Guidelines Revised for Emergency Responses to Nankai Trough Earthquake Threats

On August 9, 2024, train delays and service cancellations were recorded at JR Tokyo Station following the announcement of a potential megathrust earthquake in the Nankai Trough. In response, the Cabinet Office revised its guidelines, emphasizing that businesses and railway operations should not necessarily halt during an earthquake advisory and that it may be more beneficial to proceed with events instead.

The government has issued various levels of advisories regarding the expected impact of earthquakes, specifically mentioning the likelihood of a magnitude 7.0 to under 8.0 quake in the Nankai Trough, with an alarming 80 percent probability of a significant event occurring within the next three decades. In light of this, projections indicate devastating consequences, potentially leading to up to 298,000 deaths in the worst-case scenario.

Previously, the guidelines were vague on addressing events and services during such advisories, which caused confusion for many. Now, local governments and companies are encouraged to maintain regular activities, provided that safety remains a priority and that they exercise their judgment wisely.

In Shirahama, Wakayama Prefecture, where tsunami waves could reach the shore just minutes after a megaquake, local authorities opted to close four beaches for safety last year after an advisory was issued. This decision was made because the national guidelines had not clarified the operational status of tourism facilities. The mayor insisted that preserving tourist safety was paramount, though this led to a significant economic impact, resulting in around 5,800 canceled hotel bookings and an estimated loss of 510 million yen.

Despite the new recommendations suggesting continuity in operations, the town plans to close its beaches again if another advisory arises. Meanwhile, in Nichinan, Miyazaki Prefecture, officials acknowledged their inadequacy in informing residents about the advisory, which had led many to mistakenly believe an earthquake was imminent.

To enhance their emergency response, the city upgraded its crisis management infrastructure and established a new communication system to keep residents informed in the event of a disaster. This initiative has reportedly improved disaster readiness within the community.

Mayumi Sakamoto, a disaster information expert, remarked that the Nankai Trough Earthquake Extra Information advisory aims to encourage individuals to prepare better, rather than provide exact predictions about when an earthquake will occur. She recognized the government's revisions as practical and reiterated the importance of using such information to bolster personal preparedness across various settings.