Nankai Trough megaquake with around 80% chance of occurring within 30 years: Damages now projected at S$13 trillion

Japanese experts estimated that the massive earthquake expected to occur along the Nankai Trough within the next 30 years could cause up to 1.47 quadrillion yen (S$13 trillion) in economic damage, five times the government’s estimate in March.

Japan Today reported that on Jun.11, a panel from the Japan Society of Civil Engineers (JSCE) announced its forecast for the megaquake’s economic impact.

The JSCE noted that, based on experiences with the 2011 Tohoku earthquake, it would take about 22 years for the economy to recover following the Nankai Trough megaquake and its resulting tsunami.

According to NHK News, the projected damage was inclusive of property damages that could reach 225 trillion yen.

The other 1.24 quadrillion yen (S$11 trillion) was attributed to a long-term decline in economic activity.

The total estimated damage is up 56 trillion yen (S$499 billion) from the JSCE’s estimate in 2018.

They however said that the damages would be significantly reduced if more money is spent on making infrastructure quake resistant.

Five times the government’s estimate

In March, a Japanese government task force projected that economic damage from the Nankai Trough earthquake would amount to 292 trillion yen (S$2.6 trillion), a mere fraction of the JSCE's estimates.

Kyodo News has since reported that the government aims to further cut damages, striving to halve the maximum number of buildings expected to be fully destroyed in the quake from the current estimate of 2.35 million.

The government's estimates in March also included a 298,000 death toll, which they now plan to cut by 80 per cent within the next ten years.

This will be hopefully achieved with over 130 priority measures the government is aiming for.

The government had earlier, in 2014, planned to cut the then-projected death toll of 332,000 by 80 per cent within a decade.

However the March figures represented only about a 10 per cent cut in the projected death toll since 2014.

The Nankai Trough

The Nankai Trough, which lies off the southwest Pacific coast of Japan, has earthquakes occurring along it roughly once every 100 to 150 years.

The last large-scale Nankai Trough earthquake occured in 1944.

In January, the Japanese government stated that the chances of a megaquake occurring along the Nankai Trough within the next 30 years had risen to about 80 per cent.

Top image via Jiji Press & Headquarters for Earthquake Research Promotion