Japan Lifts Megaquake Advisory Amid Ongoing Seismic Activity

On December 8, 2025, a powerful magnitude 7.5 earthquake struck off the northeastern coast of Japan, particularly affecting Aomori Prefecture. This event prompted the Japan Meteorological Agency (JMA) to issue a rare megaquake advisory, warning of an increased risk of a subsequent major earthquake. The advisory covered 182 municipalities across seven prefectures, including Hokkaido and Chiba. By December 16, the JMA lifted the advisory, indicating that while the immediate risk had decreased, residents should remain vigilant and prepared for potential future seismic events.

ABC NewsJapan lifts one-week earthquake alert after powerful M7.5 quakeChannel News Asia - CNAThe Straits TimesSouth China Morning Post

The December 8 quake resulted in injuries to over 40 individuals and caused minor damage to properties, with tsunami waves reaching up to 70 centimeters recorded in parts of the region. Following the earthquake, authorities urged residents to review their emergency plans and maintain preparedness measures. The JMA recorded 40 additional earthquakes registering intensity 1 or higher on Japan’s seismic scale during the advisory period, indicating elevated seismic activity.

Associated Press

Japan is situated on the Pacific "Ring of Fire," making it highly susceptible to earthquakes. Experts warn that the region is overdue for a significant megathrust earthquake along the Nankai Trough, which could occur within the next 30 years. Historical data suggests that such megaquakes can lead to catastrophic consequences, including tsunamis and mass casualties. A recent government study projected that a magnitude 9 earthquake could result in up to 199,000 deaths and massive economic damage, potentially exceeding ¥31 trillion (approximately $200 billion).

Japan braces for once-in-a-century mega earthquake that could unleash 33-foot tsunamisABC NewsAssociated PressSouth China Morning Post

Issei Suganuma, a JMA official, emphasized the importance of continued vigilance, stating, "The special warning period for residents had expired at midnight. But it doesn’t mean that quakes will not happen again." The JMA's advisory system, introduced in December 2022, aims to improve disaster preparedness following lessons learned from the devastating 2011 earthquake and tsunami.

The Straits Times

Despite the lifting of the advisory, some opposition lawmakers criticized the government's response, highlighting that many residents were uncertain about how to prepare adequately during the advisory period. This criticism underscores the need for clearer communication and guidance for residents, particularly in light of Japan's ongoing seismic risks.

Japan lifts one-week earthquake alert after powerful M7.5 quake

While the JMA reported over 40 injuries from the December 8 quake, other sources indicated that the number of injuries could be higher, reflecting discrepancies in casualty reporting. Additionally, the exact nature of the ongoing seismic activity remains a concern, with experts warning of the potential for future significant earthquakes.

The Straits Times

As Japan continues to navigate its seismic landscape, the recent lifting of the megaquake advisory serves as a reminder of the country's vulnerability to natural disasters. Authorities are urging residents to remain prepared and vigilant, as the risk of future earthquakes persists.

ABC News