About the earthquake risk areas that Sichuan Province needs to focus on monitoring this year
We have comprehensively analyzed the following two risk areas obtained by the historical strong earthquake distribution in Sichuan Province and the earthquake blank areas appearing on various fault zones.
It is recommended that relevant departments improve earthquake precursor monitoring of the Xianshui River fault zone and Anning River fault zone in Sichuan Province.
1, Xianshuihe fault zone
1, Xianshuihe fault zone is located in the western part of Sichuan Province. The Xianshuihe fault zone in geological structure is located at the junction of Bayankala plot and the Sichuan-Yunnan rhombus plot. The Xianshuihe fault zone is the fault zone with the highest frequency of earthquakes of magnitude 7 or above in Sichuan Province, and is also the most active fault zone with strong earthquakes in Sichuan Province.
Free Fault Belt starts from northwest from northwest from Zhuwo Township northwest, through Dandu Township, Yade Township , Luhuo County county town, Simu Township , Renda Township, Kongse Township, Mazi Township , Daofu County county town, Gexi Township , Longdeng Township , Bamei Town , Tagong Town, Yala Township , Kangding City , Yanzigou Town, Moxi Town, Detuo Town, and until the northwest Tianwan Township of Shimian County. The entire Xianshui River fault zone is about 300 kilometers long.
In addition, the Xianshui River fault zone is the fault zone with the highest frequency of magnitude 7 or above in Sichuan Province. Data shows that 9 earthquakes of magnitude 7 or above occurred in the Xianshui River fault zone in the period from 1700 to the present 322 years. The following is the information on earthquakes of magnitude 7 or above in the historical magnitude 7 or above.
On August 1, 11725, a magnitude 7 earthquake occurred west of Kangding City, Sichuan Province.
On August 30, 1748, the magnitude 7 earthquake occurred in the southeast of Daofu County, northwest of Kangding, Sichuan Province.
1 On June 1, 1786, a magnitude 7.75 earthquake occurred between Moxi Town, southern Kangding City, Sichuan Province - Luding County. The earthquake caused a large-scale landslide along the Dadu River. It formed a dam-breaking lake. The strong aftershock after the earthquake caused the dam-breaking lake. The flood rushed along the Dadu River to the present Yichang, Hubei. This is also the most serious secondary earthquake disaster in Chinese history. The earthquake and floods killed about 100,000 people.
On December 8, 1816, a magnitude 7.5 earthquake occurred near the county town of Luhuo County, Sichuan Province.
On August 29, 1893, a magnitude 7 earthquake occurred near Qianning, Daofu County, Sichuan Province.
On August 30, 1904, a magnitude 7 earthquake occurred near Daofu County, Sichuan Province.
On March 24, 1923, a magnitude 7.25 earthquake occurred on the front line of Luhuo County and Daofu County, Sichuan Province.
On April 14, 1955, the magnitude 7.5 earthquake occurred near Zeduotang, Kangding City, Sichuan Province.
On February 6, 1973, a magnitude 7.6 earthquake occurred near Luhuo County, Sichuan Province.
According to the historical frequency of earthquakes of magnitude 7 or above in the Xianshui River fault zone, there have been 9 earthquakes of magnitude 7 or above in the Xianshui River fault zone in the past 322 years, with an average of every 35.77 years. It is worth noting that the latest earthquake of magnitude 7 or above in the Xianshui River fault zone was a magnitude 7.6 earthquake near Luhuo County, Sichuan on February 6, 1973, 49 years ago.
Therefore, it is recommended that relevant departments strengthen the monitoring of earthquake precursors in the Xianshui River fault zone, especially the monitoring of earthquake precursors near the Daofu section of the Xianshui River fault zone.
2, Anning River fault zone
Anning River fault zone is located in the central and southern regions of Sichuan Province. The Anning River fault zone in geological structure is located at the junction of the Sichuan-Yunnan rhombus plot and the Yangtze River Huai plot.
Anning River fault zone starts from the north of Tianwan Township, Shimian County, Sichuan Province, through Xinmin Township, Anshun Township, the western part of Shimian County, Liziping Township, Tuowu Township, , Yihai Town, , Caogu Township, , Mianning County, Linli Township, , Fuxing Town, , Pioneer Township, , Lugu Town, , Yuehua Township, Lizhou Town, Xingsheng Township, Anning Town, Xichang to the west of the city, Madao Town, Jingjiu Township, , Zhongba Township, Huangshui Township, Mali Town, Dechang County, Miyi County to Jinshajiang . If the entire Anning River fault zone is included in the extension section of Yunnan Province, the length will exceed 400 kilometers.
Historically, there was a magnitude 7.5 earthquake in the Anning River fault zone on September 27, 1480 in Sichuan, and a magnitude 7.5 earthquake in northern Xichang, Sichuan on March 29, 1536.
From the frequency of strong earthquake activity, although the Anning River fault zone is not as active as the Xianshui River fault zone, its long interval between strong earthquakes makes it easier for the earthquake fault zone to accumulate greater stress to complete greater stress release. At present, the northern section of the Anning River fault zone is an area that needs to be paid attention to. [The last earthquake of magnitude 7 or above in the northern section of the Anning River fault zone was 1480, which has been around for 542 years, and is a typical seismic blank area]
Therefore, it is recommended that relevant departments strengthen the monitoring of earthquake precursors in the Anning River fault zone, especially the northern section of the Anning River fault zone.
Some suggestions on earthquake prevention and disaster reduction in Sichuan Province in the future
1. It is recommended to raise the fortification standards for some areas with high earthquake risks, especially for some buildings with potential major earthquake risk areas or earthquake blank areas. For example, a large earthquake of magnitude 7 or above occurred in a region hundreds of years ago, but no major earthquake of magnitude 7 or above in recent hundreds of years or even in the past thousand years. This area constitutes a blank area of earthquakes. It is necessary to raise the seismic fortification standards for buildings in these potential major earthquake risk areas to prevent major earthquakes once in a century.
2. It is recommended to do a good job in group testing and prevention, mobilize the masses, and improve the masses' awareness of earthquake prevention and recognition ability of earthquake precursors. Do a good job in popularizing science in earthquake prevention and disaster reduction in villages, towns and villages.
3. It is recommended that relevant departments set up disaster prevention material reserve warehouses in Kangding, Xichang, Sichuan, Ya'an, , and Chengdu. According to the historical frequency of earthquake activity in Sichuan Province, Sichuan Province will encounter a destructive earthquake of magnitude 7 or above every 8 to 10 years. Since the historical frequency of destructive earthquakes in Sichuan Province is relatively high, and considering the historical distribution of destructive earthquakes in Sichuan Province, it is recommended that relevant departments set up disaster prevention material reserves in the above four places [to reserve some emergency food, drinking water, tents, shovels, helmets and other earthquake-resistant materials].
In this way, if a strong earthquake or destructive earthquake occurs in Sichuan in the future, these materials can be quickly mobilized for earthquake relief work. [In addition, you can also store some flood control and disaster relief materials, such as kayak , sandbags, etc., so that if there are flood disasters in Sichuan in the future, it can also be used for flood control and disaster relief work]
