Listric Fault Modeling of 2011 Mw 7.1 Turkey Van Earthquake Derived from AZISAR and Conventional Interferometry
Feng, Wanpeng1; Li, Zhenhong1; Singleton, Andrew1; Li, Yongsheng2
1School of Geographical and Earth Sciences, University of Glasgow, UNITED KINGDOM; 2Institute of crustal and dynamics, China Earthquake Administration, Beijing, China, CHINA
A great thrust-slip event with a magnitude of 7.1 hit Van, Eastern Turkey on 23 October 2011 (UTC 10:41:21, Local time 13:41:21), causing 604 fatalities and over 60k homeless. The hypocenter of this event is located in the north of the Bitlis structure zone, a convergence zone between the Arabian and Eurasian plates in the Eastern Anatolia. In this study, we firstly produced coseismic conventional InSAR and AZISAR InSAR maps associated with the 23 October 2011, Mw 7.1 Van earthquake using C-band Envisat and X-band COSMO-SkyMED images together with a limited number of GPS stations. We then employed a self-developed modelling package to determine slip distribution of this large event using geodetic observations. In order to build an optimal listric-fault model, we tested the relationship between depths and dip angles with three different formulas, i.e. linear, exponential and power functions. Our best-fitting model suggested that: (a) the maximum slip was at a depth of 12 km with a mean dip angle of ~ 46°, and (2) a seismic moment of 4.13 χ1019 N.m has released during the coseismic rupture, which is equivalent to the magnitude of 7.0 and consistent with previous seismic solutions.