Following a magnitude 7.5 earthquake off the eastern coast of Aomori Prefecture, Japan issued its first-ever megaquake advisory for 182 municipalities from Hokkaido to Chiba. The advisory, lasting one week, urges residents to prepare for immediate evacuation. While some elderly care facilities report readiness, others express uncertainty in responding.
A magnitude 7.5 earthquake struck off the eastern coast of Aomori Prefecture around 11:15 p.m. on December 8, 2025, registering upper 6 on Japan's seismic intensity scale in Hachinohe. Injuries were reported across areas, along with residential fires. Tsunami warnings covered a wide region from Hokkaido to the Tohoku area, prompting temporary evacuations for over 110,000 people. The late-night occurrence amid severe cold may have caused some hesitation in fleeing.
In response, the Japan Meteorological Agency issued its first 'subsequent earthquake advisory,' with the Cabinet Office calling for vigilance in Hokkaido and the Sanriku Pacific coastal areas for one week. Introduced in December 2022 based on lessons from the 2011 Great East Japan Earthquake, the system activates after a magnitude 7.0 or greater quake in assumed epicenter zones along the Japan and Chishima trenches. The probability of a magnitude 8 or larger event rises from about 0.1% normally to 1% within a week, though it decreases over time. Cabinet Office official Tsukasa Morikubo stated at a Tuesday press conference, “It’s uncertain whether a large-scale earthquake will actually occur, but we ask residents to take disaster prevention measures that prioritize the protection of their own lives,” urging calm responses.
The advisory affects 182 municipalities in seven prefectures from Hokkaido to Chiba. Residents are advised to secure furniture, confirm evacuation routes, and review family communication methods while continuing daily activities. At Hachinohe Japan Red Cross Hospital, which experienced upper 6 shaking, Vice President Kentaro Fujisawa said, “We mustn’t be caught unprepared for unforeseeable situations. We must protect the safety of the elderly and others requiring medical care,” as they checked stockpiles of fuel, food, and water.
A previous Nankai Trough extra information notice last August reached 83% awareness among 4,400 surveyed residents, but only 6% verified evacuation sites and 9.8% family contact methods. Prof. Naoya Sekiya of the University of Tokyo noted, “The government’s message was ambiguous last time on balancing normal life and precautions. It has been improved, but we need to check perceptions and actions now.” At Horiguchi Hibari-en nursing home in Misawa, Aomori, Director Yutaro Deto, 32, reported rechecking doors, securing furniture, and confirming routes, emphasizing constant alertness. Historically, the area saw a magnitude 8.5 quake 18 hours after a magnitude 7 in 1963 and a magnitude 7.3 two days before the 2011 magnitude 9.0 event.
