Interseismic slip rate of the northwestern Xianshuihe fault from InSAR data
Interseismic slip rate of the northwestern Xianshuihe fault from InSAR data
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DOI：
10.1029/2008gl036560
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发表时间：
2009-02
影响因子：
5.2
通讯作者：
Hua Wang;Tim J. Wright;Juliet Biggs
中科院分区：
文献类型：
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作者：
Hua Wang;Tim J. Wright;Juliet Biggs
鲜水河断裂是青藏高原东缘附近一个高度活跃的走滑断裂系统。我们利用多干涉图方法，根据欧洲遥感卫星1号/2号（ERS - 1/2）和环境卫星（Envisat）获取的十年合成孔径雷达（SAR）数据，绘制了鲜水河断裂西北段由于震间应变积累导致的视线向变形速率图。该速率图显示出与断裂相关的明显变形梯度，但相对于地表痕迹向东北稍有偏移。利用蒙特卡罗方法对合成孔径雷达干涉测量（InSAR）速率图和全球定位系统（GPS）数据进行联合反演，我们在90%置信水平下估计滑动速率为9 - 12毫米/年，闭锁深度为3 - 6千米。该滑动速率与全新世断层滑动速率和历史地震相符。我们的结果还表明不存在明显的跨断层伸展。未来，来自升轨和降轨的合成孔径雷达干涉测量数据可能会进一步约束该断层的三维断层滑动速率。
The Xianshuihe fault is a highly active strike‐slip fault system near the eastern margin of the Tibetan plateau. We use a multi‐interferogram method to construct a map of line‐of‐sight deformation rate due to interseismic strain accumulation on the northwestern Xianshuihe fault from a decade of SAR data acquired by the ERS‐1/2 and Envisat satellites. The rate map shows a clear deformation gradient associated with the fault, but slightly offset to the northeast from the surface trace. Joint inversion of InSAR rate map and GPS data using Monte‐Carlo method, we estimate a slip rate of 9‐12 mm/yr with a locking depth of 3‐6 km at the 90% confidence level. The slip rate agrees with the Holocene fault slip rate and the historical earthquakes. Our results also suggest no significant across‐fault extension. In the future, InSAR data from both ascending and descending orbits may further constrain the 3‐D fault slip rate on this fault.