汶川地震区北西向断裂带遥感分析

利用北京一号小卫星遥感影像判读汶川地震区的断裂构造,发现了一系列100km左右等间距排列的北西向断裂,结果已部分地得到实地考察验证。龙门山断裂与北西向断裂的交汇部位发生强烈地震的几率较高。这些新发现将对汶川Ms8.0级地震发生机理、龙门山断裂带活动性分段、断裂同震位移自南西向北东、由右旋走滑逆断层向右旋走滑断层转变等重大问题提供了新的合理解释。

Remote sensing analysis of northewest-striking fault in Wenchuan earthquake zone

By interpreting remote sensing image of Wenchuan earthquake region from Beijing-1 Microsatellite Sensors data, there are a series of NW trending faults which ruptured the belt of Longmen shan faults at a length of 90—110 km, and this phenomenon has been conf irmed partly in f ield. We suggest that Longmen shan faults may show a NS trending faults, the same as Anninghe-Xiaojiang faults before Himalayan orogeny. India began colliding with Eurasia over 50 million years ago, this plate collision makes Tibetan plateau uplift rapidly and elevate the highest mountains in the world and thus attributed the area of the high plateau to eastward-moving along large-scale slip-striking faults, and the mechanically strong lithosphere of the Sichuan Basin obstructs it eastward in Longmen Shan region, thrust and strike slip faulting occur. These faults gradually translate from NNE to NE to NEE from south to north and form the structural pattern which we saw in remote sensing image of Longmen Shan region. If these faults can be validated in the further study in the future, it will provide new ideas to solve many geologic questions, including the reasonable explanations about seismic mechanism of Wenchuan Ms8.0, rupture segmentation of active deformation zones of Longmen Shan fault zones, the transformation of the coseismic displacement that reverse and right-slip components are of comparable magnitude along the southwestern portion of the rupture, but right-slip dominates the northeastern portion of the rupture.