New evidence for active tectonics at the boundary of the Kashi Depression, China, from time series InSAR observations
New evidence for active tectonics at the boundary of the Kashi Depression, China, from time series InSAR observations
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DOI：
10.1016/j.tecto.2015.04.011
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发表时间：
2015-06
期刊：
影响因子：
2.9
通讯作者：
P. He;Yangmao Wen;Caijun Xu;Yang Liu;H. Fok
中科院分区：
文献类型：
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作者：
P. He;Yangmao Wen;Caijun Xu;Yang Liu;H. Fok
喀什凹陷是天山南翼构造活动最复杂的地区之一。由于缺乏地面观测资料，天山盆山过渡带的边界和震间活动一直没有明确的确定。利用2003 ~ 2010年获得的48幅Envisat高级合成孔径雷达（ASAR）图像，构建了喀什凹陷高分辨率地震间形变测量的干涉图。利用欧洲中期天气预报中心（ECMWF）提供的全球大气模式ERA-Interim和全球网络轨道改正，分别消除了大气影响和长波长轨道误差。利用干涉SAR时间序列和大气估计模型（干涉合成孔径雷达TS + AEM），获得喀什凹陷地区的形变速率图。干涉合成孔径雷达速率图显示，阿图什南断裂北段相对于南段有约3 mm/a的抬升。这一结果表明，主要的构造变形可能发生在沿着阿图什断裂南段。根据简单的刃位错模型，求得天山造山带与喀什凹陷之间的南阿图什断裂的倾角为31 ± 0.6°，滑动速率为2.3 ± 0.1mm/a，闭锁深度为10.6 ± 0.4km。该模型的计算结果与干涉合成孔径雷达的计算结果吻合较好。结果表明，阿图什南断裂是南天山与塔里木盆地块体边界地区的主要活动断裂。
Kashi Depression is one of the most complex active tectonic areas in the southern flank of Tianshan, China. Due to the lack of ground observations, the boundary of basin mountain transition zone and the interseismic activity of the Tianshan have not been clearly determined. In this study, 48 Envisat Advanced Synthetic Aperture Radar (ASAR) imagery acquired from 2003 to 2010 are used to construct interferograms for measuring high-resolution interseismic deformation in the Kashi Depression area. A global atmospheric model ERA-Interim provided by the European Center for Medium Range Weather Forecast (ECMWF) and a global network orbital correction are applied to remove atmospheric effect, and the long-wavelength orbital errors, respectively, for the interferograms. Interferometric SAR time series with Atmospheric Estimation Model (InSAR TS + AEM) are then used to obtain a deformation rate map for the Kashi Depression area. The InSAR rate map indicates that the north part of South Atushi Fault has ~ 3 mm/year uplift relative to that of the south part. This result manifests the main tectonic deformation potentially occurs along the Southern Atushi Fault. Based on a simple edge dislocation model, the dip angle of 31 ± 0.6°, slip rate of 2.3 ± 0.1 mm/year, and locking depth of 10.6 ± 0.4 km for the Southern Atushi Fault between Tianshan Orogenic Belt and the Kashi Depression are obtained. This modeling result shows in good agreement with the InSAR derived rates. Our results show that the Southern Atushi Fault is the main active fault in block boundary region between the south of Tianshan and the Tarim Basin.