Bedrock map of Antarctica obtained by the BEDMAP2 project of the British Antarctic Survey
Bedrock map of Antarctica obtained by the BEDMAP2 project of the British Antarctic Survey

By Bianca

There have been quite a few articles about Antarctica by now, but none of them actually about Antarctica itself.

For most people the seventh continent is isolated from everything, and that is actually true. Located at the South Pole, it is not easily visited. Not only because it is at the South Pole, but also because we are talking about an area almost double the size of Australia, with 98% of its area covered in ice throughout the year.

But it’s not only the ice coverage that makes the continent so unpleasant and fascinating at the same time. With an average temperature of -49°C, Antarctica is the coldest place on Earth and holds, with -89°C at Vostok, the record for the lowest temperature ever recorded on our planet.

Antarctica2Essentially, Antarctica is not just one big continent, but rather a combination of land, fjords and islands. The Transantarctic Mountains divide Antarctica into two contrasting parts: East and West Antarctica (including the Antarctic Peninsula).

While the East Antarctic ice sheet is widely build on bedrock, an old thick craton, the West Antarctic ice sheet is located on a puzzle of islands, with its bedrock largely below sea level. For that reason the mainly marine ice sheet is much more sensitive to changes in the surrounding ocean than the East Antarctic ice sheet and shows a rapid mass loss. [e.g. Remy and Frezzotti, 2006].

Antarctica3In total the surface ice coverage is around 14 million km2, containing 30 million km3 of ice, which is around 90% of all terrestrial ice. It has an average ice thickness of 2200m, reaching its maximum thickness of up to 4700m in parts of the East Antarctic interior. That amount of ice holds around 90% of the Earth’s fresh water, an equivalent of almost 70m of water in the world’s oceans.

Antarctica4Small wonder you can only find small ice-free areas (less than 1%), however, these areas are meant to have some of the most spectacular mountain ranges, with the 3000km long Transantarctic Mountains, and the Antarctic Peninsula, 1700km. The highest mountain is the Vinson Massif in the Ellsworth Mountains with a height of 4897m.

Strong winds make walking difficult
Strong winds make walking difficult

Antarctica is not only the coldest but also the driest and windiest continent on Earth. Known as a frozen desert, the interior hardly sees any precipitation, while there can be several meters of snowfall along the coastline. Once the snow has fallen it will likely be redistributed by the strong down-slope winds, known as katabatic winds. These winds form due to the high elevation of the polar plateau, carrying cold, dense air from higher elevation down the vertical slopes under the force of gravity. Under certain conditions these winds can reach hurricane speed, with the highest wind speed recorded at Dumont d’Urville station: 327 km/h.

As a result of these weather impacts, Antarctica even has ‘oases’, known as the Dry Valleys. Due to local and regional weather patterns there is no snow or ice in that rocky landscape – a paradise for geologists to collect rock samples and fossils, delivering hints on the multi-million-year history of Antarctica.

That is of great importance as the bedrock under the ice contains some of the oldest rocks on Earth, rocks as old as 4 billion years. Fossils found on the continent include dinosaurs, amphibians and marsupials from ages when Antarctica was joined to the supercontinent Gondwana. Back then Antarctica was a tropical place until it separated and started its way to its current position.

Nowadays, Antarctica is isolated and surrounded by the cold Southern Ocean and the climate is much harsher. Not many animals are living in these conditions; on land you mainly find penguins and other birds, seals, and insects (on the sub-Antarctic islands). These animals have to cope with dark, long and extreme winters, rather cold summers and sudden weather changes. The climate is controlled by the surrounding ocean and atmospheric changes but due to its size the continent also has a strong influence on its own weather.

At the South Pole you can only experience one sunrise and one sunset throughout the year. Annually, the sun rises on September 21 and doesn’t set until March 21. For weather phenomena such as halos or the aurora, Antarctica is the place to be.

Antarctica6