More than 520,000 people in Japan would be urged to evacuate for a week if an alert is issued for a possible megaquake in the Nankai Trough off the country’s Pacific coast, a government survey showed on Wednesday.

The figure surpasses the 470,000 evacuees recorded during the 2011 Great East Japan Earthquake and the Fukushima nuclear disaster.

As tsunami is expected to reach some areas within minutes after a Nankai Trough megaquake, the government is asking municipalities to designate areas where advance evacuation is necessary.

These designated areas are divided into two types: those where all residents are required to evacuate in advance, and those affecting only residents who need more time to move, including the elderly.

The survey, conducted by the Cabinet Office from June to August, covered a total of 707 municipalities in 29 prefectures that were designated areas for promoting disaster countermeasures as of May. (PNA)