Fuji disaster management council said Monday pyroclastic flows could sever major roads in the instance of an eruption of Japan's tallest mountain, underscoring the need to review existing evacuation plans that use the roads.
In an interim report on a review of a Mt.
The latest report covered pyroclastic flows and small lava flows, and the council was expected to simulate medium- to large-scale lava flows by the end of fiscal 2020.
The report altered the size of pyroclastic flows to 10 million cubic meters from 2.4 million cubic meters in a simulation after taking into consideration the largest pyroclastic flow that has occurred in the last 5,600 years.
Some 60 percent of the eruptions caused lava flows, but pyroclastic flows -- destructive, fast movements of hot rock and volcanic ash -- only occurred in up to 10 percent of the total cases, it said.