Editing Fumarole (section)

{{Short description|Volcanic opening that emits hot gases}}
{{Redirect|Solfatara|the volcanic crater in Italy|Solfatara (volcano)}}
{{Use dmy dates|date=July 2022}}

[[File:Sol de Mañana 2018.jpg|thumb|Fumarole at [[Sol de Mañana]], Bolivia]]

A '''fumarole''' (or '''fumerole''')<ref name="MerriamWebsterE">{{cite web | url=https://www.merriam-webster.com/dictionary/fumerole | title=fumerole – Definition and meaning | publisher=[[Merriam-Webster]] | work=Merriam-Webster.com Dictionary | accessdate=4 June 2023}}</ref> is a vent in the surface of the Earth or another rocky planet from which hot [[volcanic gas]]es and [[vapor]]s are emitted, without any accompanying liquids or solids. Fumaroles are characteristic of the late stages of [[volcanic activity]], but fumarole activity can also precede a volcanic eruption and has been used for [[Prediction of volcanic activity|eruption prediction]]. Most fumaroles die down within a few days or weeks of the end of an eruption, but a few are persistent, lasting for decades or longer. An area containing fumaroles is known as a '''fumarole field'''.

The predominant vapor emitted by fumaroles is [[steam]], formed by the circulation of [[groundwater]] through heated rock. This is typically accompanied by volcanic gases given off by magma cooling deep below the surface. These volcanic gases include [[sulfur]] compounds, such as various [[sulfur oxides]] and [[hydrogen sulfide]], and sometimes [[hydrogen chloride]], [[hydrogen fluoride]], and other gases. A fumarole that emits significant sulfur compounds is sometimes called a '''solfatara'''.

Fumarole activity can break down rock around the vent, while simultaneously depositing sulfur and other minerals. Valuable [[hydrothermal mineral deposit]]s can form beneath fumaroles. However, active fumaroles can be a hazard due to their emission of hot, poisonous gases.