View source for Earth:Hydrothermal vent

{{Short description|Fissure in a planet's surface from which heated water emits}}
[[File:Blacksmoker in Atlantic Ocean.jpg|thumb|Black smoker in the [[Earth:Atlantic Ocean|Atlantic Ocean]]]]
[[File:Champagne vent white smokers.jpg|thumb|White smokers at Champagne Vent, [[Earth:Eifuku|Eifuku]], Japan]]
'''Hydrothermal vents''' are fissures on the [[Earth:Seabed|seabed]] from which [[Geothermal gradient|geothermally]] heated water discharges. They are commonly found near [[Earth:Volcano|volcanically]] active places, areas where tectonic plates are moving apart at [[Earth:Mid-ocean ridge|mid-ocean ridge]]s, ocean basins, and [[Earth:Hotspot (geology)|hotspots]].<ref name="Colín-García 2016">{{cite journal |last1=Colín-García |first1=María |title=Hydrothermal vents and prebiotic chemistry: a review |journal=Boletín de la Sociedad Geológica Mexicana |date=2016 |volume=68 |issue=3 |pages=599–620 |doi=10.18268/BSGM2016v68n3a13 |doi-access=free }}</ref> [[Chemistry:Ore genesis#Classification of ore deposits|Hydrothermal deposits]] are rocks and mineral ore deposits formed by the action of hydrothermal vents.

Hydrothermal vents exist because the earth is both geologically active and has large amounts of water on its surface and within its crust. Under the sea, they may form features called black smokers or white smokers. Relative to the majority of the deep sea, the areas around hydrothermal vents are biologically more productive, often hosting complex communities fueled by the chemicals dissolved in the vent fluids. [[Earth:Chemosynthesis|Chemosynthetic]] bacteria and archaea found around hydrothermal vents form the base of the food chain, supporting diverse organisms including giant tube worms, clams, [[Biology:Limpet|limpet]]s, and shrimp. Active hydrothermal vents are thought to exist on [[Astronomy:Jupiter|Jupiter]]'s moon [[Astronomy:Europa (moon)|Europa]] and [[Astronomy:Saturn|Saturn]]'s moon [[Astronomy:Enceladus|Enceladus]],<ref name="NYT-20170413">{{cite news |last=Chang |first=Kenneth |title=Conditions for Life Detected on Saturn Moon Enceladus |url=https://www.nytimes.com/2017/04/13/science/saturn-cassini-moon-enceladus.html |date=13 April 2017 |work={{wipe|New York Times}} |access-date=14 April 2017 }}</ref><ref>{{cite news|url=http://www.nasa.gov/press/2015/march/spacecraft-data-suggest-saturn-moons-ocean-may-harbor-hydrothermal-activity/index.html |title=Spacecraft Data Suggest Saturn Moon's Ocean May Harbor Hydrothermal Activity |work=NASA |date=11 March 2015 |access-date=12 March 2015}}</ref> and it is speculated that ancient hydrothermal vents once existed on [[Astronomy:Mars|Mars]].<ref name="Colín-García 2016"/><ref>{{cite web |last=Paine |first=M. |date=15 May 2001 |title=Mars Explorers to Benefit from Australian Research |url=http://www.space.com/missionlaunches/missions/mars_society_conference_010515-1.html |work=Space.com |url-status=dead |archive-url=https://web.archive.org/web/20060221011414/http://www.space.com/missionlaunches/missions/mars_society_conference_010515-1.html |archive-date=21 February 2006 }}</ref>

Hydrothermal vents have been [[Hypothesis|hypothesized]] to have been a significant factor to starting [[Biology:Abiogenesis|abiogenesis]] and the survival of primitive life.

==Physical properties==
[[File:0501-hydrothermal-vents-640x360.webm|thumb|[[Organization:National Oceanic and Atmospheric Administration|NOAA]] video on hydrothermal vents]]Hydrothermal vents in the deep ocean typically form along the mid-ocean ridges, such as the East Pacific Rise and the [[Earth:Mid-Atlantic Ridge|Mid-Atlantic Ridge]]. These are locations where two tectonic plates are diverging and new crust is being formed.

The water that issues from seafloor hydrothermal vents consists mostly of [[Earth:Seawater|seawater]] drawn into the hydrothermal system close to the volcanic edifice through faults and porous sediments or volcanic strata, plus some magmatic water released by the upwelling [[Biology:Magma|magma]].<ref name="Colín-García 2016" /> In terrestrial hydrothermal systems, the majority of water circulated within the fumarole and [[Earth:Geyser|geyser]] systems, is meteoric water plus ground water that has percolated down into the thermal system from the surface, but also commonly contains some portion of [[Earth:Metamorphism#Hydrothermal|metamorphic water]], [[Chemistry:Magmatic water|magmatic water]], and sedimentary formational [[Earth:Brine|brine]] that is released by the magma. The proportion of each varies from location to location.{{citation needed|date=February 2023}}

In contrast to the approximately {{convert|2|C|F|abbr=on}} ambient water temperature at these depths, water emerges from these vents at temperatures ranging from {{convert|60|C|F|abbr=on}}<ref>{{cite book |author=Garcia, Elena Guijarro |author2=Ragnarsson, Stefán Akí |author3=Steingrimsson, Sigmar Arnar |author4=Nævestad, Dag |author5=Haraldsson, Haukur |author6=Fosså, Jan Helge |author7=Tendal, Ole Secher |author8=Eiríksson, Hrafnkell | year=2007 | title=Bottom trawling and scallop dredging in the Arctic: Impacts of fishing on non-target species, vulnerable habitats and cultural heritage | publisher=Nordic Council of Ministers | page=278 | isbn=978-92-893-1332-2}}</ref> up to as high as {{convert|464|C|F|abbr=on}}.<ref name="Haas2007">
{{Cite journal
 |last=Haase |first=K. M.
 |year=2007
 |title=Young volcanism and related hydrothermal activity at 5°S on the slow-spreading southern Mid-Atlantic Ridge
 |journal=Geochemistry, Geophysics, Geosystems
 |volume=8 |issue=11 |pages=Q11002
 |doi=10.1029/2006GC001509
 |bibcode=2007GGG.....811002H
|s2cid=53495818
 |display-authors=0|doi-access=free
 }}</ref><ref name="Karst2009">
{{Cite journal
 |last=Haase |first=K. M.
 |year=2009
 |title=Fluid compositions and mineralogy of precipitates from Mid Atlantic Ridge hydrothermal vents at 4°48'S
 |journal=Pangaea
 |doi=10.1594/PANGAEA.727454
|display-authors=0}}</ref> Due to the high hydrostatic pressure at these depths, water may exist in either its liquid form or as a [[Physics:Supercritical fluid|supercritical fluid]] at such temperatures. The [[Critical point (thermodynamics)|critical point]] of (pure) water is {{convert|375|C|F|abbr=on}} at a pressure of 218&nbsp;[[Physics:Atmosphere (unit)|atmospheres]].

However, introducing salinity into the fluid raises the critical point to higher temperatures and pressures. The critical point of seawater (3.2 wt. % NaCl) is {{convert|407|C|F|abbr=on}} and 298.5&nbsp;bars,<ref name="bischoff1988">{{cite journal|last1=Bischoff|first1=James L|last2=Rosenbauer|first2=Robert J|title=Liquid-vapor relations in the critical region of the system NaCl-H2O from 380 to 415°C: A refined determination of the critical point and two-phase boundary of seawater|journal=Geochimica et Cosmochimica Acta|volume=52|issue=8|pages=2121–2126|doi=10.1016/0016-7037(88)90192-5|year=1988|bibcode=1988GeCoA..52.2121B|url=https://zenodo.org/record/1253886|type=Submitted manuscript}}</ref> corresponding to a depth of ~{{convert|2960|m|ft|abbr=on}} below sea level. Accordingly, if a hydrothermal fluid with a salinity of 3.2 wt. % NaCl vents above {{convert|407|C|F|abbr=on}} and 298.5&nbsp;bars, it is supercritical. Furthermore, the salinity of vent fluids have been shown to vary widely due to phase separation in the crust.<ref name="VonDamm1991">{{cite journal|last1=Von Damm|first1=K L|title=Seafloor Hydrothermal Activity: Black Smoker Chemistry and Chimneys|journal=Annual Review of Earth and Planetary Sciences|volume=18|issue=1|pages=173–204|doi=10.1146/annurev.ea.18.050190.001133|year=1990|bibcode=1990AREPS..18..173V|url=https://zenodo.org/record/1234953|type=Submitted manuscript}}</ref> The critical point for lower salinity fluids is at lower temperature and pressure conditions than that for seawater, but higher than that for pure water. For example, a vent fluid with a 2.24 wt. % NaCl salinity has the critical point at {{convert|400|C|F|abbr=on}} and 280.5&nbsp;bars. Thus, water emerging from the hottest parts of some hydrothermal vents can be a [[Physics:Supercritical fluid#Submarine volcanoes|supercritical fluid]], possessing physical properties between those of a [[Physics:Gas|gas]] and those of a [[Physics:Liquid|liquid]].<ref name="Haas2007" /><ref name="Karst2009" />[[Image:Phase-diag2.svg|thumb|upright=1.2|In this [[Phase diagram|phase diagram]], the green dotted line illustrates the anomalous behavior of water. The dotted green line marks the melting point and the blue line the boiling point, showing how they vary with pressure; the solid green line shows the typical melting point behavior for other substances.]]Examples of supercritical venting are found at several sites. ''Sister Peak'' (Comfortless Cove Hydrothermal Field, {{Coord|4|48|S|12|22|W|}}, depth {{convert|2996|m|ft|abbr=on|disp=or}}) vents low salinity phase-separated, vapor-type fluids. Sustained venting was not found to be supercritical but a brief injection of {{convert|464|C|F|abbr=on}} was well above supercritical conditions. A nearby site, Turtle Pits, was found to vent low salinity fluid at {{convert|407|C|F|abbr=on}}, which is above the critical point of the fluid at that salinity. A vent site in the Cayman Trough named [[Earth:Beebe Hydrothermal Vent Field|Beebe]], which is the world's deepest known hydrothermal site at ~{{convert|5000|m|ft|abbr=on}} below sea level, has shown sustained supercritical venting at {{convert|401|C|F|abbr=on}} and 2.3 wt% NaCl.<ref>{{cite web|last1=Webber|first1=A.P.|last2=Murton|first2=B.|last3=Roberts|first3=S.|last4=Hodgkinson|first4=M.|title=Supercritical Venting and VMS Formation at the Beebe Hydrothermal Field, Cayman Spreading Centre|url=http://goldschmidt.info/2014/abstracts/abstractView?abstractId=2504|website=Goldschmidt Conference Abstracts 2014|publisher=Geochemical Society|access-date=29 July 2014|archive-url=https://web.archive.org/web/20140729183137/http://goldschmidt.info/2014/abstracts/abstractView?abstractId=2504|archive-date=29 July 2014|url-status=dead}}</ref>

Although supercritical conditions have been observed at several sites, it is not yet known what significance, if any, supercritical venting has in terms of hydrothermal circulation, mineral deposit formation, geochemical fluxes or biological activity.{{citation needed|date=February 2023}}

The initial stages of a vent chimney begin with the deposition of the mineral [[Chemistry:Anhydrite|anhydrite]]. [[Chemistry:Sulfide mineral|Sulfides]] of [[Chemistry:Copper|copper]], [[Chemistry:Iron|iron]], and [[Chemistry:Zinc|zinc]] then precipitate in the chimney gaps, making it less [[Earth:Porosity|porous]] over the course of time. Vent growths on the order of {{convert|30|cm|ft|abbr=on|0}} per day have been recorded.<ref name="black_smoker">
{{Cite web
 |last=Tivey|first=M. K.
 |date=1 December 1998
 |url=http://www.whoi.edu/oceanus/viewArticle.do?id=2400
 |title=How to Build a Black Smoker Chimney: The Formation of Mineral Deposits At Mid-Ocean Ridges
 |publisher=[[Organization:Woods Hole Oceanographic Institution|Woods Hole Oceanographic Institution]]
 |access-date=2006-07-07
}}</ref> An April 2007 exploration of the deep-sea vents off the coast of Fiji found those vents to be a significant source of dissolved iron (see [[Earth:Iron cycle|iron cycle]]).<ref>{{cite journal |last1=Petkewich |first1=Rachel |title=Tracking ocean iron |journal=Chemical & Engineering News |date=September 2008 |volume=86 |issue=35 |pages=62–63 |doi=10.1021/cen-v086n035.p062 }}</ref>

==Black smokers and white smokers==
{{Anchor|Black smokers and white smokers|Black smokers|White smokers}}[[File:Blackdiamante hirez.jpg|thumb|Extinct smokers]]

Some hydrothermal vents form roughly cylindrical chimney structures. These from minerals that are dissolved in the vent fluid. When the superheated water contacts the near-freezing sea water, the minerals precipitate out to form particles which add to the height of the stacks. Some of these chimney structures can reach heights of 60&nbsp;m.<ref>
{{Cite journal
 |last=Perkins |first=S.
 |year=2001
 |title=New type of hydrothermal vent looms large
 |journal=Science News
 |volume=160 |issue=2 |pages=21
 |doi=10.2307/4012715
 |jstor=4012715
}}</ref> An example of such a towering vent was "Godzilla", a structure on the Pacific Ocean deep seafloor near Oregon that rose to 40&nbsp;m before it fell over in 1996.<ref>{{cite web |last1=Kelley |first1=Deborah S. |title=Black Smokers: Incubators on the Seafloor |page=2 |url=http://www.amnh.org/learn/pd/earth/pdf/black_smokers_incubators.pdf}}</ref>

=== Black smokers ===
[[File:MARUM Schwarzer Raucher.jpg|thumb|The black smoker "Candelabra" in the Logatchev hydrothermal field on the Mid-Atlantic Ridge at a water depth of 3300 m]]
[[File:Black smoker hydrothermal vent.ogg|thumb|Sound recording from a black smoker]]

A black smoker or deep-sea vent is a type of hydrothermal vent found on the [[Earth:Seabed|seabed]], typically in the [[Earth:Bathyal zone|bathyal zone]] (with largest frequency in depths from 2,500 to 3,000&nbsp;m), but also in lesser depths as well as deeper in the [[Earth:Abyssal zone|abyssal zone]].<ref name="Colín-García 2016" /><!-- per graph 3C in the reference :0 --> They appear as black, chimney-like structures that emit a cloud of black material. Black smokers typically emit particles with high levels of sulfur-bearing minerals, or sulfides. Black smokers are formed in fields hundreds of meters wide when [[Physics:Superheating|superheated]] water from below [[Earth:Earth's crust|Earth's crust]] comes through the ocean floor (water may attain temperatures above 400&nbsp;°C).<ref name="Colín-García 2016" /> This water is rich in dissolved minerals from the crust, most notably [[Chemistry:Sulfide|sulfide]]s. When it comes in contact with cold ocean water, many minerals precipitate, forming a black, chimney-like structure around each vent. The deposited metal sulfides can become [[Earth:Volcanogenic massive sulfide ore deposit|massive sulfide ore deposits]] in time. Some black smokers on the Azores portion of the [[Earth:Mid-Atlantic Ridge|Mid Atlantic Ridge]] are extremely rich in [[Chemistry:Metal|metal]] content, such as Rainbow with 24,000&nbsp;[[Physics:Molar concentration|μM]] concentrations of [[Chemistry:Iron|iron]].<ref>{{cite journal|last1=Douville|first1=E|last2=Charlou|first2=J.L|last3=Oelkers|first3=E.H|last4=Bienvenu|first4=P|last5=Jove Colon|first5=C.F|last6=Donval|first6=J.P|last7=Fouquet|first7=Y|last8=Prieur|first8=D|last9=Appriou|first9=P|title=The rainbow vent fluids (36°14′N, MAR): the influence of ultramafic rocks and phase separation on trace metal content in Mid-Atlantic Ridge hydrothermal fluids|journal=Chemical Geology|date=March 2002|volume=184|issue=1–2|pages=37–48|doi=10.1016/S0009-2541(01)00351-5|bibcode=2002ChGeo.184...37D}}</ref>[[Image:Deep_Sea_Vent_Chemistry_Diagram.svg|thumb|Biogeochemical diagram of a deep-sea vent]]Black smokers were first discovered in 1979 on the East Pacific Rise by scientists from Scripps Institution of Oceanography during the RISE Project.<ref name="Spiess et al 1980" /> They were observed using the deep submergence vehicle ALVIN from the Woods Hole Oceanographic Institution. Now, black smokers are known to exist in the Atlantic and [[Earth:Pacific Ocean|Pacific]] Oceans, at an average depth of {{convert|2,100|m|abbr=on}}. The most northerly black smokers are a cluster of five named Loki's Castle,<ref>
{{Cite web
 |url=http://www.livescience.com/environment/080724-black-smokers.html
 |title=Boiling Hot Water Found in Frigid Arctic Sea
 |access-date=2008-07-25
 |work=LiveScience
 |date=24 July 2008
}}</ref> discovered in 2008 by scientists from the University of Bergen at 73°N, on the [[Earth:Mid-Atlantic Ridge|Mid-Atlantic Ridge]] between [[Place:Greenland|Greenland]] and {{wipe|Norway}}. These black smokers are of interest as they are in a more stable area of the Earth's crust, where tectonic forces are less and consequently fields of hydrothermal vents are less common.<ref>
{{cite web
 |url=https://www.sciencedaily.com/releases/2008/07/080724153941.htm
 |title=Scientists Break Record By Finding Northernmost Hydrothermal Vent Field
 |access-date=2008-07-25
 |work=Science Daily
 |date=24 July 2008
}}</ref> The world's deepest known black smokers are located in the [[Earth:Cayman Trough|Cayman Trough]], 5,000&nbsp;m (3.1&nbsp;miles) below the ocean's surface.<ref>
{{Cite web
 |last=Cross |first=A.
 |url=http://news.bbc.co.uk/2/hi/science/nature/8611771.stm
 |title=World's deepest undersea vents discovered in Caribbean
 |access-date=2010-04-13
 |work=BBC News
 |date=12 April 2010
}}</ref>

=== White smokers ===
[[File:Eifuku chimneys bubbles.jpg|thumb|Carbon dioxide bubbles are emitted from white smokers at the Champagne vent site in Eifuku.]]
White smoker vents emit lighter-hued minerals, such as those containing [[Chemistry:Barium|barium]], [[Chemistry:Calcium|calcium]] and [[Chemistry:Silicon|silicon]]. These vents also tend to have lower-temperature plumes probably because they are generally distant from their heat source.<ref name="Colín-García 2016" />

Black and white smokers may coexist in the same hydrothermal field, but they generally represent proximal (close) and distal (distant) vents to the main upflow zone, respectively. However, white smokers correspond mostly to waning stages of such hydrothermal fields, as magmatic heat sources become progressively more distant from the source (due to magma crystallization) and hydrothermal fluids become dominated by seawater instead of magmatic water. Mineralizing fluids from this type of vent are rich in calcium and they form dominantly [[Chemistry:Sulfate|sulfate]]-rich (i.e., barite and [[Chemistry:Anhydrite|anhydrite]]) and [[Chemistry:Carbonate|carbonate]] deposits.<ref name="Colín-García 2016" />

==Biology of hydrothermal vents==
Life has traditionally been seen as driven by energy from the sun, but deep-sea organisms have no access to sunlight, so biological communities around hydrothermal vents must depend on nutrients found in the dusty chemical deposits and hydrothermal fluids in which they live. Previously, Benthic oceanographers assumed that vent organisms were dependent on [[Biology:Marine snow|marine snow]], as deep-sea organisms are. This would leave them dependent on plant life and thus the sun. Some hydrothermal vent organisms do consume this "rain", but with only such a system, life forms would be sparse. Compared to the surrounding sea floor, however, hydrothermal vent zones have a density of organisms 10,000 to 100,000 times greater. These organisms include yeti crabs, which have long hairy arms that they reach out over the vent to collect food with.{{citation needed|date=February 2023}}

The hydrothermal vents are recognized as a type of chemosynthetic based ecosystems (CBE) where primary productivity is fuelled by chemical compounds as energy sources instead of light (chemoautotrophy).<ref>{{cite book |last1=Ramirez-Llodra |first1=E | last2=Keith |first2=DA |title=IUCN Global Ecosystem Typology 2.0: Descriptive profiles for biomes and ecosystem functional groups |year=2020 |chapter=M3.7 Chemosynthetic-based-ecosystems (CBE) |chapter-url=https://global-ecosystems.org/explore/groups/M3.7 |editor1-last=Keith |editor1-first=D.A. |editor2-last=Ferrer-Paris |editor2-first=J.R. |editor3-last=Nicholson |editor3-first=E. |editor4-last=Kingsford |editor4-first=R.T. |location=Gland, Switzerland |publisher=IUCN | doi=10.2305/IUCN.CH.2020.13.en | isbn= 978-2-8317-2077-7|s2cid=241360441 }}</ref> Hydrothermal vent communities are able to sustain such vast amounts of life because vent organisms depend on chemosynthetic bacteria for food. The water from the hydrothermal vent is rich in dissolved minerals and supports a large population of chemoautotrophic bacteria. These bacteria use sulfur compounds, particularly [[Chemistry:Hydrogen sulfide|hydrogen sulfide]], a chemical highly toxic to most known organisms, to produce organic material through the process of [[Earth:Chemosynthesis|chemosynthesis]].

The vents' impact on the living environment goes beyond the organisms that lives around them, as they act as a significant source of iron in the oceans, providing iron for the phytoplankton.<ref>[https://www.washington.edu/news/2015/07/08/seafloor-hot-springs-a-significant-source-of-iron-in-the-oceans/ Seafloor hot springs a significant source of iron in the oceans]</ref>

===Biological communities===

{{Further|Hyperthermophile|Thermophile}}[[File:MARUM Schwarzer Raucher Fauna.jpg|thumb|Living community at hydrothermal seeps on the Mid-Ocean Ridge at a water depth of 3030 m]]

The ecosystem so formed is reliant upon the continued existence of the hydrothermal vent field as the primary source of energy, which differs from most surface life on Earth, which is based on [[Physics:Solar energy|solar energy]]. However, although it is often said that these communities exist independently of the sun, some of the organisms are actually dependent upon oxygen produced by photosynthetic organisms, while others are [[Biology:Anaerobic organism|anaerobic]].[[File:Riftia tube worm colony Galapagos 2011.jpg|thumb|Giant tube worms (''Riftia pachyptila'') cluster around vents in the Galapagos Rift ]]The chemosynthetic bacteria grow into a thick mat which attracts other organisms, such as amphipods and copepods, which graze upon the bacteria directly. Larger organisms, such as snails, shrimp, crabs, tube worms, fish (especially eelpout, cutthroat eel, ophidiiforms and ''Symphurus thermophilus''), and octopuses (notably ''Vulcanoctopus hydrothermalis''), form a food chain of predator and prey relationships above the primary consumers. The main families of organisms found around seafloor vents are annelids, pogonophorans, gastropods, and crustaceans, with large bivalves, vestimentiferan worms, and "eyeless" shrimp making up the bulk of nonmicrobial organisms.{{citation needed|date=February 2023}}thumb|Swarms of small synaphobranchid eels, ''Dysommina rugosa'', live in the crevices on the summit of Nafanua. Scientists dubbed this site "Eel City".Siboglinid tube worms, which may grow to over {{convert|2|m|ft|abbr=on}} tall in the largest species, often form an important part of the community around a hydrothermal vent. They have no mouth or digestive tract, and like parasitic worms, absorb nutrients produced by the bacteria in their tissues. About 285 billion bacteria are found per ounce of tubeworm tissue. Tubeworms have red plumes which contain hemoglobin. Hemoglobin combines with hydrogen sulfide and transfers it to the bacteria living inside the worm. In return, the bacteria nourish the worm with carbon compounds. Two of the species that inhabit a hydrothermal vent are ''Tevnia jerichonana'', and ''Riftia pachyptila''. One discovered community, dubbed "Eel City", consists predominantly of the eel ''[[Biology:Dysommina rugosa|Dysommina rugosa]]''. Though eels are not uncommon, invertebrates typically dominate hydrothermal vents. Eel City is located near Nafanua volcanic cone, American Samoa.<ref>
{{cite web
 |date=28 May 2008
 |title=Extremes of Eel City
 |url=http://www.astrobio.net/pressrelease/1577/extremes-of-eel-city
 |work=Astrobiology Magazine
 |access-date=2007-08-30
 |archive-url=https://web.archive.org/web/20110628184030/http://www.astrobio.net/pressrelease/1577/extremes-of-eel-city
 |archive-date=2011-06-28
 |url-status=usurped}}</ref>

In 1993, already more than 100 gastropod species were known to occur in hydrothermal vents.<ref name="Sysoev 1995">
{{cite journal
 |last1=Sysoev |first1=A. V.
 |last2=Kantor |first2=Yu. I.
 |year=1995
 |title=Two new species of ''Phymorhynchus'' (Gastropoda, Conoidea, Conidae) from the hydrothermal vents
 |journal=Ruthenica
 |volume=5 |pages=17–26
 |url=http://www.ruthenica.com/documents/Vol5_Sysoev_Kantor_17-26_abstract.pdf
}}</ref> Over 300 new species have been discovered at hydrothermal vents,<ref>
{{Cite web
 |last=Botos |first=S.
 |title=Life on a hydrothermal vent
 |work=Hydrothermal Vent Communities
 |url=http://www.botos.com/marine/vents01.html#body_4
}}</ref> many of them "sister species" to others found in geographically separated vent areas. It has been proposed that before the North American plate overrode the [[Earth:Mid-ocean ridge|mid-ocean ridge]], there was a single biogeographic vent region found in the eastern Pacific.<ref>
{{Cite web
 |last=Van Dover |first=C. L.
 |title=Hot Topics: Biogeography of deep-sea hydrothermal vent faunas
 |url=http://www.divediscover.whoi.edu/hottopics/biogeo.html
 |publisher=Woods Hole Oceanographic Institution
}}</ref> The subsequent barrier to travel began the evolutionary divergence of species in different locations. The examples of convergent evolution seen between distinct hydrothermal vents is seen as major support for the theory of natural selection and of evolution as a whole.

[[File:Sully Vent.jpg|thumb|Giant tube worms at the base of a hydrothermal mount]]Although life is very sparse at these depths, black smokers are the centers of entire ecosystems. Sunlight is nonexistent, so many organisms, such as archaea and extremophiles, convert the heat, methane, and sulfur compounds provided by black smokers into energy through a process called chemosynthesis. More complex life forms, such as clams and tubeworms, feed on these organisms. The organisms at the base of the food chain also deposit minerals into the base of the black smoker, therefore completing the [[Biology:Biological life cycle|life cycle]].

A species of phototrophic bacterium has been found living near a black smoker off the coast of Mexico at a depth of {{convert|2500|m|ft|abbr=on}}. No sunlight penetrates that far into the waters. Instead, the bacteria, part of the [[Biology:Green sulfur bacteria|Chlorobiaceae]] family, use the faint glow from the black smoker for [[Earth:Photosynthesis|photosynthesis]]. This is the first organism discovered in nature to exclusively use a light other than sunlight for photosynthesis.<ref>
{{cite journal
 |last1=Beatty |first1=J.T.
 |year=2005
 |title=An obligately photosynthetic bacterial anaerobe from a deep-sea hydrothermal vent
 |journal=Proceedings of the National Academy of Sciences
 |volume=102 |issue=26 |pages=9306–10
 |bibcode = 2005PNAS..102.9306B
 |doi=10.1073/pnas.0503674102
 |pmc=1166624
 |pmid=15967984
|display-authors=0|doi-access=free
 }}</ref>

New and unusual species are constantly being discovered in the neighborhood of black smokers. The Pompeii worm ''Alvinella pompejana'', which is capable of withstanding temperatures up to {{convert|80|C|F}}, was found in the 1980s, and a [[Biology:Scaly-foot gastropod|scaly-foot gastropod]] ''Chrysomallon squamiferum'' in 2001 during an expedition to the [[Earth:Indian Ocean|Indian Ocean]]'s [[Earth:Kairei vent field|Kairei hydrothermal vent field]]. The latter uses iron sulfides ([[Chemistry:Pyrite|pyrite]] and greigite) for the structure of its dermal sclerites (hardened body parts), instead of [[Chemistry:Calcium carbonate|calcium carbonate]]. The extreme pressure of 2,500&nbsp;m of water (approximately 25&nbsp;megapascals or 250&nbsp;[[Physics:Atmosphere (unit)|atmospheres]]) is thought to play a role in stabilizing iron sulfide for biological purposes. This armor plating probably serves as a defense against the venomous [[Biology:Radula|radula]] (teeth) of predatory [[Biology:Snail|snail]]s in that community.

In March 2017, researchers reported evidence of possibly the [[Biology:Abiogenesis|oldest forms of life on Earth]]. Putative fossilized microorganisms were discovered in hydrothermal vent precipitates in the Nuvvuagittuq Belt of Quebec, Canada, that may have lived as [[Biology:Earliest known life forms|early as 4.280 billion years ago]], not long after the oceans [[Earth:Origin of water on Earth#History of water on Earth|formed 4.4 billion years ago]], and not long after the [[Earth:Age of the Earth|formation of the Earth]] 4.54 billion years ago.<ref name="NAT-20170301">{{cite journal |last1=Dodd |first1=Matthew S. |last2=Papineau |first2=Dominic |last3=Grenne |first3=Tor |last4=Slack |first4=John F. |last5=Rittner |first5=Martin |last6=Pirajno |first6=Franco |last7=O'Neil |first7=Jonathan |last8=Little |first8=Crispin T. S. |title=Evidence for early life in Earth's oldest hydrothermal vent precipitates |journal=Nature |date=2 March 2017 |volume=543 |issue=7643 |pages=60–64 |doi=10.1038/nature21377 |pmid=28252057 |bibcode=2017Natur.543...60D |s2cid=2420384 |url=http://eprints.whiterose.ac.uk/112179/1/ppnature21377_Dodd_for%20Symplectic.pdf }}</ref><ref name="NYT-20170301">{{cite news |last=Zimmer |first=Carl |title=Scientists Say Canadian Bacteria Fossils May Be Earth's Oldest |url=https://www.nytimes.com/2017/03/01/science/earths-oldest-bacteria-fossils.html |date=1 March 2017 |work={{wipe|The New York Times}} |access-date=2 March 2017 }}</ref><ref name="BBC-20170301">{{Cite news |last=Ghosh |first=Pallab |title=Earliest evidence of life on Earth 'found' |url=https://www.bbc.co.uk/news/science-environment-39117523 |work=BBC News |date=1 March 2017 |access-date=2 March 2017}}</ref>[[File:Fauna on hydrothermal vents.jpg|thumb|Shrimp (''Alvinocaris''), a few squat lobsters, and hundreds of bivalves (''Bathymodiolus'')]]
[[File:Macrouridae.jpg|thumb|A Macrouridae next to an extinct smoker.]]

===Animal-bacterial symbiosis===
[[File:Dense mass of anomuran crab Kiwa around deep-sea hydrothermal vent.jpg|thumb|A dense fauna (''[[Biology:Kiwaidae|Kiwa]]'' anomurans and ''Vulcanolepas''-like stalked barnacles) near East Scotia Ridge vents]]
Hydrothermal vent ecosystems have enormous biomass and productivity, but this rests on the symbiotic relationships that have evolved at vents. Deep-sea hydrothermal vent ecosystems differ from their shallow-water and terrestrial hydrothermal counterparts due to the symbiosis that occurs between macroinvertebrate hosts and chemoautotrophic microbial symbionts in the former.<ref>Van Dover 2000{{full citation needed|date=August 2019}}</ref> Since sunlight does not reach deep-sea hydrothermal vents, organisms in deep-sea hydrothermal vents cannot obtain energy from the sun to perform photosynthesis. Instead, the microbial life found at hydrothermal vents is chemosynthetic; they fix carbon by using energy from chemicals such as sulfide, as opposed to light energy from the sun. In other words, the symbiont converts inorganic molecules (H<sub>2</sub>S, CO<sub>2</sub>, O) to organic molecules that the host then uses as nutrition. However, sulfide is an extremely toxic substance to most life on Earth. For this reason, scientists were astounded when they first found hydrothermal vents teeming with life in 1977. What was discovered was the ubiquitous symbiosis of chemoautotrophs living in (endosymbiosis) the vent animals' gills; the reason why multicellular life is capable to survive the toxicity of vent systems. Scientists are therefore now studying how the microbial symbionts aid in sulfide detoxification (therefore allowing the host to survive the otherwise toxic conditions). Work on [[Biology:Microbiome|microbiome]] function shows that host-associated microbiomes are also important in host development, nutrition, defense against predators, and detoxification. In return, the host provides the symbiont with chemicals required for chemosynthesis, such as carbon, sulfide, and oxygen.{{citation needed|date=August 2019}}

In the early stages of studying life at hydrothermal vents, there were differing theories regarding the mechanisms by which multicellular organisms were able to acquire nutrients from these environments, and how they were able to survive in such extreme conditions. In 1977, it was hypothesized that the chemoautotrophic bacteria at hydrothermal vents might be responsible for contributing to the diet of suspension-feeding bivalves.<ref>{{cite journal |doi=10.1016/0146-6291(77)90478-7 |title=Clustering of suspension-feeding macrobenthos near abyssal hydrothermal vents at oceanic spreading centers |journal=Deep Sea Research |volume=24 |issue=9 |pages=857–863 |year=1977 |last1=Lonsdale |first1=Peter |bibcode=1977DSR....24..857L |s2cid=128478123 }}</ref>

Finally, in 1981, it was understood that giant tubeworm nutrition acquisition occurred as a result of chemoautotrophic bacterial endosymbionts.<ref>Cavanaug eta al 1981{{full citation needed|date=August 2019}}</ref><ref>Felback 1981{{full citation needed|date=August 2019}}</ref><ref>Rau 1981{{full citation needed|date=August 2019}}</ref> As scientists continued to study life at hydrothermal vents, it was understood that symbiotic relationships between chemoautotrophs and macrofauna invertebrate species was ubiquitous. For instance, in 1983, clam gill tissue was confirmed to contain bacterial endosymbionts;<ref>Cavanaugh 1983{{full citation needed|date=August 2019}}</ref> in 1984 vent bathymodiolid mussels and vesicomyid clams were also found to carry endosymbionts.<ref>{{cite journal |last1=Fiala-Médioni |first1=A. |title=Ultrastructural evidence of abundance of intracellular symbiotic bacteria in the gill of bivalve molluscs of deep hydrothermal vents |journal=Comptes rendus de l'Académie des Sciences |volume=298 |issue=17 |year=1984 |pages=487–492 }}</ref><ref>{{cite journal |last1=Le Pennec |first1=M. |last2=Hily |first2=A. |title=Anatomie, structure et ultrastructure de la branchie d'un Mytilidae des sites hydrothermaux du Pacifique oriental |trans-title=Anatomy, structure and ultrastructure of the gill of a Mytilidae of the hydrothermal sites of the eastern Pacific |language=fr |journal=Oceanologica Acta |volume=7 |issue=4 |year=1984 |pages=517–523 }}</ref>

However, the mechanisms by which organisms acquire their symbionts differ, as do the metabolic relationships. For instance, tubeworms have no mouth and no gut, but they do have a "trophosome", which is where they deal with nutrition and where their endosymbionts are found. They also have a bright red plume, which they use to uptake compounds such as O, H<sub>2</sub>S, and CO<sub>2</sub>, which feed the endosymbionts in their trophosome. Remarkably, the tubeworms hemoglobin (which incidentally is the reason for the bright red color of the plume) is capable of carrying oxygen without interference or inhibition from sulfide, despite the fact that oxygen and sulfide are typically very reactive. In 2005, it was discovered that this is possible due to zinc ions that bind the hydrogen sulfide in the tubeworms hemoglobin, therefore preventing the sulfide from reacting with the oxygen. It also reduces the tubeworms tissue from exposure to the sulfide and provides the bacteria with the sulfide to perform chemoautotrophy.<ref>{{cite journal |doi=10.1073/pnas.0407455102 |pmid=15710902 |pmc=549462 |title=Sulfide binding is mediated by zinc ions discovered in the crystal structure of a hydrothermal vent tubeworm hemoglobin |journal=Proceedings of the National Academy of Sciences |volume=102 |issue=8 |pages=2713–2718 |year=2005 |last1=Flores |first1=J. F. |last2=Fisher |first2=C. R. |last3=Carney |first3=S. L. |last4=Green |first4=B. N. |last5=Freytag |first5=J. K. |last6=Schaeffer |first6=S. W. |last7=Royer |first7=W. E. |bibcode=2005PNAS..102.2713F |doi-access=free }}</ref> It has also been discovered that tubeworms can metabolize CO<sub>2</sub> in two different ways, and can alternate between the two as needed as environmental conditions change.<ref>{{cite journal |doi=10.3389/fmicb.2012.00423 |pmid=23248622 |pmc=3522073 |title=Widespread Occurrence of Two Carbon Fixation Pathways in Tubeworm Endosymbionts: Lessons from Hydrothermal Vent Associated Tubeworms from the Mediterranean Sea |journal=Frontiers in Microbiology |volume=3 |pages=423 |year=2012 |last1=Thiel |first1=Vera |last2=Hügler |first2=Michael |last3=Blümel |first3=Martina |last4=Baumann |first4=Heike I. |last5=Gärtner |first5=Andrea |last6=Schmaljohann |first6=Rolf |last7=Strauss |first7=Harald |last8=Garbe-Schönberg |first8=Dieter |last9=Petersen |first9=Sven |last10=Cowart |first10=Dominique A. |last11=Fisher |first11=Charles R. |last12=Imhoff |first12=Johannes F. |doi-access=free }}</ref>

In 1988, research confirmed thiotrophic (sulfide-oxidizing) bacteria in ''Alviniconcha hessleri'', a large vent mollusk.<ref>Stein et al 1988{{full citation needed|date=August 2019}}</ref> In order to circumvent the toxicity of sulfide, mussels first convert it to thiosulfate before carrying it over to the symbionts.<ref>Biology of the Deep Sea, Peter Herring{{full citation needed|date=August 2019}}</ref> In the case of motile organisms such as alvinocarid shrimp, they must track oxic (oxygen-rich) / anoxic (oxygen-poor) environments as they fluctuate in the environment.{{citation needed|date=August 2019}}

Organisms living at the edge of hydrothermal vent fields, such as pectinid scallops, also carry endosymbionts in their gills, and as a result their bacterial density is low relative to organisms living nearer to the vent. However, the scallop's dependence on the microbial endosymbiont for obtaining their nutrition is therefore also lessened.{{citation needed|date=August 2019}}

Furthermore, not all host animals have endosymbionts; some have episymbionts—symbionts living on the animal as opposed to inside the animal. Shrimp found at vents in the Mid-Atlantic Ridge were once thought of as an exception to the necessity of symbiosis for macroinvertebrate survival at vents. That changed in 1988 when they were discovered to carry episymbionts.<ref>Van Dover et al 1988{{full citation needed|date=August 2019}}</ref> Since then, other organisms at vents have been found to carry episymbionts as well,<ref>Desbruyeres et al 1985{{full citation needed|date=August 2019}}</ref> such as Lepetodrilis fucensis.<ref>{{cite journal |last1=de Burgh |first1=M. E. |last2=Singla |first2=C. L. |title=Bacterial colonization and endocytosis on the gill of a new limpet species from a hydrothermal vent |journal=Marine Biology |date=December 1984 |volume=84 |issue=1 |pages=1–6 |doi=10.1007/BF00394520 |s2cid=85072202 }}</ref>

Furthermore, while some symbionts reduce sulfur compounds, others are known as "[[Biology:Methanotroph|methanotroph]]s" and reduce carbon compounds, namely methane. Bathmodiolid mussels are an example of a host that contains methanotrophic endosymbionts; however, the latter mostly occur in cold seeps as opposed to hydrothermal vents.{{citation needed|date=August 2019}}

While chemosynthesis occurring at the deep ocean allows organisms to live without sunlight in the immediate sense, they technically still rely on the sun for survival, since oxygen in the ocean is a byproduct of photosynthesis. However, if the sun were to suddenly disappear and photosynthesis ceased to occur on our planet, life at the deep-sea hydrothermal vents could continue for millennia (until the oxygen was depleted).{{citation needed|date=August 2019}}

===Theory of hydrothermal origin of life===
The chemical and thermal dynamics in hydrothermal vents makes such environments highly suitable thermodynamically for chemical evolution processes to take place. Therefore, thermal energy flux is a permanent agent and is hypothesized to have contributed to the evolution of the planet, including prebiotic chemistry.<ref name="Colín-García 2016" />

Günter Wächtershäuser proposed the iron-sulfur world theory and suggested that life might have [[Biology:Abiogenesis|originated]] at hydrothermal vents. Wächtershäuser proposed that an early form of metabolism predated genetics. By metabolism he meant a cycle of chemical reactions that release energy in a form that can be harnessed by other processes.<ref>{{cite journal |last1=Wachtershauser |first1=G. |title=Evolution of the first metabolic cycles. |journal=Proceedings of the National Academy of Sciences |date=1 January 1990 |volume=87 |issue=1 |pages=200–204 |doi=10.1073/pnas.87.1.200 |pmid=2296579 |pmc=53229 |bibcode=1990PNAS...87..200W |doi-access=free }}</ref>

It has been proposed that [[Chemistry:Amino acid|amino acid]] synthesis could have occurred deep in the Earth's crust and that these amino acids were subsequently shot up along with hydrothermal fluids into cooler waters, where lower temperatures and the presence of clay minerals would have fostered the formation of peptides and [[Biology:Protocell|protocell]]s.<ref>
{{cite journal
 |last1=Tunnicliffe |first1=V.
 |year=1991
 |title=The Biology of Hydrothermal Vents: Ecology and Evolution
 |journal=[[Biology:Oceanography and Marine Biology: An Annual Review|Oceanography and Marine Biology]]
 |volume=29 |pages=319–408
}}</ref> This is an attractive hypothesis because of the abundance of CH<sub>4</sub> ([[Chemistry:Methane|methane]]) and NH<sub>3</sub> ([[Chemistry:Ammonia|ammonia]]) present in hydrothermal vent regions, a condition that was not provided by the Earth's primitive atmosphere. A major limitation to this hypothesis is the lack of stability of organic molecules at high temperatures, but some have suggested that life would have originated outside of the zones of highest temperature.<ref>{{cite journal|last1=Chandru|first1=Kuhan|last2=Imai|first2=EiIchi|last3=Kaneko|first3=Takeo|last4=Obayashi|first4=Yumiko|last5=Kobayashi|first5=Kensei|title=Survivability and Abiotic Reactions of Selected Amino Acids in Different Hydrothermal System Simulators|journal=Origins of Life and Biosphere|volume=43|issue=2|pages=99–108|doi=10.1007/s11084-013-9330-9|pmid=23625039|year=2013|bibcode=2013OLEB...43...99C|s2cid=15200910}}</ref> There are numerous species of [[Earth:Extremophile|extremophile]]s and other organisms currently living immediately around deep-sea vents, suggesting that this is indeed a possible scenario.{{citation needed|date=February 2023}}

Experimental research and computer modeling indicate that the surfaces of mineral particles inside hydrothermal vents have similar catalytic properties to enzymes and are able to create simple organic molecules, such as [[Chemistry:Methanol|methanol]] (CH<sub>3</sub>OH) and [[Chemistry:Formic acid|formic acid]] (HCO<sub>2</sub>H), out of the dissolved CO<sub>2</sub> in the water.<ref name="organics">[https://web.archive.org/web/20150905234013/http://www.astrobio.net/topic/origins/origin-and-evolution-of-life/chemistry-of-seabeds-hot-vents-could-explain-emergence-of-life/ Chemistry of seabed's hot vents could explain emergence of life]. ''Astrobiology Magazine'' 27 April 2015.</ref><ref>{{cite journal |last1=Roldan |first1=A. |last2=Hollingsworth |first2=N. |last3=Roffey |first3=A. |last4=Islam |first4=H.-U. |last5=Goodall |first5=J. B. M. |last6=Catlow |first6=C. R. A. |last7=Darr |first7=J. A. |last8=Bras |first8=W. |last9=Sankar |first9=G. |last10=Holt |first10=K. B. |last11=Hogartha |first11=G. |last12=de Leeuw |first12=N. H. |date=24 March 2015 |title=Bio-inspired CO<sub>2</sub> conversion by iron sulfide catalysts under sustainable conditions |journal=Chemical Communications |volume=51 |issue=35 |pages=7501–7504 |doi=10.1039/C5CC02078F |url=http://pubs.rsc.org/en/content/articlepdf/2015/cc/c5cc02078f |format=PDF |pmid=25835242|s2cid=217970758 |doi-access=free }}</ref><ref>{{cite journal|last1=Aubrey|first1=A. D.|last2=Cleaves|first2=H.J|last3=Bada|first3=J.L|title=The Role of Submarine Hydrothermal Systems in the Synthesis of Amino Acids|journal=Origins of Life and Biosphere|volume=39|issue=2|pages=91–108|doi=10.1007/s11084-008-9153-2|pmid=19034685|year=2008|bibcode=2009OLEB...39...91A|s2cid=207224268}}</ref>

It is thought that alkaline hydrothermal vents (white smokers) might be more suitable for emerging life than black smokers due to their pH conditions.<ref>Joseph F. Sutherland: [http://prehistoricict.blogspot.de/2014/08/on-origin-of-bacteria-and-archaea.html on The Origin Of Tha Bacteria And The Archaea], auf B.C vom 16. August 2014</ref><ref name="NLane_Funke">Nick Lane: [https://books.google.com/books?id=IfJYBQAAQBAJ&pg=PT77 The Vital Question - Energy, Evolution, and the Origins of Complex Life], Ww Norton, 2015-07-20, {{ISBN|978-0-393-08881-6}}, [http://armscoop.com/wp-content/uploads/2016/08/Lane_Nick-The_vital_question_why_is_life_the_way_it_is_-Profile_Books_2015.pdf PDF] {{Webarchive|url=https://web.archive.org/web/20170910173549/http://armscoop.com/wp-content/uploads/2016/08/Lane_Nick-The_vital_question_why_is_life_the_way_it_is_-Profile_Books_2015.pdf |date=2017-09-10 }}</ref>

However, this view of deep sea hydrothermal vents as an ideal environment is controversial since wet-dry cycles and exposure to UV light are absent at these environments, which promote the formation of membranous vesicles and synthesis of many biomolecules.<ref>{{Cite journal |last1=Da Silva |first1=Laura |last2=Maurel |first2=Marie-Christine |last3=Deamer |first3=David |date=2015-02-01 |title=Salt-Promoted Synthesis of RNA-like Molecules in Simulated Hydrothermal Conditions |url=https://www.researchgate.net/publication/269289616 |journal=Journal of Molecular Evolution |language=en |volume=80 |issue=2 |pages=86–97 |doi=10.1007/s00239-014-9661-9 |pmid=25487518 |bibcode=2015JMolE..80...86D |s2cid=15603239 |issn=1432-1432}}</ref><ref>{{Cite journal |last1=Patel |first1=Bhavesh H. |last2=Percivalle |first2=Claudia |last3=Ritson |first3=Dougal J. |last4=Duffy |first4=Colm D. |last5=Sutherland |first5=John D. |date=March 16, 2015 |title=Common origins of RNA, protein and lipid precursors in a cyanosulfidic protometabolism |journal=Nature Chemistry |language=en |volume=7 |issue=4 |pages=301–307 |doi=10.1038/nchem.2202 |pmid=25803468 |pmc=4568310 |bibcode=2015NatCh...7..301P |issn=1755-4349}}</ref><ref>{{Cite journal |last1=Deamer |first1=David |last2=Damer |first2=Bruce |last3=Kompanichenko |first3=Vladimir |date=2019-12-01 |title=Hydrothermal Chemistry and the Origin of Cellular Life |url=https://www.researchgate.net/publication/336403247 |journal=Astrobiology |volume=19 |issue=12 |pages=1523–1537 |doi=10.1089/ast.2018.1979 |pmid=31596608 |bibcode=2019AsBio..19.1523D |s2cid=204029724 |issn=1531-1074}}</ref> The ionic concentrations of hydrothermal vents differs from the intracellular fluid within the majority of life. They have instead suggested that terrestrial freshwater environments are more likely to be an ideal environment for the formation of early cells.<ref>{{Cite journal |last1=Pearce |first1=Ben K. D. |last2=Pudritz |first2=Ralph E. |last3=Semenov |first3=Dmitry A. |last4=Henning |first4=Thomas K. |date=2017-10-24 |title=Origin of the RNA world: The fate of nucleobases in warm little ponds |journal=Proceedings of the National Academy of Sciences |language=en |volume=114 |issue=43 |pages=11327–11332 |doi=10.1073/pnas.1710339114 |issn=0027-8424 |pmc=5664528 |pmid=28973920|arxiv=1710.00434 |bibcode=2017PNAS..11411327P |doi-access=free }}</ref><ref>{{Cite journal |last1=Damer |first1=Bruce |last2=Deamer |first2=David |date=2020-04-01 |title=The Hot Spring Hypothesis for an Origin of Life |journal=Astrobiology |volume=20 |issue=4 |pages=429–452 |doi=10.1089/ast.2019.2045 |issn=1531-1074 |pmc=7133448 |pmid=31841362|bibcode=2020AsBio..20..429D }}</ref> Meanwhile, proponents of the deep sea hydrothermal vent hypothesis suggest thermophoresis in mineral cavities to be an alternative compartment for polymerization of biopolymers.<ref>{{Cite journal |last1=Russell |first1=Michael J. |last2=Barge |first2=Laura M. |last3=Bhartia |first3=Rohit |last4=Bocanegra |first4=Dylan |last5=Bracher |first5=Paul J. |last6=Branscomb |first6=Elbert |last7=Kidd |first7=Richard |last8=McGlynn |first8=Shawn |last9=Meier |first9=David H. |last10=Nitschke |first10=Wolfgang |last11=Shibuya |first11=Takazo |last12=Vance |first12=Steve |last13=White |first13=Lauren |last14=Kanik |first14=Isik |date=2014-04-01 |title=The Drive to Life on Wet and Icy Worlds |journal=Astrobiology |volume=14 |issue=4 |pages=308–343 |doi=10.1089/ast.2013.1110 |issn=1531-1074 |pmc=3995032 |pmid=24697642|bibcode=2014AsBio..14..308R }}</ref><ref>{{Cite journal |last1=Baaske |first1=Philipp |last2=Weinert |first2=Franz M. |last3=Duhr |first3=Stefan |last4=Lemke |first4=Kono H. |last5=Russell |first5=Michael J. |last6=Braun |first6=Dieter |date=2007-05-29 |title=Extreme accumulation of nucleotides in simulated hydrothermal pore systems |journal=Proceedings of the National Academy of Sciences |language=en |volume=104 |issue=22 |pages=9346–9351 |doi=10.1073/pnas.0609592104 |issn=0027-8424 |pmc=1890497 |pmid=17494767 |doi-access=free }}</ref>

How thermophoresis within mineral cavities could promote coding and metabolism is unknown. Nick Lane suggests that nucleotide polymerization at high concentrations of nucleotides within self-replicating protocells, where "Molecular crowding and phosphorylation in such confined, high-energy protocells could potentially promote the polymerization of nucleotides to form RNA".<ref>{{Cite journal |last1=West |first1=Timothy |last2=Sojo |first2=Victor |last3=Pomiankowski |first3=Andrew |last4=Lane |first4=Nick |date=2017-12-05 |title=The origin of heredity in protocells |journal=Philosophical Transactions of the Royal Society B: Biological Sciences |language=en |volume=372 |issue=1735 |pages=20160419 |doi=10.1098/rstb.2016.0419 |issn=0962-8436 |pmc=5665807 |pmid=29061892}}</ref> Acetyl phosphate could possibly promote polymerization at mineral surfaces or at low water activity.<ref>{{Cite journal |last1=Whicher |first1=Alexandra |last2=Camprubi |first2=Eloi |last3=Pinna |first3=Silvana |last4=Herschy |first4=Barry |last5=Lane |first5=Nick |date=2018-06-01 |title=Acetyl Phosphate as a Primordial Energy Currency at the Origin of Life |url=https://doi.org/10.1007/s11084-018-9555-8 |journal=Origins of Life and Evolution of Biospheres |language=en |volume=48 |issue=2 |pages=159–179 |doi=10.1007/s11084-018-9555-8 |issn=1573-0875 |pmc=6061221 |pmid=29502283|bibcode=2018OLEB...48..159W }}</ref> A computational simulation shows that nucleotide concentration of nucleotide catalysis of "the energy currency pathway is favored, as energy is limiting; favoring this pathway feeds forward into a greater nucleotide synthesis". Fast nucleotide catalysis of {{CO2}} fixation lowers nucleotide concentration as protocell growth and division is rapid which then leads to halving of nucleotide concentration, weak nucleotide catalysis of {{CO2}} fixation promotes little to protocell growth and division.<ref>{{Cite journal |last1=Nunes Palmeira |first1=Raquel |last2=Colnaghi |first2=Marco |last3=Harrison |first3=Stuart A. |last4=Pomiankowski |first4=Andrew |last5=Lane |first5=Nick |date=2022-11-09 |title=The limits of metabolic heredity in protocells |journal=Proceedings of the Royal Society B: Biological Sciences |language=en |volume=289 |issue=1986 |doi=10.1098/rspb.2022.1469 |issn=0962-8452 |pmc=9653231 |pmid=36350219}}</ref>

In biochemistry, reactions with CO<sub>2</sub> and H<sub>2</sub> produce precursors to biomolecules that are also produced from the acetyl-CoA pathway and Krebs cycle which would support an origin of life at deep sea alkaline vents. Acetyl phosphate produced from the reactions are capable of phosphorylating ADP to ATP,<ref>{{Cite journal |last1=Harrison |first1=Stuart A. |last2=Lane |first2=Nick |date=2018-12-12 |title=Life as a guide to prebiotic nucleotide synthesis |journal=Nature Communications |language=en |volume=9 |issue=1 |pages=5176 |bibcode=2018NatCo...9.5176H |doi=10.1038/s41467-018-07220-y |issn=2041-1723 |pmc=6289992 |pmid=30538225}}</ref> with maximum synthesis occurring at high water activity and low concentrations of ions, the Hadean ocean likely had lower concentrations of ions than modern oceans. The concentrations of Mg<sup>2+</sup> and Ca<sup>2+</sup>  at alkaline hydrothermal systems are lower than the at the ocean.<ref>{{Cite journal |last1=Pinna |first1=Silvana |last2=Kunz |first2=Cäcilia |last3=Halpern |first3=Aaron |last4=Harrison |first4=Stuart A. |last5=Jordan |first5=Sean F. |last6=Ward |first6=John |last7=Werner |first7=Finn |last8=Lane |first8=Nick |date=2022-10-04 |title=A prebiotic basis for ATP as the universal energy currency |journal=PLOS Biology |language=en |volume=20 |issue=10 |pages=e3001437 |doi=10.1371/journal.pbio.3001437 |issn=1545-7885 |pmc=9531788 |pmid=36194581 |doi-access=free }}</ref> The high concentration of potassium within most life forms could be readily explained that protocells might have evolved sodium-hydrogen antiporters to pump out Na<sup>+</sup> as prebiotic lipid membranes are less permeable to Na<sup>+</sup> than H<sup>+</sup>.<ref>{{Cite journal |last1=Sojo |first1=Víctor |last2=Pomiankowski |first2=Andrew |last3=Lane |first3=Nick |date=2014-08-12 |title=A Bioenergetic Basis for Membrane Divergence in Archaea and Bacteria |journal=PLOS Biology |language=en |volume=12 |issue=8 |pages=e1001926 |doi=10.1371/journal.pbio.1001926 |issn=1545-7885 |pmc=4130499 |pmid=25116890 |doi-access=free }}</ref> If cells originated at these environments, they would have been autotrophs with a Wood-Ljungdahl pathway and incomplete reverse Krebs cycle.<ref>{{Cite journal |last1=Harrison |first1=Stuart A. |last2=Palmeira |first2=Raquel Nunes |last3=Halpern |first3=Aaron |last4=Lane |first4=Nick |date=2022-11-01 |title=A biophysical basis for the emergence of the genetic code in protocells |url=https://www.sciencedirect.com/science/article/pii/S0005272822000664 |journal=Biochimica et Biophysica Acta (BBA) - Bioenergetics |volume=1863 |issue=8 |pages=148597 |doi=10.1016/j.bbabio.2022.148597 |pmid=35868450 |s2cid=250707510 |issn=0005-2728|doi-access=free }}</ref> Mathematical modelling of organic synthesis of carboxylic acids to lipids, nucleotides, amino acids, and sugars, and polymerization reactions are favorable at alkaline hydrothermal vents.<ref>{{Cite journal |last1=Amend |first1=Jan P. |last2=LaRowe |first2=Douglas E. |last3=McCollom |first3=Thomas M. |last4=Shock |first4=Everett L. |date=2013-07-19 |title=The energetics of organic synthesis inside and outside the cell |journal=Philosophical Transactions of the Royal Society B: Biological Sciences |language=en |volume=368 |issue=1622 |pages=20120255 |doi=10.1098/rstb.2012.0255 |issn=0962-8436 |pmc=3685458 |pmid=23754809}}</ref>

===''The Deep Hot Biosphere''===
At the beginning of his 1992 paper ''The Deep Hot Biosphere'', [[Biography:Thomas Gold|Thomas Gold]] referred to ''ocean vents'' in support of his theory that the lower levels of the earth are rich in living biological material that finds its way to the surface.<ref>
{{cite journal
 |last=Gold |first=T.
 |year=1992
 |title=The Deep Hot Biosphere
 |journal=Proceedings of the National Academy of Sciences
 |volume=89 |issue=13 |pages=6045–9
 |pmid=1631089
 |pmc=49434
 |doi=10.1073/pnas.89.13.6045
|bibcode = 1992PNAS...89.6045G |doi-access=free
 }}</ref> He further expanded his ideas in the book ''The Deep Hot Biosphere''.<ref>
{{cite book
 |last=Gold |first=T.
 |title=The deep, hot biosphere
 |publisher=Springer Science+Business Media
 |isbn=978-0-387-95253-6
|title-link=The Deep Hot Biosphere
 |journal=Proceedings of the National Academy of Sciences
 |date=1992
 |volume=89
 |issue=13
 |pages=6045–6049
 |doi=10.1073/pnas.89.13.6045
 |pmid=1631089
 |pmc=49434
 |bibcode=1992PNAS...89.6045G
 |doi-access=free
 }}</ref>

An article on ''abiogenic hydrocarbon production'' in the February 2008 issue of Science journal used data from experiments at the Lost City hydrothermal field to report how the abiotic synthesis of low molecular mass hydrocarbons from mantle derived carbon dioxide may occur in the presence of ultramafic rocks, water, and moderate amounts of heat.<ref>{{cite journal |last1=Proskurowski |first1=G. |last2=Lilley |first2=M. D. |last3=Seewald |first3=J. S. |last4=Fru h-Green |first4=G. L. |last5=Olson |first5=E. J. |last6=Lupton |first6=J. E. |last7=Sylva |first7=S. P. |last8=Kelley |first8=D. S. |title=Abiogenic Hydrocarbon Production at Lost City Hydrothermal Field |journal=Science |date=1 February 2008 |volume=319 |issue=5863 |pages=604–607 |doi=10.1126/science.1151194 |pmid=18239121 |s2cid=22824382 }}</ref>

==Discovery and exploration==
In 1949, a deep water survey reported anomalously hot brines in the central portion of the Red Sea. Later work in the 1960s confirmed the presence of hot, 60&nbsp;°C (140&nbsp;°F), saline brines and associated metalliferous muds. The hot solutions were emanating from an active subseafloor rift. The highly saline character of the waters was not hospitable to living organisms.<ref>
{{cite book
 |last=Degens |first=E. T.
 |year=1969
 |title=Hot Brines and Recent Heavy Metal Deposits in the Red Sea
 |publisher=Springer-Verlag
}} </ref> The brines and associated muds are currently under investigation as a source of mineable precious and base metals.[[File:BlackSmoker.jpg|thumb|Black smokers were first discovered in 1979 on the East Pacific Rise at 21° north latitude]][[File:ALVIN submersible.jpg|thumb|''Alvin'' in 1978, a year after first exploring hydrothermal vents. The rack hanging at the bow holds sample containers.]]

In June 1976, scientists from the [[Organization:Scripps Institution of Oceanography|Scripps Institution of Oceanography]] obtained the first evidence for submarine hydrothermal vents along the Galápagos Rift, a spur of the [[Earth:East Pacific Rise|East Pacific Rise]], on the ''Pleiades II'' expedition, using the Deep-Tow seafloor imaging system.<ref>{{Cite book|title=Sea legs: tales of a woman oceanographer|last=Kathleen.|first=Crane|date=2003|publisher=Westview Press|isbn=9780813342856|location=Boulder, Colo.|oclc=51553643|url-access=registration|url=https://archive.org/details/sealegstalesofwo00cran}}{{page needed|date=August 2019}}</ref> In 1977, the first scientific papers on hydrothermal vents were published<ref>{{Cite web |url=https://oceanservice.noaa.gov/facts/vents.html |title=What is a hydrothermal vent? |website=National Ocean Service |publisher=National Oceanic and Atmospheric Administration |access-date=10 April 2018}}</ref> by scientists from the [[Organization:Scripps Institution of Oceanography|Scripps Institution of Oceanography]]; research scientist Peter Lonsdale published photographs taken from deep-towed cameras,<ref>{{cite journal|last1=Lonsdale|first1=P.|year=1977|title=Clustering of suspension-feeding macrobenthos near abyssal hydrothermal vents at oceanic spreading centers|journal=Deep-Sea Research|volume=24|issue=9|pages=857–863|bibcode=1977DSR....24..857L|doi=10.1016/0146-6291(77)90478-7|s2cid=128478123 }}</ref> and PhD student Kathleen Crane published maps and temperature anomaly data.<ref>{{cite journal |last1=Crane |first1=Kathleen |last2=Normark |first2=William R. |title=Hydrothermal activity and crestal structure of the East Pacific Rise at 21°N |journal=Journal of Geophysical Research |date=10 November 1977 |volume=82 |issue=33 |pages=5336–5348 |doi=10.1029/jb082i033p05336 |bibcode=1977JGR....82.5336C }}</ref> Transponders were deployed at the site, which was nicknamed "Clam-bake", to enable an expedition to return the following year for direct observations with the DSV ''Alvin''.

Chemosynthetic ecosystems surrounding the Galápagos Rift submarine hydrothermal vents were first directly observed in 1977, when a group of marine geologists funded by the [[Organization:National Science Foundation|National Science Foundation]] returned to the Clambake sites. The principal investigator for the submersible study was [[Biography:Jack Corliss|Jack Corliss]] of [[Organization:Oregon State University|Oregon State University]]. Corliss and Tjeerd van Andel from [[Organization:Stanford University|Stanford University]] observed and sampled the vents and their ecosystem on February 17, 1977, while diving in the DSV ''Alvin'', a research submersible operated by the [[Organization:Woods Hole Oceanographic Institution|Woods Hole Oceanographic Institution]] (WHOI).<ref name="divediscover.whoi.edu">{{Cite web|title = Dive and Discover: Expeditions to the Seafloor|url = http://www.divediscover.whoi.edu/ventcd/vent_discovery/thediscovery/timeline_p.html|website = www.divediscover.whoi.edu|access-date = 2016-01-04}}</ref> Other scientists on the research cruise included Richard (Dick) Von Herzen and Robert Ballard of WHOI, Jack Dymond and Louis Gordon of Oregon State University, John Edmond and Tanya Atwater of the [[Organization:Massachusetts Institute of Technology|Massachusetts Institute of Technology]], Dave Williams of the U.S. Geological Survey, and Kathleen Crane of [[Organization:Scripps Institution of Oceanography|Scripps Institution of Oceanography]].<ref name="divediscover.whoi.edu" /><ref>{{Cite news|url=https://www.npr.org/2011/12/05/142678239/the-deep-sea-find-that-changed-biology|title=The Deep-Sea Find That Changed Biology|last1=Davis|first1=Rebecca|date=December 5, 2011|work=NPR.org|access-date=2018-04-09|last2=Joyce|first2=Christopher|language=en}}</ref> This team published their observations of the vents, organisms, and the composition of the vent fluids in the journal Science.<ref>{{cite journal |last1=Corliss |first1=John B. |last2=Dymond |first2=Jack |last3=Gordon |first3=Louis I. |last4=Edmond |first4=John M. |last5=von Herzen |first5=Richard P. |last6=Ballard |first6=Robert D. |last7=Green |first7=Kenneth |last8=Williams |first8=David |last9=Bainbridge |first9=Arnold |last10=Crane |first10=Kathy |last11=van Andel |first11=Tjeerd H. |title=Submarine Thermal Springs on the Galápagos Rift |journal=Science |date=16 March 1979 |volume=203 |issue=4385 |pages=1073–1083 |doi=10.1126/science.203.4385.1073 |pmid=17776033 |bibcode=1979Sci...203.1073C |s2cid=39869961 }}</ref> In 1979, a team of biologists led by J. Frederick Grassle, at the time at [[Organization:Woods Hole Oceanographic Institution|WHOI]], returned to the same location to investigate the biological communities discovered two year earlier.

High temperature hydrothermal vents, the "black smokers", were discovered in spring 1979 by a team from the Scripps Institution of Oceanography using the submersible ''Alvin''. The RISE expedition explored the East Pacific Rise at 21° N with the goals of testing geophysical mapping of the sea floor with the ''Alvin'' and finding another hydrothermal field beyond the Galápagos Rift vents. The expedition was led by Fred Spiess and Ken Macdonald and included participants from the U.S., Mexico and France.<ref name="Spiess et al 1980">{{cite journal |last1=Spiess |first1=F. N. |last2=Macdonald |first2=K. C. |last3=Atwater |first3=T. |last4=Ballard |first4=R. |last5=Carranza |first5=A. |last6=Cordoba |first6=D. |last7=Cox |first7=C. |last8=Garcia |first8=V. M. D. |last9=Francheteau |first9=J. |last10=Guerrero |first10=J. |last11=Hawkins |first11=J. |last12=Haymon |first12=R. |last13=Hessler |first13=R. |last14=Juteau |first14=T. |last15=Kastner |first15=M. |last16=Larson |first16=R. |last17=Luyendyk |first17=B. |last18=Macdougall |first18=J. D. |last19=Miller |first19=S. |last20=Normark |first20=W. |last21=Orcutt |first21=J. |last22=Rangin |first22=C. |title=East Pacific Rise: Hot Springs and Geophysical Experiments |journal=Science |date=28 March 1980 |volume=207 |issue=4438 |pages=1421–1433 |doi=10.1126/science.207.4438.1421 |pmid=17779602 |bibcode=1980Sci...207.1421S |s2cid=28363398 }}</ref> The dive region was selected based on the discovery of sea floor mounds of sulfide minerals by the French CYAMEX expedition in 1978.<ref>{{cite journal | last1 = Francheteau | first1 = J | year = 1979 | title = Massive deep-sea sulphide ore deposits discovered on the East Pacific Rise | url = https://archimer.ifremer.fr/doc/1979/publication-5278.pdf| journal = Nature | volume = 277 | issue = 5697| page = 523 | doi=10.1038/277523a0| bibcode = 1979Natur.277..523F| s2cid = 4356666 }}</ref>&nbsp;Prior to dive operations, expedition member Robert Ballard located near-bottom water temperature anomalies using a deeply towed instrument package. The first dive was targeted at one of those anomalies. On Easter Sunday April 15, 1979 during a dive of ''Alvin'' to 2,600 meters, Roger Larson and [[Biography:Bruce P. Luyendyk|Bruce Luyendyk]] found a hydrothermal vent field with a biological community similar to the Galápagos vents. On a subsequent dive on April 21, William Normark and Thierry Juteau discovered the high temperature vents emitting black mineral particle jets from chimneys; the black smokers.<ref>[https://www.whoi.edu/feature/history-hydrothermal-vents/discovery/1979-2.html WHOI website]</ref> Following this Macdonald and Jim Aiken rigged a temperature probe to ''Alvin'' to measure the water temperature at the black smoker vents. This observed the highest temperatures then recorded at deep sea hydrothermal vents (380±30&nbsp;°C).<ref>{{Cite journal|last1=Macdonald|first1=K. C.|last2=Becker|first2=Keir|last3=Spiess|first3=F. N.|last4=Ballard|first4=R. D.|year=1980|title=Hydrothermal heat flux of the "black smoker" vents on the East Pacific Rise|journal=Earth and Planetary Science Letters|volume=48|issue=1|pages=1–7|doi=10.1016/0012-821X(80)90163-6|bibcode=1980E&PSL..48....1M}}</ref> Analysis of black smoker material and the chimneys that fed them revealed that iron sulfide precipitates are the common minerals in the "smoke" and walls of the chimneys.<ref>{{Cite journal|last1=Haymon|first1=Rachel M.|author-link1=Rachel Haymon|last2=Kastner|first2=Miriam|author-link2=Miriam Kastner|date=1981|title=Hot spring deposits on the East Pacific Rise at 21°N: preliminary description of mineralogy and genesis|journal=Earth and Planetary Science Letters|language=en|volume=53|issue=3|pages=363–381|doi=10.1016/0012-821X(81)90041-8|bibcode=1981E&PSL..53..363H}}</ref>&nbsp;

[[File:Brothers blacksmoker hires.jpg|thumb|A black smoker known as The Brothers]]In 2005, Neptune Resources NL, a mineral exploration company, applied for and was granted 35,000&nbsp;km<sup>2</sup> of exploration rights over the Kermadec Arc in New Zealand's Exclusive Economic Zone to explore for seafloor massive sulfide deposits, a potential new source of lead-zinc-copper sulfides formed from modern hydrothermal vent fields. The discovery of a vent in the Pacific Ocean offshore of Costa Rica, named the Medusa hydrothermal vent field (after the serpent-haired Medusa of [[Religion:Greek mythology|Greek mythology]]), was announced in April 2007.<ref>{{cite press release
 |title=New undersea vent suggests snake-headed mythology
 |date=18 April 2007
 |url=http://www.eurekalert.org/pub_releases/2007-04/du-nuv041707.php
 |publisher=EurekAlert!
 |access-date=2007-04-18
}}</ref> The Ashadze hydrothermal field (13°N on the Mid-Atlantic Ridge, elevation -4200&nbsp;m) was the deepest known high-temperature hydrothermal field until 2010, when a hydrothermal plume emanating from the Beebe<ref>{{cite web|title=Beebe|url=http://vents-data.interridge.org/ventfield/beebe|publisher=Interridge Vents Database}}</ref> site ({{Coord|18|33|N|81|43|W|}}, elevation -5000&nbsp;m) was detected by a group of scientists from NASA [[Organization:Jet Propulsion Laboratory|Jet Propulsion Laboratory]] and Woods Hole Oceanographic Institution. This site is located on the 110&nbsp;km long, ultraslow spreading Mid-Cayman Rise within the [[Earth:Cayman Trough|Cayman Trough]].<ref>{{cite journal
 |url= http://www.geology.wisc.edu/astrobiology/docs/German_et_al_2010_PNAS.pdf
 |title = Diverse styles of submarine venting on the ultraslow spreading Mid-Cayman Rise
 |last = German |first=C. R.
 |date=2010
 |journal=Proceedings of the National Academy of Sciences
 |volume=107 |issue=32 |pages=14020–5
 |bibcode = 2010PNAS..10714020G
 |doi=10.1073/pnas.1009205107
 |pmid=20660317
 |pmc=2922602
 |access-date=2010-12-31
|display-authors=0|doi-access = free
 }}
* {{cite web |date=11 October 2010 |title=Exploring Oceanfloor Hydrothermal Vents- Geysers that Entice Astrobiologists |website=SciGuru |url=http://www.sciguru.com/newsitem/4532/Exploring-Oceanfloor-Hydrothermal-Vents-Geysers-that-Entice-Astrobiologists |archive-url=https://web.archive.org/web/20101018045839/http://www.sciguru.com/newsitem/4532/Exploring-Oceanfloor-Hydrothermal-Vents-Geysers-that-Entice-Astrobiologists/ |archive-date=2010-10-18}}</ref>
In early 2013, the deepest known hydrothermal vents were discovered in the Caribbean Sea at a depth of almost {{convert|5000|m|ft}}.<ref>{{Cite news|url=https://www.bbc.co.uk/news/science-environment-21520404|title=Deepest undersea vents discovered by UK team|journal=BBC News|date=21 February 2013|access-date=21 February 2013|last1=Shukman|first1=David}}</ref>

Oceanographers are studying the volcanoes and hydrothermal vents of the [[Earth:Juan de Fuca Plate|Juan de Fuca]] mid ocean ridge where [[Earth:Plate tectonics|tectonic plates]] are moving away from each other.<ref>{{Cite news|title = The 40,000-Mile Volcano|url = https://www.nytimes.com/2016/01/12/science/midocean-ridges-volcano-underwater.html|newspaper = The New York Times|date = 2016-01-12|access-date = 2016-01-17|issn = 0362-4331|first = William J.|last = Broad}}</ref>

Hydrothermal vents and other geothermal manifestations are currently being explored in the Bahía de Concepción, Baja California Sur, Mexico.<ref>{{cite journal |last1=Leal-Acosta |first1=María Luisa |last2=Prol-Ledesma |first2=Rosa María |title=Caracterización geoquímica de las manifestaciones termales intermareales de Bahía Concepción en la Península de Baja California |trans-title=Geochemical characterization of the intertidal thermal manifestations of Concepción Bay in the Baja California Peninsula |language=es |journal=Boletín de la Sociedad Geológica Mexicana |date=2016 |volume=68 |issue=3 |pages=395–407 |doi=10.18268/bsgm2016v68n3a2 |jstor=24921551 |doi-access=free }}</ref>

==Distribution==
Hydrothermal vents are distributed along the Earth's plate boundaries, although they may also be found at intra-plate locations such as hotspot volcanoes. As of 2009 there were approximately 500 known active submarine hydrothermal vent fields, with about half visually observed at the seafloor and the other half suspected from water column indicators and/or seafloor deposits.<ref>{{cite journal |last1=Beaulieu |first1=Stace E. |last2=Baker |first2=Edward T. |last3=German |first3=Christopher R. |last4=Maffei |first4=Andrew |title=An authoritative global database for active submarine hydrothermal vent fields |journal=Geochemistry, Geophysics, Geosystems |date=November 2013 |volume=14 |issue=11 |pages=4892–4905 |doi=10.1002/2013GC004998 |bibcode=2013GGG....14.4892B |s2cid=53604809 |doi-access=free |hdl=1912/6496 |hdl-access=free }}</ref>

[[File:Distribution of hydrothermal vent fields.png|thumb|upright=2|center|Distribution of hydrothermal vents]]

Rogers et al. (2012)<ref>{{cite journal |last1=Rogers |first1=Alex D. |last2=Tyler |first2=Paul A. |last3=Connelly |first3=Douglas P. |last4=Copley |first4=Jon T. |last5=James |first5=Rachael |last6=Larter |first6=Robert D. |last7=Linse |first7=Katrin |last8=Mills |first8=Rachel A. |last9=Garabato |first9=Alfredo Naveira |last10=Pancost |first10=Richard D. |last11=Pearce |first11=David A. |last12=Polunin |first12=Nicholas V. C. |last13=German |first13=Christopher R. |last14=Shank |first14=Timothy |last15=Boersch-Supan |first15=Philipp H. |last16=Alker |first16=Belinda J. |last17=Aquilina |first17=Alfred |last18=Bennett |first18=Sarah A. |last19=Clarke |first19=Andrew |last20=Dinley |first20=Robert J. J. |last21=Graham |first21=Alastair G. C. |last22=Green |first22=Darryl R. H. |last23=Hawkes |first23=Jeffrey A. |last24=Hepburn |first24=Laura |last25=Hilario |first25=Ana |last26=Huvenne |first26=Veerle A. I. |last27=Marsh |first27=Leigh |last28=Ramirez-Llodra |first28=Eva |last29=Reid |first29=William D. K. |last30=Roterman |first30=Christopher N. |last31=Sweeting |first31=Christopher J. |last32=Thatje |first32=Sven |last33=Zwirglmaier |first33=Katrin |last34=Eisen |first34=Jonathan A. |title=The Discovery of New Deep-Sea Hydrothermal Vent Communities in the Southern Ocean and Implications for Biogeography |journal=PLOS Biology |date=3 January 2012 |volume=10 |issue=1 |pages=e1001234 |doi=10.1371/journal.pbio.1001234 |pmid=22235194 |pmc=3250512 |doi-access=free }}</ref> recognized at least 11 biogeographic provinces of hydrothermal vent systems:
# [[Earth:Mid-Atlantic Ridge|Mid-Atlantic Ridge]] province,
# East Scotia Ridge province,
# northern [[Earth:East Pacific Rise|East Pacific Rise]] province,
# central East Pacific Rise province,
# southern East Pacific Rise province,
# south of the Easter Microplate,
# Indian Ocean province,
# four provinces in the western Pacific and lots more.

==Exploitation==
[[File:Minerals sediments.jpg|thumb|Hydrothermal fluids contain dissolved minerals that cool and react with seawater and then precipitate as sediment on the surrounding seabed.]]
Hydrothermal vents, in some instances, have led to the formation of exploitable mineral resources via the deposition of [[Earth:Seafloor massive sulfide deposits|seafloor massive sulfide deposits]]. The Mount Isa orebody, located in Queensland, {{wipe|Australia}}, is an excellent example.<ref>{{cite journal |last1=Perkins |first1=W. G. |title=Mount Isa silica dolomite and copper orebodies; the result of a syntectonic hydrothermal alteration system |journal=Economic Geology |date=1 July 1984 |volume=79 |issue=4 |pages=601–637 |doi=10.2113/gsecongeo.79.4.601 |bibcode=1984EcGeo..79..601P }}</ref> Many hydrothermal vents are rich in [[Chemistry:Cobalt|cobalt]], [[Chemistry:Gold|gold]], [[Chemistry:Copper|copper]], and rare earth metals essential for electronic components.<ref name="Mining 2015">[http://nautil.us/blog/we-are-about-to-start-mining-hydrothermal-vents-on-the-ocean-floor We Are About to Start Mining Hydrothermal Vents on the Ocean Floor] {{Webarchive|url=https://web.archive.org/web/20220117175811/https://nautil.us/blog/we-are-about-to-start-mining-hydrothermal-vents-on-the-ocean-floor |date=2022-01-17 }}. ''Nautilus''; Brandon Keim. 12 September 2015.</ref> Hydrothermal venting on the [[Earth:Archean|Archean]] seafloor is considered to have formed Algoma-type [[Earth:Banded iron formation|banded iron formation]]s, which have been a source of [[Earth:Iron ore|iron ore]].<ref>{{cite web|url=https://goldschmidtabstracts.info/2014/807.pdf|title=Categorizing mineralogy and geochemistry of Algoma type banded iron formation, Temagami, ON|last1=Ginley|first1=S.|last2=Diekrup|first2=D.|last3=Hannington|first3=M.|year=2014|access-date=2017-11-14}}</ref>

Recently, mineral exploration companies, driven by the elevated price activity in the base metals sector during the mid-2000s, have turned their attention to the extraction of mineral resources from hydrothermal fields on the seafloor. Significant cost reductions are, in theory, possible.<ref>{{cite web
 |date=2006
 |title=The dawn of deep ocean mining
 |url=http://www.theallineed.com/ecology/06030301.htm
 |work=The All I Need
 |access-date=2008-08-21
 |archive-date=2021-03-03
 |archive-url=https://web.archive.org/web/20210303013200/https://www.theallineed.com/ecology/06030301.htm
 |url-status=dead
 }}</ref>

In countries such as {{wipe|Japan}}, where mineral resources are primarily derived from international imports,<ref>{{Cite web|url=https://www.tradecommissioner.gc.ca/japan-japon/market-reports-etudes-de-marches/0001460.aspx?lang=eng|title=Mining Sector Market Overview 2016 – Japan|last=Government of Canada|first=Global Affairs Canada|date=2017-01-23|website=www.tradecommissioner.gc.ca|access-date=2019-03-11}}</ref> there is a particular push for the extraction of seafloor mineral resources.<ref>{{cite news |title=Liberating Japan's resources |url=https://www.japantimes.co.jp/opinion/2012/06/25/commentary/japan-commentary/liberating-japans-resources/ |work=The Japan Times |date=25 June 2012 }}</ref> The world's first "large-scale" mining of hydrothermal vent mineral deposits was carried out by Japan Oil, Gas and Metals National Corporation (JOGMEC) in August – September, 2017. JOGMEC carried out this operation using the Research Vessel [[Engineering:List of research vessels by country|Hakurei]]. This mining was carried out at the 'Izena hole/cauldron' vent field within the hydrothermally active back-arc basin known as the [[Earth:Okinawa Trough|Okinawa Trough]], which contains 15 confirmed vent fields according to the InterRidge Vents Database.

Two companies are currently engaged in the late stages of commencing to mine seafloor massive sulfides (SMS). [[Company:Nautilus Minerals|Nautilus Minerals]] is in the advanced stages of commencing extraction from its Solwarra deposit, in the Bismarck Archipelago, and Neptune Minerals is at an earlier stage with its Rumble II West deposit, located on the Kermadec Arc, near the Kermadec Islands. Both companies are proposing using modified existing technology. Nautilus Minerals, in partnership with Placer Dome (now part of [[Company:Barrick Gold|Barrick Gold]]), succeeded in 2006 in returning over 10&nbsp;metric tons of mined SMS to the surface using modified drum cutters mounted on an ROV, a world first.<ref>
{{cite press release
 |date=25 May 2006
 |title=Nautilus Outlines High Grade Au - Cu Seabed Sulphide Zone
 |url=http://www.nautilusminerals.com/s/Media-NewsReleases.asp?ReportID=138787&_Type=News-Releases&_Title=Nautilus-Outlines-High-Grade-Au-Cu-Seabed-Sulphide-Zone
 |publisher=Nautilus Minerals
 |url-status=dead
 |archive-url=https://web.archive.org/web/20090129204714/http://www.nautilusminerals.com/s/Media-NewsReleases.asp?ReportID=138787&_Type=News-Releases&_Title=Nautilus-Outlines-High-Grade-Au-Cu-Seabed-Sulphide-Zone
 |archive-date=29 January 2009
}}</ref> Neptune Minerals in 2007 succeeded in recovering SMS sediment samples using a modified oil industry suction pump mounted on an ROV, also a world first.<ref>
{{cite web
 |url=http://www.neptuneminerals.com|title=Neptune Minerals|access-date=August 2, 2012}}</ref>

Potential seafloor mining has environmental impacts, including dust plumes from mining machinery affecting filter-feeding organisms,<ref name="Mining 2015"/> collapsing or reopening vents, [[Chemistry:Methane clathrate|methane clathrate]] release, or even sub-oceanic land slides.<ref>{{cite web
 |last=Birney
 |first=K.
 |title=Potential Deep-Sea Mining of Seafloor Massive Sulfides: A case study in Papua New Guinea
 |url=http://www.bren.ucsb.edu/research/documents/VentsThesis.pdf
 |publisher=University of California, Santa Barbara, B
 |display-authors=0
 |access-date=2009-11-22
 |archive-date=2015-09-23
 |archive-url=https://web.archive.org/web/20150923194430/http://www.bren.ucsb.edu/research/documents/VentsThesis.pdf
 |url-status=dead
 }}</ref>[[File:Alvinocaris.jpg|thumb|A swarm of shrimp from the genus ''Alvinocaris'' near a vent in the Pacific Ring of Fire]]There are also potential environmental effects from the tools needed for mining these hydrothermal vent ecosystems, including noise pollution and anthropogenic light. Hydrothermal vent system mining would require the use of both submerged mining tools on the seafloor, including remotely operated underwater vehicles (ROVs), as well as surface support vessels on the ocean surface.<ref name="Miller">{{Cite journal |last1=Miller |first1=Kathryn A. |last2=Thompson |first2=Kirsten F. |last3=Johnston |first3=Paul |last4=Santillo |first4=David |date=2018 |title=An Overview of Seabed Mining Including the Current State of Development, Environmental Impacts, and Knowledge Gaps |journal=Frontiers in Marine Science |volume=4 |doi=10.3389/fmars.2017.00418 |issn=2296-7745|doi-access=free |hdl=10871/130175 |hdl-access=free }}</ref> Inevitably, through the operation of these machines, some level of noise will be created, which presents a problem for hydrothermal vent organisms because, as they are up to 12,000 feet below the surface of the ocean, they experience very little sound.<ref name="Miller" /> As a result of this, these organisms have evolved to have highly sensitive hearing organs, so if there is a sudden increase in noise, such as that created by mining machinery, there is potential to damage these auditory organs and harm the vent organisms.<ref name="Miller" /> It is also important to consider that many studies have been able to show that a large percent of benthic organisms communicate using very low-frequency sounds; therefore, increasing ambient noise levels on the seafloor could potentially mask communication between the organisms and alter behavioral patterns.<ref name="Miller" /> Similar to how deep-sea SMS mining tools create noise pollution, they also create anthropogenic light sources on the seafloor (from mining tools) and the ocean surface (from surface support vessels). Organisms at these hydrothermal vent systems are in the [[Earth:Aphotic zone|aphotic zone]] of the ocean and have adapted to very low light conditions. Studies on deep sea shrimp have shown the potential for flood lights used on the sea floor used in studying the vent systems to cause permanent retinal damage,<ref name="Miller" /> warranting further research into the potential risk to other vent organisms. On top of the risk presented to deep-sea organisms, the surface support vessels use nocturnal anthropogenic lighting.<ref name="Miller" /> Research has shown that this type of lighting on the ocean surface can disorient seabirds and cause fallout, where they fly toward the anthropogenic light and become exhausted or collide with man-made objects, resulting in injury or death.<ref name="Miller" /> There is consideration for both aquatic and land organisms when evaluating the environmental effects of hydrothermal vent mining.

There are three mining waste processes, known as the side cast sediment release, dewatering process, and sediment shift or disturbance, that would be expected with the deep-sea mining processes and could result in the accumulation of a sediment plume or cloud, which can have substantial environmental implications. The side cast sediment release is a process that would occur at the seafloor and would involve the move of material at the seafloor by the submerged ROV's and would most likely contribute to the formation of sediment plumes at the seafloor.<ref name=Miller/> The idea of side cast release is that the ROV's would discard economically invaluable material to the side of the mining sight before transporting the sulfide material to the supporting vessel at the surface. The goal of this process is to reduce the amount of material being transferred to the surface and minimize land-based.<ref name=Miller/> The dewatering process is a mining waste process that would most likely contribute to the formation of sediment plumes from the surface. The method of mine waste disposal releases water from the ship that may have been obtained during the extraction and transport of the material from the seafloor to the surface. The third contribution to the formation of the sediment plume or cloud would be sediment disturbance and release. This mining waste contribution is mainly associated with the mining activity on the seafloor associated with the movement of the ROVs and the destructive disturbance of the seafloor as part of the mining process itself.<ref name=Miller/>

The two main environmental concerns as a result of these waste mining processes that contribute to the formation of the sediment plume would be the release of heavy metals and increased amounts of sediment released. The release of heavy metals is mainly associated with the dewatering process that would take place on board the ship at the surface of the water.<ref name=Miller/> The main problem associated with dewatering is that it is not just the release of seawater re-entering the water column. Heavy metals such as copper and cobalt that would be sourced from the material extracted on the seafloor are also mixed in with the water that is released into the water column. The first environmental concern associated with the release of heavy metals is that it has the potential to change ocean chemistry within that localized water column area. The second concern would be that some of the heavy metals that could be released can have some level of toxicity to not only organisms inhabiting that area but also organisms passing through the mining site area.<ref name=Miller/> The concerns surrounding increased sediment release are mainly related to the other two mining waste processes, side cast sediment and seafloor sediment disturbance. The main environmental concern would be the smothering of organisms below as a result of redistributing large amounts of sediment to other areas on the seafloor, which could potentially threaten the population of organisms inhabiting the area. Redistribution of large quantities of sediment can also affect the feeding and gas exchange processes between organisms, posing a serious threat to the population. Finally, these processes can also increase the sedimentation rate on the seafloor, resulting in a predicted minimum of 500&nbsp;m per every 1–10&nbsp;km.<ref name=Miller/>

A large amount of work is currently being engaged in by both of the above-mentioned companies to ensure that the potential environmental impacts of seafloor mining are well understood and control measures are implemented before exploitation commences.<ref>
{{cite journal |date=January 2007 |title=Treasures from the deep |url=http://www.rsc.org/chemistryworld/issues/2007/january/treasuresdeep.asp |journal=Chemistry World}}</ref> However, this process has been arguably hindered by the disproportionate distribution of research effort among vent ecosystems; the best studied and understood hydrothermal vent ecosystems are not representative of those targeted for mining.<ref>{{Cite journal| last1=Amon| first1=Diva| last2=Thaler| first2=Andrew D. |date=2019-08-06 |title=262 Voyages Beneath the Sea: a global assessment of macro- and megafaunal biodiversity and research effort at deep-sea hydrothermal vents | journal=PeerJ| language=en|volume=7| pages=e7397| doi=10.7717/peerj.7397| pmid=31404427| pmc=6688594| issn=2167-8359| doi-access=free}}</ref>

Attempts have been made in the past to exploit minerals from the seafloor. The 1960s and 1970s saw a great deal of activity (and expenditure) in the recovery of [[Earth:Manganese nodule|manganese nodule]]s from the [[Earth:Abyssal plain|abyssal plain]]s, with varying degrees of success. This does demonstrate, however, that the recovery of minerals from the seafloor is possible and has been possible for some time. Mining of manganese nodules served as a cover story for the elaborate attempt in 1974 by the CIA to raise the sunken Soviet submarine ''K-129'' using the Glomar Explorer, a ship purpose-built for the task by [[Biography:Howard Hughes|Howard Hughes]].<ref>[https://www.bbc.co.uk/news/resources/idt-sh/deep_sea_mining The secret on the ocean floor]. David Shukman, ''BBC News''. 19 February 2018.</ref> The operation was known as [[Unsolved:Project Azorian|Project Azorian]], and the cover story of seafloor mining of manganese nodules may have served as the impetus to propel other companies to make the attempt.

==Conservation==
The conservation of hydrothermal vents has been the subject of sometimes heated discussion in the oceanographic community for the last 20&nbsp;years.<ref>
{{cite journal
 |last1=Devey
 |first1=C.W.
 |last2=Fisher
 |first2=C.R.
 |last3=Scott
 |first3=S.
 |year=2007
 |title=Responsible Science at Hydrothermal Vents
 |url=http://www.tos.org/oceanography/issues/issue_archive/issue_pdfs/20_1/20.1_devey_et_al.pdf
 |journal=Oceanography
 |volume=20
 |issue=1
 |pages=162–72
 |doi=10.5670/oceanog.2007.90
 |url-status=dead
 |archive-url=https://web.archive.org/web/20110723054816/http://www.tos.org/oceanography/issues/issue_archive/issue_pdfs/20_1/20.1_devey_et_al.pdf
 |archive-date=2011-07-23
}}</ref> It has been pointed out that it may be that those causing the most damage to these fairly rare habitats are scientists.<ref>
{{cite journal
 |last1=Johnson |first1=M.
 |year=2005
 |title=Oceans need protection from scientists too
 |pages=105
 |journal=Nature
 |volume=433 |issue=7022
 |doi=10.1038/433105a
 |pmid=15650716
 |bibcode = 2005Natur.433..105J
|s2cid=52819654
 |doi-access=free
 }}</ref><ref>
{{cite journal
 |last1=Johnson |first1=M.
 |year=2005
 |title=Deepsea vents should be world heritage sites
 |url=https://mpanews.openchannels.org/news/mpa-news/mpa-perspective-deep-sea-vents-should-be-world-heritage-sites
 |journal=MPA News
 |volume=6 |page=10
}}</ref> There have been attempts to forge agreements over the behaviour of scientists investigating vent sites, but, although there is an agreed code of practice, there is no formal international and legally binding agreement.<ref>
{{cite journal
 |last1=Tyler |first1=P.
 |last2=German|first2=C.
 |last3=Tunnicliff |first3=V.
 |year=2005
 |title=Biologists do not pose a threat to deep-sea vents
 |journal=Nature
 |volume=434 |issue=7029 |page=18
 |bibcode = 2005Natur.434...18T
 |doi=10.1038/434018b
 |pmid=15744272
|s2cid=205033213
 |doi-access=free
 }}</ref>

Conservation of hydrothermal vent ecosystems after the fact of mining of an active system would depend on the recolonization of chemosynthetic bacteria, and therefore the continuation of the hydrothermal vent fluid as it is the main hydrothermal energy source.<ref name="Miller"/> It is very difficult to get an idea of the effects of mining on the hydrothermal vent fluid because there have been no large scale studies done.<ref name="Miller"/> However, there have been studies on the recolonization of these vent ecosystems after volcanic destruction.<ref name="Lauren S 2018">{{Cite journal |last1=Mullineaux |first1=Lauren S. |last2=Metaxas |first2=Anna |last3=Beaulieu |first3=Stace E. |last4=Bright |first4=Monika |last5=Gollner |first5=Sabine |last6=Grupe |first6=Benjamin M. |last7=Herrera |first7=Santiago |last8=Kellner |first8=Julie B. |last9=Levin |first9=Lisa A. |last10=Mitarai |first10=Satoshi |last11=Neubert |first11=Michael G. |last12=Thurnherr |first12=Andreas M. |last13=Tunnicliffe |first13=Verena |last14=Watanabe |first14=Hiromi K. |last15=Won |first15=Yong-Jin |date=2018-02-21 |title=Exploring the Ecology of Deep-Sea Hydrothermal Vents in a Metacommunity Framework |journal=Frontiers in Marine Science |volume=5 |pages=49 |doi=10.3389/fmars.2018.00049 |issn=2296-7745|doi-access=free |hdl=1912/10332 |hdl-access=free }}</ref> From these we can develop insight on the potential effects of [[Earth:Deep sea mining|mining destruction]], and have learned it took 3–5 years for bacteria to recolonize the area, and around 10 years for megafauna to return.<ref name="Lauren S 2018"/> It was also found that there was a shift in the composition of species in the ecosystem compared to before the destruction, and the presence of immigrant species.<ref name="Miller"/> Though further research into the effects of sustained seafloor SMS mining on species recolonization is needed.

== Geochronological dating ==
Common methods to find out the ages of hydrothermal vents are to date the [[Chemistry:Sulfide mineral|sulfide]] (e.g., [[Chemistry:Pyrite|pyrite]]) and [[Chemistry:Sulfate mineral|sulphate minerals]] (e.g., [[Chemistry:Baryte|baryte]]).<ref name=":0">{{Cite journal |last1=You |first1=C.-F. |last2=Bickle |first2=M. J. |date=August 1998 |title=Evolution of an active sea-floor massive sulphide deposit |url=http://www.nature.com/articles/29279 |journal=Nature |language=en |volume=394 |issue=6694 |pages=668–671 |doi=10.1038/29279 |bibcode=1998Natur.394..668Y |s2cid=4379956 |issn=0028-0836}}</ref><ref name=":1">{{Cite journal |last1=Noguchi |first1=Takuroh |last2=Shinjo |first2=Ryuichi |last3=Ito |first3=Michihiro |last4=Takada |first4=Jitsuya |last5=Oomori |first5=Tamotsu |date=2011 |title=Barite geochemistry from hydrothermal chimneys of the Okinawa Trough: insight into chimney formation and fluid/sediment interaction |url=http://www.jstage.jst.go.jp/article/jmps/106/1/106_090825/_article |journal=Journal of Mineralogical and Petrological Sciences |language=en |volume=106 |issue=1 |pages=26–35 |doi=10.2465/jmps.090825 |bibcode=2011JMPeS.106...26N |s2cid=129266361 |issn=1345-6296|doi-access=free }}</ref><ref name=":2">{{Cite journal |last1=Takamasa |first1=Asako |last2=Nakai |first2=Shun'ichi |last3=Sato |first3=Fumihiro |last4=Toyoda |first4=Shin |last5=Banerjee |first5=Debabrata |last6=Ishibashi |first6=Junichiro |date=February 2013 |title=U–Th radioactive disequilibrium and ESR dating of a barite-containing sulfide crust from South Mariana Trough |url=https://linkinghub.elsevier.com/retrieve/pii/S1871101412001896 |journal=Quaternary Geochronology |language=en |volume=15 |pages=38–46 |doi=10.1016/j.quageo.2012.12.002|bibcode=2013QuGeo..15...38T |s2cid=129020357 }}</ref><ref name=":3">{{Citation |last1=Fujiwara |first1=Taisei |title=ESR Dating of Barite in Sea-Floor Hydrothermal Sulfide Deposits in the Okinawa Trough |date=2015 |url=http://link.springer.com/10.1007/978-4-431-54865-2_29 |work=Subseafloor Biosphere Linked to Hydrothermal Systems |pages=369–386 |editor-last=Ishibashi |editor-first=Jun-ichiro |place=Tokyo |publisher=Springer Japan |language=en |doi=10.1007/978-4-431-54865-2_29 |isbn=978-4-431-54864-5 |access-date=2022-05-18 |last2=Toyoda |first2=Shin |last3=Uchida |first3=Ai |last4=Ishibashi |first4=Jun-ichiro |last5=Nakai |first5=Shun’ichi |last6=Takamasa |first6=Asako |editor2-last=Okino |editor2-first=Kyoko |editor3-last=Sunamura |editor3-first=Michinari|doi-access=free }}</ref><ref name=":4">{{Cite journal |last1=Tsang |first1=Man-Yin |last2=Toyoda |first2=Shin |last3=Tomita |first3=Makiko |last4=Yamamoto |first4=Yuzuru |date=2022-08-01 |title=Thermal stability and closure temperature of barite for electron spin resonance dating |url=https://www.sciencedirect.com/science/article/pii/S1871101422000802 |journal=Quaternary Geochronology |language=en |volume=71 |pages=101332 |doi=10.1016/j.quageo.2022.101332 |bibcode=2022QuGeo..7101332T |s2cid=248614826 |issn=1871-1014}}</ref> Common dating methods include [[Physics:Radiometric dating|radiometric dating]]<ref name=":0" /><ref name=":1" /> and [[Earth:Electron spin resonance dating|electron spin resonance dating]].<ref name=":2" /><ref name=":3" /><ref name=":4" /> Different dating methods have their own limitations, assumptions and challenges. General challenges include the high purity of extracted [[Earth:Mineral|mineral]]s required for dating, the age range of each dating method, heating above [[Physics:Closure temperature|closure temperature]]s erasing ages of older minerals, and multiple episodes of mineral formation resulting in a mixture of ages. In environments with multiple phases of [[Earth:Mineral|mineral]] formation, generally, [[Earth:Electron spin resonance dating|electron spin resonance dating]] gives the average age of the bulk mineral while [[Physics:Radiometric dating|radiometric dates]] are biased to the ages of younger phases because of the decay of parent nuclei. These explain why different methods can give different ages to the same sample and why the same hydrothermal chimney can have samples with different ages.<ref name=":3" /><ref name=":4" /><ref>{{Citation |last1=Uchida |first1=Ai |title=226Ra-210Pb and 228Ra-228Th Dating of Barite in Submarine Hydrothermal Sulfide Deposits Collected at the Okinawa Trough and the Southern Mariana Trough |date=2015 |url=https://doi.org/10.1007/978-4-431-54865-2_47 |work=Subseafloor Biosphere Linked to Hydrothermal Systems: TAIGA Concept |pages=607–615 |editor-last=Ishibashi |editor-first=Jun-ichiro |place=Tokyo |publisher=Springer Japan |language=en |doi=10.1007/978-4-431-54865-2_47 |isbn=978-4-431-54865-2 |access-date=2022-05-18 |last2=Toyoda |first2=Shin |last3=Ishibashi |first3=Jun-ichiro |last4=Nakai |first4=Shun’ichi |s2cid=129751032 |editor2-last=Okino |editor2-first=Kyoko |editor3-last=Sunamura |editor3-first=Michinari|doi-access=free }}</ref>

==See also==
{{ocean habitat topics}}
* {{annotated link|Biology:Abiogenesis|ake=Origin of life}}
* {{annotated link|Earth:Brine pool}}
* {{annotated link|Earth:Endeavour Hydrothermal Vents}}
* [[Biology:Hydrogen sulfide chemosynthesis|Hydrogen sulfide chemosynthesis]] - system of generating energy used in hydrothermal vents
* Lost City Hydrothermal Field
* {{annotated link|Earth:Magic Mountain (British Columbia)}}
* {{annotated link|Earth:9 North|9° North}}
* {{annotated link|Earth:Submarine volcano}}
* {{annotated link|Earth:Volcanogenic massive sulfide ore deposit|aka=VMS deposit}}
*[[Earth:Deep sea mining|Deep sea mining]]

==References==
{{Reflist}}

==Further reading==
* {{cite book |doi=10.1016/b978-0-12-409548-9.09050-3 |chapter=Hydrothermal Vents at Mid-Ocean Ridges |title=Reference Module in Earth Systems and Environmental Sciences |year=2014 |last1=Haymon |first1=R.M. |isbn=978-0-12-409548-9 }}
* {{cite journal |last1=Van Dover |first1=C. L. |last2=Humphris |first2=SE |last3=Fornari |first3=D |last4=Cavanaugh |first4=CM |last5=Collier |first5=R |last6=Goffredi |first6=SK |last7=Hashimoto |first7=J |last8=Lilley |first8=MD |last9=Reysenbach |first9=AL |last10=Shank |first10=TM |last11=Von Damm |first11=KL |last12=Banta |first12=A |last13=Gallant |first13=RM |last14=Gotz |first14=D |last15=Green |first15=D |last16=Hall |first16=J |last17=Harmer |first17=TL |last18=Hurtado |first18=LA |last19=Johnson |first19=P |last20=McKiness |first20=ZP |last21=Meredith |first21=C |last22=Olson |first22=E |last23=Pan |first23=IL |last24=Turnipseed |first24=M |last25=Won |first25=Y |last26=Young CR |first26=3rd |last27=Vrijenhoek |first27=RC |title=Biogeography and Ecological Setting of Indian Ocean Hydrothermal Vents |journal=Science |date=13 September 2001 |volume=294 |issue=5543 |pages=818–823 |doi=10.1126/science.1064574 |pmid=11557843 |bibcode = 2001Sci...294..818V |s2cid=543841 |doi-access=free }}
* {{Cite book|author1=Van Dover |author2=Cindy Lee |title=The Ecology of Deep-Sea Hydrothermal Vents|publisher=Princeton University Press|year=2000|isbn=978-0-691-04929-8}}
* {{cite journal |last1=Beatty |first1=J. T. |last2=Overmann |first2=J. |last3=Lince |first3=M. T. |last4=Manske |first4=A. K. |last5=Lang |first5=A. S.|author6-link=Robert E. Blankenship |last6=Blankenship |first6=R. E. |last7=Van Dover |first7=C. L. |last8=Martinson |first8=T. A. |last9=Plumley |first9=F. G. |title=An obligately photosynthetic bacterial anaerobe from a deep-sea hydrothermal vent |journal=Proceedings of the National Academy of Sciences |date=20 June 2005 |volume=102 |issue=26 |pages=9306–9310 |doi=10.1073/pnas.0503674102 |pmid=15967984 |pmc=1166624 |bibcode=2005PNAS..102.9306B |doi-access=free }}
* [http://www.saudiaramcoworld.com/issue/198205/silver.from.the.sea.htm Glyn Ford and Jonathan Simnett, ''Silver from the Sea'', September/October 1982, Volume 33, Number 5, Saudi Aramco World] Accessed 17 October 2005
* Ballard, Robert D., 2000, ''The Eternal Darkness'', Princeton University Press.
* {{cite journal |last1=Csotonyi |first1=J. T. |last2=Stackebrandt |first2=E. |last3=Yurkov |first3=V. |title=Anaerobic Respiration on Tellurate and Other Metalloids in Bacteria from Hydrothermal Vent Fields in the Eastern Pacific Ocean |journal=Applied and Environmental Microbiology |date=4 July 2006 |volume=72 |issue=7 |pages=4950–4956 |doi=10.1128/AEM.00223-06 |pmid=16820492 |pmc=1489322 |bibcode=2006ApEnM..72.4950C }}
* {{cite journal |last1=Koschinsky |first1=Andrea |last2=Garbe-Schönberg |first2=Dieter |last3=Sander |first3=Sylvia |last4=Schmidt |first4=Katja |last5=Gennerich |first5=Hans-Hermann |last6=Strauss |first6=Harald |title=Hydrothermal venting at pressure-temperature conditions above the critical point of seawater, 5°S on the Mid-Atlantic Ridge |journal=Geology |date=2008 |volume=36 |issue=8 |pages=615 |doi=10.1130/G24726A.1 |bibcode=2008Geo....36..615K }}
* {{Cite web|author=Catherine Brahic|date=4 August 2008|url=https://www.newscientist.com/article/dn14456-found-the-hottest-water-on-earth.html|title=Found: The hottest water on Earth|publisher=New Scientist|access-date=18 June 2010}}

==External links==
* [https://vents-data.interridge.org/ InterRidge Vents Database] – global database of the locations of known active submarine hydrothermal vent fields, hosted by [[Earth:InterRidge|InterRidge]]
* [http://oceanexplorer.noaa.gov Ocean Explorer] – public outreach site for explorations sponsored by the [[Organization:Office of Ocean Exploration and Research|US Office of Ocean Exploration]]
* [https://www.youtube.com/watch?v=QH5keLsOM2o Video] by [[Engineering:EV Nautilus|EV Nautilus]]
* [https://www.youtube.com/watch?v=-amsWf-_-Go Video] by [[Organization:Schmidt Ocean Institute|Schmidt Ocean]]

{{aquatic ecosystem topics|expanded=none}}
{{modelling ecosystems|expanded=none}}
{{physical oceanography|expanded=other}}
{{Biomes}}

[[Category:Economic geology]]

{{Sourceattribution|Hydrothermal vent}}