Lake Vostok
| Lake Vostok | |
|---|---|
| Russian: озеро Восток | |
Radar satellite image of Lake Vostok | |
| Coordinates | 77°30′S 106°00′E / 77.500°S 106.000°E |
| Lake type | Ancient lake, Subglacial rift lake |
| Basin countries | Antarctica |
| Max. length | 250 km (160 mi) |
| Max. width | 50 km (30 mi) |
| Surface area | 12,500 km2 (4,830 sq mi) |
| Average depth | 432 m (1,417 ft) |
| Max. depth | 510 m (1,700 ft) to 900 m (3,000 ft) |
| Water volume | 5,400 km3 (1,300 cu mi) ± 1,600 km3 (400 cu mi) |
| Residence time | 13,300 yrs |
| Surface elevation | c. −500 m (−1,600 ft) |
| Islands | 1 |
| Settlements | Vostok Station |
Lake Vostok (Russian: озеро Восток, romanized: ozero Vostok) is the largest of Antarctica's 675 known subglacial lakes. 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 3,488 m (11,444 ft) above mean sea level. The surface of this fresh water lake is approximately 4,000 m (13,100 ft) under the surface of the ice, which places it at approximately 500 m (1,600 ft) below sea level.
The lake is named after the Vostok Station, which derives its name from Vostok (Восток), a sloop-of-war, which means "East" in Russian (the lake is also located in East Antarctica). The existence of a subglacial lake was first suggested by Russian geographer Andrey Kapitsa based on seismic soundings made during the Soviet Antarctic Expeditions in 1959 and 1964 to measure the thickness of the ice sheet. The continued research by Russian and British scientists led to the final confirmation of the existence of the lake in 1993 by J. P. Ridley using ERS-1 laser altimetry.
The overlying ice provides a continuous paleoclimatic record of 400,000 years, although the lake water itself may have been isolated for 15 to 25 million years. 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, and Saturn's moon Enceladus.
On 5 February 2012, a team of Russian scientists completed the longest ever ice core of 3,768 m (12,400 ft) and pierced the ice shield to the surface of the lake. The first core of freshly frozen lake ice was obtained on 10 January 2013 at a depth of 3,406 m (11,175 ft). 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. It is hypothesized that unusual forms of life could be found in the lake's liquid layer, a fossil water reserve. The drilling project has been opposed by some environmental groups and scientists who have argued that hot-water drilling would have a more limited environmental impact.