A geodetic study of the 23 October 2011 Van, Turkey earthquake
A geodetic study of the 23 October 2011 Van, Turkey earthquake
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DOI：
10.1016/j.tecto.2012.12.005
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发表时间：
2013-03
期刊：
影响因子：
2.9
通讯作者：
Y. Altiner;W. Soehne;C. Guney;J. Perlt;Rongjiang Wang;M. Muzli
中科院分区：
文献类型：
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作者：
Y. Altiner;W. Soehne;C. Guney;J. Perlt;Rongjiang Wang;M. Muzli
货车（土耳其安纳托利亚东部）地震发生在2011年10月23日星期日，矩震级为7. 2级。该地区的构造特征是在Bitlis缝合带上的走滑断层，以及在Zagros褶皱和冲断带的逆冲断层。利用CORS-TR网络永久性GNSS台站的高速率（1秒）GPS数据，在这次地震期间使用精确的单点定位确定了11个台站的同震位移。利用14个CORS-TR台站的坐标变化时间序列，计算了地震前后的地壳运动。根据GPS高频数据计算的PPP解确定台站的同震运动，我们得出货车地震的发震时间为10：41：22（UTC）。没有观测到震前水平位移超过5 mm的台站。这意味着在地震发生前没有任何运动学警告或预测。沿着货车海以北约100 km的东西水平线，该线的北方部分经历了0.2- 1 ppm的西北-东南方向延伸。南部经历了0.5-1.5ppm的南北缩短。我们在大地测量上估计的南北缩短与美国地质调查局使用地震数据独立推导出的南北缩短和逆冲震源机制非常匹配。由GPS资料得到的同震地表位移与美国地质勘探局给出的震源模型一致。从GPS数据导出的大地震源模型再现了与地球物理模型相同的矩震级和质心，但表现出更高的滑动分布的空间分辨率。我们还分析了主震后的前两周内从GPS数据得出的震后地表位移。在同震断层面上没有发现合理的滑移分布，表明震后早期形变的震源可能来自于分布较广的余震。
The Van (Eastern Anatolia, Turkey) earthquake occurred on Sunday, October 23, 2011 with a moment magnitude of 7.2. The tectonics of this region is characterized by strike–slip faulting on the Bitlis Suture Zone, and thrusting in the Zagros fold and thrust belt. Using high-rate (1second) GPS data from permanent GNSS stations from the CORS-TR network, co-seismic displacements of eleven stations were determined using precise point positioning during this earthquake. We used the time series of coordinate changes for fourteen CORS-TR stations, and calculated the crust movements before and after the earthquake. According to the PPP solutions computed using high frequency GPS data to determine the co-seismic motions of stations, we conclude for the Van earthquake an occurrence time of 10:41:22 (UTC). No pre-seismic horizontal movement of stations at the level more than 5mm before the earthquake could be observed. That means that no kinematic warning or prediction before the earthquake exists. Along an east–west horizontal line north of the Van Sea with a length of about 100km, the northern part of this line experienced extension of 0.2–1ppm in a NW–SE direction. The southern part experienced N–S shortening of 0.5–1.5ppm. The N–S shortening we estimated geodetically matches well with the N–S shortening and thrust focal mechanism derived independently using seismic data by the USGS. Co-seismic surface displacements derived from the GPS data are consistent with the teleseismic source model given by the USGS. The geodetic source model derived from the GPS data reproduces the same moment magnitude and centroid as the teleseismic model, but shows a higher spatial resolution of the slip distribution. We also analyzed the post-seismic surface displacements derived from the GPS data within the first two weeks after the mainshock. No reasonable slip distribution on the co-seismic fault plane could be found, indicating that the sources for the early post-seismic deformation might come from the widely scattered aftershocks.