Magnitude 7.5 Quake Hits Northern Japan; Tsunami Warnings Downgraded Amid Vigilance

A magnitude 7.5 earthquake struck off the coast of Aomori Prefecture in Northern Japan late on Monday, December 8, 2025, at 23:15 local time, or 14:15 GMT. The Japan Meteorological Agency (JMA) initially reported the tremor at magnitude 7.6 before revising the figure to 7.5, locating the epicenter approximately 50 kilometers deep. The seismic event registered an upper 6 intensity on the Japanese scale in the northeast region, a level where maintaining an upright posture is difficult and common structural damage occurs in buildings.

Immediate consequences included reports of at least 30 individuals sustaining injuries and a residential fire in the affected zone. The powerful shaking was felt as far as Tokyo, roughly 700 kilometers away. In response, the government mobilized swiftly, with Prime Minister Sanae Takaichi, who assumed office on October 21, 2025, establishing a crisis response task force at the Kantei headquarters. The Prime Minister stressed the necessity for the public to remain vigilant for subsequent seismic activity in the coming days.

Tsunami warnings were immediately issued for coastal areas spanning Hokkaido, Aomori, and Iwate Prefectures, leading to the precautionary evacuation of over 20,000 residents from vulnerable zones. Observed tide rises were modest compared to initial projections; a maximum surge of 70 centimeters was recorded at Kuji Port in Iwate, while Hokkaido’s Urakawa Town saw approximately 50 centimeters and Aomori’s Mutsuogawara Port registered 40 centimeters. Authorities subsequently downgraded the warnings to advisories by Tuesday morning, December 9.

The event tested infrastructure resilience, notably impacting the transportation network. East Japan Railway (JR East) suspended partial services on the vital Tohoku Shinkansen line for necessary track inspections between Morioka and Shin-Aomori, temporarily affecting three bullet trains, one carrying 94 passengers. Furthermore, the JMA issued an 'Information for caution regarding possible large aftershocks off Hokkaidō and Sanriku' on December 9, the first deployment of this specific alert category since its 2022 implementation, signaling an estimated one percent probability of a magnitude 8-level follow-up quake along the Japan Trench.

Compounding the situation, the Nuclear Regulation Authority confirmed a minor spill of about 450 liters of water from a spent fuel cooling area at the Rokkasho fuel reprocessing plant in Aomori; however, the water level remained within normal parameters, mitigating immediate safety concerns. Chief Cabinet Secretary Minoru Kihara continued to coordinate search-and-rescue operations and damage assessment into Tuesday, following the recording of at least 15 aftershocks greater than magnitude 3 by morning, highlighting the nation's established, multi-layered disaster protocols.