Abstract—A devastating earthquake with magnitude Mw = 7.2 occurred in the Van region, Eastern Turkey, on October 23, 2011. This study analyzes the characteristics of surface deformation before, during, and after the earthquake. The data from 300 × 300 km² permanent GPS network are used to quantitatively estimate surface deformations in the epicentral zone of the earthquake in the interval from January 16, 2009 to October 29, 2012 with daily time resolution. The dilatation, total shear, horizontal and vertical displacements are determined approximately three years before and one year after the 2011 Van earthquake. The spatial distributions of strains for each day are combined into a video to track the variations in the deformation process before and after the earthquake. The anomalous deformations are revealed a few months before the earthquake at a distance of about 100 km from the future epicenter. The evolution of the motions and deformations in the study region indicates a probable connection between the development of anomalous strains in the Varto fault zone and Bitlis–Zagros suture zone and the preparation of the Van earthquake. This suggests that preparatory deformation processes may take place at distances of dozens and hundreds km from the future seismic source.

摘要——2011年 10 月 23 日，土耳其东部凡地区发生了Mw = 7.2 的破坏性地震。本研究分析了震前、震中和震后的地表变形特征。来自 300 × 300 km ^{2 的数据}利用永久GPS网络对2009年1月16日至2012年10月29日地震震中区地表变形进行日时间分辨率定量估计。膨胀、总剪切、水平和垂直位移是在 2011 年范地震前大约三年和一年后确定的。每天应变的空间分布被组合成一个视频，以跟踪地震前后变形过程的变化。地震前几个月在距未来震中约 100 公里处发现了异常变形。研究区运动和变形的演变表明，Varto 断层带和 Bitlis-Zagros 缝合带异常应变的发展与 Van 地震的准备之间可能存在联系。这表明预备变形过程可能发生在距未来震源数十和数百公里的地方。