A council working on measures to be taken in the event that Mount Fuji erupts met Wednesday and received a report by experts on the creation of a map of areas that could be affected.
"We will draw up an outline for measures in case of an eruption on Mount Fuji," Tadahiro Matsushita, senior vice minister of the Cabinet Office, told the meeting.
The report says that if Mount Fuji erupts with a force similar to its last eruption in 1707, known as the Hoei eruption, some 12.5 million people could be affected.
The report also shows areas that would probably be covered by lava in the event of an eruption of the 3,776-meter dormant volcano on the border of Shizuoka and Yamanashi prefectures.
Shizuoka Gov. Yoshinobu Ishikawa said: "An eruption of Mount Fuji would cause tremendous damage over a wide area. We should prepare to deal with it, as with earthquakes."
The council consists of officials from the Cabinet Office; the Land, Infrastructure and Transport Ministry; and the Public Management, Home Affairs, Posts and Telecommunications Ministry; as well as local government officials from Yamanashi, Shizuoka and Kanagawa prefectures, and 15 municipalities.
The council is working on drawing up a map of areas that would be affected by a Mount Fuji eruption, including evacuation routes and envisioned evacuation centers.
The mountain has shown signs of volcanic activity in recent years, with low-frequency rumblings of quakes there being recorded from October to December 2000 and in spring 2001.
A research committee of experts, headed by Shigeo Aramaki, an honorary professor at the University of Tokyo, plans to submit its final report to the council by the end of March 2003, the officials said.