Copahue Volcano | John Seach



37.85 S, 71.17 W
summit elevation 2997 m

Copahue Volcano is located in central Chile, east of the South Volcanic Zone of the Andes, and on the border with Argentina. The volcano contains a 6.5 x 8.5 km wide caldera, and a 2 km long, line of nine craters.

Crater Lake
The eastern summit crater of Copahue Volcano contains an acidic 300 m-wide crater lake. A small glacier provides meltwater to the crater lake. The crater lake and hot springs are both fed by deep hydrothermal fluids, which contain up to 70% magmatic brine. Both the lake and the hot spring had high concentrations of toxic elements; arsenic, lead, beryllium, zinc, and chromium.

2018 Activity
A hydrothermal explosion occurred at Copahue volcano on 23rd March 2018. Alert was raised to YELLOW, the second highest level.

2012-13 Eruption
An eruption occurred at Copahue volcano on 22nd December 2012. Ash reached an altitude of 31,000 ft and extended 110 km southeast of the volcano. Satellite images showed sulphur dioxide plume from Copahue eruption reached Tristan da Cunha in the south Atlantic Ocean 2700 km ENE of the volcano on 24th December 2012.

2000 Eruptions
An eruption of Copahue began on 1st July 2000. This was the largest eruption at the volcano in 100 years. Eruption of lapilli, ash, and bombs occurred at the volcano. Bombs up to 13 cm in diameter, were ejected more than 8 km from the summit, and ash fell 100 km away. Over a five day period, more than 50 phreatic explosions were reported. Strombolian eruptions began on 6th July and continued for another six weeks.

1992 Eruption
A new eruptive cycle began in July 1992. The crater lake explosions ejected rock fragments, white dust, large amounts of green and yellow liquid sulphur.

Further reading
Báez, Alejandro D., et al. "The glaciovolcanic evolution of the Copahue volcano, Andean Southern Volcanic Zone, Argentina-Chile." Journal of Volcanology and Geothermal Research 396 (2020): 106866.

Lundgren, Paul, et al. "Source model for the Copahue volcano magma plumbing system constrained by InSAR surface deformation observations." Journal of Geophysical Research: Solid Earth 122.7 (2017): 5729-5747.

Varekamp, J.C., Ouimette, A. and Kreulen, R., 2004, September. The magmato-hydrothermal system of Copahue volcano, Argentina. In Proceedings International Conference on Water-Rock Interaction (No. 11, pp. 215-218).

Copahue Volcano Eruptions

2021, 2020, 2019, 2017, 2012-13, 2000, 1992, 1961, 1937, 1867?, 1759?, 1750