Latest report
Fetching…
Source: Japan Meteorological Agency. Intensity is measured per station and varies within a prefecture. The JMA publishes this data in Japanese only, so the headline sentence and the epicentre name are shown exactly as issued; prefecture names carry an English reading.
History
Loads the last few months of earthquakes.
Shows the latest earthquake report from the Japan Meteorological Agency, refreshing automatically — epicentre, magnitude, maximum intensity and the intensity recorded in each prefecture. Note: these are published records, not alerts.
This tool fetches directly from the Japan Meteorological Agency (www.data.jma.go.jp / www.jma.go.jp); it does not pass through this site’s server. Auto-refresh runs every 90 seconds only while the tab is visible, and stops when hidden. The history file is about 40KB over the wire (roughly 550KB once decompressed) — about twenty times the news feed — so it loads only when you ask for it.
Questions
Can I use this as an early warning?
No. An early warning is worth having because it arrives seconds before the shaking; this approach cannot — measured at roughly 2 minutes 30 seconds from event to publication. Beyond that, anything that depends on a tab being open and the network being up fails silently. Use broadcast media or an official disaster app built for the purpose.
How often does it refresh?
Every 90 seconds while you are looking at the tab, and not at all while it is hidden — so abandoned tabs do not keep hitting JMA’s servers.
Where does the data come from?
JMA’s published feed and report documents, read directly by your browser. Nothing passes through this site and nothing is altered.
How much data does it use?
About 2KB to check for news and 1–2KB for a report — transfer sizes, measured in August 2026; they rise and fall with seismic activity. Only the optional history is larger, at about 40KB.
I felt it but nothing appeared here.
Three likely reasons. The delay before publication (measured at about 2 minutes 30 seconds). Shaking below intensity 1, which is not reported at all. Or the tab was hidden, which pauses refreshing — returning to it reloads. Failing those, what you felt may not have been an earthquake.
Does it cover earthquakes outside Japan?
Only those with a recorded intensity in Japan, or that could send a tsunami to Japan. This displays what JMA publishes, so distant events with no effect on Japan are absent. To follow worldwide seismicity, the USGS public data is the better source.
How far back does the history go?
As far as the published feed carries — which is not far enough for long-term statistics or historical research. Use the seismic intensity database published by JMA for that. The history loads on demand because it is around 40KB — about twenty times the news feed.