HR: 08:15h
AN: G21D-02 INVITED    [Abstracts]
TI: Long-lasting afterslip due to a magnitude-5 earthquake at the Chaman fault, Afghanistan
AU: * Furuya, M
EM: furuya@eri.u-tokyo.ac.jp
AF: Earthquake Research Institute, The University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo, 113- 0032, Japan
AU: * Furuya, M
EM: furuya@eri.u-tokyo.ac.jp
AF: Now at Department of Natural History Sciences, Hokkaido University, N10 W8, Kita-ku, Sapporo, 060-0810, Japan
AU: Satyabala, S P
EM: satyabala1978@yahoo.com
AF: National Geophysical Research Institute, Hydelabad, Hydelabad, 500 007, India
AB: The Chaman fault system forms a prominent ~900-km-long left-lateral transform plate boundary between the Indian and Eurasian plates in Afghanistan and Pakistan. Whereas geological investigations on the fault indicate a long term slip rate of 20-40 mm/yr, historical records show an absence of large earthquakes at a 300- 400 km segment of the Chaman Fault, suggesting that this segment of the fault is either locked or slipping aseismically. Here we show satellite radar interferometry (InSAR) data that revealed that afterslip signal following an earthquake of magnitude 5.0 lasted for more than a year and at least quadrupled its moment release. We detected no contiguous surface slip before the earthquake during the 1.5 years sampled by our data. This finding of long-lasting afterslip suggests that the plate motion along the Chaman Fault is at least accommodated by slow slip episodes following moderate earthquakes in the fault.
DE: 1207 Transient deformation (6924, 7230, 7240)
DE: 1240 Satellite geodesy: results (6929, 7215, 7230, 7240)
DE: 8111 Continental tectonics: strike-slip and transform
DE: 8123 Dynamics: seismotectonics
DE: 8163 Rheology and friction of fault zones (8034)
SC: Geodesy [G]
MN: 2007 Fall Meeting