Since the 9.0-magnitude earthquake in March 2011, there have been some 12,000 tremors in the Mt Fuji area, increasing the pressure to the mountain's magma chamber.
Toshitsugu Fujii, who is head of Japan's task force on disaster response, told Reuters
, “They always forget about the volcanoes,” and said that the Japanese government “never included Mt. Fuji in its earthquake scenarios,” despite the fact that the rise in tremors “greatly increases” the chance of an eruption.
pressure is building inside the volcano, due to the numerous aftershocks following the disaster in March 2011. On top of this, a recent 6.4-magnitude tremor has left a 20-meter-long crack in the mountain, straining Fuji's magma chamber even further.
Eisuke Fujita is a senior volcano researcher with the National Research Institute for Earth Science and Disaster Prevention. He told reporters that no irregularities have been detected at Mt Fuji yet, but that, “We need to watch [Mount Fuji] very carefully for another two or three years."
"The government has to prepare for a logistical nightmare. They've said they are going to do something but they haven't got their act together so far,” he added.
The National Research Institute for Earth Science and Disaster Prevention reports that the last eruption of Mt Fuji took place in 1707, and was triggered at the time by a quake of a lesser magnitude than occurred in March 2011.
Mt Fuji erupt, this would devastate the surrounding area and would also pose a serious threat to the nation's capital, located just 100 kilometers away.
Apparently part of the problem is caused by the fractured nature of Japanese bureaucracy, meaning that there is a division between teams planning for earthquakes and volcanic eruptions.
A Cabinet office spokesman told Reuters, "We don't include an eruption at Mt. Fuji in our earthquake scenarios because we simply don't know whether a quake would cause one or not."
However, Masaki Takahashi, who is a professor of geology and volcanology at Nihon University, said, "Most volcanoes only have one partial collapse in their lifetime, but Fuji has already had two in 20,000 years, meaning it cannot be ruled out as a possibility in the future."