A powerful magnitude 7.5 earthquake struck off the northeastern coast of Japan on Monday, prompting authorities to issue a tsunami warning for waves of up to three metres along a wide stretch of the country's Pacific coastline. The quake hit at 4:53pm local time in the Pacific Ocean off Iwate prefecture, a coastal region on the northeastern shore of Japan's main island of Honshu, at a shallow depth of approximately 10 kilometres. The tremors were felt as far away as Tokyo, hundreds of kilometres to the south, shaking large buildings across the country.

The Japan Meteorological Agency (JMA) warned residents to evacuate immediately, urging people in coastal and riverside areas to move to higher ground or designated evacuation buildings. "Tsunami waves are expected to hit repeatedly. Do not leave safe ground until the warning is lifted," the agency said. Around 40 minutes after the quake, an 80-centimetre wave was recorded at a port in Kuji, Iwate. The biggest waves were forecast for Iwate, Aomori, and Hokkaido — Japan's northernmost island — prefectures. Footage from public broadcaster NHK showed ships sailing out of Hachinohe port in anticipation of incoming waves, and bullet train services in Aomori were halted as a precaution. Port cities including Otsuchi and Kamaishi, which were devastated in 2011, issued evacuation orders for thousands of residents. The quake registered an "upper 5" on Japan's domestic seismic intensity scale, a level strong enough to make movement difficult and cause structural damage to older buildings.

Prime Minister Sanae Takaichi said the government had activated an emergency crisis management team at the prime minister's residence and was working to confirm casualties and property damage. "For those of you who live in areas for which the warnings have been issued, please evacuate to higher, safer places," she told reporters. Energy companies operating shutdown nuclear plants in the Tohoku and Hokkaido regions said they were inspecting facilities for any impact, but no abnormalities had been reported.

Japan sits atop four major tectonic plates on the western edge of the Pacific "Ring of Fire," a zone of intense seismic and volcanic activity encircling much of the Pacific Ocean. The country experiences roughly 1,500 earthquakes a year and accounts for nearly 20 percent of global seismic activity. Monday's earthquake comes against a backdrop of heightened concern: the JMA issued rare "megaquake" advisories in both 2024 and December 2025, warning of the elevated risk of a catastrophic rupture along the Nankai Trough, an 800-kilometre undersea trench south of Japan where the Philippine Sea plate is slowly sliding beneath the continental plate. Authorities have warned such an event could kill up to 298,000 people and cause trillions of dollars in damage. Above all, Monday's events reawakened memories of the magnitude 9.0 earthquake and tsunami of March 2011, which killed approximately 18,500 people and triggered a meltdown at the Fukushima Daiichi nuclear plant — the worst nuclear disaster since Chernobyl. The JMA warned that strong aftershocks could continue in the coming days and weeks.