Note: Not an official live feed.
The Earthquake Early Warning (EEW) system in Japan provides data as soon as an earthquake is detected. Depending on a person’s location, it may provide residents an advance warning from a few seconds up to a minute before an earthquake is felt.
However, because the system is automatic and has no time to fully analyze the data, it is prone to errors. Initial alerts sometimes show a significantly higher magnitude, but in most cases it is updated within seconds.