Mt. Fuji sits on the foundation of Mt. Komitake, a volcano that erupted hundreds of thousands of years ago. Approximately 100,000 years ago, Older Fuji began to erupt on Komitake's southern incline. Older Fuji erupted repeatedly and explosively, scattering large volumes of volcanic ash over a broad area. Finally, some 10,000 years ago, the structure of the volcano changed, as Younger Fuji became active, with large quantities of molten lava flowing from the mountain's peak and sides. The last eruption took place in 1707 (the fourth year of the Hoei Era), creating Mt. Hoei. Since then, Mt. Fuji has been volcanically inactive. Recent avalanches have occurred on the mountain's slopes, centering on the Osawa Collapse.
Mt. Fuji sits on the foundation of Mt. Komitake, a volcano that erupted hundreds of thousands of years ago. Approximately 100,000 years ago, Older Fuji began to erupt on Komitake's southern incline. Older Fuji erupted repeatedly and explosively, scattering large volumes of volcanic ash over a broad area. Finally, some 10,000 years ago, the structure of the volcano changed, as Younger Fuji became active, with large quantities of molten lava flowing from the mountain's peak and sides. The last eruption took place in 1707 (the fourth year of the Hoei Era), creating Mt. Hoei. Since then, Mt. Fuji has been volcanically inactive. Recent avalanches have occurred on the mountain's slopes, centering on the Osawa Collapse.