Vostok Station
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Vostok Station is a Russian research station located near the Geomagnetic South Pole (see South Pole), at the center of the East Antarctic Ice Sheet.
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[edit] Description
The station is 3488 m above sea level. It is the most isolated of all of the established research stations on the Antarctic continent, located at . (google maps) The lowest reliably measured temperature on Earth of −89.2 °C (-128.56 F) was measured here on July 21, 1983 (although since the temperature decreases with height, it is virtually certain that lower temperatures occurred higher up towards the summit of the ice sheet). During the long winter, temperatures average about −65 °C; in the brief summer, about −30 °C. The place is known as the Southern Pole of Cold. The coldest recent day at the station occurred Aug. 8, 2005, when the high temperature reached just −78 C (-108 F) and the low fell to −85 C (-121 F). The warmest recorded temperature at Vostok has never risen above -19 C (-2 F), which occurred in January 1992, and during the month of July 1987 the temperature never rose above -72.2 C (-98 F).
[edit] History
Vostok research station was built in 1957 during the IGY and has operated year-round for more than 37 years. The station was temporarily closed in January 1994. This station is now cooperatively operated by Russian, American, and French scientists.
On July 21, 1983, the lowest temperature ever recorded on earth was in Vostok with −89.2 °C (−128.56 °F) (See Extremes on Earth)
In 1996, Russian and British scientists from the station discovered Lake Vostok, the largest known subglacial lake in the world underneath Vostok Station. Lake Vostok lies some 4000 meters (13,000 feet) below the surface of the central Antarctic ice sheet and covers an area of 14,000 square kilometers (5,400 square miles).
[edit] Ice Core Drilling
In the 1970s the Soviet Union drilled a set of cores 500–952 m deep. These have been used to study the oxygen isotope composition of the ice, which showed that ice of the last glacial period was present below about 400 m depth, Then three more holes were drilled: in 1984, Hole 3G reached a final depth of 2202 m; in 1990, Hole 4G reached a final depth of 2546 m; and in 1993 Hole 5G reached a depth of 2755 m; after a brief closure drilling continued during the winter of 1995. In 1996 it was stopped at depth 3623 m, by the request of the Scientific Committee on Antarctic Research that expressed worries about possible contamination of Lake Vostok. This ice core, drilled collaboratively with the French, produced a record of past environmental conditions stretching back 420,000 years and covering four previous glacial periods. For a long time it was the only core to cover several glacial cycles; but it has recently (2004) been exceeded by the EPICA core, which whilst shallower, covers a longer time span [1]. In 2003 drilling was permitted to continue, but was halted at the estimated distance to the lake of only 130 m.
Although the Vostok core reached a depth of 3623 m the usable climatic information does not extend down this far. The very bottom of the core is ice refrozen from the waters of Lake Vostok and contains no climate information. The usual data sources [2] give proxy information down to a depth of 3310 m or 414,000 years. Below this there is evidence of ice deformation. Raynaud et al (Nature, 2005/7/7) have suggested that the Vostok record may be extended down to 3345 m or 436,000 years, to include more of the interesting MIS11 period, by inverting a section of the record. This then produces a record in agreement with the newer longer EPICA record, although it provides no new information.
[edit] See also
- Lake Vostok
- Dome A
- Dome C
- Concordia Station
- Dome F
- Amundsen-Scott South Pole Station
- EPICA
- Soviet Antarctic Expedition
- Vostok traverse
