Two 7.8-magnitude earthquakes occurred in Turkey recently. After the earthquake, an article titled "The National Seismological Bureau's core paper shows: Turkey-Syria earthquake may cause 7-8 magnitude earthquakes in China within 3 years" has attracted widespread attention on the Internet. .
Some netizens wondered whether the recent small earthquake in China was caused by the earthquake in Turkey?
In this regard, Xiaoxin interviewed experts, let's take a look at the experts' responses!
Expert: Turkey earthquake will not cause strong earthquake in China
Wang Tun, a professor at Sichuan University, director of the Sichuan Provincial Key Laboratory of Earthquake Early Warning and Multi-hazard Early Warning Application Information Technology, and director of the Chengdu High-tech Disaster Reduction Institute, said that Turkey is thousands of kilometers away from China, and the earthquake caused a displacement of 10 meters near the epicenter in Turkey. Left and right, the strain caused by the Chinese location was minimal.
"From the analysis of stress and intensity, the earthquake in Turkey will not cause a strong earthquake in China." Wang Tun said.
Wang Tun introduced the relevant situation.
Photo by Che Xiaoxi
Wang Yunsheng, a professor at the State Key Laboratory of Geohazard Prevention and Geoenvironmental Protection at Chengdu University of Technology, said that the interval between global strong earthquakes is roughly measured in centuries.
From the 1920s to the 1930s, the earth entered a period of relatively high occurrence of strong earthquake disasters. A series of large and extraordinarily large earthquakes occurred successively, causing heavy casualties.
Since 2001, judging from the abnormal performance of dynamic geological processes in the world, the earth may have entered a new period of high incidence of strong earthquake disasters.
"The plates on the earth are mainly driven by the asthenospheric convection. The relative movement between the plates accelerates during the active period, and the frequency and scale of volcanic activities increase." Wang Yunsheng said that the volcanic anomaly symbolizes that the mantle activity has entered a relatively active period , accelerated the convergence of the African plate, the Indian Ocean plate and the Eurasian plate, and made strong earthquakes more active.
Major epicenters of the Turkish seismic swarm and their associated tectonic settings.
Photo courtesy of Chengli National Key Laboratory of Earthquake Disasters
In Wang Yunsheng's view, in terms of probability, the probability of strong earthquakes in the world will increase in the future, and the probability of strong earthquakes in China may also increase.
Most earthquakes in China are intraplate (Eurasian plate) earthquakes. In history, most earthquakes with magnitudes 7.0 to 8.0 are located around the Qinghai-Tibet Plateau, and the probability of large earthquakes in the eastern region is extremely low.
The 7.8-magnitude earthquake in Turkey occurred in the plate junction zone, and the frequency of strong earthquakes in China is much lower than that in the Turkish earthquake zone. That is to say, there is no causal relationship between the Turkish earthquake and whether there will be strong earthquakes in China in the next few years.
Wang Yunsheng was interviewed.
Photo by An Yuan
Have there been more small earthquakes in China after the Turkey earthquake?
After the Turkey earthquake, a 3.0-magnitude earthquake occurred in Delingha City, Haixi Prefecture, Qinghai on February 9, a 3.0-magnitude earthquake occurred in Ruru County, Nagqu City, Tibet on February 10, and a 4.3-magnitude earthquake occurred in Yuancheng District, Heyuan City, Guangdong Province on February 11. A 2.8-magnitude earthquake occurred in Fangshan District, Beijing on the 12th, a 3.1-magnitude earthquake occurred in Luding County, Ganzi Prefecture, Sichuan Province on February 13, and a 4.3-magnitude earthquake occurred in Mangya City, Haixi Prefecture, Qinghai Province on February 14.
Have there been more small earthquakes in China after the Turkey earthquake?
Wang Tun said that the reason why some netizens on the Internet think that the number of small earthquakes in China has increased in the past week is actually because the earthquake in Turkey has made everyone pay more attention to earthquakes.
Heyuan City in Guangdong, Nagqu City in Tibet, Beijing, Luding County in Ganzi Prefecture in Sichuan Province, and Mangya City in Haixi Prefecture in Qinghai Province are all located in seismic zones, and earthquakes of magnitude 3.0 or so occur almost every year.
How far is human being from impending earthquake prediction?
Imminent earthquake forecast refers to the forecast of the time, place and magnitude of an earthquake that will occur within 10 days.
"Rumors about impending earthquake forecasts are not recent, even before the Wenchuan earthquake, but in fact these forecasts often have no scientific basis." Wang Tun said.
Wang Yunsheng also pointed out that the prediction of impending earthquakes is a worldwide problem, and any inference that "an earthquake of a certain magnitude will occur in a certain place at a certain time" is "unreliable" from a scientific point of view.
Studies have shown that the focal depths of earthquakes that are destructive to humans are almost all less than 20 kilometers, such as the Tangshan earthquake, the Wenchuan earthquake, and the Jiuzhaigou earthquake.
In order to study the impending prediction of destructive earthquakes with shallow sources (depths less than 20 kilometers), the Chengdu High-tech Disaster Reduction Institute began to build China's first underground cloud map network in Sichuan and Yunnan in 2018.
The Sichuan-Yunnan Underground Cloud Atlas Network plans to build 2,000 underground cloud atlas monitoring stations in Sichuan and Yunnan. By collecting destructive earthquake cases and data, after analyzing and generating underground cloud atlases, we can explore and predict earthquakes.
At present, the first phase of the Sichuan-Yunnan Underground Cloud Atlas project has entered the commissioning stage, and it is planned to start trial operation this year.
Wang Tun expects that in the next five to ten years, through scientific and technological progress, the probability of an earthquake in a certain place will be significantly increased 3 hours to 3 weeks in advance.
"However, if an earthquake with a certain magnitude is known at a certain time and place, this possibility is not yet seen."
Disaster prevention and mitigation continue to move forward
China is one of the countries most severely affected by natural disasters in the world.
After the Wenchuan Earthquake, in order to arouse people's awareness of disaster prevention and mitigation, popularize and popularize disaster prevention and mitigation knowledge and disaster avoidance and self-rescue skills, with the approval of the State Council, May 12 has been established as the national "Disaster Prevention and Mitigation Day" since 2009. .
Nowadays, reverence for nature and scientific disaster prevention and mitigation have been deeply rooted in the hearts of the people.
"Through extensive publicity, the Chinese people's awareness of earthquake prevention has been greatly improved, and schools in Sichuan will conduct earthquake emergency drills every semester." Wang Yunsheng said that after the Wenchuan earthquake, China has stricter the seismic design of buildings in high-intensity areas, especially in high-intensity areas. For urban buildings, the new standards require that buildings not collapse in major earthquakes, be repairable in moderate earthquakes, and not damaged in small earthquakes.
Wang Yunsheng pointed out that what a city is most afraid of is an earthquake directly below the city, that is, the city is above the earthquake-generating fault, and the city is located within the epicenter and the extreme earthquake zone during the earthquake.
"Man is very small in front of nature, and any reinforced concrete on the surface rupture zone during an earthquake is pale." Wang Yunsheng said that now China's urban planning will build public green spaces on the fault zone after finding out the exact location of urban active faults. and other measures to avoid the dislocation disaster of active faults.
In addition to raising the awareness of disaster prevention and reduction, China's earthquake technology has also made great progress.
After the Wenchuan Earthquake, the Chengdu High-tech Disaster Reduction Institute cooperated with relevant departments to establish a Chinese earthquake early warning network covering 2.4 million square kilometers from scratch, and successfully warned 73 destructive earthquakes, including the Lushan earthquake in Sichuan in 2013 and the Jiuzhaigou earthquake in 2017. Earthquake, Luding Earthquake in 2022, etc.
"Sichuan Smart Manufacturing" special earthquake alarm system for rescue sites.
Photo courtesy of Chengdu High-tech Disaster Reduction Research Institute
"The China Earthquake Early Warning Network is the largest earthquake early warning network in the world. Now there are 800 million mobile phones and TVs in China with built-in earthquake early warning functions." With the help of the Federation of Returned Overseas Chinese, Chengdu Hi-Tech Disaster Reduction Institute helped Nepal build an earthquake early warning network.
In 2019, the Institute cooperated with the Indonesian Meteorological Department to build an earthquake early warning network in some areas of Indonesia.
Last week, the special earthquake alarm system for the rescue site provided by the Chengdu High-tech Disaster Reduction Institute set off with the Sichuan Blue Sky Rescue Team and put it into Turkey's earthquake rescue.
Members of the blue sky rescue team consigned the rescue equipment.
Photo courtesy of Chengdu High-tech Disaster Reduction Research Institute
(He Shaoqing wishes joy)