Jiangsu Province Earthquake Intensity Rapid Reporting and Early Warning Project is currently underway, and by 2024, Jiangsu is expected to achieve magnitude earthquake early warning within one second of the onset of the quake, said the Jiangsu Provincial Seismological Bureau.
When an earthquake occurs, longitudinal and transverse waves are generated. The propagation speed of longitudinal waves is fast but not as destructive, while the propagation speed of transverse waves is slow and destructive. Earthquake warning is achieved by using the principle that longitudinal waves propagate faster than transverse waves, and electromagnetic waves propagate much faster than seismic waves. Warning is issued to the target area before the arrival of transverse waves.
“According to the distance from the epicenter, there is usually a time difference of a few seconds or one to two minutes. Taking Jiangsu as an example, from an earthquake in northern Jiangsu to southern Jiangsu, it may have a warning time of two minutes”, Wang Jun, Researcher at the Jiangsu Earthquake Rapid Reporting and Warning Center, said.
In recent years, Jiangsu has continuously increased investment in earthquake monitoring infrastructure that has come up with a seismic measurement network, geophysical network, intensity rapid reporting network, and information network system.
Jiangsu is promoting the provincial earthquake intensity rapid reporting and early warning engineering project, with over 1000 earthquake early warning observation stations under construction and network density among the top in the country. When completed by 2024, Jiangsu is expected to achieve second-based magnitude earthquake early warning.
“After an earthquake occurs, we usually receive information within 2 to 3 seconds, and the waveform data is transmitted in real-time to our center. There is also a millisecond level difference between this. Our processing usually takes 2 to 3 seconds, and the entire process may take 4 to 6 seconds after the earthquake. We can quickly determine the initial location of the earthquake and its impact range”, Wang Jun said.
Being a modern early warning system that integrates multiple observation methods, the Jiangsu Provincial Earthquake Early Warning System can be immediately released to the public through channels such as earthquake warning terminals, television, mobile phones, emergency speakers, etc.
“After the earthquake warning information is sent out, user terminals such as mobile phones will automatically calculate the warning time based on the distance from the epicenter, that is, the arrival time of destructive shear waves. For densely populated places such as schools and hospitals, including some important smart centers, earthquake warning information terminals will be provided, which will emit sound and optical alarms based on the level of warning”, Wang Jun said.
Experts suggest that when encountering an earthquake, people should take shelter nearby and choose places with load-bearing structures such as bathrooms, storage rooms, and bathrooms with relatively small space, or hide under sturdy furniture such as tables and beds. People should try to protect the head and stay away from easily falling objects such as doors, windows, and lighting fixtures. It is not desirable to run to the balcony, jump off windows, or jump out of a building in panic. When evacuating, take the stairs instead of taking the elevator.
