A tsunami of about 80 centimetres (31 inches) hit Kuji port on Japan’s northeast coast after a powerful earthquake struck offshore on Monday, public broadcaster NHK said, with smaller waves subsequently observed in other areas.
There were no immediate reports of damage or injuries, Chief Cabinet Secretary Minoru Kihara told reporters.
Warnings remain in place for Aomori prefecture and parts of the northernmost main island of Hokkaido, which have so far seen relatively mild tsunami of tens of centimetres — a size that’s unlikely to cause damage. Nevertheless, the broadcaster urged those in affected areas to stay away from the coast and riverbanks out of concern that larger tsunami could follow later.
The earthquake, which struck just after 4:50 p.m. local time, was centred off the northeast coast of Japan and had a magnitude estimated at 7.4, according to the US Geological Survey.
The tremors shook buildings in Tokyo, several hundred kilometres away from the epicenter, and its depth was estimated at about 10 kilometres (6 miles), according to the Japan Meteorological Agency.
Prime Minister Sanae Takaichi said an emergency response centre was being set up by the government, and called for those in areas affected by the earthquake to find safe locations. “Please go quickly to elevated places and evacuation areas,” she said in televised remarks. She said authorities were trying to establish the extent of damage from the quake and if there were any casualties.
Tokyo Electric Power Co said it was investigating the impact of the earthquake on its facilities, while Hokkaido Electric Power Co said it had not confirmed any abnormalities at its thermal or nuclear power plants. Tohoku Electric Power Co said there were no abnormalities detected in their nuclear or thermal power plants. The quake caused the suspension of Shinkansen high speed rail services in Iwate, NHK said.
The destructive tsunami that hit the region in 2011, killing thousands and triggering a nuclear disaster, was estimated at a maximum of more than 40.5 metres.
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Published on April 20, 2026