Japan revises Nankai Trough megaquake risk to 60-90% in next 30 years

The probability of a megaquake occurring in the Nankai Trough within the next 30 years has been revised from 80 per cent to a range of around 60 to 90 per cent, or higher, Japan’s earthquake investigation panel has said.

The revision reflects a new calculation method that takes into account data errors and uncertainties in predictions, and does not mean that the risk of an earthquake has increased, according to the government panel.

“The situation remains that an earthquake could occur at any time. We urge continued progress in disaster preparedness,” the panel’s chairman Naoshi Hirata, professor emeritus at the University of Tokyo, said on Friday.

In 2013, the panel put the probability at 60 to 70 per cent, based on intervals between past quakes and records of crustal uplift at the Murotsu port in Kochi prefecture on Shikoku Island, linked to three major events dating back to the 1700s.

That figure was gradually raised as more time passed since the last earthquake, reaching about 80 per cent in January this year.

The latest revision incorporates new research showing errors in the Murotsu uplift data as well as non-constant plate strain accumulation, according to a Jiji Press report.

  

​Read More