Hua county earthquake clay sculpture
1. Why do scientists infer that the intensity of the earthquake in Huaxian County is 8.3?
In ancient times, there was no way to measure the magnitude and intensity of the earthquake at that time, and it could only be estimated through the records of historians. Ming Shi described the earthquake like this at that time: "In December of 34, earthquakes occurred in Shanxi, Shaanxi and Henan at the same time, and the sound was like thunder. This is especially true in Weinan, Huazhou, Chaoyi, Sanyuan and Zhou Pu. Or there are cracks in the ground, fish in the water, or houses with walls fall into the ground, or the ground suddenly becomes a mound, or earthquakes occur several times a day, or earthquakes continue day after day. Rivers, Wei, Hua Yue and Zhong Nanshan have been clear for several days. It is really strange that officials, soldiers and the people have suppressed 80,000 to 30,000. "
Qin Keda, an official of the Ming Dynasty, had personally experienced earthquakes. At that time, he wrote: "The number of people affected by the disaster was 0/7 in Tong, Pu/Kloc, 0/6 in Tong, Hua/Kloc, 0/5 in Weinan/Kloc, 0/4 in Lintong/Kloc, 0/3 in provincial capital, and 0/3 in other counties. Then it is far away from the depth of the country. "
Judging from the records in these ancient books, the symptoms at that time were: the ground fissures and springs, and the houses fell into the ground, indicating that the ground cracks were large and the groundwater gushed out; Ridges protruding on the flat land mean that the crust is squeezed and deformed. At present, human beings classify earthquakes as 12, and those with magnitude less than 4.5 are called felt earthquakes, which have almost no destructive power; If the magnitude is above 7, the destructive power will increase with the increase of magnitude. When the magnitude is 8, branches will break and collapse. When the magnitude is 9, underground water pipes will break, cracks will appear on the ground, and small buildings will collapse. In addition, judging from the intensity of the earthquake, when the intensity is 10 degree, buildings are generally destroyed, which shows that houses collapse, roads are destroyed, a large number of rocks collapse and waves rise on the water surface; When the intensity is 1 1 degree, it shows that a large number of houses have collapsed, subgrade and embankment have collapsed in a large area, and the surface has changed greatly. Therefore, according to the expression recorded in ancient books, modern scientists determined that the earthquake at that time was at least above magnitude 8 and the intensity was 1 1 degree.
The Huaxian earthquake also affected the formation of Huashan wonders.
2. Why did the earthquake cause so many deaths?
According to historical records, the earthquake killed 830,000 people and was the deadliest natural disaster in human history. Then why did so many people die?
First of all, Huaxian County is located in Guanzhong Plain. From the Qin and Han Dynasties to the end of the Tang Dynasty, Guanzhong has always been the political and economic center of the country, with a dense population. Although the economic center moved eastward since the Five Dynasties, due to the accumulation of more than one thousand years, the Ming Dynasty was still the most populous place in China, so the earthquake caused the most casualties.
The second is the time when the earthquake happened. According to records, the earthquake occurred at midnight, that is, around 12 in the afternoon, and the time was the twelfth lunar month. In other words, this time, which coincides with April 9, is the coldest time of the year. It was freezing, and the ancients had already got into bed and slept soundly. Suddenly, there was an earthquake, and in the middle of the night, they didn't know what happened at all, and they didn't have time to escape. Qin Keda said that 70% people died in Tongguan and other places, indicating that many people were buried directly under the rubble.
In addition, the cause of a large number of casualties is housing construction. Shaanxi lies in the northwest. Since ancient times, buildings have been built of adobe, and the poor earthquake resistance of houses is also an objective reason.
The secondary disasters caused by the earthquake are more serious. Guanzhong Plain borders Weihe River in the north and Qinling Mountain in the south. The earthquake caused the river to rise and landslides, which also became an important factor causing too many casualties.
The last point is the weak epidemic prevention after the earthquake, which led to the post-disaster pandemic. Due to the inconvenient transportation, the capital of the Ming Dynasty was far from Beijing. When Emperor Jiajing received the report, it was already February of the following year, three months had passed, and there was no post-earthquake relief. In addition, after the earthquake, the victims had nowhere to resettle, causing countless people to freeze to death and starve to death. In addition, the second year's crop failure and the spread of plague also became the cause of heavy casualties.
Fuling Cemetery in Tang Gaozong was destroyed in the earthquake.
3. What is the impact of the earthquake?
In the face of nature, human beings are very small, especially earthquakes are very destructive to human beings. However, earthquakes will also reshape nature and even reach the realm of ingenuity. Huashan Mountain and Cuihuashan Mountain in Shaanxi have created today's magnificent scenery through many crustal movements. There is a Tianchi Lake on Cuihua Mountain, which is actually a dammed lake caused by an earthquake.
For ancient buildings, earthquakes are very destructive. The Little Wild Goose Pagoda in Xi 'an originally had 15 floors. After the earthquake in hua county, the two floors at the top of the tower were destroyed and became 13 floors, which is what it looks like now. Tang Gaozong Ganling Cemetery in Ganxian County was completely destroyed.
The top two floors of Little Wild Goose Pagoda were destroyed by the earthquake, and the 15 floor became the 13 floor.
4. Will there be another big earthquake in Guanzhong?
Judging from the earthquake distribution belt in China, the Weihe Plain seismic belt is located in Weihe Plain or Weihe Basin, which is a graben-type structural plain. Located in the middle of Shaanxi Province, between Qinling Mountain and Weibei Mountain (Laolongshan Mountain, Guishan Mountain, Wangyaoshan Mountain, etc.). ). The distribution range is from Baoji in the west to Tongguan in the east, with an altitude of about 325-800 meters and a length of about 300 kilometers. The width varies from north to south, with the widest in the east reaching100km, about 75km near Xi 'an and only 20km around Meixian. It gradually shrinks into a canyon in Baoji, which looks like a "new moon". It covers an area of about 34,000 square kilometers.
Since recorded, there have been about 160 earthquakes of magnitude 4.7 or above in this seismic zone. Among them, the earthquake was 7-7.9; There were 2 earthquakes of magnitude 8 or above. It's really hard to say whether there will be a big earthquake in the future. Compared with the Weihe plain seismic belt, it is more active.
Tianchi Lake in Cuihua Mountain is a dammed lake formed after the earthquake in Huaxian County.