Copahue

Copahue
Copahue's southwest face with Laguna Las Totoras in the foreground.
Elevation	2,997 m (9,833 ft) [1]
Location
Copahue Location on Argentina/Chile border
Location	Argentina and Chile
Range	Andes
Coordinates	37°51′S 71°10′W / 37.85°S 71.167°W / -37.85; -71.167Coordinates: 37°51′S 71°10′W / 37.85°S 71.167°W / -37.85; -71.167[1]
Geology
Type	Stratovolcano
Last eruption	2000[1]

Copahue is a stratovolcano on the border between Argentina and Chile. There are nine volcanic craters along a 2 km (1.2 mi) line, and the eastern summit crater contains a briny, acidic 300 m (1000 ft) wide crater lake. Twentieth-century eruptions from the crater lake have ejected pyroclastic rocks and chilled liquid sulfur fragments. ^[1]

Geology and Geography

Copahue sits on a basement of sedimentary and volcanic rocks ranging from the Eocene to the Pliocene^[2]. The modern volcano sits in a volcanically active area, with a caldera from the Pliocene, measuring 20 km by 15 km, lying to the east of Copahue. The modern

Copahue Crater Lake.

volcano became active roughly 1.2 Ma^[2]. The modern caldera formed .6 to .4 Ma, and produced large pyroclastic flows, extending up to 37 kilometers from the volcano^[2].

The modern structure is an elongated shield volcano, with a maximum thickness of 22 kilometers and a minimum of 8 kilometers^[2]. There have been at least 6 eruptions within the Holocene, with the most recent in 2000. The easternmost (and most active) crater contains a crater lake with a pH ranging between .18 and .30^[2]. While it emptied during the 2000 eruption, it has returned to its previous levels.

References

1. ^ ^{a b c d} "Copahue". Global Volcanism Program, Smithsonian Institution. http://www.volcano.si.edu/world/volcano.cfm?vnum=1507-09=. Retrieved 2005-02-11. 
2. ^ ^{a b c d e} Naranjo, Jose; Polanco, Edmundo (2004). "The 2000 AD eruption of Copahue Volcano, Southern Andes". Revisita Geologica de Chile 31 (2): 279–292. 

Bibliography

• González-Ferrán, Oscar (1995). Volcanes de Chile. Santiago, Chile: Instituto Geográfico Militar. p. 640 pp. ISBN 956-202-054-1.  (in Spanish; also includes volcanoes of Argentina, Bolivia, and Peru)
• Biggar, John (2005). The Andes: A Guide for Climbers (3rd ed.). Andes Publishing (Scotland). p. 304 pp. ISBN 0-9536087-2-7. http://www.andes.org.uk/. 

See also

• List of volcanoes in Chile
• List of volcanoes in Argentina