User:Kertiati/Déli-sark

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Nagyít
Kép:SPSM.05.jpg
Amundsen-Scott South Pole Station. The ceremonial pole and flags can be seen in the background, slightly to the left of center, below the tracks behind the buildings. The actual geographic pole is a few more metres to the left. The buildings are raised on stilts to prevent snow buildup.

Ha nincs külön jelezve, a Déli-sark vagy Déli-pólus kifejezés a földrajzi értelmembe vett Déli-pólust, azaz a Föld felületének legdélibb pontját jelöli, mely pontosan az Föld Északi-sarkának ellentétes oldalán van.

Eredetileg az "Északi-pólus" és "Déli-pólus" kifejezés a Föld mágneses mezőjének hasonlósága miatt általában a mágnesekre is alkalmazható, a mágnes két végének megkülönböztetésére. Ehhez lásd a Mágnes vagy Mágnesesség címszavakat.

When not otherwise qualified, the term South Pole normally refers to the Geographic South Pole – the southernmost point on the surface of the Earth, on the opposite side of the Earth from the North Pole. Other "South Poles" described in this article include the Ceremonial South Pole, the South Magnetic and Geomagnetic Poles, and the Southern Pole of Inaccessibility.

Originally by analogy with the earth's magnetic field, the terms "south pole" and "north pole" are also applied to magnets in general, in order to distinguish one "end" of the magnet from the other. For this use see under Magnet and Magnetism.


Tartalomjegyzék

[szerkesztés] Földrajzi Déli-sark

A legáltalánosabb definíció szerint, a földrajzi Déli-sark, a Föld forgástengelyének a Föld felszínét metsző két metszéspontja közül az egyik. (A másik metszéspont az Északi-sark) Azonban a Föld forgástengelye a valóságban egy picit ingadozik ezért a fenti meghatározás nem kielégítő a precíz munkához.

[szerkesztés] Geographic South Pole

The Geographic South Pole is defined for most purposes as one of two points where the earth's axis of rotation intersects its surface (the other being the Geographic North Pole). However, the earth's axis of rotation is actually subject to very small "wobbles", so this definition is not adequate for very precise work; see Geographic North Pole for further information. The projection of the Geographic South Pole onto the celestial sphere gives the south celestial pole.

At present, Antarctica is located over the South Pole, although this has not been the case for all of Earth's history because of continental drift. The land (i.e. rock) at the South Pole lies near sea level, but the ice cap is 3000 metres thick so the surface is actually at high altitude.

The polar ice sheet is moving at a rate of roughly 10 metres per year, so the exact position of the Pole, relative to the ice surface and the buildings constructed on it, gradually shifts over time. The South Pole marker is repositioned each year to reflect this.

[szerkesztés] Exploration

See also: History of Antarctica, List of Antarctica expeditions and Polar exploration.

The first humans to reach the Geographic South Pole were Norwegian Roald Amundsen and his party on December 14, 1911. Amundsen named his camp Polheim and the entire plateau surrounding the Pole Haakon VII's Vidde in honour of King Haakon VII of Norway. Amundsen's competitor Robert Falcon Scott reached the Pole a month later. On the return trip Scott and his four companions all died of hunger and extreme cold. In 1914 British explorer Ernest Shackleton's Imperial Trans-Antarctic Expedition set out with the goal of crossing Antarctica via the South Pole but ended in failure.

US Admiral Richard Byrd, with the assistance of his first pilot Bernt Balchen, became the first person to fly over the South Pole on November 29, 1929. However, it was not until 31st October 1956 that men once again set foot at the Pole, when a party led by Admiral George Dufek of the US Navy landed there in a R4D Skytrain (Douglas DC-3) aircraft. The US Amundsen-Scott South Pole Station was established by air over 1956–1957 for the International Geophysical Year, and has been continuously staffed since then by research and support personnel.

After Amundsen and Scott, the next people to reach the South Pole overland (albeit with air support) were Edmund Hillary (4th Jan 1958) and Vivian Fuchs (19th Jan 1958), and their respective parties, during the Commonwealth Trans-Antarctic Expedition. There have been many subsequent expeditions to arrive at the South Pole by surface transportation, including those by Havola, Crary and Fiennes.

The fastest unsupported walking journey to the Geographic South Pole from the ocean is 47 days and was set in 1999 by explorers Tim Jarvis and Peter Treseder, who manhauled 200 kg sleds containing food and cooking fuel.

[szerkesztés] Climate

See also Climate of Antarctica.

During the southern winter the South Pole receives no sunlight at all, and in summer the sun, though continuously above the horizon, is always low in the sky. Much of the sunlight that does reach the surface is reflected by the white snow. This lack of warmth from the sun, combined with the high altitude (about 3200 meters), means that the South Pole has one of the coldest climates on earth. Temperatures at the South Pole are much lower than at the North Pole, primarily because the South Pole is located at altitude in the middle of a continental land mass, while the North Pole is at sea level in the middle of an ocean (which acts as a reservoir of heat).

In midsummer, as the sun reaches its maximum elevation of about 23.5 degrees, temperatures at the South Pole average around −25°C (−12°F). As the year-long "day" wears on and the sun gets lower, temperatures drop as well, with temperatures around sunset (late March) and sunrise (late September) being about −45°C (−49°F). In winter, the temperature remains steady at around −65°C (−85°F). The highest temperature ever recorded at the Amundsen-Scott South Pole Station is −14°C (7°F), and the lowest is −83°C (however, this is not the lowest recorded anywhere on earth, that being −89.6°C at Vostok Station).

The South Pole has a desert climate, almost never receiving any precipitation. However, high winds can cause the blowing of snowfall, which slowly buries the South Pole station over time.


Average monthly temperatures and precipitation (Fahrenheit, inches) at the South Pole, Antarctica

Month Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Year
Avg high °F -14 -35 -58 -63 -64 -65 -68 -68 -67 -54 -33 -15 -50
Avg low °F -20 -44 -70 -76 -78 -79 -82 -81 -81 -64 -39 -20 -61
Precipitation inches --- --- --- --- --- --- --- --- --- --- --- --- 0.1


Average monthly temperatures and precipitation (Celsius, millimetres) at the South Pole, Antarctica

Month Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Year
Avg high °C -25 -37 -50 -52 -53 -55 -55 -55 -55 -47 -36 -26 -45
Avg low °C -28 -42 -56 -60 -61 -61 -63 -62 -62 -53 -39 -28 -51
Precipitation millimeters --- --- --- --- --- --- --- --- --- --- --- --- 2.5

Source: weatherbase.com

[szerkesztés] Ceremonial South Pole

The ceremonial South Pole.  Flags of the Antarctic Treaty signatories are arrayed around it, and the Pole Station's old dome is in the background.
Nagyít
The ceremonial South Pole. Flags of the Antarctic Treaty signatories are arrayed around it, and the Pole Station's old dome is in the background.

The Ceremonial South Pole is an area set aside for photo opportunities at Amundsen-Scott South Pole Station. It consists of a metallic sphere on a plinth, surrounded by the flags of the Antarctic Treaty signatories. It is located a few metres from the Geographic South Pole (see above), which is marked only by a small sign, and a stake. Because the ice cap is moving at approximately 10 meters per year, the stake is replaced every year on New Year’s Day.

The dome seen in the pictures is partially buried due to snow storms. The entrance to the dome has to be regularly bulldozed to uncover it. More recent buildings are now built on stilts so that the snow does not build up against the side of them.

[szerkesztés] South Magnetic Pole

For additional information about the Earth's magnetic poles, see under North Pole.

The South Magnetic Pole is the point on the Earth's surface where the geomagnetic field lines are directed vertically upwards. The South Magnetic Pole is constantly wandering due to changes in the Earth's magnetic field; as of 2005 it was calculated to lie at 64.53°S and 137.86°E [1], just off the coast of Wilkes Land, Antarctica.

For historical reasons, the "end" of a magnet that points towards the Earth's North Pole is itself called the "north pole" of the magnet, with the other end being the magnet's "south pole". Because it is unlike poles that attract, the Earth's North Magnetic Pole is therefore actually a magnetic south pole, and the Earth's South Magnetic Pole is actually a magnetic north pole.

On January 16, 1909 three men (Douglas Mawson, Edgeworth David, and Alistair Mackay) from an expedition led by Sir Ernest Shackleton, claimed to have found the South Magnetic Pole [2], which was at that time located on land. However, there is now some doubt as to whether their location was correct [3].

[szerkesztés] South Geomagnetic Pole

The Earth's geomagnetic field can be approximated by a tilted dipole placed at the center of the Earth. The South Geomagnetic Pole is the point where the axis of this best-fitting tilted dipole intersects the Earth's surface in the southern hemisphere. As of 2005 it was calculated to be located at 79.74°S and 108.22°E [4], near to Vostok Station. Because the field is not an exact dipole, the South Geomagnetic Pole does not coincide with the South Magnetic Pole. Furthermore, the South Geomagnetic Pole is wandering for the same reason its magnetic counterpart wanders.

[szerkesztés] The Southern Pole of Inaccessibility

The Southern Pole of Inaccessibility is the point on the Antarctic continent that is most distant from the Southern Ocean. It is located at d. sz. 85°50′ k. h. 65°47′ and was reached on December 14, 1958 by the 3rd Soviet Antarctic Expedition, led by Yevgeny Tolstikov. At that point they established a temporary station Polyus Nedostupnosti. On the road to the Pole, at d. sz. 78°24′ k. h. 87°32′ another station, Sovetskaya, was established by the expedition, which existed between February 16, 1958 and January 3, 1959.

The Southern Pole of Inaccessibility is far more remote and hard to reach than the Geographic South Pole, and to date no one has travelled there by non-mechanical means. Team N2i hope to be the first to achieve this feat in November 2006, using a combination of traditional man hauling and kite skiing.

[szerkesztés] South Poles in astronomy

For information about the definition of Poles on planets and other astronomical bodies, see under North Pole.

[szerkesztés] See also

  • Antarctica
  • List of Antarctica expeditions
  • North Pole
  • 300 degree club
  • Chilean Antarctic Territory

[szerkesztés] References

Sablon:Unreferenced

[szerkesztés] External links