NHK



 

The Japanese government says up to nearly 200,000 people could be killed if a massive earthquake strikes in one of two deep-sea trenches off the country's northeast coast.

A government panel of experts has been studying the possible damage from an earthquake in the Chishima and Japan trenches, and the tsunami waves it could trigger.

The part of the Chishima Trench they studied extends from waters off the Kuril Islands to Hokkaido. The area of the Japan Trench looked at extends from waters south of Hokkaido to Iwate Prefecture. The study began after the 2011 disaster in northeastern Japan.

In a report released on Tuesday, the panel says if a mega quake with a magnitude of 9.1 occurs along the Japan Trench, tsunami waves higher than 10 meters could reach parts of the Tohoku region and Hokkaido.

It also estimates that 199,000 people could be killed and 220,000 houses and buildings could be completely destroyed.

The panel also estimated the impact of a magnitude 9.3 mega quake along the Chishima Trench. It said waves more than 20 meters high could hit eastern parts of Hokkaido, killing as many as 100,000 people and destroying up to 84,000 structures.

A mega quake in winter in the Japan Trench could put 42,000 people at risk of dying of hypothermia due to their being forced to stay outdoors for extended periods. The same scenario in Chishima could put 22,000 at risk.

The panel estimates the possible death toll could be reduced by about 80 percent if enhanced anti-disaster measures are put into effect. These steps include preparing tsunami evacuation shelters and ensuring that everyone in risky areas starts evacuating within 10 minutes of an earthquake.