我想問點解會有四川地震

At least 68,800 people killed and severe damage in the Dujiangyan-Mianzhu-Mianyang area. Landslides blocked roads and buried buildings in the Beichuan-Wenchuan area.

The Sichuan earthquake of May 12, 2008, occurred as the result of motion on a northeast striking reverse fault (逆斷地層) or thrust fault on the northwestern margin of the Sichuan Basin. The earthquake's epicenter and focal-mechanism are consistent with it having occurred as the result of movement on the Longmenshan fault (龍門山斷層) or a tectonically related fault. The earthquake reflects tectonic stresses resulting from the convergence of crustal material slowly moving from the high Tibetan Plateau (青藏高原), to the west, against strong crust underlying the Sichuan Basin and southeastern China.
On a continental scale (大範圍來說), the seismicity of central and eastern Asia is a result of northward convergence (聚合) of the India plate (印度板塊) against the Eurasia plate (歐亞板塊)with a velocity of about 50 mm/y. The convergence of the two plates is broadly accommodated by the uplift of the Asian highlands and by the motion of crustal material to the east away from the uplifted Tibetan Plateau.
The northwestern margin of the Sichuan Basin has previously experienced destructive earthquakes. The magnitude 7.5 earthquake of August 25, 1933, killed more than 9,300 people.

The 2008 Sichuan earthquake (Chinese: 四川大地震), or Great Sichuan Earthquake which measured at 8.0 Ms[5] and 8.3 Mw[6] according to PRC's China Seismological Bureau, and 7.9 Mw according to USGS, occurred at 14:28:01.42 CST (06:28:01.42 UTC) on 12 May 2008 in Sichuan province of China. It was also known as the Wenchuan earthquake (Chinese: 汶川大地震), after the earthquake's epicenter in Wenchuan County, Ngawa Tibetan and Qiang Autonomous Prefecture, Sichuan province. The epicenter was 80 kilometres (50 mi) west-northwest of Chengdu, the capital of Sichuan, with a depth of 19 kilometres (12 mi).[2] The earthquake was felt as far away as Beijing (1,500 km away) and Shanghai (1,700 km away), where office buildings swayed with the tremor.[7] The earthquake was also felt in nearby countries.
Official figures (as of June 3, 12:00 CST) state that 69,107 are confirmed dead, including 68,509 in Sichuan province[8], and 373,577 injured, with 18,230 listed as missing.[4] The earthquake left about 4.8 million people homeless,[9] though the number could be as high as 11 million.[10] It is the deadliest and strongest earthquake to hit China since the 1976 Tangshan earthquake, which killed at least 240,000 people. Approximately 15 million people lived in the affected area.
On May 25, a major aftershock of 6.0 Mw hit northeast of the original earthquake's epicenter, in Qingchuan County, causing eight deaths, 1000 injuries, and destroying thousands of buildings.[11] On May 27, two more major aftershocks, a 5.2 Mw in Qingchuan County and a 5.7 Mw in Ningqiang in Shaanxi Province, led to the collapse of more than 420,000 homes and injured 63 people.[