Fault parameters of the October 2008 Damxung Mw6.3 earthquake from InSAR inversion and its tectonic implication

An M_W6.3 earthquake occurred in Damxung,Tibet,on October 6th,2008.We determined the fault parameters using a descending coseismic interferogram from ENVISAT ASAR images.In addition,we examined the uncertainties in the InSAR-derived source parameters using the variance-covariance matrix of InSAR data points estimated with a 1-D semivariogram function.The inverted results showed that the earthquake occurred on a secondary-fault in the eastern margin of the Yangyi basin,with a strike of 178°,a dip of 58° and dipping to west,which was normal faulting with a little of right-lateral strike slipping.It also appeared that the impact of the measurement errors on the uncertainties in InSAR derived source parameters was limited.This earthquake led to a subsidence of at least 30 cm at the epicenter,implying the Yangyi basin in the northern Yadong-Gulu Rift Belt was subsiding probably.