The 2005, M_w 7.6 Kashmir earthquake: Sub-pixel correlation of ASTER images and seismic waveforms analysis
We analyze the M_w 7.6 Kashmir earthquake of October 8, 2005, using sub-pixel correlation of ASTER images to measure ground deformation, and modeling seismic waveforms. The surface rupture is continuous over a distance of 75 km and cuts across the Hazara syntaxis reactivating the Tanda and the Muzaffarabad faults. North of Muzaffarabad the surface rupture coincides approximately with the MBT, on the southwestern flank of the syntaxis, although the two faults have opposite dip angles. The rupture terminates abruptly at the hairpin turn of the MBT showing a strong structural control. The fault offset is 4 m on average and peaks to 7 m northwest of Muzaffarabad. The rupture lasted about 25 s and propagated updip and bi-laterally ~2 km/s, with a rise time of 2–5 s. The shallowness and compactness of the rupture, both in time and space, provide an explanation for the intensity of destructions. This kind of analysis could be achieved as soon as a post-earthquake image is available, and would provide key information for early assessment of damages. The study sheds some light on seismic hazard in the Himalaya, and raises concern regarding the possibility of a repetition of the 1555 event which presumably ruptured the Himalayan front south of the Kashmir basin and may have reached a magnitude M_w > 8.
Additional Information© 2006 Elsevier B.V. Received 6 April 2006; revised 16 June 2006; accepted 16 June 2006. Editor: R.D. van der Hilst. Available online 17 August 2006. This study has benefited from useful discussions with Kerry Sieh, Chen Ji, James Jackson, Eric Fielding, Mohamed Chlieh, Laurent Bollinger, Roland Burgmann. We are most grateful to Bob Yeats and Barry Parsons for helpful reviews.
Supplemental Material - avouacEPSL2006SupplFigs.pdf