A working group of the government’s Central Disaster Management Council has compiled a report on the expected damage that would be caused by a magnitude-9 Nankai Trough triple earthquake, in which the so-called Tokai, Tonankai and Nankai quakes happen simultaneously.
The huge quake is forecast to cause about 220 trillion yen ($2.31 trillion) in economic damage, in the worst-case scenario.
The quake and subsequent tsunami is forecast to cause about 170 trillion yen of damage to homes and office buildings, about 10 times the damage caused by the Great East Japan Earthquake and tsunami.
The public and private sectors will need to cooperate and boost the nation’s preparedness for such a massive disaster.
The prediction was made on the assumption that densely populated areas and key industrial bases from the Tokyo metropolitan area along to the Chubu, Kansai, Shikoku and Kyushu regions would be rocked violently by the quake, followed by tsunami higher than 30 meters in some areas.
Last summer, the working group released a prediction that up to about 320,000 people would die in Tokyo, Osaka and 28 other prefectures following the Nankai Trough triple earthquake. The latest report focused on likely economic damage.
The group forecast the total value of corporate production of goods and services―the core of Japan’s economic activity―would decline by as much as about 45 trillion yen, nearly 10 per cent of gross domestic product, in the year following the disaster, due to suspended production at destroyed factories and other factors.
The group said such a quake occurs “at a frequency of less than once every 1,000 years,” emphasising that such a disaster would be extremely rare.
Although there is no need to worry excessively about such a megaquake, the devastating quake that struck off the Tohoku coast on March 11, 2011, also was an event expected to occur once every 1,000 years. Complacency is not an option.
The important thing is to put in place as many “disaster mitigation” preparations as possible. The central government and local municipalities likely to be affected by the disaster should review their disaster-management processes based on the latest estimate.
According to the group’s calculation, making buildings more quake-resistant could halve the economic damage wrought by the disaster. The group also said quick evacuations could reduce tsunami deaths by 90 per cent.
The central and local governments have already been making such efforts.
The important thing is to, first of all, take basic steps such as accelerating the repair of buildings that lack quake-resistance and securing evacuation facilities and tsunami escape routes.
It is also essential to reinforce networks of trunk roads, harbours and airports to enable immediate rescue and relief operations and reduce damage to the economy.
When the Liberal Democratic Party and New Komeito were in the opposition camp last year, they submitted to the Diet a bill concerning special measures to deal with the potential Nankai Trough triple quake. The bill would provide more government subsidies for making disaster management facilities more quake-resistant. However, the bill was abandoned with the dissolution of the House of Representatives.
The bill would reinforce the present special measures law that promotes steps to deal with the Tonankai and Nankai quakes. The LDP and Komeito are considering resubmitting the bill. We hope the bill will be thoroughly discussed in the Diet.
Aside from the Nankai Trough quake, the government has predicted a separate Tokai quake has an 88 percent chance of occurring in the next 30 years, while a Tonankai quake has a 70 per cent chance and the Nankai quake a 60 per cent chance.
There is no time to waste in getting prepared to handle these disasters.
