by Yong Chen, Li Li, Juan Li, and Gang Li
Wenchuan Earthquake: Way of thinking is changed
On 12 May, 2008, at 14:28:04 local time, an Ms 8.0 earthquake struck the Wenchuan County, Sichuan Province, in southwest China (Figure 1). This quake left about 70,000 people dead, 18,000 missing and over 370,000 injured. In the 75 days after the main shock, 20,000 aftershocks were recorded, which included 241 with Ms°›4.0, 205 with 4.0°‹Ms°‹4.9, 30 with 5.0°‹Ms°‹5.9, and 6 with Ms°›6.0. The largest aftershock took place 13 days after the main shock, in Qingchuan County, 110 km northeast of the epicenter of the quake (Chen, 2008). The losses from the quake-triggered geological disasters accounted for over a third of the total quake losses, which is extremely rare in the history of earthquake disasters. Secondary disasters, such as landslides, rockslides, landfalls, debris flows, etc., were widely distributed. Large numbers of buildings collapsed, including ones with steel reinforcing in the area of the epicenter. Infrastructure was badly damaged. In many areas, communications, and power and water supplies were cut off. The earthquake left over 35 large quake-dammed lakes, which threatened further disasters in the catchment areas.
The 5.12 quake broke several records in the history of modern China. It was the most devastating quake and had the widest range of destruction. In addition, it involved the greatest rescue efforts. It affected the lives of about 28 million people in an area of over 130,000 km2, caused severe damage to about a million urban and four million rural buildings, and left some 10 million people homeless. Preliminary estimates show that the total economic losses topped 10 trillion RMB, which is equivalent to the 2007 GDP of Sichuan Province and 1.6 times higher than that caused by the Hanshin Earthquake in Japan in 1995.
The 5.12 quake reminded scientists of the urgency of continuous research to improve earthquake prediction and damage prevention. This article provides geological and geophysical information intended to help scientists to better understand the impacts of this quake and to predict such events in the future.