CENC Explains the Speed, Accuracy, and Technical Limitations of Earthquake Early Warning

On September 3, the China Earthquake Administration gave a public science explanation of the earthquake early warning system, introducing the construction progress of the National Earthquake Intensity Rapid Report and Early Warning Project in terms of secondlevel early warning and minutelevel rapid reporting. The project was fully completed in July 2024, and has formed strong earthquake early warning capabilities in key areas such as North China, the southeastern coastal regions, the NorthSouth Seismic Belt, the central section of the Tianshan Mountains in Xinjiang, and Lhasa, Tibet. According to the introduction, earthquake early warning must complete identification, location, magnitude estimation, and impact range assessment within an extremely short time after an earthquake occurs, so multiple links such as monitoring, transmission, processing, and release need to work in coordination. The China Earthquake Administration said that through technologies such as multisource realtime data processing, interference signal screening, and multicenter comprehensive analysis, the project has improved the timeliness and accuracy of early warning. In key warning areas, the average time for the first report is about 7 to 8 seconds, with the fastest being about 5 seconds. The article also pointed out that earthquake early warning still has technical limitations. Because seismic waves travel quickly, areas near the epicenter may not receive an early warning in time, creating blind zones for early warning; and the closer a region is to the epicenter and the more severe the damage, the shorter the available warning time is usually. In addition, the early warning system needs to strike a balance between being "fast" and being "accurate". The fewer the triggering stations and the shorter the judgment time, the faster the release, but the risk of false alarms and missed alerts also increases. The China Earthquake Administration said it will continue to promote technological upgrades