Calbuco has had at least 9 eruptions since 1837, with the latest one in 1972. One of the largest historical eruptions in southern Chile took place there in 1893–1894. Violent eruptions ejected 30-cm bombs to distances of 8 km from the crater, accompanied by voluminous hot lahars. Strong explosions occurred in April 1917, and a lava dome formed in the crater accompanied by hot lahars. Another short explosive eruption in January 1929 also included an apparent pyroclastic flow and a lava flow. The last major eruption of Calbuco, in 1961, sent ash columns 12–15 km high and produced plumes that dispersed mainly to the SE and two lava flows were also emitted. There was a minor, 4-hour eruption on August 26, 1972. Strong fumarolic emission from the main crater was observed on August 12, 1996.