Powerful quake off northern Japan triggers tsunami alert and mass evacuations

A powerful earthquake with a magnitude estimated between 7.5 and 7.6 struck off the northeastern coast of Japan late Monday night, shaking a wide area, triggering tsunami warnings and forcing around 90,000 residents to evacuate before the alerts were lifted early Tuesday.

The quake hit at about 11:15 p.m. local time, with its epicenter roughly 80 kilometers off the coast of Aomori Prefecture in the Pacific Ocean at a depth of about 44–54 kilometers, according to Japan’s Meteorological Agency (JMA) and international monitoring agencies. It has been dubbed the 2025 Sanriku earthquake by seismologists.

The tremor registered an “upper 6” on Japan’s 1–7 seismic intensity scale in the city of Hachinohe in Aomori, strong enough to topple furniture, crack walls and cause some structural damage. Shaking was felt as far away as Tokyo, hundreds of kilometers to the south, and lasted for more than 30 seconds.

Authorities reported at least 30–35 people injured across Aomori, Iwate and Hokkaido prefectures, most struck by falling objects or hurt while trying to evacuate. No deaths have been confirmed. Local media said some buildings suffered broken windows and minor damage, and at least two small fires were reported in Aomori City.

JMA initially issued tsunami warnings for parts of the northern Pacific coast, warning waves could reach up to 3 meters. Residents in low-lying coastal areas of Aomori, Iwate and Hokkaido were urged to move to higher ground or designated shelters, leading to the evacuation of about 90,000 people.

In the end, observed tsunami heights ranged between roughly 20 and 70 centimeters in several ports, including Kuji in Iwate Prefecture. The tsunami warnings and advisories were gradually downgraded and then lifted after no large waves or widespread coastal flooding were recorded.

The quake caused temporary disruption to transport and utilities across northern Honshu and Hokkaido:

• Sections of the Tōhoku Shinkansen (bullet train) line were suspended, and one train with about 90 passengers was stranded in Aomori until safety checks were completed.
• Local rail services in affected areas were also halted overnight.
• Tens of thousands briefly lost electricity; by Tuesday morning, outages had been reduced to a few thousand households.

Officials said there were no reports of serious problems at nuclear facilities. Monitoring at plants in the region, including the Rokkasho complex and the Fukushima Daiichi site further south, showed no abnormalities beyond minor issues such as small water spills, which did not pose safety risks, according to plant operators and government agencies.

Seismologists reported multiple aftershocks, including at least one tremor above magnitude 6. Authorities warned that strong aftershocks, and even the possibility of a larger event, could not be ruled out over the coming days, urging residents to stay away from damaged structures and remain ready to evacuate again if needed.

Japan’s Cabinet Office and local governments have begun detailed damage assessments in the coastal Sanriku region, which has a long history of devastating tsunamis. The area was also heavily affected by the 2011 Great East Japan Earthquake and tsunami, a disaster that killed nearly 20,000 people and reshaped the country’s disaster-preparedness policies.

While Monday’s quake caused injuries and disruption, early indications are that Japan’s strict building standards, extensive sea walls and rapid warning systems helped limit the damage. Officials stressed, however, that residents should not become complacent, as the country remains one of the most seismically active regions in the world.