Up to 298,000 deaths & 20m tsunami predicted in potential ‘megaquake’, Japan govt warns

A possible magnitude-nine earthquake along the Nankai Trough, a submarine trough near the South of Japan, may lead to up to 298,000 deaths and a loss of up to 270 trillion yen (S$2.43 trillion) in Japan's economy.

This is in a worst case scenario where the earthquake occurs on a late winter night with few prepared for early evacuation.

The report released by the Japanese government on Mar. 31 is the latest projection of the dreaded "megaquake" which has an 80 per cent chance of occurring within 30 years, as reported by local news outlets.

A seismic intensity at the highest level caused by the potential Nankai Trough earthquake may lead to tremors felt in 149 municipalities in 10 of the country's 47 prefectures, with a tsunami of over 20 metres hitting Tokyo and seven other prefectures.

The Japanese government's previous projection in 2012 and 2013 predicted the potential Nankai Trough earthquake's death toll to be around 323,000.

The deaths are predicted to mainly result from the tsunami and collapsed buildings from the earthquake's aftermath.

Economic damage also rose from its previous estimation of 237.2 trillion yen (S$2.126 trillion) due to higher prices.

Warning of possible Nakai Trough earthquake in August 2024

In August last year, a 7.1 earthquake struck southwestern Japan, 30km southeast of Miyazaki, on Aug. 8, 2024, though no major damage was reported.

The Japan Meteorological Agency (JMA) issued an alert warning of a further possible megaquake along the Nankai Trough area soon after the earthquake occurred.

A research team in Japan had also recently issued a warning of a potential megaquake that could occur off the country's northern coast, citing unreleased stress energy in the Chishima Trench off Hokkaido.

Japan is one of the most earthquake-prone countries, with a 2011 earthquake and tsunami in the East of Japan leading to more than 15,000 people killed.