43.57 N, 144.57 E
summit elevation 855 m
Mashu volcano is located in NE Hokkaido, Japan, at the eastern edge of Kutcharo caldera.
A 7 km wide caldera formed 7000 years ago. A summit crater 1.5 km in diameter is located at Kamuinupuri. Lake Mashu is one of the world's clearest lakes.
Eruption in the past 10,000 years are divided into four stages (late stage of stratovolcano, caldera-forming stage, post-caldera Kamuinupuri-forming stage, and kamuinupuri).
970 AD approx, 180 AD, 2200 BC, 4880 BC, 5820 BC.