Japanese Earthquake Early Warning System

Japan's Earthquake Early Warning System detects initial seismic waves from an upcoming quake, providing seconds to a minute of alert before stronger shaking arrives. It uses a network of sensors that monitor ground movements nationwide. When activity indicative of a larger quake is detected, the system quickly calculates its location and intensity, sending alerts via television, radio, sirens, and mobile devices. This advance notice enables people and systems to take protective actions—such as stopping trains, shutting down equipment, or dropping to the ground—thereby reducing injuries and damage. The system continually improves through integration of real-time data and advanced research.