At 23: 59 on December 18th, an earthquake of magnitude 6.2 occurred in Jishishan County, Linxia Prefecture, Gansu Province. On December 19th, Chen Huizhong, a former researcher at the Institute of Earthquake Prediction, Seismological Bureau of China, said in an interview with national business daily that Jishishan in Gansu is located in the north-south seismic belt of China. Relevant research data also show that Gansu Province has always been in an earthquake-active area. From 1996 to 2019, there were 122 earthquakes of magnitude 5 or above in Gansu Province.
For the current rescue in the earthquake area, Chen Huizhong believes that the main task at present is to ensure the living and cold-resistant and warm conditions of the residents in the earthquake area.
Chen Huizhong further pointed out that "the best way to deal with earthquakes is to build strong houses", especially in rural areas.
In addition, the State Key Laboratory of Geological Disaster Prevention and Geological Environmental Protection (Chengdu University of Technology) (hereinafter referred to as the State Key Laboratory of Geological Disaster Prevention and Control) also reminded that the probability of geological disasters induced by earthquakes in the central, western and northwestern regions of the earthquake is relatively high, and it is suggested that local government departments strengthen on-site investigation of geological disasters in major towns and villages in high-intensity areas.
Chen Huizhong told reporters that Jishi Mountain in Gansu is an area with relatively active earthquakes. It is located in the north-south seismic belt of China, from Ningxia and Gansu to Sichuan and Yunnan, and the longitude line is 75 degrees west of this area. Compared with Sichuan and Yunnan, Shaanxi, Gansu and eastern Qinghai are not so strong in seismic activity, but they are also in a seismic activity area, and there have been earthquakes of magnitude 6 or above in history.
The reporter noted that the paper "Study on the Present Crustal Seismic Activity in Gansu Province" published this year by Liu Shu, the Second Monitoring Center of China Earthquake Administration, showed that geographically, Gansu Province is at the junction of the Loess Plateau, the Inner Mongolia Plateau and the Qinghai-Tibet Plateau, and the role of geology and topographic structure is obvious, which is influenced by Ordos Platform, Alashan-Beishan Platform, West Qinling Fold and Qilian Mountain Fold.
Historically, Gansu province is in an earthquake-active area. "According to statistics, from 1996 to 2019, there were 122 earthquakes of magnitude 5 or above in Gansu Province. Among them, there were 107 earthquakes of magnitude 5.0 ~ 5.9, 19 earthquakes of magnitude 6.0 ~ 6.9 and 2 earthquakes of magnitude 7.0 ~ 7.9. It can be seen that the magnitude of the main earthquakes in these 23 years is in the range of 5.0 ~ 5.9, and the number of major earthquakes is not many. The earthquakes in Gansu Province are mainly distributed in the Qilian Mountain seismic belt, the North-South seismic belt and the Hexi Corridor seismic belt. " The above papers show that.
It is worth mentioning that the geomagnetic storm activity some time ago has attracted a lot of attention from the outside world. Chen Huizhong believes that geomagnetic storm activity caused by solar activity has a great influence on the electromagnetic field of the earth’s space and atmosphere, and even affects communication and power supply when it is severe, but there is no definite basis for causing earthquakes. Moreover, it has been some time since the earthquake and the last magnetic storm activity, so it should have little to do with it.
The development of rescue is undoubtedly the most influential thing at present. According to CCTV news at noon on the 19th, the Jishishan earthquake in Gansu has killed 118 people.
Chen Huizhong told reporters that according to his understanding, the strong earthquake caused collapse or damage to houses with poor earthquake resistance, but some houses that were severely damaged in the epicenter did not completely collapse, resulting in casualties mainly because of insufficient earthquake resistance of houses and the collapse or fall of things inside houses.
According to Xinhua News Agency, on the morning of December 19th, Gansu Earthquake Relief Headquarters held a press conference. Gao Xiaoming, deputy director of the Seismological Bureau of Gansu Province, said that after the earthquake, the Seismological Bureau of Gansu Province immediately joined forces with China Seismological Network Center, Institute of Earthquake Prediction of China Seismological Bureau, Qinghai Seismological Bureau and other relevant units to quickly carry out the post-earthquake trend judgment. According to comprehensive analysis, there is still the possibility of a strong aftershock of magnitude 5 in the original earthquake area of Jishishan on December 18.According to the report of the Central Broadcasting Network, according to the results of comprehensive consultation on historical earthquakes, attenuation characteristics of earthquake sequences and earthquake precursor data, it is preliminarily judged that the earthquake is a main earthquake-aftershock earthquake, and the aftershock attenuation is basically normal.Chen Huizhong said that from the current situation, there is a high probability that an earthquake bigger than the main earthquake will not occur.
"In the earthquake rescue, it is necessary to ensure the residents’ living and cold-resistant conditions, be able to eat, be cold-resistant and not be frozen. This may be the main thing." Chen Huizhong believes.
So, how to ensure the people’s living in the earthquake zone? Chen Huizhong believes that some houses in the earthquake zone are still relatively intact. After the safety appraisal by earthquake experts, the affected people can also live in them. It is even more no problem for houses in areas a little far from the epicenter. After all, cold is also an important factor that may cause secondary disasters.
In addition to rescue, attention to secondary disasters is also crucial.
The Spatial Probability Prediction of Geological Hazards Induced by the Jishishan M6.2 Earthquake in Gansu released by the State Key Laboratory of Disaster Prevention and Control in its official operation in WeChat official account pointed out that due to the influence of this earthquake, the probability of geological disasters induced by earthquakes in the central, western and northwestern regions of the earthquake is relatively high, and the middle-and-high-prone areas are distributed in bands along the southern margin of Laji Mountain, mainly involving steep slopes of Laji Mountain and Jishishan. According to the prediction, geological disasters are mainly small-scale collapses and landslides, and a few large-scale deep landslides may occur locally.
"It is suggested that local government departments should strengthen the on-site investigation of geological disasters in major towns and villages in high-intensity areas, paying special attention to key areas such as 2km near faults, along major roads, and cutting (sloping) slopes behind houses. The risk of post-earthquake secondary geological disasters around the site should be fully considered when selecting temporary resettlement sites. " The State Key Laboratory of Disaster Prevention and Control suggested in the above article.
Chen Huizhong believes that the most important thing is to build houses in strict accordance with the seismic standards, especially in rural areas, where most houses are built by craftsmen, so the implementation of seismic standards may not be so strict in some places.
"The best way to deal with the earthquake is to build a strong house. Because the earthquake warning at most will send an alarm immediately after the earthquake, so that people who are far away from the earthquake have time to escape and run out quickly. If the house is strong, it is truly effective protection and can reduce casualties. " Chen Huizhong added.
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