Expected to add tens of millions of people to activate earthquake warning function. Dialogue with earthquake warning expert Wang Tun: Source | Earthquake | Warning after Plain Earthquake

At 2:33 am on August 6th, a 5.5 magnitude earthquake occurred in Pingyuan County, Dezhou City, Shandong Province, with a depth of 10 kilometers. When an earthquake occurred, the China Earthquake Warning Network issued an earthquake warning message to the residents of Dezhou city, which is 31 kilometers away from the epicenter, a few seconds in advance, while the residents of Beijing, who are more than 300 kilometers away from the epicenter, also received the warning more than 70 seconds in advance.

The China Earthquake Early Warning Network was jointly constructed by the Chengdu High tech Disaster Reduction Research Institute and the China Earthquake Administration. On August 6th, Dr. Wang Tun, founder of Chengdu High tech Disaster Reduction Research Institute, said in an interview with Pengpai News that as early as ten years ago, China Earthquake Warning Network had installed 8500 earthquake warning sensors nationwide, covering an area of 2.3 to 2.4 million square kilometers, covering 96.6% of the population in China's earthquake prone areas. "This earthquake warning in Pingyuan County is just a demonstration of the effect of installing earthquake warning sensors earlier."

Many people receive earthquake warning messages through mobile apps, television, or public broadcasts and quickly take evacuation protection measures. This has also sparked discussions on the internet about activating the earthquake warning function on mobile phones. Wang Tun predicts that on August 6th, the number of users who have newly launched earthquake warning functions will reach 60 million to 100 million. In his view, earthquakes have enhanced people's awareness of the importance of earthquake prevention and disaster reduction.

[The following is a conversation between Pengpai News and Wang Tun]

Pengpai News: After a 5.5 magnitude earthquake occurred in Pingyuan County, Dezhou City, Shandong Province, before the arrival of the earthquake wave, how many seconds of warning time did the China Earthquake Warning Network provide for areas with different distances from the epicenter?

Wang Tun: Distance determines time. Within a range of 20km from the epicenter, there is a blind spot for earthquake warning. Residents within this range will first feel the shaking and then receive the warning. The city center of Texas, located 31 kilometers from the epicenter, received a warning about five seconds before the arrival of the earthquake wave, while Beijing, located about 300 kilometers from the epicenter, received a warning about 70 seconds before the arrival of the earthquake wave.

Pengpai News: In areas with tremors, many people have received early warnings that earthquake waves are about to arrive, but there are also some people who have not received earthquake warnings. What are the reasons for this?

Wang Tun: On the one hand, it depends on the phone he uses. The four major domestic mobile phone manufacturers, Xiaomi, Huawei, OPPO, and vivo, have all integrated earthquake warning functions, but Apple, Samsung, and other mobile phone users need to download the "earthquake warning" app themselves; On the other hand, even if domestic mobile phones have earthquake warning function, if users do not activate this function, they will not receive warning information; The third point is to maintain smooth mobile network signals.

Pengpai News: How to Monitor Earthquakes? How can we ensure both speed and accuracy?

Wang Tun: In addition to utilizing the principle that radio waves propagate faster than seismic waves, it is definitely necessary to install sensors on the surface. As early as 2013, 10 years ago, we installed 8500 earthquake warning sensors nationwide, with sensors spaced approximately 18 kilometers apart. This Shandong earthquake warning is just a demonstration of the effect of installing earthquake warning sensors 10 years ago. These sensors are installed in a corner of the load-bearing wall of the local township government or primary and secondary schools, constantly monitoring the surrounding vibrations in real time.

By transmitting the information it monitors to the servers of the early warning center through the mobile network, the center processes real-time data from the national earthquake early warning monitoring instruments, determines whether an earthquake has occurred in a certain area, quickly determines the warning magnitude, epicenter position, and time of the earthquake, and then decides which areas to issue earthquake early warning alerts to the public and factories. The earthquake early warning system can achieve fully automatic second level response.

Pengpai News: According to a paper on the Tan Lu earthquake zone, some netizens mentioned that the active period of the earthquake zone is about 350 years, and thus predicted the Shandong earthquake on social media. Some netizens believe that this post is a "divine prophecy". From a professional perspective, can earthquakes be predicted?

Wang Tun: I firmly believe that earthquakes can be predicted because there is no scientific reason to say that earthquakes cannot be predicted. But so far, there is no reliable earthquake prediction technology globally, although many global experts are committed to technological innovation in earthquake prediction. Even with the development of earthquake prediction technology in the future, a certain earthquake prediction network system is needed to monitor a lot of data, which can be analyzed and processed to produce reliable earthquake prediction information.

Pengpai News: At present, what stage has the earthquake warning function of China Earthquake Warning Network developed?

Wang Tun: 15 years ago, China did not have an earthquake warning network or earthquake warning science popularization. In 2013, China had the world's largest earthquake warning network, and the China Earthquake Warning Network, jointly built by Chengdu High tech Disaster Reduction Research Institute, emergency departments, and earthquake departments, covered 2.4 million square kilometers, accounting for 90% of the densely populated multi earthquake areas in China. 8500 earthquake warning sensors have been installed nationwide, covering approximately 660 million people. After 2019, the number of users of China Earthquake Warning Network has surpassed Japan, becoming the largest earthquake warning system in the world. The number of users with built-in earthquake warning function on mobile TV terminals has reached 800 million.

I estimate that there are currently 200 to 300 million users who have activated the earthquake warning function, and there may be 60 to 100 million users who activated it in one day today. Due to the promotion by the national emergency management department and media, the public is paying more attention to earthquake warning. This time, the effect of users activating earthquake warning function after the 6.0 magnitude earthquake in Changning County, Yibin City, Sichuan Province in 2019 is similar, but that wave mainly affected the people in West China, and this wave affected the people in North China.

Pengpai News: After receiving an earthquake warning, what actions should the public take in seconds before the earthquake wave arrives?

Wang Tun: One principle is to take refuge in a nearby safe place, not jump off buildings, and not take the elevator. The Disaster Reduction Institute has developed a risk avoidance strategy. After an earthquake warning, if there is only 20 seconds of evacuation time, residents on the second floor and below should turn off the fire source and evacuate to a safe area outside the building. Residents on the third floor and above should take refuge nearby, protect their heads, and take refuge in the nearby life triangle area. After the earthquake wave, they should evacuate outside.

Assuming the ceiling falls, first hit the bed and table, you can let the load-bearing wall, bed, and table help you bear these. But at the same time, it is important to note that excessive force can cause furniture to collapse, and it is necessary to stay away from moving furniture such as tall wardrobes, glass, ceiling chandeliers, etc.

Our next task is to push earthquake warnings to each user's mobile phone. In the future, we will achieve accurate early warning for various disasters such as earthquakes, landslides, mudslides, and flash floods.

Pengpai News: What seismic standards are generally required for urban buildings with different functional attributes in different regions?

Wang Tun: Firstly, to minimize casualties, it is important to ensure that the seismic resistance of the building meets the standards. In 2016, China implemented the fifth generation of China Seismic Parameter Zoning Map to eliminate "undefended zones". In addition, the seismic risk level varies in different regions, and the seismic fortification level of buildings also varies. For example, the seismic fortification intensity of Aba Tibetan and Qiang Autonomous Prefecture in Sichuan Province is 8 degrees, and the designed basic seismic acceleration is 0.20g. In some areas with lower earthquake risks, the seismic fortification level of buildings is lower.

The greater the seismic intensity of a building, the greater the investment. After the Wenchuan earthquake, the Ministry of Education and the Ministry of Housing and Urban Rural Development issued a notice requiring nationwide seismic safety inspections of school buildings. At present, the seismic intensity of buildings in public places such as schools and hospitals is one degree higher than that of general buildings in the local area.

Pengpai News: What factors will exacerbate the frequency of such large-scale geological activities?

Wang Tun: Firstly, natural causes are the fundamental cause of frequent geological disasters. At present, artificial activities can affect the weather, but their impact on earthquakes is relatively limited. The construction of reservoirs and power plants, changes in the local crustal stress state, or shale gas extraction may trigger seismic activity.

Pengpai News: What are the service contents of earthquake early warning?

Wang Tun: The earthquake early warning center transmits the earthquake early warning information to the people, factories, satellite launch centers, nuclear power plants, military units, etc. by means of second level response, television, radio, mobile phone apps, mobile phone SMS, the Internet and special terminals. The warning information released includes: time of occurrence, epicenter location, magnitude, local intensity, warning level, and warning time. Currently, only six countries worldwide have earthquake warning capabilities, including China, Indonesia, Nepal, the United States, Japan, and Mexico. Indonesia and Nepal are both supported by China's earthquake early warning technology.

Pengpai News: How is the function of receiving earthquake magnitude and intensity thresholds for early warning information set? Is it easy to send warning messages to users immediately in the event of an earthquake, which may cause panic on the one hand, and on the other hand, the frequent occurrence of "wolves" makes it easy for users to relax their vigilance?

Wang Tun: This is indeed a problem, but an earthquake itself is a small probability event, such as the earthquake in Pingyuan County, Dezhou, Shandong. The people who receive earthquake warning information are the local and surrounding areas, so most people will not be disturbed. But once such a small probability earthquake event occurs, it can serve to educate the public and remind them to take real-time precautions against earthquake disasters. In addition, the public's understanding of earthquake warning will become clearer in the future, and it is possible to increase the intensity threshold setting.

Pengpai News: How is the scope of earthquake warning set? Why did people in Tianjin, Hebei, Shandong, Beijing and other places receive earthquake warnings for the 5.5 magnitude earthquake in Pingyuan County?

Wang Tun: Usually, the impact of this magnitude covers areas between 300 to 400 kilometers from the epicenter. This earthquake warning has a slightly larger magnitude, with an actual magnitude of 5.5. However, the earthquake warning has a magnitude of 6.4, which is expected to have a greater impact. This is also why the area covered by this earthquake warning has increased.

Pengpai News: What legal protections does China provide in terms of earthquake prevention and disaster reduction? Is there any room for improvement?

Wang Tun: After the SARS outbreak in 2003, China's first emergency response law was the Emergency State Law. By 2007, the Standing Committee of the National People's Congress had passed the Emergency Response Law of the People's Republic of China. The Law of the People's Republic of China on Earthquake Prevention and Disaster Reduction, which came into effect on May 1, 2009, proposes that new construction, expansion, and renovation projects should meet the requirements for earthquake resistance. The state provides necessary support to rural residential buildings and public facilities that require earthquake resistance. The country develops earthquake disaster insurance with financial support, and encourages units and individuals to participate in earthquake disaster insurance. In 2014, the government proposed to include insurance in the disaster prevention and rescue system and establish a catastrophic insurance system.

Individuals can purchase earthquake and disaster insurance, but most people believe that disasters are a rare event and have nothing to do with themselves, so they do not have the awareness to purchase disaster insurance. However, in areas such as Sichuan Province and Tangshan City in Hebei Province that have experienced major disasters, the effectiveness of promoting disaster insurance is slightly better than in other regions. If this insurance can enter schools, enterprises, and strengthen popular science education, the overall effect will be better.