2025年12月8日深夜，日本本州東部海域在23時15分發生規模7.5的強烈地震，震源深度約50公里。由於震央位置靠近東北沿岸，此次地震不僅造成日本多地劇烈搖晃，也引發一定規模的海嘯與多項次生災害，令整個東北與北海道地區在深夜陷入高度緊張狀態。

地震發生後，青森縣、北海道、岩手縣等地都回報不同程度的受災情況。至少16人在震動與建築物受損中受傷，超過10萬名居民被要求緊急避難。各地基礎設施受到衝擊，部分地區道路出現裂縫與塌陷，局部傳出火災事故，電力也一度中斷——其中青森縣約3,900戶停電、岩手縣約300戶受影響。海嘯警報發布後，岩手縣久慈市率先觀測到70公分高的海嘯浪，氣象廳一度預測浪高可能達到3公尺，並在沿岸地區發布最高等級的警戒。不過在9日清晨，海嘯觀測逐漸穩定，所有海嘯警報與注意報才得以解除。

地震同時引發外界對核設施安全的關注。位於青森縣的六所村核廢料處理廠在地震中出現乏燃料池水溢出的情況，溢出量超過100公升，但官方表示並未外洩至外部環境，系統冷卻功能維持正常運作，核安全無立即風險。福島第一核電站則因安全考量暫停核污染水排海作業，並於9日下午恢復相關程序。福島、青森等地的其他核電站也進行全面檢查，目前未回報異常狀況。

值得注意的是，日本氣象廳在地震後首次啟動「北海道·三陸沖後續地震注意信息」機制，警告未來一週內可能發生規模7級以上的更大地震，呼籲民眾保持警戒並做好防災準備。此次警示涵蓋北海道、青森等在內的182個市町村，是自2022年建立此預警制度以來首次啟用，反映氣象廳對地震後續活動的高度重視。

On the night of December 8, 2025, a powerful magnitude-7.5 earthquake struck the eastern offshore area of Japan’s Honshu at 11:15 p.m. (10:15 p.m. Taiwan time). With a focal depth of about 50 kilometers, the quake shook a wide area across northeastern Japan and triggered both tsunamis and multiple secondary disasters, plunging regions of Tohoku and Hokkaido into a tense and chaotic situation late at night.

Following the earthquake, Aomori, Hokkaido, Iwate, and other prefectures reported varying degrees of damage. At least sixteen people were injured, and more than 100,000 residents were ordered to evacuate. Infrastructure was disrupted: several roads cracked or collapsed, isolated fires were reported, and power outages occurred in multiple locations—Aomori saw about 3,900 households go dark, while 300 households in Iwate were also affected. After tsunami alerts were issued, the city of Kuji in Iwate Prefecture recorded waves reaching 70 centimeters. The Japan Meteorological Agency once warned that tsunami heights could reach up to three meters and issued the highest-level alerts for coastal communities. By early morning on December 9, as wave activity stabilized, all tsunami warnings and advisories were lifted.

The quake also raised concerns regarding nuclear safety. At the Rokkasho nuclear fuel reprocessing facility in Aomori Prefecture, more than 100 liters of water spilled from a spent-fuel pool during the tremor, but authorities stated that none of it leaked outside the building and that cooling functions remained fully operational. There was no immediate safety risk. At the Fukushima Daiichi nuclear power plant, the release of treated radioactive wastewater was suspended as a precaution, with operations resuming on the afternoon of December 9. Other nuclear plants in Fukushima and Aomori underwent inspections as well, and no abnormalities were reported.

Notably, the Japan Meteorological Agency activated its “Hokkaido–Sanriku Offshore Aftershock Advisory” for the first time since the system was established in 2022. The advisory warns that another major earthquake—potentially magnitude 7 or stronger—may occur within the next week. Residents in 182 municipalities, including those in Hokkaido and Aomori, were urged to stay vigilant and maintain thorough disaster-preparedness measures, reflecting the agency’s heightened concern about significant aftershock activity.

Overall, the magnitude-7.5 earthquake caused extensive disruptions. Although some conditions have gradually stabilized, the risk of major aftershocks remains, and the tense atmosphere across northeastern Japan and Hokkaido is unlikely to subside in the short term.