How many South Poles are there?
There are at least seven South Poles
Everyone who visits Antarctica finds that most friends think they have been to the South Pole. Santa Claus, of course, lives at the other end of the earth at the North Pole – surely an uncomfortably aquatic address when the sea ice melts. Santa’s domiciliary confusion is aided by the existence of a Santa attraction at North Pole, a small village outside Fairbanks Alaska that doesn’t even lie within the Arctic Circle. In fact, there are several poles. Some poles move over time while others are fixed but their markers may move as the polar ice cap slides inexorably to the sea.
Geographic South Pole: This is the fixed position of 90°S. Halfway between the poles lies the equator – exactly 10,000 km from each. That’s no coincidence – the kilometre was defined in the late 18th C as 1/10,000 of this distance.
South Pole of Rotation: This is the point that the earth spins around. It is very close to the geographic pole – within about 20 metres – and it constantly rotates around the geographic pole over 435 days. The geographic pole is the average of the rotational pole.
South Celestial Pole: The point if you took a line through the geographic poles and extended it into the heavens. The combination of the earth’s equatorial bulge and the moon’s gravitational pull causes the whole earth to wobble on its axis on a 23,000 year cycle. Right now the north celestial pole lies within a degree of the North Star or Polaris but it wasn’t when ancient Greeks first mapped the skies..
South Magnetic Pole: This is a moving point where the magnetic field is at right angles to the Earth’s surface. It fluctuates daily from the effect of solar winds and it can move up to 15 kilometres in a year. Since 1841, when James Clark Ross first determined its position, the south magnetic pole has been moving north-west at an average of about 9 km a year. It is now estimated to be in the Southern Ocean about 2825 km from the south geographic pole.
South Geomagnetic Pole: A purely mathematical abstraction of where the magnetic pole would be if our magnetic field worked like a bar magnet (it moves about 4 km per year).
South Pole of Inaccessibility: Is the centre of Antarctica defined as the point furthest from the sea. In the Arctic it’s the point equidistant from the surrounding land masses.
South Pole of Cold: Is the coldest point of the coldest place on earth. The Russian Vostok Base here, high on the Antarctic icecap, recorded -128.6° F (-89.2° C), the world’s lowest recorded temperature, on July 21, 1983.
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