Vostok Station
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Vostok Station (Russian: Станция Восток) is a Russian (formerly Soviet) research station located near the Southern Pole of Inaccessibility, at the center of the East Antarctic Ice Sheet. Vostok Station is located within the Australian Antarctic Territory (although as a signatory to the Antarctic Treaty System, Australia does not exercise sovereignty over the territory).
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[edit] History
Vostok research station was established on December 16, 1957 (during the International Geophysical Year) by the 2nd Soviet Antarctic Expedition 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, U.S., and French scientists.
On July 21, 1983, the lowest temperature ever recorded on earth was in Vostok with −89.2 °C (−128.6 °F)[1] (See List of weather records) Though unconfirmed, it has been reported that Vostok reached the temperature of −91 °C (−132 °F) during the winter of 1997.[2] 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 4,000 meters (13,000 ft) below the surface of the central Antarctic ice sheet and covers an area of 14,000 km² (5,400 sq mi).
[edit] Description
The station is 3,488 meters (11,444 ft) above sea level. It is the most isolated of all of the established research stations on the Antarctic continent, located about 1,300 km from the Geographic South Pole. Its location near the South Geomagnetic Pole makes it one of the optimal places to observe changes in the Earth's magnetic sphere. Other studies include aerometeorology, actinometry, geophysics, medicine, climatology and others. The station typically contains 25 scientists and engineers in the summer—in winter, their number drops to 13.
[edit] Climate
The lowest reliably measured temperature on Earth of −89.2 °C (−128.6 °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 (−85 °F); in the brief summer, about −30 °C (−25 °F). The place is known as the Southern Pole of Cold. The coldest recent day at the station occurred August 8, 2005, when the high temperature reached just −78 °C (−108 °F) and the low fell to −85.4 °C (−121.7 °F). The warmest recorded temperature at Vostok is −12.2 °C (10.4 °F), which occurred on January 11, 2002, and during the month of July 1987 the temperature never rose above −72.2 °C (−98 °F). The minimum monthly mean surface temperature was occurred in August 1987 with -75.4 °C.
In addition to the cold temperatures, other factors make Vostok one of the most difficult places on Earth for human habitation:
- An almost complete lack of moisture in the air.
- An average windspeed of 5 m/s (11 mph), sometimes rising to as high as 27 m/s (60 mph).
- An acute lack of oxygen because of the high 3,488-meter (11,444 ft) altitude. Accounting for the fact that oxygen density gets lower as one approaches the poles, it is estimated that the oxygen density at Vostok is equivalent to that of a mountain over 5,000 meters (16,400 ft) tall at more temperate latitudes.
- A higher ionization of the air.
- A partial pressure of gases that is different from that which most humans are used to.
- A lack of carbon dioxide in the air, which leads to irregularities in a person's breathing mechanism.
- A polar night that lasts three months of the year.
Acclimatization to such conditions can take from a week to two months and is accompanied by headaches, eye twitches, ear pains, nose bleeds, perceived suffocation, sudden rises in blood pressure, loss of sleep, reduced appetite, vomiting, joint and muscle pain, and weight loss of 3-5 kg (7-11 lb) (sometimes as high as 12 kg (26 lb)).
[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.[3] 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 give proxy information down to a depth of 3310 m or 414,000 years.[4] Below this there is evidence of ice deformation. It has been 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.[5] This then produces a record in agreement with the newer longer EPICA record, although it provides no new information.
[edit] See also
[edit] References
- ^ Budretsky, A.B. (1984). "New absolute minimum of air temperature" (in Russian). Bulletin of the Soviet Antarctic Expedition (105). Leningrad: Gidrometeoizdat.
- ^ Liang, Yong Li (2000). Coldest Temperature On Earth. The Physics Factbook. Retrieved on 2007-09-02.
- ^ Deciphering Mysteries of Past Climate From Antarctic Ice Cores Earth in Space, Vol. 8, No. 3, November 1995, p. 9. © 1995 American Geophysical Union. Retrieved 2007-03-27.
- ^ Vostok Ice Core Data www.ncdc.noaa.gov, 2005-12-22. Retrieved 2007-03-27.
- ^ Dominique Raynaud, Jean-Marc Barnola, Roland Souchez, Reginald Lorrain, Jean-Robert Petit, Paul Duval and Vladimir Y. Lipenkov. (2005). "Palaeoclimatology: The record for marine isotopic stage 11". Nature 436: 39-40. doi:10.1038/43639b.
[edit] External links
- Russian Antarctic Expedition, Vostok page
- Vostok average temperature data
- Vostok current met data
- Antarctic Connection article on Vostok Station
