View source for Lake Vostok

{{short description|Antarctica's largest known subglacial lake}}
{{Good article}}
{{Use dmy dates|date=September 2020}}
{{Infobox body of water
 |name = Lake Vostok
 | other_name = {{langx|ru|'''озеро Восток'''}}
 |image = Lake Vostok Sat Photo color.jpg
 |caption = Radar satellite image of Lake Vostok
 |image_bathymetry =
 |caption_bathymetry =
 |coords = {{coord|77|30|S|106|00|E|type:waterbody_region:AQ_scale:4000000|display=inline,title}}
 |lake_type = [[Ancient lake]], [[subglacial lake|Subglacial]] [[rift lake]]
 |inflow =
 |outflow =
 |catchment =
 |basin_countries = [[Antarctica]]
 |length = {{Convert|250|km|mi|-1|abbr=on}}<ref name='ASOC'/> 
 |width = {{Convert|50|km|mi|-1|abbr=on}}<ref name='ASOC'/> 
 |area = {{Convert|12500|km2|mi2|-1|abbr=on}}
 |depth = {{Convert|432|m|ft|0|abbr=on}}
 |max-depth = {{Convert|510|m|ft|-2|abbr=on}}<ref name='ASOC'/> to {{Convert|900|m|ft|-2|abbr=on}}<ref name=facts/>
 |volume = {{Convert|5400|km3|mi3|-2|abbr=on}}<ref name=facts/> ± {{Convert|1600|km3|mi3|-2|abbr=on}}
 |residence_time = 13,300&nbsp;yrs
 |shore =
 |elevation = c. {{Convert|-500|m|ft|-2|abbr=on}}
 |islands = 1
 |cities = [[Vostok Station]]
 <!--      Map      -->
| pushpin_map             = Antarctica
| pushpin_label_position  = 
| pushpin_map_alt         = Location of Lake Vostok in Antarctica.
| pushpin_map_caption     = 
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| website            = 
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'''Lake Vostok''' ({{langx|ru|озеро Восток|ozero Vostok}}) is the largest of [[Antarctica]]'s 675 known<ref>{{cite journal |last1=Livingstone |first1=S.J. |last2=Li |first2=Y. |last3=Rutishauser |first3=A. |last4=Sanderson |first4=R.J. |last5=Winter |first5=K. |last6=Mikucki |first6=J.A. |last7=Björnsson |first7=H. |last8=Bowling |first8=J.S. |last9=Chu |first9=W. |last10=Dow |first10=C.F. |last11=Fricker |first11=H.A. |title=Subglacial lakes and their changing role in a warming climate |journal=Nature Reviews Earth & Environment |date=February 2022 |volume=3 |issue=2 |pages=106–124 |doi=10.1038/s43017-021-00246-9|bibcode=2022NRvEE...3..106L |hdl=10044/1/93683 |hdl-access=free }}</ref> [[subglacial lake]]s.
Lake Vostok is located at the southern [[Pole of Cold]], beneath Russia's [[Vostok Station]] under the surface of the central [[East Antarctic Ice Sheet]], which is at {{Convert|3488|m|ft|0|abbr=on}} [[sea level|above mean sea level]]. The surface of this [[fresh water]] lake is approximately {{Convert|4000|m|ft|-2|abbr=on}} under the surface of the ice, which places it at approximately {{Convert|500|m|ft|-2|abbr=on}} below sea level.

Measuring {{Convert|250|km|mi|-1|abbr=on}} long by {{Convert|50|km|mi|-1|abbr=on}} wide at its widest point,<ref name="ASOC" /> it covers an area of {{Convert|12500|km2|sqmi|-1|abbr=on}} making it the [[List of lakes by area|16th largest lake by surface area]]. With an average depth of {{Convert|432|m|ft|0|abbr=on}}, it has an estimated volume of {{Convert|5400|km3|mi3|-2|abbr=on}},<ref name="facts">{{cite web |url=https://www.ldeo.columbia.edu/~mstuding/facts_about_lakes.html |title=Subglacial Lake Facts |publisher=Ldeo.columbia.edu |access-date=7 February 2012 |archive-url=https://web.archive.org/web/20120102111109/https://www.ldeo.columbia.edu/~mstuding/facts_about_lakes.html |archive-date=2 January 2012}}</ref> making it the [[List of lakes by volume|6th largest lake by volume]].

The lake is divided into two deep [[Endorheic basin|basins]] by a ridge. The liquid water depth over the ridge is about {{Convert|200|m|ft|-2|abbr=on}}, compared to roughly {{Convert|400|m|ft|-2|abbr=on}} deep in the northern basin and {{Convert|800|m|ft|-2|abbr=on}} deep in the southern.

The lake is named after Vostok Station, which in turn is named after the ''[[Vostok (sloop-of-war)|Vostok]]'' (Восток), a [[sloop-of-war]], which means "East" in Russian.<ref name="vostokcoin">{{cite book |title=Watercraft on World Coins: Europe, 1800-2005 |publisher=The Alpha Press |last=Dotan |first=Yossi |date=2007 |page=220 |isbn=978-1-898595-49-6 |quote=The 900-ton Vostok was built in 1818 at the Okhta Shipyard of Stoke and Kolodnin in St. Petersburg. }}</ref> The existence of a subglacial lake in the Vostok region was first suggested by Russian geographer [[Andrey Kapitsa]] based on seismic soundings made during the [[Soviet Antarctic Expedition]]s in 1959 and 1964 to measure the thickness of the ice sheet.<ref name=appeal/><ref name=lenta-kapitsa/> The continued research by Russian and British scientists<ref name=lenta-kapitsa/><ref>{{cite web |url=https://newsru.com/russia/03aug2011/kapica.html |title=Умер ученый Андрей Капица, сделавший в Антарктиде одно из крупнейших открытий XX века |language=ru |trans-title=The author of one of the greatest discoveries, Andrey Kapitsa, died |publisher=NEWSru.com |date=3 August 2011 |access-date=25 August 2012 }}</ref> led to the final confirmation of the existence of the lake in 1993 by J. P. Ridley using [[European Remote-Sensing Satellite|ERS-1]] laser altimetry.<ref name=appeal/>

The overlying ice provides a continuous [[Paleoclimatology|paleoclimatic record]] of 400,000&nbsp;years, although the lake water itself may have been isolated for 15<ref name="January 2011">{{cite news |first=K |last=Moskvitch |title=Lake Vostok drilling in Antarctic 'running out of time' |date=27 January 2011 |url=https://www.bbc.co.uk/news/science-environment-12275979 |work=[[BBC News]] |access-date=28 January 2011 }}</ref><ref>{{cite news |author=Casey Kazan |title=Secrets of Antarctica's 15-Million Year-Old Lake -A Galaxy Classic |date=5 December 2007 |url=https://www.dailygalaxy.com/my_weblog/2007/12/secret-life-o-1.html |work=The Daily Galaxy |access-date=20 August 2012 |archive-url=https://web.archive.org/web/20080316014449/https://www.dailygalaxy.com/my_weblog/2007/12/secret-life-o-1.html |archive-date=16 March 2008 }}</ref> to 25 million years.<ref name="Studinger">{{cite web |url=https://www.ldeo.columbia.edu/~mstuding/vostok.html |title=Subglacial Lake Vostok |first=M |last=Studinger |date=2008 |publisher=Columbia University |access-date=1 February 2011 }}</ref> On 5 February 2012, a team of Russian scientists completed the longest ever [[ice core]] of {{Convert |3768 |m |ft |-2 |abbr=on}} and pierced the ice shield to the surface of the lake.<ref name=Kaufman>{{cite news |author=Marc Kaufman |title=Russians drill into previously untouched Lake Vostok below Antarctic glacier |date=6 February 2012 |url=https://www.washingtonpost.com/national/health-science/russians-drill-into-previously-untouched-lake-vostok-below-antarctica/2012/02/06/gIQAGziNuQ_story.html |newspaper=The Washington Post |access-date=6 February 2012 }}</ref>

The first core of freshly frozen lake ice was obtained on 10 January 2013 at a depth of {{convert|3406|m|ft|abbr=on}}.<ref>{{cite news |author=Amir Khan |title=Buried Lake Reached: Lake Vostok Water Retrieved After 14 Million Years |date=15 January 2013 |url=https://www.isciencetimes.com/articles/4375/20130115/buried-lake-reached-vostok-water-retrieved-14-million-years.htm |work=International Science Times |access-date=22 January 2013 |archive-url=https://web.archive.org/web/20130119234157/https://www.isciencetimes.com/articles/4375/20130115/buried-lake-reached-vostok-water-retrieved-14-million-years.htm |archive-date=19 January 2013 }}</ref> However, as soon as the ice was pierced, water from the underlying lake gushed up the [[borehole]], mixing it with the [[Freon]] and [[kerosene]] used to keep the borehole from freezing.<ref name="SECRETS">{{cite news |author=Douglas Fox |title=Hidden Antarctic Lake Spills Its Secrets |date=February 2013 |url=https://www.discovermagazine.com/environment/35-hidden-antarctic-lake-spills-its-secrets |work=Discover Magazine |access-date=2021-02-19}}</ref><ref name="DNA analyses"/> A new borehole was drilled and an allegedly pristine water sample was obtained in January 2015.{{citation needed|date=December 2020}} The Russian team plans to eventually lower a probe into the lake to collect water samples and sediments from the bottom. It is hypothesized that unusual forms of life could be found in the lake's liquid layer, a [[fossil water]] reserve. Because Lake Vostok may contain an environment sealed off below the ice for millions of years, the conditions could resemble those of ice-covered oceans hypothesized to exist on [[Jupiter]]'s moon [[Europa (moon)|Europa]],<ref name="SECRETS"/><ref>{{cite web |url=https://solarsystem.nasa.gov/moons/jupiter-moons/europa/in-depth/ |title=Europa: Ocean Moon |website=solarsystem.nasa.gov |publisher=[[NASA]] |access-date=2021-02-19}}</ref> and [[Saturn]]'s moon [[Enceladus]].<ref>{{cite news |url=https://www.dailygalaxy.com/my_weblog/2014/07/the-geysers-of-enceladus-will-saturns-moon-reveal-a-second-genesis.html |title=The Geysers of Enceladus - Will Saturn's Moon Reveal a "Second Genesis"? |work=The Daily Galaxy |date=31 July 2014 |access-date=2015-10-27 |archive-url=https://web.archive.org/web/20151117023547/https://www.dailygalaxy.com/my_weblog/2014/07/the-geysers-of-enceladus-will-saturns-moon-reveal-a-second-genesis.html |archive-date=17 November 2015 }}</ref>

==Discovery==
[[File:LakeVostok-Location.jpg|thumb |left |Location of Lake Vostok in [[East Antarctica]]]]
Russian scientist [[Pyotr Kropotkin (geologist)|Peter Kropotkin]] first proposed the idea of fresh water under Antarctic [[ice sheet]]s at the end of the 19th century.<ref>"Research on the [[Ice age]]", ''Notices of the Imperial Russian Geographical Society'', 1876.</ref> He theorized that the tremendous pressure exerted by the cumulative mass of thousands of vertical meters of ice could decrease the melting point at the lowest portions of the ice sheet to the [[Pressure melting point|point where the ice would become liquid water]]. Kropotkin's theory was further developed by Russian [[glaciology|glaciologist]] [[Igor Zotikov]], who wrote his [[Doctor of Philosophy|PhD]] thesis on this subject in 1967.<ref name=appeal/>

Russian geographer [[Andrey Kapitsa]] used seismic soundings in the region of [[Vostok Station]] made during the [[Soviet Antarctic Expedition]] in 1959 and 1964 to measure the thickness of the ice sheet.<ref name=appeal>{{cite web |url=https://www.asoc.org/storage/documents/Other_publications/asoc_vostok_statement041408.pdf |title=Appeal to the Duma on Lake Vostok, Antarctica |date=14 April 2008 |work=Antarctic and Southern Ocean Coalition |access-date=10 February 2011 |archive-date=4 March 2016 |archive-url=https://web.archive.org/web/20160304055957/https://www.asoc.org/storage/documents/Other_publications/asoc_vostok_statement041408.pdf }}</ref> Kapitsa was the first to suggest the existence of a subglacial lake in the region,<ref name=lenta-kapitsa>{{cite web |url=https://lenta.ru/news/2011/08/03/kapitsa/ |script-title=ru:Скончался первооткрыватель озера Восток в Антарктиде |trans-title=Discoverer of the Lake Vostok in the Antarctica died |publisher=[[Lenta.ru]] |language=ru |date=3 March 2011 }}</ref> and the subsequent research confirmed his hypothesis.<ref name="rgs">{{cite news|date=3 August 2011|title=Andrey Kapitsa dies in Moscow|work=[[Russian Geographical Society]]|url=https://int.rgo.ru/news/andrey-kapitsa-dies-in-moscow/|archive-url=https://web.archive.org/web/20131202222218/https://int.rgo.ru/news/andrey-kapitsa-dies-in-moscow/|archive-date=2 December 2013|url-status=live|access-date=4 August 2011|quote=In cooperation with other scientists, Andrey Kapitsa made one of the most remarkable geographical discoveries of the 20th century – a vast lake beneath the Antarctic ice, near the polar research station Vostok.}}</ref>

When British scientists in Antarctica performed airborne [[ice-penetrating radar]] surveys in the early 1970s, they detected unusual radar readings at the site which suggested the presence of a liquid freshwater lake below the ice.<ref>{{cite journal |last1=Oswald |first1=GKA |last2=Robin |first2=G. de Q. |date=1973 |title=Lakes beneath the Antarctic Ice Sheet |journal=Nature |volume=245 |issue=5423 |pages=251–4 |doi=10.1038/245251a0 |bibcode=1973Natur.245..251O |s2cid=4271414 }}</ref> In 1991, Jeff Ridley, a [[remote sensing]] specialist with the [[Mullard Space Science Laboratory]] at [[University College London]], directed the [[European Remote-Sensing Satellite|ERS-1]] satellite to turn its high-frequency array toward the center of the Antarctic [[ice cap]]. The data from ERS-1 confirmed the findings from the 1973 British surveys,<ref name="Morton">{{cite magazine|last=Morton|first=O|date=April 2000|title=Ice Station Vostok|url=https://www.wired.com/2000/04/vostok/|magazine=Wired|access-date=25 July 2020}}</ref> but these new data were not published in the ''[[Journal of Glaciology]]'' until 1993. [[Space-based radar]] revealed that this subglacial body of fresh water is one of the largest lakes in the world, and one of some 140 subglacial lakes in Antarctica. Russian and British scientists delineated the lake in by integrating a variety of data, including airborne ice-penetrating [[radar imaging]] observations and space-based radar altimetry, and the discovery of the lake was published in the science journal ''[[Nature (journal)|Nature]]'' on 20 June 1996.<ref>{{cite journal|url=https://www.nature.com/articles/381684a0|title=A large deep freshwater lake beneath the ice of central East Antarctica|journal=Nature|language=English|date=20 June 1996|doi=10.1038/381684a0|access-date=7 February 2021|last1=Kapitsa|first1=A. P.|last2=Ridley|first2=J. K.|last3=De q. Robin|first3=G.|last4=Siegert|first4=M. J.|last5=Zotikov|first5=I. A.|volume=381|issue=6584|pages=684–686|bibcode=1996Natur.381..684K |s2cid=4335254}}</ref> It has been confirmed that the lake contains large amounts of liquid water under the more than {{convert|3|km|mi|sp=us|adj=mid|-thick}} ice cap. The lake has at least 22 [[Glacier cave|cavities of liquid water]], averaging {{convert|10|km|mi|sp=us|0}} each.<ref name="FüttererKleinschmidt2006">{{cite book |first1=Dieter |last1=Fütterer |first2=Georg |last2=Kleinschmidt |title=Antarctica: contributions to global Earth sciences: proceedings of the IX International Symposium of Antarctic Earth Sciences Potsdam, 2003 |url=https://books.google.com/books?id=PcJcEvPFpT4C&pg=PA138 |date=2006 |publisher=Birkhäuser |isbn=978-3-540-30673-3 |page=138 |access-date=15 May 2011 }}</ref>

The station after which the lake is named commemorates the ''[[Vostok (sloop-of-war)|Vostok]]'' (Восток), the 900-ton [[sloop-of-war]] ship sailed by one of the discoverers of Antarctica, [[Russian explorers|Russian explorer]] Admiral [[Fabian Gottlieb von Bellingshausen|Fabian von Bellingshausen]].<ref name="vostokcoin" /> Because the word ''Vostok'' means "East" in Russian, the names of the station and lake also reflect the fact that they are located in East Antarctica.

In 2005 an island was found in the central part of the lake.<ref name=island>{{cite news |first=D |last=Whitehouse |title=Russia to resume Vostok drilling |date=25 May 2005 |url=https://news.bbc.co.uk/2/hi/science/nature/4577627.stm |work=BBC News |access-date=28 January 2011 }}</ref> Then, in January 2006, the discovery of two nearby smaller lakes under the ice cap was published; they are named [[90 Degrees East]] and [[Sovetskaya (lake)|Sovetskaya]].<ref>Robin Bell and Michael Studinger, [[Geophysical]] researchers from [[Columbia University]], published in ''[[Geophysical Research Letters]]''</ref> It is suspected that these Antarctic subglacial lakes may be connected by a network of subglacial rivers. [[Centre for Polar Observation & Modelling]] glaciologists propose that many of the subglacial lakes of Antarctica are at least temporarily interconnected.<ref name="Siegert"/> Because of varying water pressure in individual lakes, large subsurface rivers may suddenly form and then force large amounts of water through the solid ice.<ref name="Siegert"/>

==Geological history==
{{further |Geology of Antarctica |Gondwana}}
Africa separated from Antarctica around 160&nbsp;million years ago, followed by the [[Indian subcontinent]], in the early [[Cretaceous]] (about 125 million years ago). About 66 million years ago, Antarctica (then connected to Australia) still had a [[tropics|tropical]] to [[subtropics|subtropical]] climate, complete with [[marsupial]] [[fauna]] and an extensive [[temperate rainforest]].<ref>{{cite news|first=L |last=O'Hanl |title=Antarctic Forests Reveal Ancient Trees |date=5 November 2004 |url=https://dsc.discovery.com/news/briefs/20041101/leaves.html?ct=6817.32046957226 |work=Discovery News |access-date=31 January 2011 |archive-url=https://web.archive.org/web/20110628230903/https://dsc.discovery.com/news/briefs/20041101/leaves.html?ct=6817.32046957226 |archive-date=28 June 2011 }}</ref><ref>{{cite news|date=2012|title=Frozen in time: Fossils from the Antarctic|work=[[British Antarctic Survey]]|url=https://www.antarctica.ac.uk//about_antarctica/geography/rock/fossil-collection.php|archive-url=https://web.archive.org/web/20150709062807/https://www.antarctica.ac.uk//about_antarctica/geography/rock/fossil-collection.php|archive-date=2015-07-09|url-status=live|access-date=20 August 2012}}</ref>

The Lake Vostok basin is a small ({{convert|50|km|mi|sp=us|adj=mid|-wide}}) [[Tectonics|tectonic]] feature within the overall setting of a several-hundred-kilometer-wide [[continental collision]] zone between the [[Gamburtsev Mountain Range]], a subglacial [[mountain range]] and the [[Dome C]] region.<ref>{{cite web |url=https://www.ldeo.columbia.edu/~mstuding/tectonic_control.html |title=Tectonic Control of Subglacial Lakes |author=Michael Studinger |date=2006 |work=Lamont–Doherty Earth Observatory |publisher=Lamon–Doherty Earth Observatory, [[Columbia University]] |access-date=20 August 2012 |archive-url=https://web.archive.org/web/20120614090825/https://www.ldeo.columbia.edu/~mstuding/tectonic_control.html |archive-date=14 June 2012 }}</ref> The lake water is cradled on a bed of [[Glaciolacustrine deposits|sediments]] {{convert|70|m|ft|sp=us}} thick, offering the possibility that they contain a unique record of the climate and life in Antarctica before the ice cap formed.<ref name=Morton/><ref>{{cite news |author=Robert Lee Hotz |title=Miles Below Antarctic Ice, a Freshwater Lake May Harbor Ancient Life |date=3 March 2001 |url=https://www.earthinstitute.columbia.edu/news/story3_2_01a.html |work=Los Angeles Times|access-date=20 August 2012 }}</ref>

==Traits==
[[File:Wostok-Station core32.jpg|thumb |[[Vostok Station]]]]
The lake water is estimated to have been sealed off under the thick ice sheet about 15 million years ago.<ref name="January 2011" /> Initially, it was thought that the same water had made up the lake since the time of its formation, giving a [[Residence time (fluid dynamics)|residence time]] in the order of one million years.<ref name="Siegert"/> Later research by [[Robin Bell (scientist)|Robin Bell]] and Michael Studinger from the [[Lamont–Doherty Earth Observatory]] of [[Columbia University]] suggested that the water of the lake is continually freezing and being carried away by the motion of the [[Antarctic ice sheet]], while being replaced by water melting from other parts of the ice sheet in these high pressure conditions. This resulted in an estimate that the entire volume of the lake is replaced every 13,300&nbsp;years – its effective mean residence time.<ref name="bell_2003">{{cite web |url=https://www.earthinstitute.columbia.edu/news/2003/story08-27-03.html |publisher=[[The Earth Institute]] at [[Columbia University]] |title=Columbia University Scientists Present Long Sought Opportunities to Safely Explore Life Within Earth's Most Ancient and Inaccessible Ecosystem |date=21 March 2002 |access-date=31 March 2010 }}</ref>

The coldest naturally occurring temperature ever observed on Earth, {{convert|-89|°C|°F|0|abbr=on|lk=on}}, was recorded at Vostok Station on 21 July 1983.<ref name="January 2011" /> The average water temperature is calculated to be around {{convert|-3|°C|°F|0|abbr=on}}; it remains liquid below the normal [[melting point|freezing point]] because of high pressure from the weight of the ice above it.<ref>{{cite web|date=2012|title=Lake Vostok, Antarctica|url=https://www.lakelubbers.com/lake-vostok-978/|access-date=25 July 2020|publisher=Lakelubbers LLC}}</ref> [[Geothermal gradient|Geothermal]] heat from the Earth's interior may warm the bottom of the lake,<ref name="vincent">{{cite book |first1=Warwick F. |last1=Vincent |first2=Johanna |last2=Laybourn-Parry |title=Polar lakes and rivers: limnology of Arctic and Antarctic aquatic ecosystems |year=2008 |publisher=Oxford University Press |page=129 |doi=10.1093/acprof:oso/9780199213887.001.0001 |isbn=978-0-19-921388-7 }}</ref><ref>{{cite web |url=https://www.sale.scar.org/key-programs/limnology-the-long-version.html |archive-url=https://archive.today/20121203051651/https://www.sale.scar.org/key-programs/limnology-the-long-version.html |archive-date=3 December 2012 |title=Subglacial Lake Environments |access-date=6 February 2012}}</ref><ref>{{cite book |first=Igorʹ Alekseevich |last=Zotikov |title=The Antarctic subglacial Lake Vostok: glaciology, biology and planetology |publisher=Springer Praxis Books / Geophysical Sciences |date=26 July 2006 |url=https://books.google.com/books?id=imR2nsVPTWcC&q=lake+vostok+oxygen+geothermal&pg=PA85 |isbn=978-3-540-42649-3 |access-date=6 February 2012 }}</ref> while the ice sheet itself insulates the lake from cold temperatures on the surface.

Lake Vostok is an [[oligotroph]]ic extreme environment, one that is expected to be [[Supersaturation|supersaturated]] with nitrogen and oxygen,<ref>{{cite journal |title=Insights into hydrological regime of Lake Vostok from differential behavior of deuterium and oxygen-18 in accreted ice |journal=Journal of Geophysical Research |date=2010 |first1=AA |display-authors=4 |last1=Ekaykin |first2=VY |last2=Lipenkov |first3=JR |last3=Petit |first4=S |last4=Johnsen |first5=J |last5=Jouzel |first6=V |last6=Masson-Delmotte |volume=115 |issue=C05003 |pages=C05003 |doi=10.1029/2009JC005329 |bibcode=2010JGRC..115.5003E|s2cid=129827337 |url=https://hal-insu.archives-ouvertes.fr/insu-00653223/file/Journal%20of%20Geophysical%20Research%20Oceans%20-%202010%20-%20Ekaykin%20-%20Insights%20into%20hydrological%20regime%20of%20Lake%20Vostok%20from.pdf |archive-url=https://web.archive.org/web/20220518064709/https://hal-insu.archives-ouvertes.fr/insu-00653223/file/Journal%20of%20Geophysical%20Research%20Oceans%20-%202010%20-%20Ekaykin%20-%20Insights%20into%20hydrological%20regime%20of%20Lake%20Vostok%20from.pdf |archive-date=2022-05-18 |url-status=live }}</ref><ref name="Bulat">{{cite journal |title=Searching for life in extreme environments relevant to Jovian's Europa: Lessons from subglacial ice studies at Lake Vostok (East Antarctica) |journal=Advances in Space Research |date=2010 |first1=SA |display-authors=4 |last1=Bulat |first2=Irina A. |last2=Alekhina |first3=Dominique |last3=Marie |first4=Jean |last4=Martins |first5=Jean Robert |last5=Petit  |doi=10.1016/j.asr.2010.11.024 |bibcode=2011AdSpR..48..697B |volume=48 |issue=4 |pages=697–701 }}</ref> measuring {{convert|2.5|L|cuft}} of nitrogen and oxygen per {{convert|1|kg|lb|abbr=on}} of water,<ref name="Burton">{{cite news |first=K |last=Burton |title=Researchers find antarctic lake water will fizz like a soda |date=11 August 2003 |url=https://www.nasa.gov/centers/ames/news/releases/2003/03_57AR.html |work=NASA |access-date=28 January 2011 |archive-date=11 January 2011 |archive-url=https://web.archive.org/web/20110111115654/https://www.nasa.gov/centers/ames/news/releases/2003/03_57AR.html }}</ref> that is 50 times higher than those typically found in ordinary freshwater lakes on Earth's surface. The sheer weight and pressure around {{convert|345|bar|psi|lk=on}} of the continental ice cap on top of Lake Vostok is estimated to contribute to the high gas concentration.<ref>{{cite journal |title=Physical, chemical and biological processes in Lake Vostok and other Antarctic subglacial lakes |journal=Nature |first1=MJ |display-authors=4 |last1=Siegert |first2=J. Cynan |last2=Ellis-Evans |first3=Martyn |last3=Tranter |first4=Christoph |last4=Mayer |first5=Jean-Robert |last5=Petit |first6=Andrey |last6=Salamatin |first7=John C. |last7=Priscu |volume=414 |pages=603–9 |doi=10.1038/414603a |date=2001 |issue=6864 |pmid=11740551 |s2cid=4423510 }}</ref>

Besides dissolving in the water, oxygen and other gases are trapped in a type of structure called a [[Clathrate hydrate|clathrate]]. In clathrate structures, gases are enclosed in an icy cage and look like packed snow. These structures form at the high-pressure depths of Lake Vostok and would become unstable if brought to the surface.<ref name="Siegert">{{cite journal |last=Siegert |first=MJ |title=The identification, examination and exploration of Antarctic subglacial lakes |journal=Sci Prog |volume=83 |issue=3 |pages=223–42 |date=2000 |pmid=11077478 }}</ref><ref name="Burton" />

In April 2005, German, Russian, and Japanese researchers found that the lake has [[tide]]s.<ref>{{cite journal |title=The response of the subglacial Lake Vostok, Antarctica, to tidal and atmospheric pressure forcing |journal=[[Geophysical Journal International]] |first1=A |display-authors=4 |last1=Wendt |first2=Reinhard |last2=Dietrich |first3=Jens |last3=Wendt |first4=Mathias |last4=Fritsche |first5=Valery |last5=Lukin |first6=Alexander |last6=Yuskevich |first7=Andrey |last7=Kokhanov |first8=Anton |last8=Senatorov |first9=Kazuo |last9=Shibuya |first10=Koichiro |last10=Doi |volume=161 |issue=1 |pages=41–9 |doi=10.1111/j.1365-246X.2005.02575.x |date=2005 |bibcode=2005GeoJI.161...41W |doi-access=free }}</ref> Depending on the position of the Sun and the Moon, the surface of the lake rises about {{convert|12|mm|in|abbr=on}}.<ref>{{cite journal |title=Evidence for tides in the subglacial Lake Vostok, Antarctica |journal=Geophysical Research Letters |date=2001 |first1=R |last1=Dietrich |first2=K. |last2=Shibuya |first3=A. |last3=Pötzsch |first4=T. |last4=Ozawa |volume=28 |issue=15 |pages=2971–4 |doi=10.1029/2001GL013230 |bibcode=2001GeoRL..28.2971D |s2cid=140606157 }}</ref> The lake is under complete darkness, under {{convert|355|bar|psi|abbr=on}} of pressure, and expected to be rich in oxygen, so there is speculation that any organisms inhabiting the lake could have evolved in a manner unique to this environment.<ref name=Morton/><ref name="Burton" /> There is a 1 [[Tesla (unit)|microtesla]] [[magnetic anomaly]] on the east coast of the lake, spanning {{Convert |105 |by |75 |km |mi |abbr=on}}. Researchers hypothesize that the anomaly may be caused by a thinning of the Earth's crust in that location.<ref>{{cite news |title=SOARing Below Vostok |first=Kristan Hutchinson |last=Sabbatini |url=https://antarcticsun.usap.gov/pastIssues/2000-2001/2001_02_04.pdf |archive-url=https://web.archive.org/web/20100609094511/https://antarcticsun.usap.gov/pastIssues/2000-2001/2001_02_04.pdf |archive-date=2010-06-09 |url-status=live |newspaper=The Antarctic Sun |date=4 February 2001 |access-date=3 February 2012 }}</ref>

Living ''[[Hydrogenophilaceae|Hydrogenophilus thermoluteolus]]'' micro-organisms have been found in Lake Vostok's deep ice core drillings; they are an [[Extant taxon|extant]] surface-dwelling species.<ref name="Bulat" /><ref name="Bull2004">{{cite book |first=Alan T. |last=Bull |title=Microbial diversity and bioprospecting |url=https://books.google.com/books?id=cDeuY0ON6RQC&pg=PA139 |date=2004 |publisher=ASM Press |isbn=978-1-55581-267-6 |pages=139– |access-date=15 May 2011 }}</ref> This suggests the presence of a [[deep biosphere]] utilizing a geothermal system of the bedrock encircling the subglacial lake. There is optimism that microbial life in the lake may be possible despite high pressure, constant cold, low nutrient input, potentially high oxygen concentration and an absence of sunlight.<ref name="Bulat" /><ref>{{cite journal |title=DNA signature of thermophilic bacteria from the aged accretion ice of Lake Vostok, Antarctica: implications for searching for life in extreme icy environments |journal=[[International Journal of Astrobiology]] |date=August 2004 |first1=SA |display-authors=4 |last1=Bulat |first2=Irina A. |last2=Alekhina |first3=Michel |last3=Blot |first4=Jean-Robert |last4=Petit |first5=Martine |last5=de Angelis |first6=Dietmar |last6=Wagenbach |first7=Vladimir Ya. |last7=Lipenkov |first8=Lada P. |last8=Vasilyeva |first9=Dominika M. |last9=Wloch |first10=Dominique |last10=Raynaud |first11=Valery V. |last11=Lukin |volume=3 |issue=1 |pages=1–12 |doi=10.1017/S1473550404001879 |bibcode=2004IJAsB...3....1B |doi-access=free }}</ref> [[Jupiter]]'s moon [[Europa (moon)|Europa]] and [[Saturn]]'s moon [[Enceladus (moon)|Enceladus]] may also harbor lakes or oceans below a thick crust of ice. Any confirmation of life in Lake Vostok could strengthen the prospect for the presence of life on icy moons.<ref name="Bulat" /><ref name="tdg">{{cite web |url=https://www.dailygalaxy.com/my_weblog/2007/12/secret-life-o-1.html |title=Mystery of Antarctica's 15-Million Year-Old Lake |date=4 December 2007 |work=The Daily Galaxy |access-date=5 December 2007 |archive-url=https://web.archive.org/web/20080316014449/https://www.dailygalaxy.com/my_weblog/2007/12/secret-life-o-1.html |archive-date=16 March 2008 }}</ref>

==Research==
[[File:GISP2 team photo core37.jpeg|thumb |[[Ice core]]s drilled at Vostok Station, which is seen in the background]]
Researchers working at Vostok Station produced one of the world's longest [[ice core]]s in 1998. A joint Russian, French, and United States team drilled and analyzed the core, which is {{convert|3623|m|ft|abbr=on}} long. Ice samples from cores drilled close to the top of the lake have been assessed to be as old as 420,000&nbsp;years. The assumption is that the lake has been sealed from the surface since the ice sheet was formed 15 million years ago.  Drilling of the core was deliberately halted roughly {{convert |100|m|ft|sigfig=1|abbr=on}}<ref name="Jouzel">{{cite journal |display-authors=4 |last1=Jouzel |first1=J |last2=Petit |first2=JR |last3=Souchez |first3=R |last4=Barkov |first4=NI |last5=Lipenkov |first5=VY |last6=Raynaud |first6=D |last7=Stievenard |first7=M |last8=Vassiliev |first8=NI |last9=Verbeke |first9=V |last10=Vimeux |first10=F |title=More than 200&nbsp;meters of lake ice above subglacial Lake Vostok, Antarctica |journal=Science |volume=286 |issue=5447 |pages=2138–41 |date=1999 |pmid=10591641 |doi=10.1126/science.286.5447.2138 }}</ref> above the suspected boundary between the ice sheet and the liquid waters of the lake. This was to prevent contamination of the lake with the 60-ton column of [[Chlorofluorocarbon|Freon]] and [[kerosene]] used to prevent the borehole from collapsing and freezing over.<ref name=Morton/>

From this core, specifically from ice that is thought to have formed from lake water freezing onto the base of the ice sheet, [[extremophile|extremophile microbes]] were found, suggesting that the lake water supports life. Scientists suggested that the lake could possess a unique habitat for ancient [[bacteria]] with an isolated microbial [[gene pool]] containing characteristics developed perhaps 500,000&nbsp;years ago.<ref>{{cite journal |display-authors=4 |last1=Priscu |first1=JC |last2=Adams |first2=EE |last3=Lyons |first3=WB |last4=Voytek |first4=MA |last5=Mogk |first5=DW |last6=Brown |first6=RL |last7=McKay |first7=CP |last8=Takacs |first8=CD |last9=Welch |first9=KA |last10=Wolf |first10=CF |last11=Kirshtein |first11=JD |last12=Avci |first12=R |title=Geomicrobiology of subglacial ice above Lake Vostok, Antarctica |journal=Science |volume=286 |issue=5447 |pages=2141–4 |date=1999 |pmid=10591642 |doi=10.1126/science.286.5447.2141 |s2cid=20376311 }}</ref>

[[File:Lake Vostok drill 2011.jpg|thumb|left |An artist's cross-section of Lake Vostok's drilling]]
In January 2011, the head of the Russian Antarctic Expedition, Valery Lukin, announced that his team had only {{Convert |50 |m |ft |-2 |abbr=on}} of ice left to drill in order to reach the water.<ref name="January 2011" /> The researchers then switched to a new thermal drill head with a "clean" [[silicone oil]] fluid to drill the rest of the way.<ref>{{cite news |first=L |last=Edwards |title=Russians hope to reach Lake Vostok for the first time soon |date=10 January 2011 |url=https://www.physorg.com/news/2011-01-russians-lake-vostok.html |work=Physorg |access-date=29 January 2011 }}</ref> Instead of drilling all the way into the water, they said they would stop just above it when a sensor on the thermal drill detected free water. At that point, the drill was to be stopped and extracted from the bore hole. Removal of the drill would lower the pressure beneath it, drawing water into the hole to be left to freeze, creating a plug of ice in the bottom of the hole.<ref>{{cite journal |last1=Vasiliev |first1=N. I. |last2=Talalay |first2=Pavel G. |title=Twenty years of drilling the deepest hole in ice |journal=Scientific Drilling |volume=11 |pages=41–45 |doi=10.2204/iodp.sd.11.05.2011 |date=2011 |issue=11, March 2011 |doi-access=free }}</ref> Drilling stopped on 5 February 2011 at a depth of {{convert|3720|m|ft|abbr=on}} so that the research team could make it off the ice before the beginning of the Antarctic winter season. The drilling team left by aircraft on 6 February 2011.<ref>{{cite news |first=B |last=Israel |title=Lake Vostok Drilling Mission Iced |date=7 February 2011 |url=https://www.ouramazingplanet.com/lake-vosotk-drilling-110207-1075/ |work=Our Amazing Planet |access-date=7 February 2011 |archive-url=https://web.archive.org/web/20110210011309/https://www.ouramazingplanet.com/lake-vosotk-drilling-110207-1075/ |archive-date=10 February 2011 }}</ref>

By plan, the following summer, the team was to drill down again to take a sample of that ice and analyze it.<ref name="January 2011" /><ref name="Nature 469">{{cite journal |last=Schiermeier |first=Q |title=Race against time for raiders of the lost lake |journal=Nature |volume=469 |issue=7330 |page=275 |date=January 2011 |pmid=21248808 |doi=10.1038/469275a |bibcode=2011Natur.469..275S |doi-access=free }}</ref> The Russians resumed drilling into the lake in January 2012 and reached the upper surface of the water on 6 February 2012.<ref name=Kaufman/><ref>{{cite news |first=D |last=Cressey |title='Too soon' to confirm success of Antarctic lake drilling |date=7 February 2012 |url=https://www.nature.com/news/too-soon-to-confirm-success-of-antarctic-lake-drilling-1.9986 |work=[[Nature (journal)|Nature]] |access-date=8 February 2012 }}</ref> The researchers allowed the rushing lake water to freeze within the bore hole and months later; they collected ice core samples of this newly formed ice and sent them to the Laboratory for Glaciology and Environmental Geophysics in Grenoble, France, for analysis.{{cn|date=May 2023}}

===Biology results===

====United Kingdom and United States====
Scientists first reported evidence of microbes in the accretion ice in 1999.<ref>{{cite news|url=https://news.discovery.com/earth/lake-vostok-accretion-ice-life-130709.htm|title=Ice Above Lake Vostok Includes DNA From Animals|author=Becky Oskin|date=9 June 2013|work=Our Amazing Planet|access-date=10 July 2013|archive-url=https://web.archive.org/web/20160315151107/https://news.discovery.com/earth/lake-vostok-accretion-ice-life-130709.htm|archive-date=2016-03-15|publisher=Discovery}}</ref><ref>{{Cite web|url=https://science.nasa.gov/science-news/science-at-nasa/1999/ast10dec99_2|title=Exotic microbes discovered near Lake Vostok {{!}} Science Mission Directorate|date=1999-12-10|website=science.nasa.gov|language=en|access-date=2018-10-31|archive-date=27 January 2019|archive-url=https://web.archive.org/web/20190127120155/https://science.nasa.gov/science-news/science-at-nasa/1999/ast10dec99_2/|url-status=dead}}</ref> Since then, a different team led by Scott O. Rogers has been identifying a variety of bacteria and fungi from accretion ice (not from the subglacial water layer) collected during U.S. drilling projects in the 1990s.<ref>{{cite journal |title=Isolation of Microbes from Lake Vostok Accretion Ice |journal=Appl. Environ. Microbiol. |date=1 August 2008 |first1=Tom |last1=D'Elia |first2=Ram |last2=Veerapaneni |first3=Scott O. |last3=Rogers |volume=74 |issue=15 |pages=4962–4965 |doi=10.1128/AEM.02501-07 |pmid=18552196 |pmc=2519340 |bibcode=2008ApEnM..74.4962D }}</ref><ref>{{cite journal |title=Isolation of fungi from Lake Vostok accretion ice |journal=Mycologia |date=17 July 2009 |first1=Tom |last1=d'Elia |first2=Ram |last2=Veerapaneni |first3=Vincent |last3=Theraisnathan |first4=Scott O. |last4=Rogers |volume=101 |pages=751–763 |doi=10.3852/08-184 |issue=6 |pmid=19927741 |s2cid=32676468 |url=https://scholarworks.bgsu.edu/cgi/viewcontent.cgi?article=1013&context=bio_sci_pub }}</ref> According to him, this indicates that the lake below the ice is not sterile but contains a unique ecosystem. Then Scott Rogers published in July 2013 that his team performed [[nucleic acid]] ([[DNA]] and [[RNA]]) sequencing and the results allowed deduction of the metabolic pathways represented in the accretion ice and, by extension, in the lake. The team found 3,507 unique gene sequences, and approximately 94% of the sequences were from bacteria and 6% were from [[Eukarya]].<ref name="Shtarkman and Koçer">{{cite journal |title=Subglacial Lake Vostok (Antarctica) Accretion Ice Contains a Diverse Set of Sequences from Aquatic, Marine and Sediment-Inhabiting Bacteria and Eukarya |journal=PLOS ONE |date=3 July 2013 |first1=Yury M. |display-authors=4 |last1=Shtarkman |first2=Zeynep A. |last2=Koçer |first3=Robyn |last3=Edgar |first4=Ram S. |last4=Veerapanenimm |first5=Tom |last5=D'Eliam |first6=Paul F. |last6=Morris |first7=Scott O. |last7=Rogers |volume=8 |issue=7 |pages=e67221 |doi=10.1371/journal.pone.0067221 |pmid=23843994 |editor-last=Watson |editor-first=Michael |bibcode=2013PLoSO...867221S |pmc=3700977|doi-access=free }}</ref><ref>{{cite web |url=https://www.nbcnews.com/science/antarcticas-hidden-lake-vostok-found-teem-life-6C10561955 |title=Antarctica's hidden Lake Vostok found to teem with life |first=Alan |last=Boyle |publisher=[[NBC News]] |date=8 July 2013 }}</ref> Taxonomic classifications (to genus and/or species) or identification were possible for 1,623 of the sequences. In general, the taxa were similar to organisms previously described from lakes, brackish water, marine environments, soil, glaciers, ice, lake sediments, deep-sea sediments, deep-sea thermal vents, animals and plants. Sequences from [[Aerobic organism|aerobic]], [[Anaerobic organism|anaerobic]], [[Psychrophile|psychrophilic]], [[Thermophile|thermophilic]], [[Halophile|halophilic]], [[Alkaliphile|alkaliphilic]], [[acidophile|acidophilic]], desiccation-resistant, [[autotroph]]ic, and [[heterotroph]]ic organisms were present, including a number from multicellular eukaryotes.<ref name="Shtarkman and Koçer" />

In 2020, Colby Gura and Scott Rogers extended their study of Lake Vostok accretion ice, as well as the basal ice flowing into the lake.<ref>{{Cite journal|last=Gura|first=Colby|title=Metatranscriptomic and Metagenomic Analysis of Biological Diversity in Subglacial Lake Vostok (Antarctica)|journal=Biology|year=2020|volume=9|issue=3|page=55|doi=10.3390/biology9030055|pmid=32188079|pmc=7150893|doi-access=free}}</ref> They found that the basal ice contained an almost completely different community of organisms compared to those found in the lake accretion ice, indicating that they signified two completely different ecosystems. Additional bacteria and eukaryotes were reported. The highest diversity of organisms in the lake ice was significantly associated (p<0.05) with higher concentrations of ions and amino acids. While their previous work indicated the presence of bacteria that inhabit fish intestines, no sequences from fish were found. However, in the 2020 study, they found an rRNA sequence that was >97% similar to that from a rock cod common along the coast of Antarctica (''[[Notothenia coriiceps]]''). This is the first report of a fish species possibly residing in Lake Vostok. The fish is known to produce antifreeze proteins.

Microbiologist David Pearce of the University of Northumbria in Newcastle, UK, stated that the DNA could simply be contamination from the drilling process, and not representative of Lake Vostok itself. The old ice cores were drilled in the 1990s to look for evidence of past climates buried in the ice, rather than for life, so the drilling equipment was not [[Sterilization (microbiology)|sterilized]].<ref name="DNA analyses">{{cite news |author=Michael Marshall |title=Lake Vostok may boast a thriving ecosystem |date=8 July 2013 |url=https://www.newscientist.com/article/dn23832-lake-vostok-may-boast-a-thriving-ecosystem.html |work=New Scientist |access-date=10 July 2013 }}</ref> Also Sergey Bulat, a Lake Vostok expert at the Petersburg Nuclear Physics Institute in Gatchina, Russia, doubts that any of the cells or DNA fragments in the samples would belong to organisms that might actually exist in the lake. He says that it is very probable that the samples are heavily contaminated with tissue and microbes from the outside world.<ref name="Nature 2013">{{cite journal |title=Claims of Lake Vostok fish get frosty response |journal=Nature |date=9 July 2013 |first1=Quirin Schiermeier |doi=10.1038/nature.2013.13364 |url=https://www.nature.com/news/claims-of-lake-vostok-fish-get-frosty-response-1.13364 |access-date=10 July 2013 |last1=Schiermeier |s2cid=131665344 }}</ref>

The contamination possibility has been refuted by Scott Rogers, because the control measures were rigorous, and the combinations of organisms found in each of the ice samples were consistent with organisms living in a cold lake and ice (including a sequence from an Antarctic rock cod), and were inconsistent with contamination introduced while sampling or from the lab procedures. Also, all of the lab procedures were performed in parallel with ice samples from Lake Erie, and the two resulting data sets were completely different. The Lake Erie sample exhibited many signals of human habitation, while the Lake Vostok ice samples exhibited no signals of human habitation. The Lake Erie sample also had an almost completely different profile of bacterial and eukaryotic phyla.

====Russia and France====
Russian and French scientists have been carrying out molecular DNA studies of the water from Lake Vostok that was frozen in the borehole, by constructing numerous [[Library (biology)|DNA libraries]],{{cn|date=May 2023}} which are collections of fragments of DNA that allow scientists to identify which species of bacteria they may belong to. Samples taken from the lake so far contain about one part of kerosene per 1000 of water, and they are contaminated with bacteria previously present in the drill bit and the kerosene drilling fluid.{{cn|date=May 2023}} So far, the scientists have been able to identify 255 contaminant species, but also have found an unknown bacterium when they initially drilled down to the lake's surface in 2012, with no matches in any international databases, and they hope it may be a unique inhabitant of Lake Vostok.<ref name="TDT-20130307">{{cite news |title=New life form found in Lake Vostok |url=https://www.telegraph.co.uk/news/worldnews/antarctica/9915788/New-life-form-found-in-Lake-Vostok.html |archive-url=https://ghostarchive.org/archive/20220112/https://www.telegraph.co.uk/news/worldnews/antarctica/9915788/New-life-form-found-in-Lake-Vostok.html |archive-date=12 January 2022 |url-access=subscription |url-status=live |date=7 March 2013 |work=[[The Daily Telegraph]] |access-date=8 March 2013 |author=Staff }}{{cbignore}}</ref><ref name="LS-20130307">{{cite web |last=Howell |first=Elizabeth |title=New Type of Bacteria Reportedly Found in Buried Antarctic Lake |url=https://www.livescience.com/27737-new-bacteria-found-antarctic-lake.html |date=7 March 2013 |work=[[LiveScience]] |access-date=8 March 2013 }}</ref> However, Vladimar Korolev, the laboratory head of the study at the same institution, said that the bacteria could in principle be a contaminant that uses kerosene—the antifreeze used during drilling—as an energy source.<ref name="RBTH-20130309">{{cite news |author=Staff |title=No unfamiliar microorganisms found in Lake Vostok water - researcher |date=9 March 2013 |publisher=[[Russia Beyond the Headlines]] |url=https://rbth.ru/news/2013/03/09/no_unfamiliar_microorganisms_found_in_lake_vostok_water_-researcher_23670.html |work=[[Interfax]] |access-date=10 March 2013 }}{{Dead link|date=November 2023 |bot=InternetArchiveBot |fix-attempted=yes }}</ref>

Critics from the scientific community state that no valuable information can be obtained until they can test clean samples of lake water, uncontaminated by drilling fluid.{{cn|date=May 2023}} Regardless of the contamination issues, in May 2013 the drilling facility at the Russian Vostok Antarctic station was declared a historic monument as "the result of the recognition of the achievements of the Russian research of Antarctica by the international scientific community, and of the unique operations on opening the subglacial Lake Vostok performed by Russian scientists on February 5, 2012."{{cn|date=May 2023}}

In January 2015, the Russian press stated that Russian scientists have made a new "clean" borehole into Lake Vostok using a special 50-kilogram probe that collected about 1 liter of water not adulterated by the antifreezing fluid.<ref>{{cite web |last1=Cheah |first1=Carolina |title=What Does Water That Has Not Seen The Light Of Day For 20 Million Years Contain? |url=https://malaysiandigest.com/opinion/539308-what-does-water-that-has-not-seen-the-light-of-day-for-20-million-years-contain.html |website=Malaysian Digest |archive-url=https://web.archive.org/web/20180622070333/https://malaysiandigest.com/opinion/539308-what-does-water-that-has-not-seen-the-light-of-day-for-20-million-years-contain.html |access-date=22 June 2018|archive-date=22 June 2018 }}</ref><ref>{{cite web |title=RUSSIAN RESEARCHERS REACHED SUBGLACIAL LAKE VOSTOK |url=https://www.rgo.ru/en/article/russian-researchers-reached-subglacial-lake-vostok |website=Russian Geographical Society |archive-url=https://web.archive.org/web/20161115223054/https://www.rgo.ru/en/article/russian-researchers-reached-subglacial-lake-vostok |access-date=15 November 2016|archive-date=15 November 2016 }}</ref> The drilling technology used proved to be inappropriate to collect liquid water in general and clean samples in particular<ref>{{cite journal |last1=Bulat |first1=Sergey A. |title=Microbiology of the subglacial Lake Vostok: first results of borehole-frozen lake water analysis and prospects for searching for lake inhabitants |journal=Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences |date=January 2016 |volume=374 |issue=2059 |doi=10.1098/rsta.2014.0292 |pmid=26667905 |bibcode=2016RSPTA.37440292B |s2cid=8399775 |url=https://www.researchgate.net/publication/287124695 |access-date=11 October 2021|doi-access=free }}</ref> and results were unreported.<ref>{{cite web |last1=Spindler |first1=Bill |title=Lake Vostok Drilling Project |url=https://www.southpolestation.com/trivia/10s/lakevostok.html |website=Amundsen-Scott South Pole Station |access-date=11 October 2021}}</ref> It was predicted that the water would rise 30–40 m in the bottom part of the borehole, but in fact the water rose from the lake to a height of more than 500&nbsp;m. In October of that same year, the work was suspended for that southern summer because of insufficient funding by the federal Russian government.<ref name="MoscowTimes2015">{{cite news |last=Staff |url=https://www.themoscowtimes.com/news/article/russian-antarctic-expedition-halts-research-due-to-lack-of-funds/539033.html |title=Russian Antarctic Expedition Halts Research Due to Lack of Funds |work=The Moscow Times |location=Moscow |date=14 October 2015 |access-date=2015-10-15 }}</ref><ref>{{cite journal | doi = 10.1126/science.350.6260.494 | volume=350 | title=Mysterious Antarctic lake will remain out of reach | year=2015 | journal=Science | page=494  | last1 = Gramling | first1 = C.| issue=6260 | pmid=26516262 }}</ref>

In 2019 the Russian government ordered that a new wintering complex be installed at the Lake Vostok research station, funded in part by Russian billionaire [[Leonid Mikhelson]]. This complex will be capable of supporting 35 people in the summer, 15 in the winter and will have 4 diesel generators with a capacity of 200 kilowatts each. The new complex, consisting of 133 modules, was delivered to [[Progress Station]] in December 2021 and will be transported to the Lake Vostok research station and installed over the next four years.<ref name="Meduza.io">{{cite news |last=Staff |url=https://meduza.io/en/feature/2020/12/22/trouble-at-the-vostok-station |title=Trouble at the Vostok Station |work=Meduza.io |date=20 December 2020 |access-date=8 February 2022}}</ref><ref name="MNR">{{cite news |last=Staff |url=https://www.mnr.gov.ru/press/news/novyy_zimovochnyy_kompleks_stantsii_vostok_dostavlen_v_antarktidu/ |title=New wintering complex of Vostok station delivered to Antarctica |work=Ministry of Natural Resources of Russia |date=6 December 2021| access-date=8 February 2022}}</ref>

===Contamination due to drilling fluids===
The drilling project has been opposed by some [[Environmental movement|environmental groups]] and scientists who have argued that [[Ice drilling#Hot water and steam drills|hot-water drilling]] would have a more limited [[Environmental degradation|environmental impact]].<ref name="Discovery News">{{cite news|last=Niiler|first=E|date=9 February 2011|title=Antarctic Drilling Plan Raises Concerns|work=Discovery News|url=https://news.discovery.com/earth/lake-vostok-antarctica-environment-110209.html|archive-url=https://web.archive.org/web/20110212180515/https://news.discovery.com/earth/lake-vostok-antarctica-environment-110209.html|archive-date=12 February 2011|url-status=live|access-date=10 February 2011}}</ref> The main concern is that the lake could become contaminated with the antifreeze that the Russians used to keep the bore hole from refreezing. Scientists of the [[United States National Research Council]] have taken the position that it should be assumed that microbial life exists in Lake Vostok and that after such a long isolation, any life forms in the lake require strict protection from contamination.<ref>{{cite web |url=https://dels.nas.edu/resources/static-assets/materials-based-on-reports/reports-in-brief/subglacial_lakes_final.pdf |title=Exploration of Antarctic Subglacial |date=2007 |work=National Academy of Sciences |publisher=National Research Council |access-date=9 February 2011 |archive-date=12 June 2018 |archive-url=https://web.archive.org/web/20180612113359/https://dels.nas.edu/resources/static-assets/materials-based-on-reports/reports-in-brief/subglacial_lakes_final.pdf }}</ref>

The original drilling technique employed by the Russians involved the use of Freon and kerosene to lubricate the borehole and prevent it from collapsing and freezing over; {{convert|60|ST|MT|lk=on}} of these chemicals have been used thus far on the ice above Lake Vostok.<ref name="Morton" /> Other countries, particularly the United States and Britain, have failed to persuade the Russians not to pierce to the lake until cleaner technologies such as hot-water drilling are available.<ref name="sydney">{{cite news |first=A |last=Darby |title=Antarctic Treaty no match for national pride |date=8 February 2011 |url=https://www.smh.com.au/environment/conservation/antarctic-treaty-no-match-for-national-pride-20110209-1ameh.html |work=The Sydney Morning Herald |access-date=9 February 2011 }}</ref> Though the Russians claim to have improved their operations, they continue to use the same borehole, which has already been contaminated with kerosene.<ref name="ASOC">{{cite web |url=https://www.asoc.org/issues-and-advocacy/antarctic-environmental-protection/lake-vostok |title=Antarctica's Lake Vostok Controversy |date=2010 |publisher=[[Antarctic and Southern Ocean Coalition]] |access-date=10 February 2011 |archive-date=12 November 2013 |archive-url=https://web.archive.org/web/20131112011516/https://www.asoc.org/issues-and-advocacy/antarctic-environmental-protection/lake-vostok }}</ref> According to the head of Russian Antarctic Expeditions, Valery Lukin, new equipment was developed by researchers at the [[Petersburg Nuclear Physics Institute]] that would ensure the lake remains uncontaminated upon intrusion.<ref name="January 2011" /> Lukin has repeatedly reassured other signatory nations to the Antarctic Treaty System that the drilling will not affect the lake, arguing that on breakthrough, water will rush up the borehole, freeze, and seal the other fluids out.<ref>{{cite web |url=https://www.currentscience.ac.in/Volumes/102/10/1355.pdf |archive-url=https://web.archive.org/web/20140419025148/https://www.currentscience.ac.in/Volumes/102/10/1355.pdf |archive-date=2014-04-19 |url-status=live |title=Drilling at Lake Vostok by the Russians |first=Jaimini |last=Sarkar |access-date=28 December 2012 }}</ref>

Some environmentalist groups remain unconvinced by these arguments. The [[Antarctic and Southern Ocean Coalition]] has argued that this manner of drilling is a profoundly misguided step which endangers Lake Vostok and other subglacial lakes in Antarctica (which some scientists are convinced are inter-linked with Lake Vostok).<ref name="appeal" /> The coalition has asserted that "it would be far preferable to join with other countries to penetrate a smaller and more isolated lake before re-examining whether penetration of Lake Vostok is environmentally defensible. If we are wise, the Lake will be allowed to reveal its secrets in due course."<ref name="appeal" />

Lukin claims that hot-water drilling is much more dangerous for the microbiotic fauna, as it would boil the living species, and disturb the entire structure of water layers of the lake.<ref>{{cite web |url=https://www.aif.ru/society/article/52592 |script-title=ru:Озеро Восток - "кусочек" Марса на Земле? |language=ru |last=Данилевич |first=Елена |publisher=[[Argumenty i Fakty]] |date=6 June 2012 |access-date=25 December 2012 }}</ref> Additionally, hot-water drilling would have required more power than the Russian expedition could have generated at their remote camp.<ref name="Discovery News" /> However, the water samples obtained by the Russian team were heavily contaminated with drilling fluid, so they reported in May 2017 that it was impossible at this time to obtain reliable data on the real chemical and biological composition of the lake water.<ref>{{cite journal | doi = 10.1144/SP461.3 | volume=461 | title=Chemical characteristics of the ice cores obtained after the first unsealing of subglacial Lake Vostok | year=2017 | journal=Geological Society, London, Special Publications | pages=187–196 | last1 = Alekhina | first1 = Irina | last2 = Ekaykin | first2 = Alexey | last3 = Moskvin | first3 = Alexey | last4 = Lipenkov | first4 = Vladimir| s2cid=219193990 }}</ref>

== See also ==

{{portal|Lakes|Geography}}
* {{annotated link|Groundwater}}
* {{annotated link|Kola Superdeep Borehole}}
* {{annotated link|Ledoyom}}
* {{annotated link|List of lakes by volume}}

==References==
{{Reflist|colwidth=30em}}

==External links==
{{Commons category|Lake Vostok}}
* [https://www.ldeo.columbia.edu/~mstuding/vostok.html Columbia.edu: About Lake Vostok]
* [https://www.ldeo.columbia.edu/res/pi/vostok/ Columbia.edu: "Lake Vostok: A Curiosity or a Focus for Interdisciplinary Study?"] {{Webarchive|url=https://web.archive.org/web/20200427181049/https://www.ldeo.columbia.edu/res/pi/vostok/ |date=27 April 2020 }} (1998)
*[https://www.asoc.org/storage/documents/Other_publications/asoc_vostok_statement041408.pdf ASOC.org: Lake Vostok Letter of Appeal to Russia] {{Webarchive|url=https://web.archive.org/web/20160304055957/https://www.asoc.org/storage/documents/Other_publications/asoc_vostok_statement041408.pdf |date=4 March 2016 }}
*[https://archive.today/20121209073118/https://documentary.operationreality.org/2011/07/19/the-lost-world-of-lake-vostok-under-antarctica/  OperationReality.org: video documentary about Lake Vostok]

{{Antarctica}}
{{Polar exploration |state=collapsed}}

{{Authority control}}

{{DEFAULTSORT:Vostok, Lake}}
[[Category:Ancient lakes]]
[[Category:Lakes of Princess Elizabeth Land]]
[[Category:Rift lakes]]
[[Category:Subglacial lakes]]
[[Category:Extreme points of Russia|Lake Vostok]]
[[Category:Russia and the Antarctic|Lake Vostok]]
[[Category:2011 in Antarctica|Lake Vostok]]
[[Category:2012 in Antarctica|Lake Vostok]]
[[Category:2013 in Antarctica|Lake Vostok]]
[[Category:Lakes of Antarctica]]