Editorial: Megaquake advisory an opportunity to improve Japan’s disaster preparedness

A weeklong advisory for increased preparedness for a megaquake along the Nankai Trough off the coast of western to central Japan has been lifted. The Japan Meteorological Agency issued the advisory deeming the higher-than-usual possibility of a megaquake following an earthquake in the Hyuga-nada Sea off Miyazaki Prefecture on Aug. 8. It is essential to review the issues related to information distribution and response, and make good use of them for effective disaster prevention and mitigation efforts.

The areas covered in the advisory included 707 municipalities across 29 prefectures designated as disaster prevention promotion regions. For a week, the central government called on people to improve their preparedness for a major quake, such as keeping emergency supplies readily available, while continuing their daily lives and socioeconomic activities.

However, the specific measures to be taken were left to individuals, local governments and businesses, leading to varied responses. Some local bodies preemptively opened evacuation centers and closed beaches, while others took no particular action. Even within the same region, railway companies made different decisions about whether to operate limited express trains.

Many people purchased emergency supplies including water and food, or canceled their overnight accommodation reservations. At the same time, according to a survey by the University of Tokyo, about 20% of respondents said they “did not take any particular action.” This reflects varying levels of response to the government’s call.

The national government needs to gather the initiatives of local authorities and businesses and use them to improve how information is sent out.

We must first and foremost keep in mind that the Japanese archipelago may be hit by a massive earthquake at any time and at any place, and it wouldn’t be surprising.

Instead of criticizing the latest advisory as a “false alarm,” it should be viewed positively as an opportunity to check supplies and review evacuation guidance methods.

A Nankai Trough earthquake is expected to occur with a high probability of around 70-80% within the next 30 years. It is predicted to cause violent shaking measuring up to 7 on the 7-point Japanese seismic intensity scale and a tsunami over 10 meters high, with the worst-case scenario estimating more than 230,000 fatalities.

Although the advisory has been lifted, the situation where there is a high risk of a megaquake occurring has not changed.

Earthquakes strike without warning. It is crucial to continually and repeatedly check whether disaster prevention measures are adequate and if they will function when needed.