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2008年5月12日四川汶川Ms8.0地震是一条陆内活动逆断裂带最新活动的结果.地震震源断裂沿龙门山构造带中央断裂发生斜滑作用和沿前山断裂发生纯逆断裂作用,断裂产状前者陡后者缓,垂直位移前者大后者小,这是一条少见的具有右旋走滑特征的挤压性质双断坡破裂,它是深部斜滑断裂在上地壳脆性域发生应变分解的结果.地震地表破裂带的分段活动和位移分布、地震波反演、余震空间分布、主震和余震震源机制解都说明这一条活动断裂带的活动机制和震源断裂破裂机制的复杂性.北西向小鱼洞左旋走滑破裂带是调节北东向破裂带中缩短量不同的破裂段之间的捩断裂,但由于震源断裂西南段经受着强烈挤压,左旋走滑的小鱼洞断裂也具有明显的挤压分量.在中央断裂这一条走滑逆冲和逆走滑性质的断裂和破裂带中出现的走滑正断裂控制的沙坝沟槽是在一个特殊的构造和地貌条件下,由震源断裂滑动和重力共同作用的结果,重力作用加大了该段破裂的正断层型垂直位移量,它不能真正代表震源断裂的最大地表垂直位移.
May 12, 2008 Wenchuan Ms8.0 earthquake in Sichuan Province is the result of an up-to-date activity of an intracontinental reverse fault zone, where the source focal fault was inclined along the central fault of the Longmen Shan tectonic belt and the pure reverse fault ruptured along the Qianqian fault The former is steepest and the latter is slow. The latter is small. This is a rare double-slope rupture characterized by dextral strike-slip characteristics. It is a result of the deep-bedded slip faults deforming in the brittle domain of the upper crust The seismic activity and displacement distribution, seismic wave inversion, aftershock spatial distribution, main shock and aftershock focal mechanism solutions all illustrate the complexity of the active fault mechanism and focal fault rupture mechanism in the seismic surface rupture zone. The left-lateral strike-slip rupture of the cave is to regulate the 捩 fracture between different shortened amounts of rupture in the NE-trending rupture zone. However, due to strong crushing of the southwest section of the focal fault, the left- With obvious compressive component.The sag trenches under the normal strike-slip faulting that occur in the central fault-slip strike-slip and anti-strike-slip faults and rupture zones are a special Under the condition of tectonic and geomorphic conditions, the normal fault type vertical displacement due to the joint action of source rock slip and gravity, and the gravity action increase the maximum vertical displacement of the source fracture.