Japan sits where four tectonic plates meet, so the ground here is quietly busy almost every day. This map refreshes constantly with earthquakes detected across the country over the past seven days, using the official feed from the Japan Meteorological Agency (JMA). Each marker is coloured by its shindo, Japan’s 0-to-7 seismic intensity scale, which measures the shaking felt on the ground rather than the energy released at the epicentre. When a tsunami advisory or warning is in effect, it shows along the affected coast and in a banner at the top.
A note: this page is for information and curiosity, not emergency response, and it is not an official warning system. If you are in Japan during a strong earthquake or a tsunami alert, follow the instructions of the JMA and NHK, and head for higher ground the moment you’re told to.