China establishes world's largest quake early warning network

China has completed its National Earthquake Early Warning Project, unveiling the world's largest earthquake early warning network, the China Earthquake Administration (CEA) said on Friday.

The project, through the deployment of 15,899 monitoring stations across the country, will provide the public with earthquake early warning service and rapid earthquake intensity reporting service, Yin Chaomin, vice head of the administration, said at a press conference.

Earlier warnings issued by the project can reach the public through TV, IPTV, mobile APPs such as WeChat and Alipay, as well as loudspeakers in villages, according to Yin.

Earthquake early warning relies on a dense network of seismic monitoring stations to issue alerts before destructive seismic waves arrive. It takes advantage of the fact that seismic waves travel significantly slower than electromagnetic waves.

The public can take precautionary measures to reduce casualties, after receiving warnings a few seconds to tens of seconds before the arrival of the seismic waves. 

To avoid secondary disasters, major infrastructure and lifeline projects can respond timely, shutting down gas pipelines and nuclear reactors, and stopping the operation of precision instruments.

For example, a switch developed by the Hubei Earthquake Agency can stop the elevator at the nearest floor after receiving the earthquake warning signal. The device has been used in many high-rise elevators in provinces of Hubei and Anhui.

Ma Qiang, chief engineer of the project, said the quake early warning network will become increasingly relevant to individuals with the wide application of the network and related technologies. Taking the gas safety for example, Ma said that a modified gas alarm valve can automatically cut off the gas after receiving the earthquake warning signal. 

According to Yin, through the project, China made significant breakthroughs in the core technologies of earthquake early warning and rapid intensity reporting, and the overall performance of the system is comparable to international advanced standards.

For the five critical zones including north China and coastal areas of southeast China, the project can issue early warning signals within seconds of an earthquake. It can also report the intensity of any earthquake that occurred in any part of China within minutes.

The project can detect an earthquake with a magnitude of 2.5 or above for most parts of the country. In the eastern regions, it can detect any earthquake with a magnitude of 2.0 or above. In densely populated areas like the capital circle and the Yangtze River Delta, any earthquake with a magnitude of 1.0 or above will be detected by the project.

The project has been integrated with industries such as railways, pipelines, power grids, nuclear power and natural gas, Yin said.

China is a country of many earthquakes. In 2023, the country reported 18 earthquakes with a magnitude of 5 or above. Of these, 11 occurred on the Chinese mainland, including two with a magnitude greater than 6.

(With input from Xinhua)