distributed and convergence rates are higher along the eastern ∼200 km of the range.