Seismic structure of the Longmen Shan region from S‐wave tomography and its relationship with the Wenchuan Ms 8.0 earthquake on 12 May 2008, southwestern China
Seismic structure of the Longmen Shan region from S‐wave tomography and its relationship with the Wenchuan Ms 8.0 earthquake on 12 May 2008, southwestern China
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DOI：
10.1029/2009gl041835
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发表时间：
2010-01
影响因子：
5.2
通讯作者：
Yi Xu;Zhiwei Li;Run-qiu Huang;Ya Xu
中科院分区：
文献类型：
--
作者：
Yi Xu;Zhiwei Li;Run-qiu Huang;Ya Xu
利用到时数据，我们通过S波层析成像确定了龙门山的地震结构，并研究了其与中国西南部汶川8.0级地震的关系。研究结果表明，龙门山断裂带是青藏高原东部和四川盆地之间的流变边界，整个龙门山的深层地壳因韧性变形而显着增厚。青藏高原东部上部构造以高速彭关地块为核心。其与四川盆地的碰撞是造成汶川以北龙门山断裂带地震破裂的最直接原因，而汶川以南地区少震则与地壳薄弱有关。因此，8.0级地震发生在强非均匀性区域。地壳结构的变化在很大程度上控制了8.0级地震的初始破裂和余震活动。
Using arrival time data, we determined seismic structure of the Longmen Shan by S‐wave tomography and studied its relations with the Ms 8.0 earthquake in Wenchuan, southwestern China. Our results suggest that the Longmen Shan fault belt is a rheologic boundary between the eastern Tibetan plateau and the Sichuan basin, and the deep crust of the entire Longmen Shan is significantly thickened by ductile deformation. The upper structure of the eastern Tibetan plateau is cored by the high‐velocity Pengguan massif. Its collision with the Sichuan basin is the most direct reason for the seismic ruptures on the Longmen Shan fault belt north of Wenchuan, while the lack of earthquakes south of Wenchuan is related to the weakness of the crust. Therefore, The Ms 8.0 earthquake occurred in a strongly heterogeneous region. The variations in the crustal structure largely controlled the initial rupture of the Ms 8.0 earthquake and aftershock activity.