Japanese government experts have warned that a mega-quake as large as the 2011 disaster may hit the country's northern-most region within the next 30 years.
An "impending" earthquake is forecast to strike off the Pacific coastline of Hokkaido, Japan's northern-most island, most likely triggering a massive tsunami, within the coming three decades.
The government's earthquake research committee predicted a 70pc chance of a magnitude 8 to 8.6 earthquake hitting the Nemuro area, in eastern Hokkaido, within this timescale. The panel also cited a 7pc to 40pc likelihood of a magnitude 9 earthquake across the eastern Hokkaido region within the next three decades, with the potential to affect nearby Aomori Prefecture, home to nuclear power plants.
The study was based on historical data, which found a huge earthquake occurred around 400 years ago along Hokkaido's eastern coastline, according to Kyodo news agency. The research, carried out by experts at Hokkaido University, also concluded the area was historically hit by large tremors on a cycle lasting between 340 and 380 years.
Panel members warned the end of the average cycle had already been exceeded, highlighting that the region's last mega-quake triggered a tsunami more than 65-feet high and flooded nearly 4km inland.
"We are hoping this report will help local municipal governments to make necessary preparations and raise households' awareness of disaster risk," Yoshimasa Hayashi, science and technology minister, told reporters.
"I hope disaster preparations are reviewed based on the possibility that a super-gigantic quake like the one that struck the Tohoku region could also strike Hokkaido," Naoshi Hirata, a seismology professor based at the University of Tokyo, and the chairman of the panel's earthquake research committee, also told the 'Asahi' newspaper.
The Japanese archipelago is famously one of the world's most seismically active regions, accounting for around 20pc of global earthquakes of a magnitude 6.0 or higher.
It's also home to some of the most sophisticated anti-earthquake technology, from early warnings systems to mobile phones, to increasingly stringent building codes implemented in recent decades.
Despite such precautions, a 9.1-magnitude earthquake in 2011 claimed the lives of more than 18,000 people, the majority in a massive tsunami that swamped the Pacific coastline.
The disaster also triggered a nuclear crisis after the tsunami severely damaged reactors at Fukushima Daichi nuclear power plant, causing radioactive leakages.