Datensatz

Zusammenfassung

The convergence of the Indian and Eurasian plates is accommodated through stick and slip on the detachment or Main Himalayan Thrust (MHT). The part of the MHT that lies under the Outer and Lesser Himalaya is seismogenic and slips episodically and accumulates strain during the interseismic period when it is locked, which is released during the earthquakes through sudden slip on the MHT. The MHT further north slips aseismically. We report results of GPS measurements from Jammu-Kashmir and Karakoram region. The 250 km long segment of Kashmir Himalaya (Kashmir Seismic Gap) has not experienced major earthquake since 1555. We analysed GNSS data from 15 sites along with the published data from the region. The sites showed gradual increase in velocity from southwest to northeast suggesting accumulation of strain on the underlying seismically active detachment (MHT). The width of locked zone was estimated to be 175 km with an oblique convergence of 13.6mm/yr in Kashmir Himalaya. The Karakoram fault being one of the greatest strike-slip fault in the Himalayan orogen also plays a key role in Asian deformation kinematics having an average slip rate of 5±1mm/yr as estimated from GPS data. Presently, there are 14 permanent GPS stations of NGRI installed in Karakoram fault zone to access its role in Himalayan tectonics. A preliminary analysis of these data indicate that the northern segment of Karakoram fault is inactive while its southern part slips at the rate of ~2-3 mm/year.