The iconic, 3,776-meter-high Mount Fuji may violently erupt if a major earthquake were to rip open its magma chamber, according to a team of researchers.
The researchers include those from the state-run National Institute of Advanced Industrial Science and Technology, or AIST.
Mount Fuji, which was registered on UNESCO's list of World Heritage cultural sites last month, is an active stratovolcano that last erupted in 1707 in what is known as the Hoei eruption, which dumped a large amount of volcanic ash onto the Kanto region, centering on what is now Tokyo.
The researchers warn of another possible violent eruption of Mount Fuji, noting the pressure in its magma chamber has been building for the past 300 years and a massive temblor nearby could cause this to be explosively released, the researchers said.
The team looked into a number of craters on the mountain through aerial photos and field investigations to analyze past eruptions between some 10,000 years ago and the 1707 eruption.
The study showed that a large number of surface rock formations created before the 1707 eruption have prevented magma from rising.
But in the case of the Hoei eruption, two major earthquakes with a magnitude of 8 hit Mount Fuji, in 1703 and 1707, causing magma under the surface to rise.
Volcanologist Akira Takada warned that a major temblor, such as the forecast mega-quake along the Nankai Trough, could trigger a Mount Fuji eruption.