TOKYO — A powerful earthquake struck off Japan's northeastern coast on Monday, prompting the Japan Meteorological Agency to issue a tsunami warning for waves of up to 3 meters in parts of Iwate, Aomori and Hokkaido prefectures before downgrading it to an advisory, officials said.
The quake, with a preliminary magnitude of 7.5 later revised to 7.7 by the Japan Meteorological Agency, occurred at about 4:53 p.m. local time (0753 GMT) off the Sanriku coast in Iwate Prefecture at a depth of about 20 kilometers, the agency reported. The U.S. Geological Survey measured it at 7.4.
Tsunami waves of up to 80 centimeters were observed at Kuji Port in Iwate Prefecture, while smaller waves were recorded at other ports including Miyako, according to the Japan Meteorological Agency. Residents in coastal areas were urged to evacuate to higher ground, with evacuation orders issued to tens of thousands of households across multiple prefectures.
No deaths were reported, though one man in his 60s was injured after falling down a staircase in Hachinohe, Aomori Prefecture, local authorities said. Bullet trains, including sections of the Tohoku Shinkansen, were suspended, and some power outages occurred in affected areas.
Japan, located on the seismically active Pacific Ring of Fire, experiences frequent earthquakes. The agency also issued an alert for a potential larger aftershock in seven prefectures from Hokkaido to Chiba, urging residents to prepare for disaster.
A Japan Meteorological Agency official said residents should remain vigilant. "People in coastal areas are urged to stay away from the shore and follow evacuation instructions," the official stated, as cited by public broadcaster NHK.
The quake was felt strongly in parts of northern Japan, with buildings swaying as far as Tokyo. Emergency teams were mobilized for safety checks at infrastructure and nuclear facilities, though no immediate issues were reported.
As of Monday evening, the tsunami advisory remained in effect for some northern coastal areas, while the full tsunami warning had been lifted, the Japan Meteorological Agency said. Authorities continued monitoring for aftershocks and any further changes in sea levels. Damage assessments and updates on transportation disruptions were ongoing.
