Lake Vostok

Lake Vostok (Russian: озеро Восток, Ozero Vostok, lit. "Lake East") is the largest of Antarctica's more than 140 sub-glacial 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. Measuring 250 km (160 mi) long by 50 km (30 mi) wide at its widest point, and covering an area of 15,690 km2 (6,060 sq mi) and an average depth of 344 m (1,129 ft). It has an estimated volume of 5,400 km3 (1,300 cu mi). The lake is divided into two deep basins by a ridge. The liquid water over the ridge is about 200 m (700 ft), compared to roughly 400 m (1,300 ft) deep in the northern basin and 800 m (2,600 ft) deep in the southern.

The lake is named after Vostok Station, which in turn is named after the Vostok (Восток), a sloop-of-war, which mean "East" in Russian. 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 Expeditions in 1959 and 1964 to measure the thickness of the ice sheet. The continued research by Russian and British scientists led by 1993 to the final confirmation of the existence of the lake by J.P. Ridley using ERS-1 laser altimetry.

The lake was drilled into by Russian scientists in 2012. 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. On 5 February 2012, a team of Russian scientists claimed to have completed the longest ever ice core of 3,768 m (12,400 ft) and pierced the ice shield to the surface of the lake. Samples of the freshly frozen water in the ice well are expected to be collected at the end of 2012 when the new Antarctic summer starts. The Russian team plans to send a robot into the lake to collect water samples and sediments from the bottom. Unusual forms of life could be found in the lake's liquid layer, an ecosystem sealed off below the ice for millions of years, conditions which could resemble those of the hypothesized ice-covered ocean of Jupiter's moon Europa.