Editing Fumarole (section)

==Description==
[[Image:Baker Fumarole.jpg|thumb|Sampling gases at a fumarole on [[Mount Baker]] in [[Washington (state)|Washington]], United States]]
[[File:Fumarola, Vulcano, Sicilia, Italia, 2015.gif|thumb|right|Fumaroles at [[Vulcano]], [[Sicily]], Italy]]

A ''fumarole'' (or ''fumerole''; from French ''fumerolle'', a domed structure with lateral openings, built over a kitchen to permit the escape of smoke<ref>{{oed|fumarole}}</ref>) is an opening in a planet's [[Crust (geology)|crust]] which emits [[steam]] and [[gas]]es, but no liquid or solid material.<ref name=MacdonaldEtal1983>{{cite book |last1=Macdonald |first1=Gordon A. |last2=Abbott |first2=Agatin T. |last3=Peterson |first3=Frank L. |title=Volcanoes in the sea : the geology of Hawaii |date=1983 |publisher=University of Hawaii Press |location=Honolulu |isbn=0824808320 |edition=2nd |pages=53–55}}</ref> The temperature of the gases leaving the vent ranges from about {{convert|100 to 1000|C|sigfig=2|sp=us}}.<ref name=Allaby2012fumarole>{{cite book |last1=Allaby |first1=Michael |title=A dictionary of geology and earth sciences |date=2013 |publisher=Oxford University Press |location=Oxford |isbn=9780199653065 |edition=Fourth}}</ref> The steam forms when groundwater is superheated by hot rock, then flashes (boils due to depressurization) as it approaches the surface.<ref name=PhilpottsAgue2009>{{cite book |last1=Philpotts |first1=Anthony R. |last2=Ague |first2=Jay J. |title=Principles of igneous and metamorphic petrology |date=2009 |publisher=Cambridge University Press |location=Cambridge, UK |isbn=9780521880060 |edition=2nd |page=70}}</ref>

In addition to steam, gases released by fumaroles include [[carbon dioxide]], [[sulfur oxides]], [[hydrogen sulfide]], [[hydrogen chloride]], and [[hydrogen fluoride]]. These have their origin in magma cooling underground. Not all these gases are present in all fumaroles; for example, fumaroles of [[Kilauea]] in Hawaii, US, contain almost no hydrogen chloride or hydrogen fluoride.<ref name=MacdonaldEtal1983/> The gases may also include traces of [[carbonyl sulfide]], [[carbon disulfide]], [[hydrogen]], [[methane]], or [[carbon monoxide]].<ref name = hansulrich>{{cite book|last =Schmincke|date =2004|page=47|publisher= Springer Science & Business Media|isbn = 9783540436508|url = https://books.google.com/books?id=XHlJrFAhth4C&pg=PA47|first = Hans-Ulrich|title = Volcanism}}</ref> A fumarole that emits [[sulfur]]ous gases can be referred to as a ''solfatara'' (from old [[Italian language|Italian]] ''solfo'', "sulfur"<ref>{{oed|solfatara}}</ref><ref name="Merriam-Webster1">{{cite web | url=https://www.merriam-webster.com/dictionary/solfatara | title=Solfatara | publisher= Merriam-Webster | work=Merriam-Webster.com Dictionary | access-date=20 February 2020}}</ref>). Acid-sulfate [[hot spring]]s can be formed by fumaroles when some of the steam condenses at the surface. Rising acidic vapors from below, such as CO<sub>2</sub> and H<sub>2</sub>S, will then dissolve, creating steam-heated low-pH hot springs.<ref name=WhiteEtal1971>{{cite journal|last1=White |first1=D.E. |last2=Muffler |first2=L.J.P. |last3=Truesdell |first3=A.H. |title= Vapor-dominated hydrothermal systems compared with hot-water systems |journal=Economic Geology |date=1971 |volume=66 |issue=1 |pages=75–97|doi=10.2113/gsecongeo.66.1.75 |bibcode=1971EcGeo..66...75W }}</ref>

Fumaroles are normally associated with the late stages of volcanic activity,<ref name=Jackson1997fumarole>{{cite book |editor1-last=Jackson |editor1-first=Julia A. |title=Glossary of geology. |date=1997 |publisher=American Geological Institute |location=Alexandria, Virginia |isbn=0922152349 |edition=Fourth |chapter=fumarole}}</ref> although they may also precede volcanic activity<ref name=Allaby2012fumarole/> and have been used to predict volcanic eruptions.<ref name=PhilpottsAgue2009/> In particular, changes in the composition and temperature of fumarole gases may point to an imminent eruption.<ref name=MacdonaldEtal1983/> An increase in sulfur oxide emissions is a particularly robust indication that new magma is rising from the depths, and may be detectable months to years before the eruption. Continued sulfur oxide emissions after an eruption is an indication that magma is continuing to rise towards the surface.<ref name = hansulrich/>

Fumaroles may occur along tiny cracks, along long fissures, or in chaotic clusters or fields. They also occur on the surface of [[lava]] flows and [[Pyroclastic flow|pyroclastic]] flows.<ref name=usgs>{{USGS|url=http://volcanoes.usgs.gov/images/pglossary/fumarole.php|work=USGS Photo Glossary|title=Fumarole|access-date=2019-02-06}}</ref> A ''fumarole field'' is an area of [[Hot springs|thermal spring]]s and gas vents where shallow [[magma]] or hot [[igneous rock]]s release gases or interact with [[groundwater]].<ref>{{cite book
| last1                 = Neuendorf
| first1                = Klaus K. E.
| editor1-last          = Jackson
| editor1-first         = Julia A.
| editor2-last          = Mehl
| editor2-first         = James P.
| editor3-last          = Neuendorf
| editor3-first         = Klaus K. E.
| title                 = Glossary of Geology
| url                   = https://books.google.com/books?id=SfnSesBc-RgC
| publisher             = Springer Science & Business Media
| date      = 2005
| page                  = 257 
| isbn                  = 9780922152766
| access-date            = 2015-06-06
| quote                 = fumarole field[:] A group of cool fumaroles.
}}
</ref>  When they occur in freezing environments, fumaroles may cause [[fumarolic ice tower]]s.

Fumaroles may persist for decades or centuries if located above a persistent heat source; or they may disappear within weeks to months if they occur atop a fresh volcanic deposit that quickly cools.<ref name=usgs/>  The [[Valley of Ten Thousand Smokes]], for example, was formed during the 1912 eruption of [[Novarupta]] in [[Alaska]].  Initially, thousands of fumaroles occurred in the cooling [[Volcanic ash|ash]] from the eruption, but over time most of them have become extinct.<ref name="USGS2">{{cite book |last1=Hildreth |first1=W. |title=The Novarupta-Katmai eruption of 1912– largest eruption of the twentieth century; centennial perspectives |last2=Fierstein |first2=J. |date=2012 |publisher=USGS Professional Paper 1791 |location=Reston |page=135 |author-link=Wes Hildreth |author-link2=Judy Fierstein}}</ref> Persistent fumaroles are found at Sulfur Bank on the northern edge of the [[Kilauea]] [[caldera]], but most fumaroles in Hawaii last no more than a few months.<ref name=MacdonaldEtal1983/> There are still numerous active fumaroles at [[Yellowstone National Park]], US,<ref name="YellowstoneFumarole">{{cite web |title=Fumaroles |url=https://www.nps.gov/articles/fumaroles.htm |website=Volcanic Features and Landforms |publisher=National Park Service |access-date=1 March 2022}}</ref> some 70,000 years after the most recent eruption.<ref name="USGSYellowstoneEruptionHistory">{{cite web |title=Summary of Eruption History |url=https://www.usgs.gov/volcanoes/yellowstone/summary-eruption-history |website=Yellowstone Geology and History |publisher=U.S. Geological Survey |access-date=1 March 2022}}</ref>