April 21, 2020
A Japanese government panel says tsunami waves measuring more than 20 meters high could hit northern Japan if a megaquake of magnitude 9 or stronger occurs in one of two deep-sea trenches.
The government panel has been studying the possible scale of an earthquake, and tsunami waves it could trigger, in either a part of the Chishima Trench or the Japan Trench. The targeted area of the Chishima Trench extends from the Kuril Islands to Hokkaido while the area of the Japan Trench extends from Hokkaido to Iwate Prefecture. The study began after the 2011 disaster in northeastern Japan.
The panel’s latest estimate says a quake along the Chishima Trench would have a magnitude of 9.3.
Parts of eastern Hokkaido would be hit by tremors with an intensity of six-plus to seven on the Japanese scale of zero to seven.
A wide area of eastern Hokkaido would see tsunami more than 20 meters high. Waves could reach 27.9 meters in the town of Erimo.
A quake along the Japan Trench would have a magnitude of 9.1. Parts of Aomori and Iwate prefectures could have tremors with an intensity of six-plus.
Tsunami waves would top ten meters in northeastern Japan. Hachinohe City in Aomori Prefectures would be hit by tsunami as high as 26.1 meters, and Miyako City in Iwate Prefecture as high as 29.7 meters. Some areas could be hit by waves higher than those that struck in 2011.
As these areas have had powerful earthquakes in the past, the panel says massive tsunami can strike at any time.
The Cabinet Office plans to estimate the extent of damage and draw up disaster control measures based on these new figures by the end of March next year.