What seismic zone is Wenchuan located in?

Wenchuan belongs to the Longmenshan fault zone, specifically the Longmenshan fault zone in Sichuan. The Longmenshan fault in Sichuan spreads from northeast to southwest along the edge of Sichuan basin and overthrusts the Sichuan basin along the Qinghai-Tibet Plateau. This is a particularly fatal crack.

It is about 500 kilometers long and 70 kilometers wide, which is very huge. It is cut along the bottom of the northwest edge of Sichuan basin, and its position is very special. Here, the crust thickness changes suddenly, 60-70km to the west and below 50km to the east. 65,438+000 kilometers to the east are the densely populated and industrially developed Chengdu Plain and urban agglomeration.

During the Himalayan orogeny, which began 1 100 million years ago, the Indian Ocean plate moved northward and squeezed the Eurasian plate, resulting in the uplift of the Qinghai-Tibet Plateau. While the plateau is uplifting, it is also moving eastward, squeezing the Sichuan Basin.

Sichuan basin is a relatively stable block. Although the main body of Longmenshan looks weak in tectonic activity, it may be in the process of stress accumulation. When the stress accumulates to a certain extent, the crust will break and an earthquake will occur.

An earthquake of magnitude 4.8 occurred in Wenchuan County, Sichuan Province;

According to the official measurement by China Seismological Network, an earthquake of magnitude 4.8 occurred at 23: 36 on July/kloc-0 (30.97 degrees north latitude and 0/03.37 degrees east longitude) with a focal depth of 1 5km. The epicenter was 26 kilometers from Dujiangyan, 48 kilometers from chongzhou city and 76 kilometers from Chengdu. The earthquakes in Chengdu, Deyang and Leshan are obvious.

Miss Qin, who lives in chenghua district, said that she usually reacted slowly and didn't feel many earthquakes. During the earthquake, she was sitting on the sofa brushing her circle of friends and suddenly felt shaking. First I shook a few times, briefly stopped for 2 seconds, and then I continued to shake. Mr. Zhao of Jinjiang District even said in a circle of friends, "I was drinking porridge when I was shaking badly just now, and my hands shook. Alas, the porridge bowl was broken."