Antarctica is the most southerly continent located about the Geographic South Pole, the southern point of the Earth's rotational axis. The magnetic South Pole is located off the coast of Antarctica. It is the 5th largest of the worlds 7 continents but was not sighted until 1820. The nearest landmasses are South America and Australia. Antarctica is a large land mass buried under a vast ice cap and surrounded by oceans. In this respect it is very different from the Arctic which is a frozen ocean surrounded by land, the North Pole is located on shifting sea-ice. The continent holds several records as the highest, driest, coldest and windiest on earth.
No people lived in Antarctica until 1897 when the first explorers
established a winter-over station. Now there are over 60 bases situated
all over the continent and operated by several nations.
The bases are primarily oriented to
scientific research.
As you would expect the weather in Antarctica is cold, but just how cold? Around the coast the weather can be surprisingly mild, regularly reaching freezing point in summer. It is on the high polar plateau that the coldest temperatures are experienced. The lowest ever temperature on Earth, -91C, was recorded in 1997 at Vostok station, an abandoned Soviet base near the centre of the Plateau.
At the South Pole the temperature varies from -20C at the height of summer to -70 in mid-winter. During the summer the temperature rises and falls with the angle of the sun producing a peaked temperature profile. Once the sun has set the temperature drops rapidly and stays roughly constant throughout winter. Under thick cloud cover the heat of the ice (yes the ice at -50C is actually warm compared to the atmosphere) is trapped and the temperature can rise quite substantially.
Click here for a graph of the weather experienced during the year I spent at the Pole.
Antarctica is the driest continent on earth with an absolute humidity lower than that of the Sahara Desert.
| Palmer Station | 64° 46' South 64° 03'West | |
|---|---|---|
| Average annual temperature: | -3°C | +26°F |
| Average summer temperature: | +2°C | +36°F |
| Average winter temperature: | -10°C | +14°F |
| McMurdo Station | 77° 51' South 166° 40'East | |
| Average annual temperature: | -17°C | 0°F |
| Highest temperature: | +8.3°C | +47°F |
| Lowest temperature: | -50°C | -58°F |
| South Pole Station | 90° South | |
| Average annual temperature: | -48°C | -56°F |
| Highest temperature: | -16°C | +3.1°F |
| Lowest temperature: | -82.7°C | -117°F |
| Coldest natural temperature on record anywhere: | ||
| Vostok station (Russian) | -91°C | -132°F |
| This is cold enough to shatter steel | ||
Winds in Antarctica are mostly caused by heavy cold air located over the Antarctic plateau falling under gravity towards the sea. As the air falls it gathers speeds and reaches speeds of over 300 knots at the coast. Sir Douglas Mawson's journals of his Antarctic expedition contains a graphic description of these terrible storms. At the Pole the air is still moving quite slowly with top speeds of just 30 knots. However even the slightest breeze can produce a terrible wind-chill, lowering the apparent temperature below -100C
| Mawson Station (Australia) | ||
|---|---|---|
| Average wind speed: | 67km/hr | 44mph |
| Highest wind speed: | 320km/hr | 198.8mph |
Antarctica is buried under a vast ice cap up to 4 km thick in places. The weight of this ice cap is so vast that much of the ground below is pressed down below sea-level.
The South Pole, near the centre of the Plateau, is at a physical altitude of 9,301 ft and so the atmospheric pressure is roughly 60 % of that at sea level. The Earth's rotation tends to cause the atmosphere to bulge at the equator and flatten at the Pole, this causes the pressure to drop further producing a physiological altitude(how high up it feels) of between 10,000 and 11,500 ft. Such high altitudes can cause shortness of breath and even altitude sickness for recent arrivals at the Pole. Each time I have visited the Pole I required a few hours breathing oxygen to get over the worst effects.
| Elevation | |||
|---|---|---|---|
| Average elevation: | 2,300 m | 7,546 ft | 1.4 miles |
| Highest point of ice cap: | 4,100 m | 13,451 ft | 2.5 miles |
| Mt Vinson Massif | 4,897 m | 16,066 ft | 3.0 miles |
| Size | |||||||
|---|---|---|---|---|---|---|---|
| Area: | 13,000,000 km2 (Twice the size of Australia) | ||||||
| Worlds largest glacier: |
Lambert Glacier (40 km wide/ 400 km long) | 70% of the world's fresh water is tied up in Antarctic ice |
Just 0.4% of Antarctica is NOT covered in ice |
| |||