The Haiyuan earthquake occurred at 1920 (in the ninth year of the Republic of China) 12 16 at 20: 05: 53 (the seventh day of November in the year of Gengshen), and its epicenter was located at Dagoumen to Xi 'an, Haiyuan County, southern Ningxia Hui Autonomous Region. The magnitude is 8.5. The epicenter is located at 36.7 north latitude, 0/05.7 east longitude, 0/2 intensity and 0/7 km focal depth. The earthquake zone includes Guyuan, Longde, Xiji, Jingyuan, Jingtai and other counties, which are banded and spread to the northwest. It covers an area of 20000 square kilometers. The earthquake affected Xia Nan, Gansu, Shaanxi, Qinghai, Shanxi, Inner Mongolia, Henan, Hebei, Beijing, Tianjin, Shandong, Sichuan, Hubei, Anhui, Jiangsu, Shanghai, Fujian and other 17 provinces, cities and autonomous regions, with a sensing area of 25 10000 square kilometers, accounting for about 60,000 square kilometers in China. According to incomplete statistics (Journal of Geosciences, No.8 and No.9 1922), there were 234 1 17 deaths, including 73,027 deaths in Haiyuan County, accounting for 59% of the county's population and 3 1.2% of the total deaths. Tongwei death toll18208; Ren Jingning's death toll 152 13, and numerous injuries. It is the largest earthquake in the world except the Shaanxi 1556 hua county earthquake and the Hebei 1976 Tangshan earthquake, and it is the largest earthquake in the history of China. According to the post-investigation of 1949, the surface fault zone starts from Li Junbao, Haiyuan County, develops in the northwest direction, and passes through Xiaojiawan and Ganyanchi in Xi area to Jingtai, with a total length of 200 kilometers. This earthquake is a typical intraplate earthquake with a long repetition period. Because the energy released by the Haiyuan earthquake was particularly large, the strong vibration lasted for more than ten minutes, and 96 seismic stations around the world recorded the earthquake. The number of deaths caused by Haiyuan earthquake. The data shows the number of people who died in this earthquake. This strong earthquake has caused great losses to people's lives and property in the earthquake area, and the disaster is heavy. Because the earthquake happened in the mountainous area of Liupanshan, which is almost isolated from the world, the northern warlords were in chaos and unable to rescue the huge earthquake disaster. At that time, it was freezing in winter, and victims died of frostbite, hunger and plague. According to the article "A Brief Introduction to the Great Shaanxi-Gansu Earthquake" at that time, the people in the earthquake-stricken areas "have no clothes, no food, no shelter, and the tragic situation of displacement is unbearable; Many people who suffer hardships rely on the fire kang to keep warm, and their clothes are thin, and they are stripped off in one day, resulting in severe cold and strong winds. They endured the cold and hunger, slept in the cold, crawled to help the wounded, cried everywhere, and were not particularly hungry. It will be better than being frozen, livestock will die, they will get lost, and German shepherd will crowd out people. " This is a true portrayal of the tragic situation in Haiyuan earthquake-stricken area at that time.
The "Six Precursors" before the earthquake recorded in "Rebuilding the County Records of Longde in the Republic of China" had a great influence on seismology and spread widely. "Six mega-earthquakes" means: "First, the well water is quiet without waves, suddenly muddy like ink, and mud floats up, which is bound to be an earthquake. Second, the water in the pond is blown into a hub by the wind, and the algae are entangled, and the foam rises for no reason. If the tea is boiled, it will cause an earthquake. Third, it is natural that the sea meets the wind and the waves are surging; If the wind is fine and the typhoon doesn't work, the sea water will suddenly come up, which will cause an earthquake. It is dark in the middle of the night, and the sky suddenly becomes bright and radiant, just like in broad daylight, which will cause an earthquake. The weather is sunny and warm, and the blue sky is clean. Suddenly, I saw dark clouds winding like wisps, like a long snake, crossing the air for a long time, which will inevitably lead to an earthquake. 6. When it is midsummer, it is hot and transpiration, sweating like rain, feeling cold like ice and snow, cold air attacking people, and muscles are millet, which will cause earthquakes. " It is said that before the Haiyuan earthquake, there were many signs that this disaster was coming. That year was also a persistent drought, with unusually high temperature, rainy and snowy weather, or earth fog flooding the sun and the moon, or black or yellow wind blowing sand wildly, making chickens and dogs restless, cattle, horses, sheep, pigs and other livestock frightened, birds screaming past, the groundwater level fluctuating, the northwest sky rolling, the valley empty and underground thunder rumbling.
/kloc-in the second year after the Haiyuan earthquake in 0/920, the Ministry of Interior, Education and Agriculture and Commerce sent six people, including Weng and Xie, to the disaster area for investigation. They left Beijing on April 192 1, arrived in Lanzhou via Hohhot and Yinchuan, then entered the earthquake zone, went to Guyuan via Huining and Jingning, and returned to Lanzhou via Pingliang and Tianshui. The investigation lasted for four months. In addition to understanding the disaster situation, they also pay special attention to scientific investigation. The survey data of Weng Wenhao and other six people are very valuable. Although the traffic was inconvenient at that time, and their investigation scope was limited, they could not visit most places in the earthquake zone on the spot, but the large amount of first-hand information they got still has high scientific value today. This investigation by Weng and his party is the first detailed scientific investigation on the great earthquake in the history of China earthquake. Meanwhile, J. of Hunger Relief International? 6? 1w？ 6? 1 hall (j? 6? 1W？ 6? 1 hall), u? 6? 1 Klaus (u? 6? 1Clormik)、E？ 6? 1 McCormick (e? 6? 1Mcormik), etc. , also reached the earthquake zone. The survey results were published in the American Geography magazine 1922, entitled "Where to Go in the Mountains". In this report, a lot of practical information about the disaster situation is listed, especially the earthquake landslide is vividly described, and precious photos of earthquake damage are attached. 1958, the Institute of Geophysics, Chinese Academy of Sciences sent six comrades, including Guo Zengjian, to make a field trip to Haiyuan earthquake. This is another large-scale investigation after Weng et al., which lasted for more than a month, and obtained rich first-hand information, and compiled and published the book 1920 Haiyuan Earthquake. 1979, Lanzhou Institute of Seismology, State Seismological Bureau and Earthquake Team of Ningxia Hui Autonomous Region held the "1920 Haiyuan Earthquake Symposium" in Yinchuan, * *, and discussed the related issues of this earthquake. After 1980s, experts from the National Institute of Geology and Ningxia Seismological Bureau completed and published the scientific and technological works of Haiyuan Fault Zone in four years.
Haiyuan earthquake is the first time in China's modern history. There were no modern seismographs and stations in old China during the earthquake, and no one could tell where the epicenter was after the earthquake. It was not until a month later that the epicenter was delineated in Haiyuan. After the earthquake, the Central Geological Survey of Beiyang government immediately set up its own seismic station. 192 1 sending staff to study in France, 1923 started the preparation. After 7 years, until 1930, the first seismic station in China was finally built in Beiping, which opened the prelude to seismic observation in China. Famous geologists from the Central Geological Survey submitted the first report on earthquake science investigation in Chinese history. The first intensity contour map of Zhang zhen area in China was drawn. He also divided the earthquake danger zone in eastern Chinese mainland for the first time. 1922, the World Geological Congress was held in Brussels, Belgium. For the first time, China scholars stood on the world podium and read out papers about Haiyuan earthquake and China seismic active tectonic belt, which attracted the attention of experts from all over the world. According to the records of Guyuan County Records, the sequence characteristics before Haiyuan earthquake are1965438+April 24, 25, 27 and 29, and before Haiyuan earthquake 19 14+ 10/0. That was six years before the earthquake in the ninth year of the Republic of China (1920). These data show that Haiyuan was very underdeveloped before the earthquake. According to the research, it is speculated that there will be no more earthquakes for a long time after the Haiyuan earthquake in 1920.