JMA's Earthquake Early Warning System

JMA's Earthquake Early Warning System detects initial, less damaging seismic waves (P-waves) produced by an earthquake. These waves travel faster than the more destructive waves (S-waves and surface waves), allowing the system to rapidly analyze the quake's origin and magnitude. Once identified, it sends alerts seconds to minutes in advance to warning devices and the public, providing crucial time to take safety measures such as ducking, covering, or stopping trains. This early warning helps mitigate damage and protect lives by enabling immediate responses before the more severe shaking begins.