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 plate motion. 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 yr1. 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.