Lake Vostok is the biggest of the seventy lakes in Antarctica that are under the ice. It is at 77° S 105° E. It is under Russia's Vostok Station. It is 4,000 meters (13,000 feet) under Antarctica's surface.
|Type||subglacial rift lake|
|Max. length||250 km|
|Max. width||50 km|
|Surface area||15,690 km²|
|Average depth||344 m|
|Max. depth||1,000 m|
|Water volume||5,400 ± 1,600 km³|
|Residence time||1,000,000 yrs|
|Islands||1 (found May 2005)|
The lake consists of fresh water. The temperature of the water is about -3 °C. The freezing point of water is at 0 °C, but the water in the lake remains liquid because of the high pressure of the ice.
Pressure and oxygenEdit
Lake Vostok is an oligotrophic extreme environment. It is supersaturated with oxygen. The levels of oxygen are fifty times higher than those typically found in ordinary freshwater lakes on Earth. The weight of the ice on top of Lake Vostok is believed to add to the high concentration of oxygen. Oxygen from the ice gets dissolved into the water of the lake. Deposits of oxygen and other gases are trapped in the lake as well. The structure that traps them is called a clathrate. Gases trapped in clathrates are enclosed in ice and look like packed snow. These structures form at the high-pressure depths of Lake Vostok; they would become unstable if brought to the surface.
No other natural environment on Earth is as rich in oxygen. For this reason, if there are any forms of life in the lake, they would probably need to have adapted to the high levels of oxygen to be able to survive. Some adaptations might include high concentrations of protective enzymes.
The environment in the lake is very similar to that on Jupiter's moon Europa or Saturn's moon Enceladus. Finding life in the lake would therefore make it more probable that life has existed on one of these moons.
- Siegert MJ (2000). "The identification, examination and exploration of Antarctic subglacial lakes". Sci Prog. 83 ( Pt 3): 223–42. PMID 11077478.
- "Mystery of Antarctica's 15-million year-old lake". The Daily Galaxy. 2007-12-04. Retrieved 2009-07-01.
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