Editing Hot spring (section)

{{Short description|Spring produced by the emergence of geothermally heated groundwater}}
{{Redirect|Hot springs|other uses|Hot Springs (disambiguation)}}
[[File:Aerial view of Grand Prismatic (23428929375).jpg|thumb|upright=1.1|[[Grand Prismatic Spring]] and Midway Geyser Basin in [[Yellowstone National Park]]]]

A '''hot spring''', '''hydrothermal spring''', or '''geothermal spring''' is a [[Spring (hydrology)|spring]] produced by the emergence of [[Geothermal activity|geothermally heated]] [[groundwater]] onto the surface of the Earth. The groundwater is heated either by shallow bodies of [[magma]] (molten rock) or by circulation through [[fault (geology)|faults]] to hot rock deep in the [[Earth's crust]].

Hot spring water often contains large amounts of dissolved minerals. The chemistry of hot springs ranges from acid sulfate springs with a [[pH]] as low as 0.8, to alkaline chloride springs saturated with [[silica]], to bicarbonate springs saturated with [[carbon dioxide]] and [[carbonate minerals]]. Some springs also contain abundant dissolved iron. The minerals brought to the surface in hot springs often feed communities of [[extremophiles]], microorganisms adapted to extreme conditions, and it is possible that life on Earth had its origin in hot springs.<ref>{{cite journal|last1=Farmer |first1=J.D. |year=2000 |title=Hydrothermal systems: doorways to early biosphere evolution |journal=GSA Today |volume=10 |number=7 |pages=1–9 |url=https://www.geosociety.org/gsatoday/archive/10/7/pdf/gt0007.pdf |access-date=25 June 2021}}</ref><ref>{{cite journal |last1=Des Marais |first1=David J. |last2=Walter |first2=Malcolm R. |title=Terrestrial Hot Spring Systems: Introduction |journal=Astrobiology |date=2019-12-01 |volume=19 |issue=12 |pages=1419–1432 |doi=10.1089/ast.2018.1976|pmid=31424278 |pmc=6918855 |bibcode=2019AsBio..19.1419D }}</ref>

Humans have made use of hot springs for bathing, relaxation, or medical therapy for thousands of years. However, some are hot enough that immersion can be harmful, leading to scalding and, potentially, death.<ref name=":0">{{Cite web|title=Hot Springs/Geothermal Features - Geology (U.S. National Park Service)|url=https://www.nps.gov/subjects/geology/hot-springs.htm|access-date=2021-02-11|website=www.nps.gov|language=en}}</ref>