A magnitude-9.1 earthquake off the southern coast of Japan could cause 220.3 trillion yen ($2.33 trillion) in damage, or 42 percent of the country’s gross domestic product, a government panel said March 18.
A magnitude-9.1 earthquake off the southern coast of Japan could cause 220.3 trillion yen ($2.33 trillion) in damage, or 42 percent of the country’s gross domestic product, a government panel said March 18.
The estimate for a worst-case scenario of a long-expected quake along the Nankai Trough is more than 10 times the economic impact of the Great East Japan Earthquake of 2011.
With the release of the economic damage estimates, the central government is expected to accelerate efforts to map out a basic platform for disaster management measures.
The latest release complements earlier reports on estimated seismic intensities, tsunami heights, casualties and structural damages. It does not include the impact of a nuclear disaster that could be triggered by the quake and tsunami, or the effects of volcanic eruptions, which have often followed giant earthquakes in the past.
The panel report noted that such a huge earthquake is a once-a-millennium event. It also produced trial calculations to show that anti-seismic retrofitting, fire prevention and other measures could halve the potential economic damage to 118.3 trillion yen.
Yoshiaki Kawata, a professor of disaster management at Kansai University, headed the expert panel, which was set up in spring 2012 under the government's Central Disaster Management Council to deal with a possible giant earthquake along the Nankai Trough.
The council is presided by Prime Minister Shinzo Abe.
The Nankai Trough refers to a roughly 4-kilometer-deep depression on the seabed that extends about 700 km from Suruga Bay off Shizuoka Prefecture to areas off eastern Kyushu.
Magnitude-7 to 8 class earthquakes have recurred along the Nankai Trough, which constitutes a tectonic boundary where an oceanic plate begins to dive beneath a continental plate.
The panel examined a number of scenarios in determining its estimate. In the worst case, the hypothetical earthquake would be of the type that maximizes the overall shock and tsunami damage along the Pacific coast of the Tokai region. It would strike on a dry winter evening, with many heaters in use, under a relatively strong wind velocity of 28.8 kph.
Direct damages to buildings and plant facilities would total 169.5 trillion yen across 40 prefectures, the panel said.
Of that amount, Aichi Prefecture, which contains densely populated Nagoya, would suffer 30.7 trillion yen in damages, while Osaka Prefecture would receive 24 trillion yen.
Tsunami waves exceeding 30 meters in height would smash into Shizuoka and Kochi prefectures, leading to damages of 19.9 trillion yen and 10.6 trillion yen, respectively.
Miyazaki Prefecture, which has a number of tourist facilities on its coastal plains, would suffer damages of 4.8 trillion yen, the panel added.
Apart from these "direct damages," the panel report said the unavailability of products and services would cause losses of 44.7 trillion yen during the first year of the disaster. Disruptions in transport systems would cost an additional 6.1 trillion yen, the panel said.
The panel said 34.4 million people would be without water supplies, and sewerage systems would be unavailable for 32.1 million. Power blackouts would affect 27.1 million households.
Five airports--Chubu International, Kansai International, Kochi, Oita and Miyazaki--would be swamped by the tsunami. More than half of the surface area at Kochi and Miyazaki airports would be under water.
The panel report predicted a shortage of 96 million meals and 145 million liters of potable water over the first seven days of the disaster, adding that 5 million people would be living in evacuation shelters.
In August, the panel released a report predicting up to 323,000 deaths in the worst-case scenario of a Nankai Trough earthquake.
That latest estimate was based on predictions released by a separate panel, which said the worst-case scenario involving a magnitude-9.1 earthquake could result in tsunami in excess of 20 meters in eight prefectures.
The Great East Japan Earthquake that triggered the tsunami that wiped out entire communities in the Tohoku region had a magnitude of 9.0.