The 7-second seismic emergency time is available for the opening of the metropolitan area earthquake warning system

On May 7, 2014, the Earthquake Early Warning System of the Metropolitan Area has undergone construction for nearly a year and a half. It has been completed and put into operation on that day. It will provide earthquake warning services for the people in the metropolitan area and major projects such as subways and chemical engineering.

The Capital Circle is a metropolitan area formed with the national capital city as its core. The geological structure of this area is complex and it is also one of the earthquake-prone areas in eastern China. The 1976 Tangshan earthquake occurred in this area. The system covers a total area of ​​130,000 square kilometers in Beijing, Tianjin, Tangshan, Chengde, Zhangjiakou, Baoding, Langfang, Quzhou and Datong. When an earthquake occurs in the metropolitan area and the surrounding areas, the warning system can provide warnings for people and major projects within 7 seconds of the earthquake, reducing casualties and secondary disasters.

According to the director of the Chengdu High-Tech Disaster Reduction Research Institute and director of the Sichuan Provincial Key Laboratory of Earthquake Early Warning, Wang Bi introduced the ICRC earthquake warning technology independently developed by the institute. The technology was developed after the Wenchuan earthquake in 2008, with the support of experts from China Earthquake Administration and other domestic and foreign experts. After a large number of Wenchuan aftershocks inspections, the technology has gradually matured and matured, forming an earthquake warning technology with complete independent intellectual property rights in China.

According to public information, after 2000, Chinese earthquake experts have been studying the construction of the earthquake warning system in the metropolitan area. The China Earthquake Administration also plans to build an earthquake warning demonstration system in the Capital Circle and Lanzhou. Some earthquake experts had expressed hope in 2013 that they would build an early warning system that includes the 4 regions including the Capital Circle.

Up to now, there have been 15 provinces and cities in China that have begun to apply the ICL earthquake warning technology to build an earthquake warning system covering nearly 1 million square kilometers, including the north-south seismic belt and the Tanlu seismic belt. The earthquake early-warning system it has built has successfully pre-warned such destructive earthquakes as the Lushan 7-magnitude earthquake and issued warning information through mobile phones, televisions, micro-blogs, and dedicated receiving terminals. At present, earthquake warning information has been applied in some schools, communities and science museums in the metropolitan area.

Earthquake early warning refers to the technology that uses the principle that the electric wave is faster than the seismic wave before the destructive seismic wave reaches the warning target when the earthquake occurs in the epicenter, and the warning is issued several seconds to several tens of seconds before the disaster. Studies have shown that if the warning time is 3 seconds, the casualty ratio can be reduced by 14%; if it is 10 seconds, the injury-to-death ratio is reduced by 39%.

PS: Many people may not be aware of what the earthquake early warning system is used for. Let's briefly explain it by Xiao Bian.

Principles and Functions of Earthquake Early Warning System : First of all, the earthquake was caused by the sudden rupture and displacement of rock mass from a few kilometers to several hundred kilometers underground. The energy released by these ruptures and shifts radiates out in the form of seismic waves. The working principle of the earthquake early warning system is that it can detect the non-destructive seismic waves (longitudinal waves, ie, p-waves) that are launched at the beginning of the earthquake, and the destructive seismic waves (transverse waves, ie, s-waves) will be delayed due to the relatively slow propagation speed. 10-30 seconds after arriving at the surface. In-depth seismic detection instruments penetrated the underground and passed it to the calculator. Instantaneous magnitude, intensity, source, and epicentral location were calculated. Then the warning system rescues the warning through the TV box broadcast before the transverse wave arrives. Also, because the electromagnetic wave propagates faster than the seismic wave, the warning may arrive before the P wave. In other words, there is an additional emergency time available before the earthquake damages.