Tokyo(ANN)-Hokkaido's Pacific coast may be hit by tsunami as high as 35 metres if a massive earthquake strikes near Hokkaido, according to an interim report by an expert panel at the Hokkaido Disaster Management Council.
The experts, led by Minoru Kasahara, a professor emeritus at Hokkaido University, raised the maximum predicted magnitude of an earthquake near Hokkaido from 8.6 to 9.1 based on sediments collect from past tsunami.
As a result, the maximum height of the tsunami could be as high as 35.1 metres at Tokachi Port in Hiroo, Hokkaido. The figure exceeds the Cabinet Office's 34.4-metre predicted height for a tsunami in Kuroshio, Kochi Prefecture, in the event of a massive quake in the Nankai Trough.
According to the projections, a tsunami of 30 metres or higher could strike five towns in Hokkaido, while a tsunami between 20 metres and 30 metres could hit another six cities and towns, including Kushiro.
In the panel's simulations, the epicentral area of the massive earthquake was estimated to be in areas off northern Sanriku to the Nemuro coast. It is presumed that a magnitude-8 earthquake will occur about every 500 years at the boundary of the tectonic plate extending from areas off Tokachi to areas off Nemuro.
The study panel plans to release its final report in about one or two months after making more precise predictions.
The Hokkaido government had previously predicted that the largest possible earthquake would have a magnitude of 8.6 and trigger a tsunami with a maximum height of 22 metres.
However, based on lessons learned from the Great East Japan Earthquake, institutions have begun forecasting the worst possible earthquakes that may occur once every several hundreds of years, or every 1,000 years.
The Hokkaido prefectural government panel started reviewing its tsunami predictions in June last year. The central government is also reviewing its projections for a massive earthquake expected in the Nankai Trough.