Black smoker 204512 225470406 2008-07-13T21:29:29Z 24.15.215.186 [[image:Nur04506.jpg|right|thumb|A black smoker in the Atlantic Ocean]] A '''black smoker''' or sea vent, is a type of [[hydrothermal vent]] found on the [[ocean floor]]. They are formed in fields hundreds of meters wide when [[superheating|superheated]] water from below [[Earth]]'s [[Crust (geology)|crust]] comes through the ocean floor. This water is rich in dissolved [[mineral]]s from the crust, most notably [[sulfide]]s. When it comes in contact with cold ocean water, many minerals precipitate, forming a black chimney-like structure around each vent. The metal sulfides that are deposited can become [[Volcanogenic massive sulfide ore deposit|massive sulfide ore deposits]] in time. Black smokers were discovered in 1977 on the [[East Pacific Rise]] by scientists from [[Scripps Institution of Oceanography]]. They were observed using a small submersible vehicle called [[DSV Alvin|Alvin]]. Now black smokers are known to exist in the [[Atlantic Ocean|Atlantic]] and [[Pacific Ocean|Pacific]] Oceans, at an average depth of 2100&nbsp;[[metre|meters]]. The water at the vent can reach 400&nbsp;[[Celsius|°C]], but does not usually boil at the seafloor because the water pressure at that depth exceeds the [[vapor pressure]] of the aqueous [[solution]]. The water is also extremely [[acid]]ic, often having a [[pH]] value as low as 2.8&nbsp;&mdash; approximately that of [[vinegar]]. Each year 1.4 &times; 10<sup>14</sup> kg (370 trillion gallons) of water is passed through black smokers. == Ecosystems == [[Image:Deep sea vent chemistry diagram.jpg|thumb|right|400px| Deep sea vent [[ biogeochemical ]] [http://oceanexplorer.noaa.gov/explorations/04fire/background/chemistry/media/chemistry_600.html cycle diagram].]] Although life is very sparse at these depths, black smokers are the center of entire [[ecosystem]]s. Sunlight is nonexistent, so many organisms&nbsp;&mdash; such as [[archaea]] and [[extremophile]]s&nbsp;&mdash; convert the heat, [[methane]], and [[sulfur]] compounds provided by black smokers into energy through a process called [[chemosynthesis]]. More complex life forms like [[clam]]s and [[Giant tube worm|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 [[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 2500&nbsp;m. No sunlight penetrates that far into the waters. Instead, the bacteria, part of the [[Green sulfur bacteria|Chlorobiaceae]] family, use the faint glow from the black smoker for [[photosynthesis]]. This is the first organism discovered in nature to use a light other than sunlight for photosynthesis (Beatty, ''et al.'', 2005). New and unusual species are constantly being discovered in the neighborhood of black smokers: for instance, the [[Pompeii worm]] in the 1980s, and a [[scaly-foot gastropod]] in 2001 during an expedition to [[Indian Ocean]]'s Kairei hydrothermal vent field. The latter uses iron sulfides ([[pyrite]] and greigite) for the structure of its dermal ''[[sclerites]]'' (hardened body parts), instead of [[calcium carbonate]]. The extreme pressure of 2500&nbsp;m of water (approximately 25&nbsp;[[megapascal]]s or 246.73 [[Atmosphere_(unit)|atmosphere]]) is thought to play a role in stabilizing iron sulfide for biological purposes. This armor plating probably serves as a defense against the venomous ''[[radula]]'' (teeth) of [[predator]]y [[snail]]s in that community. This snail, which is unique in its kind, has not yet been named. ==See also== *[[Cold seep]] *[[Hydrothermal vent]] *[[DSV Alvin|Alvin submersible]] *[[Lost City (hydrothermal field)|Lost City]] *[[Robert Ballard]] {{Commonscat|Black smokers}} ==External links== * [http://oceanexplorer.noaa.gov Ocean Explorer (www.oceanexplorer.noaa.gov)] - Public outreach site for explorations sponsored by the Office of Ocean Exploration. * [http://oceanexplorer.noaa.gov/gallery/gallery.html NOAA, Ocean Explorer Gallery], [http://oceanexplorer.noaa.gov/explorations/06fire/logs/photolog/photolog.html Submarine Ring of Fire 2006 Gallery], [http://oceanexplorer.noaa.gov/explorations/04fire/logs/photolog/photolog.html Submarine Ring of Fire 2004 Gallery] - A rich collection of images, video, audio and [http://oceanexplorer.noaa.gov/explorations/podcast/oceanexplorer_podcast.xml podcast]. * [http://www.youtube.com/oceanexplorergov NOAA, Ocean Explorer YouTube Channel] * [http://oceanexplorer.noaa.gov/explorations/06fire/background/marianaarc/marianaarc.html Submarine Ring of Fire, Mariana Arc] - Explore the volcanoes of the Mariana Arc, Submarine Ring of Fire. *[http://www.whoi.edu/institutes/doei/viewTopic.do?o=read&id=119 Hydrothermal Vent Systems Information from the Deep Ocean Exploration Institute], [[Woods Hole Oceanographic Institution]] *[http://www.whoi.edu/oceanus/viewArticle.do?id=2400&archives=true How to Build a Hydrothermal Vent Chimney] == References == <div class="references-small"> {{Nofootnotes|date=February 2008}} * {{cite journal | author=Van Dover CL, Humphris SE, Fornari D, Cavanaugh CM, Collier R, Goffredi SK, Hashimoto J, Lilley MD, Reysenbach AL, Shank TM, Von Damm KL, Banta A, Gallant RM, Gotz D, Green D, Hall J, Harmer TL, Hurtado LA, Johnson P, McKiness ZP, Meredith C, Olson E, Pan IL, Turnipseed M, Won Y, Young CR 3rd, Vrijenhoek RC | title=Biogeography and ecological setting of Indian Ocean hydrothermal vents | journal= Science | volume=294 | issue=5543 | year=2001 | pages=818–23 | doi=10.1126/science.1064574 | pmid=11557843}} PMID 11557843 * {{cite book | author=Van Dover, Cindy Lee | title=The Ecology of Deep-Sea Hydrothermal Vents | publisher=Princeton University Press | year=2000 | id=ISBN 0-691-04929-7}} * {{cite journal | author=Beatty JT, Overmann J, Lince MT, Manske AK, Lang AS, Blankenship RE, Van Dover CL, Martinson TA, Plumley FG. | title=An obligately photosynthetic bacterial anaerobe from a deep-sea hydrothermal vent | journal=Proceedings of the National Academy of Sciences | volume=102 | issue=26 | year=2005 | pages=9306–10 | doi=10.1073/pnas.0503674102 | pmid=15967984}} PMID 15967984 </div> [[Category:Hydrothermal vents]] [[cs:Černý kuřák]] [[de:Black Smoker]] [[et:Must tossutaja]] [[it:Black smoker]] [[ja:ブラックスモーカー]] [[nl:Black smoker]] [[ru:Гидротермальные источники срединно-океанических хребтов]] [[sk:Čierny fajčiar]] [[fi:Musta savuttaja]]