Tokachi volcano (十勝岳 Tokachidake) is a group of stratovolcanoes and lava domes in central Hokkaido, Japan.
Frequent historical eruptions were mostly small to moderate phreatic explosions (VEI 1-2) and cluster in 5 periods: 1857, 1887 and 1889, 1925-1931, 1952 to 1962, and 1985 and 1989. 3 eruptions generated pyroclastic flows, but only the 1670 eruption produced lava flows.
Larger eruptions were in 1926 and 1962 and caused damage and fatalities. Partial cone collapse of the western flank of Tokachi-dake during the 1926 eruption produced a disastrous debris avalanche and lahar that killed more than 140 people.
The fields near Tokachi are a popular spot for photographers and tourists for viewing lavender fields.
The Tokachi volcano group volcanoes are dominantly andesitic in composition and are aligned along a NE-SW trend on a plateau of welded Pleistocene ignimbrite. Many explosion craters and cinder cones are found on the upper flanks of the small volcanoes. The youngest craters are at the NW end of the chain.