Lake Vida
Template:Short description Template:Infobox lake
Lake Vida is a hypersaline lake in Victoria Valley, the northernmost of the large McMurdo Dry Valleys, on the continent of Antarctica. It is isolated under year-round ice cover, and is considerably more saline than seawater. It came to public attention in 2002 when microbes frozen in its ice cover for more than 2,800 years were successfully thawed and reanimated.
IntroductionEdit
Lake Vida is one of the largest lakes in the McMurdo Dry Valley region and is a closed-basin endorheic lake. The permanent surface ice on the lake is the thickest non-glacial ice on earth, reaching a depth of at least Template:Convert. The ice at depth is saturated with brine that is seven times as saline as seawater.<ref>Template:Cite journal Figure 1: Bathymetric map of Lake Vida
- Template:Cite news</ref> The high salinity allows the brine to remain liquid at an average yearly water temperature of Template:Convert. The ice cap has sealed the saline brine from external air and water for thousands of years, creating a time capsule for ancient DNA. This combination of lake features makes Lake Vida a unique lacustrine ecosystem on Earth.<ref>Annika Mosier Template:Webarchive at Desert Research Institute</ref>
The lake gained widespread recognition in December 2002 when a research team, led by the University of Illinois at Chicago's Peter Doran, announced the discovery of 2,800‑year‑old halophile microbes (primarily filamentous cyanobacteria) preserved in ice layer core samples drilled in 1996.<ref>National Science Foundation press release for Doran et al. (2003)</ref> The microbes reanimated upon thawing, grew and reproduced. Due to this discovery and the freezing mechanisms forming Lake Vida's ice-seal, Lake Vida is now noted as a location for research into Earth's climate and life under extreme conditions, specifically the fauna that could have existed on Mars. The unmanned Lake Vida Meteorological Station monitors climate conditions around the lake year round for such scientific study.<ref>Lake Vida Meteorology Station Template:Webarchive</ref><ref>360° Panorama Template:Webarchive from Lake Vida Meteorologic Station</ref>
A 2010 field campaign, funded by the National Science Foundation through the American Recovery and Reinvestment Act of 2009, to investigate the microbiology and geochemistry of Lake Vida. Led by Peter Doran and Alison Murray from Nevada's Desert Research Institute, the expedition recovered ice cores, brine and sediment samples from the lake using clean drilling procedures to avoid contamination.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>
The lake itself has no permanent settlements or infrastructure. The nearby Lake Vida Meteorological Station is unmanned, sending meteorological data to McMurdo Dry Valleys Long Term Ecological Research organization. The closest human settlement is Scott Base McMurdo approximately Template:Convert away.<ref>Contaminents in Freezing Ground Template:Webarchive, Sanpe et al.</ref> In addition to the unmanned observation station, a 5-day emergency supply of food for 6 people is cached Template:Convert from the southwestern shore.<ref>NASA Quest Template:Webarchive, the Lake Vida cache</ref> Research teams establish temporary camps from which research activities are conducted on short term basis in the summer months.
CompositionEdit
Lake Vida does not possess many factors attributed to the existence of life formations. Lake Vida contains high levels of nitrous oxide (N2O) and also molecular hydrogen (H2). The chemicals are believed to be released from chemical reactions between the brine and underlying sediments. The molecular hydrogen may be crucial as an energy source for life in the lake and aids in justifying the presence of life in an oxygen-deprived environment.<ref>[1], Sanpe et al.</ref>
HydrologyEdit
Lake Vida has at least three named inflows: Victoria River, Kite Stream, and Dune Creek. Victoria River passes through the Vida Basin into Victoria Valley, Victoria Land as ephemeral glacial meltwater from the Upper Victoria Glacier, draining from Victoria Upper Lake, Template:Convert to the northwest, to finally drain into the west end of Lake Vida. Kite Stream is also located in the Vida Basin and flows as ephemeral glacial meltwater west from the Victoria Lower Glacier into the east end of Lake Vida. The United States Geological Survey's Atlas of Antarctic Research maps up to nine Lake Vida inflows or outflows including Victoria River and Kite Stream. The inflows and outflows are normally dry due to average annual temperatures down to Template:Convert at Lake Vida. Meltwater flows for a few weeks in the summer months when temperatures rise sufficiently for the nearby glaciers to melt. The McMurdo Dry Valleys are classified as extreme desert. The area receives less than Template:Convert of snow precipitation a year, in the form of snow that builds the nearby glaciers.
GeologyEdit
Main geological featuresEdit
In the vicinity of Lake Vida, a variety of geological features are noted, the most significant being glaciers, lakes, valleys, ridges, and summits. There are approximately 25 named glaciers within a Template:Convert radius with the nearest being Upper Victoria Glacier, Packard Glacier, Clark Glacier, and Clio Glacier. In the same radius, there are approximately 14 named ridges with the nearest being Robertsons Ridge, Helios Ridge, and Nottage Ridge. In addition to Victoria Valley, there are 16 named valleys with the nearest being Sanford Valley, Barwick Valley and McKelvey Valley. In addition to Upper Victoria Lake that feeds Lake Vida with meltwater, there are approximately 11 other lakes, the nearest being Lake Thomas. The summits around Lake Vida are as follows, Mautino Peak, Mount Saga, Mount Allen, Mount Theseus, Mount Cerberus, Mount Insel, Nickell Peak, and Sponsors Peak.
Other geological featuresEdit
Other more minor features include benches, cliffs, gaps, and streams.<ref>USGS USGS Atlas of Antarctic Research Template:Webarchive</ref> The Victoria Valley dunefield, an approximately 1.5 km2 belt which is about 3.1 km long, lies to the east of Lake Vida. It is an important site for research into the landforms and processes of perennial niveo-aeolian environments.<ref name=Bourke>Template:Cite journal</ref>
Natural historyEdit
Kite Stream is named after a researcher, James Kite, who found numerous meteorites in the area (1977–1978).<ref>Kite Stream Template:Webarchive, Australian Antarctic Data Center</ref>
HistoryEdit
Lake Vida lies north of Mount Cerberus in the Victoria Valley of Victoria Land. Named by the Victoria University of Wellington Antarctic Expedition (1958–59) after Vida (Vaida), a sledge dog of the Nimrod Expedition, 1910-13.<ref>Australian Antarctic Data Centre SCAR Gazetteer Template:Webarchive Reference No 15493</ref> Lake Vida was originally thought to be frozen to the lakebed.<ref>Synthetic Aperture Radar detection of changes in ice and soil surfaces, McMurdo Dry Valleys, Antarctica Template:Webarchive</ref>
LifeEdit
Scientists have found life in an Antarctic Lake Vida that was sealed off from the outside world by a thick sheet of ice several thousands of years ago.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref><ref>Template:Cite journal</ref> The discovery of the ecosystem pushes the boundaries of what life can endure, and may inform the search for alien microbes on other planets, such as Mars, or on icy moons, for instance, Jupiter's moon Europa.
Species listsEdit
The following eukaryote species have been catalogued within 1 degree<ref>Australian Antarctic Data Center, SCAR Gazetteer</ref> of Lake Vida:
- Phylum Arthropoda : Alloptes stercorarii (arachnida, mite), Tydeus setsukoae (arachnida, mite)
- Phylum Rotifera : Philodina spp.
- Phylum Tardigrada : Unknown sp.
Kingdom Fungi
- Division Ascomycota : Lepraria sp.
Kingdom Plantae
- Division Bryophyta : Bryum argenteum, Bryum pseudotriquetrum, Bryum subrotundifolium, Ceratodon purpureus, Didymodon gelidus, Grimmia antarctici, Grimmia sp., Pottia heimii, Sarconeurum glaciale,
- Division Marchantiophyta : Cephaloziella exiliflora
Kingdom Protista
- Phylum Ciliophora : Chilodonella sp., Epistylis sp., Euplotes sp., Halteria sp., Homalozoon sp., Nassula sp., Oxytricha sp., Pleuronema sp., Podophrya sp., Pyxidium sp., Saprophilus sp., Spathidium sp., Sphaerophrya sp., Vorticella sp.
- Phylum Sarcomastigophora : Acanthocystis sp., Actinophyrys sp.,
- Phylum Euglenozoa : Bodo sp. (kinetoplastid)
See alsoEdit
ReferencesEdit
ReferencesEdit
- McMurdo Dry Valley Long Term Ecological Research
- Terrestrial Biology
- Paleolimnology of Extreme Cold Terrestrial and Extraterrestrial Environments
- Subsurface Ice and Brine Sampling
- Antarctic Lake Yields Ancient Bacteria
- Lake Vida, AntarcticaTemplate:Dead link
- Antarctica Lake Vida Find Life
External linksEdit
- Resources
- Meteorological Station Measurements, University of Colorado, Lake Vida entry
- Antarctic Freshwater Diatoms, University of Colorado, Lake Vida entry
- Ice Coring and Drilling Services Space Science and Engineering Center, University of Wisconsin-Madison, Lake Vida entry
- McMurdo Dry Valleys Long Term Ecological Research VIAM data tables, Lake Vida entry
- David Darling's Encyclopedia of Astrobiology, Lake Vida entry
- News items
- "Lake Water Secret", BBC news item
- "Looking for lessons at Vida", The Antarctic Sun news item on borehole pollution at Lake Vida
- Photographs