Editing Copahue (section)

{{short description|Active volcano in Chile and Argentina}}
{{Infobox mountain
| name = Copahue
| photo = Astronaut Photography of Earth - Quick View - Copahue Volcano.PNG
| photo_caption = Copahue Volcano photographed from space
| elevation_m   = 2997
| elevation_ref = <ref name=gvp>{{cite gvp|vn=357090|name=Copahue|access-date=2005-02-11}}</ref>
| prominence_m  =
| prominence_ref=
| location = [[Neuquén Province]], <br />{{ARG}}
[[Bío Bío Region]], <br />{{CHI}}
| range = [[Andes]]
| map = Chile
| map_caption = Argentina-Chile
| map_size = 200
| label_position = right
| coordinates   = {{coord|37|51|S|71|10|W|type:mountain_scale:100000|format=dms|display=inline,title}}
| coordinates_ref = <ref name=gvp/>
| topo =
| type = [[Stratovolcano]]
| age =
| last_eruption = January 6, 2016<ref name=gvp/>
| first_ascent =
| easiest_route =
}}

'''Copahue''' ({{IPA|es|koˈpawe}}) is a [[stratovolcano]] in the [[Andes]] on the border of [[Bío Bío Region]], [[Chile]] and [[Neuquén Province]], [[Argentina]]. There are nine [[volcanic crater]]s along a {{convert|2|km|mi|1|abbr=on}} line, the easternmost of which is historically the most active, and contains a 300&nbsp;m (1000&nbsp;ft) wide [[Volcanic crater lake|crater lake]] with a [[pH]] ranging between 0.18 and 0.30.<ref name=Naranjo />   Eruptions from this crater lake have ejected [[pyroclastic rock]]s and chilled liquid [[sulfur]] fragments.<ref name=gvp/>  Although the lake emptied during the 2000 eruption, it later returned to its previous levels. ''Copahue'' means "sulphur waters" in [[Mapuche language|Mapuche]].<ref name="BBC"/>

Copahue sits on a [[Basement (geology)|basement]] of [[Sedimentary rock|sedimentary]] and volcanic rocks ranging in age from [[Eocene]] to [[Pliocene]].<ref name=Naranjo>{{cite journal |last1=Naranjo |first1=Jose |last2=Polanco |first2=Edmundo |year=2004 |title=The 2000 AD eruption of Copahue Volcano, Southern Andes |journal=Revista Geológica de Chile |volume=31 |issue=2 |pages=279–292|doi=10.4067/S0716-02082004000200007 |doi-access=free }}</ref> The modern volcano sits in a volcanically active area, with a [[caldera]] from the Pliocene, measuring 20&nbsp;km by 15&nbsp;km, lying to the east of Copahue. The modern volcano became active roughly 1.2 million years ago (Ma).<ref name=Naranjo /> The modern caldera formed 0.6 to 0.4 Ma, and produced large [[pyroclastic flows]], extending up to 37&nbsp;km from the volcano.<ref name=Naranjo />
[[File:Eruption of Copahue Volcano, Argentina-Chile 12-22-2012.PNG|thumb|left|Satellite image of the December 2012 eruption]]
The modern structure is an elongated [[shield volcano]], with a maximum thickness of 22&nbsp;km and a minimum of 8&nbsp;km.<ref name=Naranjo />  It has erupted ten times since 1900, most recently in March 2016.<ref name="gvp" /><ref name="BBC">{{cite news|title=Chile and Argentina on alert over Copahue volcano eruption|url=https://www.bbc.co.uk/news/world-latin-america-20828832|newspaper=BBC News|date=23 December 2012}}</ref><ref>{{Cite web|url=https://www.inverse.com/article/13432-watch-the-copahue-volcano-chile-erupt-from-space|title = Watch the Copahue Volcano Chile Erupt from Space| date=28 March 2016 }}</ref>  On 27 May 2013, it was reported that a red alert had been issued and the evacuation of around 2,000 people was to begin.<ref name="sky">{{cite news|title=Red Alert Issued For Chile Volcano|url=http://news.sky.com/story/1096220/red-alert-issued-for-chile-volcano|newspaper=Sky News|date=27 May 2013}}</ref>
[[File:CopahueCraterLake.jpg|thumb|right|alt=The crater lake at the eastern summit of Copahue Volcano.|Copahue Crater Lake.]]