The Cause of Ludian M8.3 Earthquake

The earthquake occurred near the Yu He-Zhaotong fault, which was trending from northeast to west, and the focal mechanism showed that it was a strike-slip fault.

The earthquake has several characteristics: the magnitude is relatively high, Ludian County is densely populated, Ludian County is a national poverty-stricken county, and the earthquake zone is a mountainous canyon landform, which occurred in mountainous areas.

First, the magnitude of this earthquake is relatively high. Yunnan is a province with frequent earthquake disasters in China. This earthquake is another 6.5-magnitude earthquake after the 6.5-magnitude earthquake in Yao 'an, Yunnan Province on June 5438+1October 5, 2000. In other words, there was no strong earthquake of magnitude 6.5 or above in the past 14 years. Distance1It has been 8 years since the earthquake of magnitude 7 occurred in Lijiang, Yunnan on February 3, 996/kloc-0. Therefore, this is a serious earthquake event that happened in Yunnan for more than ten years. Due to the high magnitude and shallow earthquake source, serious casualties and property losses have been caused.

Second, Ludian County is a densely populated area in Yunnan Province. Dense population makes the area affected by this earthquake have a large population and the disaster is serious.

Third, Ludian County is a national poverty-stricken county. The local economic conditions are relatively poor, and the seismic performance of buildings is generally poor, which is also the direct cause of heavy losses in this disaster.

Fourth, the earthquake zone of this earthquake is mountainous and canyon landforms. Due to the rainy season, the earthquake caused serious secondary disasters such as landslides, mudslides, rolling stones and the formation of barrier lakes, which also aggravated the losses of this disaster.

Fifth, the earthquake happened in the mountainous area, which caused the interruption of communication and traffic, which also made our rescue operation particularly difficult. At present, under the organization of the government, various disaster relief activities are being carried out rapidly, roads are being opened and detailed disasters are being collected. Pan Huaiwen said that the former side is fully grasping the 72-hour golden rescue period and putting the search and rescue of life in the first place. This is the top priority of the current earthquake relief work. First, search and rescue people buried in the earthquake to minimize personnel losses. At the same time, properly arranging the lives of the people in the disaster areas is also the key work in the current earthquake relief work.