Why is Sichuan Province so prone to earthquakes?

The frequent earthquakes in Sichuan province are mainly caused by topography. Now many hydropower stations have been built in Sichuan, which will also affect the crustal changes in Sichuan.

Western Sichuan lies on the Longmenshan fault zone. The Indian Ocean plate squeezes the Qinghai-Tibet plate, which leads to the vibration and uplift of the Qinghai-Tibet plate. Longmenshan is located on the eastern edge of the Qinghai-Tibet plate, and the violent ups and downs of cracks often lead to violent cracks in the crust. Longmen Mountain is a broken mountain range. Once the fluctuation occurs, it will lead to an earthquake with high magnitude and serious damage.

The interior of the earth can be divided into three layers: crust, mantle and core. Suppose that the egg is the earth, the eggshell is the shell, the egg white is the mantle and the yolk is the core. According to statistics, about 92% of earthquakes occurred in the crust, and the rest occurred in the upper mantle.

Earthquakes can be divided into tectonic earthquakes, volcanic earthquakes, subsidence earthquakes and induced earthquakes according to their causes. More than 90% of earthquakes in the world belong to tectonic earthquakes, which are caused by the fault and dislocation of rock strata.

Chengdu has a special terrain, and there is no new crustal movement in itself. Secondly, except for a few areas near Longmen Mountain, which belong to alluvial plain, the alluvial river sand brought by the earthquake also played a great buffer role, which made Chengdu rarely have earthquakes.