Estimates of plate velocity and crustal deformation in the Indian subcontinent using GPS geodesy

GPS studies have been carried out by CSIR Centre for Mathematical Modelling and Computer Simulation (C-MMACS), Bangalore in the Indian subcontinent since 1994 to determine displacement and strain accumulation in the region over the past few years. This communication integrates the results obtained over the years in different regions of the Indian subcontinent using GPS geodesy to get an overall picture of deformation and related interpretations and discussions. The regions broadly covered by C-MMACS are the southern Indian peninsula, Ladakh, Garhwal, Kumaun, Darjeeling, Sikkim, Gujarat, Andamans and Shillong. GPS-derived velocity vectors of about 50 sites are given in the ITRF 97 (International Terrestrial Reference Frame), Indian reference frame and relative to HSc IGS station. Notable conclusions from the above study are as follows: Southern peninsular India moves as a rigid plate with the velocity of Indian plate. Convergence of 10-20 mm/yr occurs in the 2500 km stretch of the Himalayan arc from Kashmir to Arunachal and the convergence rates vary from west to east. Extension between the Himalayan GPS sites and Lhasa (southern Tibet) site is consistent with the east-west extension of the Tibetan Plateau.