The Indian Tectonic Plate split from Godwana some 140 million years ago and started colliding into the Eurasian Plate some 40 – 50 million years ago. The Indian Plate is being subducted under the Eurasian Plate. The collision is still going on with the Indian Plate moving North East at about 6 -7 cm per year while the Eurasian Plate is moving Northwards at about 2 cm per year. The region is geologically active and earthquakes are not uncommon as the Himalayas continue to grow. It was thought that Himalayan earthquakes rarely, if ever, broke the surface and were “blind quakes”. But a new paper describes field work with novel imaging and dating techniques which show that at least the earthquakes of 1255 and 1934 have left discernible ruptures.
S. N. Sapkota, L. Bollinger, Y. Klinger, P. Tapponnier, Y. Gaudemer, D. Tiwari. Primary surface ruptures of the great Himalayan earthquakes in 1934 and 1255. Nature Geoscience, 2012; DOI: 10.1038/ngeo1669
Wikipedia: The Indo-Australian plate is still moving at 67 mm per year, and over the next 10 million years it will travel about 1,500 km into Asia. About 20 mm per year of the India-Asia convergence is absorbed by thrusting along the Himalaya southern front. This leads to the Himalayas rising by about 5 mm per year, making them geologically active. The movement of the Indian plate into the Asian plate also makes this region seismically active, leading to earthquakes from time to time.
Even blind quakes can be devastating as with the Kashmir quake of 2005:
The k2p blog 