Mount Hokkaidō-Komagatake

Occurrence of volcanic activity started some 30,000 years ago. Following roughly 5,000 years of dormancy, volcanic activity at Mount Koma-ga-take restarted in 1640. The 1640 eruption had an estimated volume of with a dense-rock equivalent of . It also contained a debris avalanche which caused a tsunami, resulting in over 700 deaths. Runup heights of > were recorded. Since then, there have been at least 50 recorded volcanic events at Mount Koma-ga-take.