Co-seismic Deformation Features and Segmentation of the Ms 8.0 Wenchuan Earthquake in Sichuan

There are two seismic fractured zones developed when the Wenchuan earthquake happened. One occurred along the active fault-zone in the central Longmen Mts. and the other in the front of Longmen Mts.. The length of which is more than 200km and about 80km respectively. The co-seismic deformation shows thrust flexural belt with strike of N45°~60°E in the ground, which caused uplift at its northwest side and subsidence. The fault face dips to northwest with dip angle ranged from 50° to 60°. The vertical offset of the flexural belt ranges 2.5-3.0m along Yingxiu-Beichuan seismic fault, and 1.5-1.1m along Doujiangyan-Hanwang fault. Movement of co-seismic deformation presents obvious segmented features along the active fault-zone in the central Longmen Mts., for instance, in the section from Yingxiu to Leigu town, thrust without evident slip occurred; while from Beichuan to Qingchuan, thrust and dextral strike-slip both happened. But main movement along the front Longmen Mts shows thrust without slip and segmented features.