Mount Asosan, also known as Aso Volcano, is a geological marvel in Japan. Encompassing one of the world’s largest calderas, stretching 25 kilometers north to south and 18 kilometers east to west, Aso is a complex volcanic system. The caldera itself formed through a series of enormous eruptions hundreds of thousands of years ago. Within this vast depression lies a cluster of central cones, with Nakadake currently holding the title of most active. As a testament to its ongoing activity, Aso has erupted as recently as 2021, spewing ash and volcanic gase

Location: Kyushu, Japan
Coordinates: 32.884800, 131.084915
Volcano Type: Complex


Asosan’s Location


Asosan’s Latest Status

2024: Not Active.


Asosan’s Eruptive History

Year Overview
2021 Eruption producing ash plume and volcanic gases. Pyroclastic flows likely occurred.
2016 Phreatomagmatic eruption on October 8th. This type of eruption involves interaction between magma and water, causing steam-driven explosions.
2015 Phreatomagmatic eruptions starting on September 14th, with ongoing activity until May.
1884 Series of eruptions throughout March-April and June, characterized by significant ash fall.
1874 Eruption
1873 Ash fall events
1872 Eruption resulting in fatalities amongst sulfur miners near the crater.
1856 Ash fall
1854 Eruption which tragically caused fatalities among a group of pilgrims.


Asosan Monitoring

For monitoring of Japan’s Volcanoes, please refer to JMA.


Asosan Images