Please note: In many cases, the station position in our database is accurate
to only one minute. Thus, the tide gauge may not appear to be on the coast.
A massive earthquake magnitude 9.0 occurred at 14.46 JST (05.46 UTC) on Friday 11th March 2011 with the epicentre approx. 70 km east of the Oshika Peninsula of Tohoku. It was the most powerful earthquake known to hit Japan triggering a tsunami with waves up to 40.5m and travelling up to 10 km inland.
Data Authority
Marine Department Japan Meteorological Agency Ote-machi, Chiyoda-ku Tokyo