The motion and active deformation of India

Abstract

Measurements of surface displacements using GPS constrain the motion and deformation of India and India-Eurasia plate boundary deformation along the Himalaya. The GPS velocities of plate-interior sites constrain the pole of the angular velocity vector of India with respect to Eurasia to lie at 25.6 ±1.0°N 11.1± 9.0°E, approximately 6°. west of the NUVEL-1A pole of <3 Ma platemotion. The angular rotation rate of 0.44 ± 0.03°Myr^-1 is 14% slower than the long-term rate of 0.51° Myr^-1. Insignificant velocities between plate interior sites indicate that the exposed Indian plate is stable to within 7 .10^-9 yr^-1. The observed contraction vector across the Himalaya (≤20 mm/yr) veers from ~N20°E in the northwest Himalaya to ~N25°W in east Nepal, consistent with east-west extension of southern Tibet.