Global Volcanism Program | Image GVP-02141
Komagatake on the Oshima Peninsula of southern Hokkaido rises to the N above Lake Onuma and is one of the most active volcanoes of Japan's northernmost island. The summit formed as a result of edifice collapse and hummocky debris avalanche deposits were responsible for the formation of Lake Onuma. A period of more frequent explosive activity began with a major explosive eruption in 1640.
Photo by Ichio Moriya (Kanazawa University).