What happens if Mount Fuji erupts? Japan lays out ‘major disaster’ action plan

While there are no signs of imminent volcanic activity, an eruption could still be “a major disaster”, scientists say – even with a response plan in place.

The report, based on a study conducted by experts and released by the government on Friday, estimates that a major eruption of Japan’s most iconic peak could release as much as 490 million cubic metres (17.3 billion cubic feet) of ash into the atmosphere.

Based on prevailing wind conditions, the debris could mostly fall to the east of the volcano, blanketing an area to the western Tokyo district of Sagamihara – some 60km (37 miles) from the peak – with up to 30cm (11.8 inches) of ash.

Virtually all of Shizuoka prefecture, the cities of Yokohama and Kawasaki as well as the 23 wards of Tokyo would receive around 3cm (1.2 inches) of ash, while smaller amounts would fall on the Kanto region in eastern Japan and as far north as Fukushima prefecture.