1August 25th, 933 15: 50: 30, a magnitude 7.5 earthquake occurred in Diexi Town, Maoxian County, Sichuan Province, China. This earthquake, the epicenter intensity 10 degrees, Diexi Town was destroyed. There is a city god temple in the east of the city with broken columns and broken beams, which is the only remaining building in the city. There are no traces of 278 houses in the city. The landslide caused by the earthquake blocked the Minjiang River in three places and became three "earthquake lakes". Longchi, which faces Longchi Mountain in Diexi City, is one of the eight scenic spots in Diexi. After the earthquake, the pool water dried up. The top of the third weir is about 300m thick and100m high. It is the strongest, largest and most impounded weir among the three weirs. Three weirs cut off the Minjiang River for 43 days, and the river flowed back more than 20 kilometers. 45 days after the earthquake, that is, at 7: 00 on October 9, 65438/kloc-0, the dam burst and the flood peak reached Maowen county, 20 kilometers away from/kloc-0, until it reached Leshan county, 260 kilometers away from Diexi.

1973 luhuo earthquake

1February 6, 973, an earthquake of magnitude 7.9 occurred in Yade, Luhuo County. The earthquake caused serious losses, with 2 175 deaths, 2,756 injuries, 88 families without families and 43 orphans. Collapsed houses 15700, damaged houses 2867, lost 40427 heads of livestock and 20 10000 Jin of grain. Almost 100% of the houses in the earthquake-stricken areas collapsed. From Omi to Zell in Luhuo County, all Tibetan houses were razed to the ground. "Stupid shell houses" and all-wood houses have also been seriously damaged or tilted. Of the 5,600 houses in the county, 4,600 were completely destroyed, 880 were seriously damaged and 90 were cracked. 17 of Sichuan-Tibet highway was seriously damaged. Landslides, ground fissures and rolling stones are common. The earthquake also caused damage to some roads, bridges and telecommunications lines, and communication was interrupted.

1On February 6th, 973, an earthquake of magnitude 7.9 occurred in Luhuo County, Ganzi Prefecture, Sichuan Province, which damaged Ganzi, Dawu, Seda, Xinlong and Rangtang counties to varying degrees.

1976 Songpan earthquake

At 22: 06 on August 1976, an earthquake of magnitude 7.2 occurred in Songpan and Pingwu areas in the northwest of our province. Before the earthquake, the earthquake department made short-and medium-term predictions and took active preventive measures such as evacuation, so there were fewer casualties. At 05: 49 on August 22nd and at 1 1 03 on August 23rd, strong earthquakes of magnitude 6.7 and 7.2 occurred in this area.

The focal depth of these earthquakes is 10-20km, and the polar earthquake area is relatively small. According to the survey, the major axis is 5km, and the minor axis is about 1.5km, covering an area of about 29 square kilometers. The earthquake zone was severely damaged, most of the brick-wood houses collapsed and most of the frame houses were damaged. Collapse and landslide occurred during the earthquake. After the earthquake, rain and mudslides flooded villages, blocked rivers, turned them into lakes, destroyed roads and interrupted communications.

Songpan and Pingwu counties are vast and sparsely populated, with a density of 6-29 people per square kilometer. The mountains in the county are towering, the forest area is large, the economy is mainly agriculture or agriculture and animal husbandry, and the industrial economy is underdeveloped. Therefore, compared with industries, transportation, economically developed areas and densely populated cities, the losses caused by this earthquake are much smaller.

According to the statistics of Songpan, Pingwu, Mao Wen and Nanping counties in that year, more than 500 houses collapsed, more than 5000 mu of cultivated land 15000 was destroyed, more than 7 million Jin of grain/kloc-0 was lost, more than 2800 livestock died, more than 30 bridges were damaged, more than 200 culverts were damaged, and several small hydropower stations with more than 2600 kilowatts were also damaged and blacked out. There were few casualties in this earthquake. According to the statistics, 4 1 person died, seriously injured 156 people and slightly injured more than 600 people.

Wenchuan earthquake in 2008