Coseismic and postseismic slip models of the 2011 Van earthquake, Turkey, from InSAR, offset-tracking, MAI, and GPS observations

We derived the coseismic and postseismic slip models of the 2011 Van earthquake from multi-source geodetic datasets, including interferometric synthetic aperture radar (InSAR), multi-aperture InSAR (MAI), offset-tracking, and GPS measurements. The constrained least squares algorithm and Laplacian smoothing were used to estimate and regularize the slip distribution. The coseismic slip model suggested two nearly W-E striking segment faults breaking during the Van event. Two main slip concentrations were found to to be located at depths ranging from 7 km to 20 km. The estimated moment reached 6.08 x 10(19) Nm (equal to an Mw 7.19 event). A stress change analysis showed that the main shock imposed an up to similar to 5 bars stress load on the causative fault of the 9 November aftershock, implying a triggering mechanism between the two events. The postseismic slips of the Van earthquake were dominated by shallow left-lateral and deep thrust components. The slips distributed in most of the unruptured area of the fault plane. The accumulated postseismic moment reached 2.04 x 10(19) Nm, which was about 34% of the main shock moment. We conclude that the future seismic hazard will be relatively low in this area. (C) 2015 Elsevier Ltd. All rights reserved.