Discover

'Lake Vida' lies in Victoria Valley, one of the McMurdo Dry Valleys, on the continent of Antarctica. It is isolated under year-round ice cover, and 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.

Contents

Introduction

Hydrology

Geology

Main geological features

Other geological features

Natural History

History

Economy

Species lists

Notes

References

See also

External links

Introduction

Lake Vida is one of the largest lakes in a class of closed-basin endorheic lakes in the McMurdo Dry Valley region. The top waters of Lake Vida are frozen year-round to a depth of at least 19 meters forming an ice-seal over briny waters that are seven times as saline as seawater^[1][2]. This icecap is the thickest non-glacial ice on earth. The high salinity allow for the lake bottom waters to remain liquid at an average yearly water temperature of -10C. The ice cap has sealed the saline lake water from external air and water for thousands of years creating a time capsule for ancient DNA. This combination of lake features make Lake Vida a unique lacustrine ecosystem on Earth^[3].
The lake gained widespread recognition in December 2002 when a research team, led by the University of 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^[4]. 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 conditions around the lake year round for such scientific study^[5][6].
The lake itself has no permanent human settlements. 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 125 km away^[7]. In addition to the unmanned observation station, a five day emergency supply of food for six people is cached 600 meters from the southwestern shore ^[8]. Research teams establish temporary camps from which research activities are conducted on short term basis in the summer months.

Hydrology

Lake Vida has at least two named inflows, Victoria River and Kite Stream. Victoria River passes through the Vida Basin into Victoria Valley, Victoria Land as ephemeral glacial meltwater from the Upper Victoria Glacier, draining from Upper Victoria Lake 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 from -15 to -30C 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 10 cm of snow precipitation a year, this snow builds the nearby glaciers.

Geology

Main geological features

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 25 km 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 features

Other more minor features include benches, cliffs, gaps, and streams^[9]. Sand dunes form between Lake Vida and Lake Victoria.

Natural History

Kite stream is named after a researcher, James Kite, who found numerous meteorites in the area (1977-1978)^[10].

History

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^[11]. Lake Vida was originally thought to be frozen to the lakebed^[12].

Economy

Lake Vida has no noted economic features. Any commercial benefits from the scientific expeditions to Lake Vida are indirect.

Species lists

The following eukaryote species have been catalogued within 1 degree^[13] of Lake Vida:
'Kingdom Animalia'

★ 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)

Notes

1. Doren, P. T. ''et al.'' (2003) Formation and character of an ancient 19-m ice cover and underlying trapped brine in an “ice-sealed” east Antarctic lake. ''Proc. Natl. Acad. Sci. USA'', '100', 26–31 (doi: 10.1073/pnas.222680999)
2. Ball, P. (2002) Buried lake could test life's limits. ''Nature'' summary of Doren ''et al.'' (2003)
3. Desert Research Institute from the homepage of Annika Mosier
4. National Science Foundation press release for Doren ''et al.'' (2003)
5. Lake Vida Meteorology Station
6. 360° Panorama from Lake Vida Meteorologic Station
7. Contaminents in Freezing Ground, Sanpe et. al,
8. NASA Quest, the Lake Vida cache
9. USGS USGS Atlas of Antarctic Research
10. Kite Stream, Australian Antarctic Data Center
11. Australian Antarctic Data Centre SCAR Gazetteer Reference No 15493
12. Synthetic Aperture Radar detection of changes in ice and soil surfaces, McMurdo Dry Valleys, Antarctica
13. Australian Antarctic Data Center, SCAR Gazetteer

References

★ 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, Antarctica

See also

★ Astrobiology

★ Extremophile

External links

; 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

★ Lake Vida bathymetry, ''Proc. Natl. Acad. Sci. USA''

★ 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

★ National Geographic photograph of Lake Vida

★ Images of Antarctica, a personal collection, Lake Vida photographs