volcano number: 1508-02= (according to Volcanoes of the World, 1994 edition)
summit elevation: 2003 m
location: 41.326°S, 72.614°W
The north of Calbuco volcano, shows strongly dissected older edifice to the right and active part of the volcano on the left. The historically active crater lies in the smooth, snow-covered area to the left. One of the 1961 lava flows (with distinct levees) extends down from the central part of the volcano, where the younger part of the edifice abuts against the older part.
Although less frequently active than Villarrica and Llaima to the north, Calbuco is one of Chile's most notable volcanoes, due to the violence of its eruptions and to the formation of large lahars during its eruptions. Based on the fact that Calbuco erupts once about every 30 years, and on a recent increase of its fumarolic activity, the volcano might be expected to be the most likely candidate for Chile's next large eruption.
Calbuco has grown during at least two stages, of which an older, strongly dissected edifice in the W part of the volcano and a younger one containing the active crater give testimony. The summit area is occupied by a plateau-like feature about 1.5 km in diameter with the active crater in its NE part. This plateau is covered with thick snow and glacial ice all year round, thus the main hazard from the volcano in the case of renewed activity is from snowmelt with the resulting formation of lahars and meltwater floods. All historical eruptions have produced lahars, causing damage in this area which, until the time of the most recent eruption, in 1961, has been little inhabited.
Eruptions from Calbuco are both explosive and effusive, and both types of activity are very likely to produce lahars during future eruptions. Another hazard is that from airborne tephra that may reach great distances from the volcano in the case of strong explosive activity (like in 1893) and may threaten aircraft flying near the volcano. (...)

Eruptive History

The record of Calbuco eruptions is very short, starting only in the late 19th century. A 1837-38 eruption listed in older compilations has recently been re-attributed to Osorno.
The first historically documented eruption began on 7 January 1893 and lasted until mid-January 1894. The initial phase of this eruption was violently explosive and led to the generation of destructive lahars. During the later stages of the activity, the volcano may have extruded lava although this is not certain.
Minor eruptions occurred in 1895, 1906, on 22 April 1907, in March 1909, and in 1911-1912; none of these events produced lava flows or lahars.
A significant eruption occurred again in April 1917 when a lava dome began to fill the crater left by the 1893-94 eruption, and overflowing lava melted part of the summit icecap. Resulting lahars caused damage along the main rivers draining the volcano.

Another major eruption occurred in January 1929. The exact dates of the beginning and end of this event are not known, but the photo above was taken on 6 January, reportedly on the day "after a large explosive eruption". Eyewitness accounts speak of "total darkness" in the area of Lago Todos los Santos whose west shore lies about 25 km from the volcano's summit. The activity lasted only four days and produced lava flows, glowing avalanches, and the resulting lahars caused devastation in valleys around the volcano. Evidence for glowing avalanches was found by Stone (1935) who reports that "brush and small trees (...) were slightly charred, killed, and partly buried by some furious wind or blast of ash that swept with devastating effect down the [Rio Blanco] valley" and "some cattle were killed [in the same area], seemingly burned to death by hot ash".

Ash emission from two vents, 1961