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2008年5月12日四川汶川8.0级地震发生在青藏高原东缘的龙门山构造带上。通过野外实地调查与测量发现,汶川8.0级地震的地表破裂发生在龙门山构造带中的北川—映秀断裂之映秀南西—平武南坝石坎子段,彭县—灌县断裂的都江堰向峨—安县桑枣段也同时发生了同震地表破裂。北川—映秀断裂上的地表破裂长约220 km,表现为逆冲–右旋走滑运动特征,最大同震位错在6 m左右,水平与垂直位错量大致相当,与先期的研究成果一致;彭县—灌县断裂上的同震地表破裂长约100 km,表现为右旋–逆冲运动特征,最大垂直位错在2 m左右,水平与垂直位错量之比为1∶1～1∶3。地震地表破裂的空间分布及同震位错特征表明,汶川8.0级地震系北川—映秀断裂的逆冲–右旋运动所导致,并同时牵动了彭县—灌县断裂发生同震地表破裂。地震灾害的特点主要表现为地震波导致的强地面运动破坏、地震地表破裂带直接撕裂、地震导致的次生地质灾害(如崩塌和滑坡等)摧毁或掩埋建(构)筑物和堰塞湖等。根据地震考察资料并参考InSAR和强震仪记录,勾绘的该次地震等震线长轴方向沿龙门山构造带呈N40°～50°E方向延伸,出现了3个XI度的破坏区,具单侧多点瞬间破裂的典型特征,导致了四川北部、甘肃和陕西南部地区灾害较正常地震衰减破坏的显著加重。
On May 12, 2008, the Wenchuan 8.0 earthquake in Sichuan Province occurred on the Longmenshan structural belt on the eastern margin of the Qinghai-Tibet Plateau. Field investigations and measurements show that the surface rupture of Wenchuan Ms 8.0 earthquake occurred in Yingxiu Nanxi-Pingnan Nanba Shizikan segment of Beichuan-Yingxiu fault, Dujiangyan fault of Pengxian-Guanxian fault in Xiangmen-An county Sangzao section also occurred at the same time the earthquake surface rupture. The surface rupture on the Beichuan-Yingxiu fault is about 220 km in length, showing the characteristics of thrust-dextral strike-slip movement. The maximum coseismic dislocations are about 6 m, and the horizontal and vertical dislocations are about the same, which is consistent with the previous research results ; The coseismic rupture on Pengxian-Guanxian fault is about 100 km in length, showing a right-lateral-thrust movement with the maximum vertical dislocation being about 2 m and the ratio of horizontal to vertical dislocation being 1: 1 ~ 1: 3. The spatial distribution of the earthquake surface rupture and the characteristics of coseismic dislocation show that the Wenchuan M8.0 earthquake is caused by the thrust-dextral movement of the Beichuan-Yingxiu fault and affects the simultaneous coseismic surface rupture of the Pengxian-Guanxian fault. The main features of the earthquake disaster include strong ground motion damage caused by seismic waves, direct tearing of earthquake surface rupture zone, secondary geological disasters such as landslides and landslides caused by earthquakes, or the destruction of buried structures and dammed lakes Wait. According to the seismic survey data and the records of InSAR and seismographs, the long axis direction of the seismic line outlined in this earthquake extends along the Longmen Shan tectonic belt in the direction of N40 ° ~50 ° E, resulting in three XI degree destructive zones, The typical characteristics of the unilateral multi-point instantaneous rupture resulted in significant aggravating disasters in the northern Sichuan, Gansu and southern Shaanxi areas as compared with normal earthquakes.