According to the China Earthquake Network, a 6.0 earthquake occurred in Changning County, Sichuan at 22:55 on June 17. In the time before the destructive earthquake waves arrived when the earthquake occurred, videos and pictures that achieved the "countdown" of earthquake warning through TV screens and community radio in many places in Sichuan became "hot searches" for a while. In particular, the short videos of the 60 community warning "speakers" in Chengdu Chengnan High-tech Zone were once "sinking the screen".
What technology is used for earthquake warning? What are the warning channels? How can the general public achieve earthquake warning? htmlOn the 518th, the reporter rushed to the Chengdu Hi-Tech Disaster Reduction Institute, the technical research and development company of the "Continental Earthquake Warning Network" system that completed the earthquake warning.
The "speaker" in the community
61 seconds before the earthquake wave arrived!
Zhang Xiao, who lives in No. 123 Guixi East Road, Chengdu Hi-Tech Zone, was a witness to the "big speaker" earthquake warning in Chengdu Hi-Tech Zone on the evening of the 17th. She was about to rest at the time when she suddenly heard the "countdown" of the community radio. "The sound is very loud, and the entire community is ringing." Zhang Xiao said that as the countdown alarm ended, she felt a significant shaking at home. "It is certain that the alarm was called first and then it started to shake." When the
earthquake occurred, many places in Sichuan received earthquake warning information through TV, mobile phones, and community radio. The information is released by the mainland earthquake warning network jointly built by Chengdu Hi-Tech Disaster Reduction Institute and emergency management departments.
Photo provided by the author
According to preliminary statistics from Chengdu Hi-Tech Disaster Reduction Institute, when the earthquake occurred, the mainland earthquake warning network issued warnings to more than 200 schools in Zhaotong City, Yunnan Province, Yibin City, Sichuan Province, Leshan City, , Lishan City, Liangshan Prefecture HTML , Deyang City, Chengdu City, Meishan City, Ziyang City, Yi'an City, Ya'an City, and other cities. 180 schools and 101 communities in Chengdu received warnings. Yibin City, Leshan City, Chengdu City, 79 districts and counties have opened radio, television and Internet TV earthquake warnings. The Mainland Earthquake Warning Network also issued earthquake warning prompts through nearly 50 government affairs and media Weibo including Sichuan Public Security and Sichuan Science and Technology.
As for the "big speaker" that resounded through 60 communities in Chengdu Hi-Tech Zone in this earthquake warning was launched by Chengdu Hi-Tech Zone and Chengdu Hi-Tech Disaster Reduction Research Institute on May 9 last year. The earthquake warning terminal system distributed in the community can be released to the community broadcasting and other platforms, and the earthquake warning information is in advance before the earthquake wave arrives to effectively ensure the personal and property safety of community residents.
How does the "big speaker" sound? Why didn't anyone receive
?
earthquake warning uses the principle that radio waves are faster than earthquake waves, which can provide users with warnings of several seconds to dozens of seconds before the destructive earthquake wave arrives when an earthquake occurs.
Specifically for this early warning process, the mainland earthquake warning network, director of the Sichuan Provincial Key Laboratory and director of the Chengdu Hi-Tech Disaster Reduction Research Institute, explained that the mainland earthquake warning network jointly built by the Chengdu Hi-Tech Disaster Reduction Research Institute and the emergency management department (formerly the earthquake prevention and disaster reduction department of the city and county) after the Wenchuan earthquake, currently covers an area of 2.2 million square kilometers, covering 90% of the population in my country's earthquake areas.
"That is to say, in this huge area, once an earthquake occurs, the earthquake warning information receiving terminals spread across the above areas can receive warning signals." He said that when an earthquake occurs, the seismic wave propagates from the underground to a dedicated ground monitoring station, and then the seismic wave summary information is extracted by the first station. In order to ensure the accuracy of the early warning, the information will be extracted by the second station again, and the on-site earthquake analysis will be completed. The earthquake information is then transmitted to the early warning center of Chengdu Hi-Tech Disaster Reduction Institute, and then after comprehensive analysis by the early warning center, the warning information is released. "When the earthquake warning information finally arrives at various publishing terminals such as mobile phones and computers, it can have different terminal positioning information and provide different countdowns," he said.
Before the earthquake wave arrives after the Changning magnitude 6 earthquake, the mainland earthquake warning network is Yibin City, 51 kilometers away from the epicenter, with a warning time of 10 seconds; Luzhou City, 80 kilometers away from the epicenter, with a warning time of 18 seconds; Zigong City, 111 kilometers away from the epicenter, with a warning time of 27 seconds.
"It can be clearly seen that the farther away from the epicenter, the longer the early warning time is." He said that terminals that reach the intensity threshold all send earthquake warnings or prompts. Terminals that do not reach the intensity threshold will not issue earthquake warnings as required. "That is, if it is lower than the preset value, the warning alarm will not sound. This is why some different publics in Sichuan have received early warnings, while others have not received it. is currently in place, provided that there are early warning terminals, TV warnings, or they have downloaded mobile phone warnings by themselves." How to receive early warning information?
multiple terminals can realize
It is worth mentioning that after yesterday's Changning earthquake, the mainland earthquake early warning network also received early warning information 10 seconds to 78 seconds in advance to major projects such as Xichang Satellite Launch Center, Chengxiang Chemical, Chengdu Railway Bureau, Chengdu, Ya'an , Liangshan electricity, etc.
Wang Ting said that the current earthquake warning methods that can realize include early warning terminal systems installed in schools, communities, and high-risk industries, network warnings on various mobile platforms, TV pop-up warnings, etc. Among them, the "early warning terminal system" can connect to the loudspeaker, industrial control system, etc. He gave an example, for example, the elevator installed in the D area of Tianfu Software Park in Chengdu Hi-Tech Zone with an earthquake warning emergency response system is also automatically triggered, realizing automatic leveling shutdown; high-risk chemical companies that have installed "early warning terminal systems" have already realized automatic shutdown of the system.
. In terms of mobile terminal, early warning information can be published on platforms such as Weibo, WeChat, APP software. Ordinary users can search for the "earthquake warning app" developed by Chengdu Hi-Tech Disaster Reduction Institute to download it, or follow the institute's Weibo to get warning information as soon as possible.
In terms of television warning, on May 27 this year, Sichuan Radio and Television Network has taken the lead in the country to connect provincial radio and television networks with earthquake warning networks. At present, Sichuan's TV earthquake warning has extended to 13 cities and prefectures, covering 79 districts and counties. Among them, 6 cities and prefectures, including Guangyuan, Leshan , Yibin , Liangshan, Deyang , Ya'an and other 6 cities and prefectures have been authorized to open the entire territory, and the other 7 cities and prefectures have been authorized to open the entire districts and counties. In the above-mentioned areas authorized by local governments at all levels and local governments, TVs with built-in earthquake warning services will issue early warnings.
Jia Huidong, general manager of the technical development department of Sichuan Cable Radio and Television Network Co., Ltd., said that the TV earthquake early warning system is a system that connects earthquake early warning information from the earthquake early warning center and transmits earthquake early warning information to the TV through the TV network. The Mainland Earthquake Warning Network is connected to the TV earthquake warning server installed on the radio and television network through a dedicated network. This server is connected to the TV set-top box through the radio and television network network. The set-top box maintains a network connection with the TV earthquake warning server. When the earthquake warning information is received, the pop-up window displays the earthquake warning and voices the earthquake warning.
According to the scheme, in actual use, when the earthquake occurs, if the intensity is between 3 degrees and 5 degrees, the TV will be warned in the form of a "small pop-up window hanging in the corner" in the lower right corner. If the intensity is greater than 5 degrees, the TV will be warned in the form of a "centered large pop-up window". The display content includes: XXX is magnitude XX earthquake, and the earthquake transverse wave arrives in XX seconds, and the shaking feeling is slight or strong.
How to locate TV warnings and achieve accurate countdown on earthquake warnings. Jia Huidong said that after each digital set-top terminal in is started, it will automatically connect to the portal router and report its own card number, model, and IP address. The system will determine the latitude and longitude of the terminal's location based on the card number and IP address, and determine the communication protocol for information release based on the model. After the earthquake occurs, the system asks for the time when the seismic wave arrives through the distance between the terminal's geographical location and the earthquake source's geographical location, and sends it to each terminal (set-top box). Once the terminal receives the warning information, it will immediately cover other display content in a pop-up window with the highest priority.
Accelerate the promotion of earthquake warning
Receive the "last mile"
For many publics who receive earthquake warnings for the first time, they are still at a loss.Wang Xu said that the CPC Central Committee and the State Council attach great importance to disaster warnings, and promoting the "last mile" of earthquake warning reception is an important measure to improve early warning methods and implement disaster warning policies.
"The so-called 'last mile' involves a larger scope and more platform coverage of early warning information, and the normalization and in-depthization of early warning drills." Wang Hung said that the Disaster Reduction Institute will continue to implement the central policies under the leadership of party committees and governments at all levels, under the leadership and supervision of emergency management departments and earthquake prevention and disaster reduction departments at all levels, and strive to do a good job in earthquake warning information services, better integrate into the national earthquake warning work, strengthen cooperation with relevant units to promote the good development of my country's earthquake warning cause, and better serve national earthquake safety.
He called for the opening of provincial and national earthquake early warnings as soon as possible to comprehensively solve the application of earthquake early warnings in Sichuan and nationwide. In addition, the earthquake warning information source also needs to be connected to all primary and secondary schools in earthquake areas, hazardous chemical enterprises, etc. to reduce casualties and prevent secondary disasters. "There are theoretical studies that show that the early warning time is 3 seconds, which can reduce the casualty ratio by 14%; if it is 10 seconds, the casualty ratio is reduced by 39%. If the early warning time is 20 seconds, the casualty ratio can reduce the casualty ratio by 63%. "
Source: Chengdu Hi-Tech Disaster Reduction Research Institute WeChat official account
