Antarctica

Background and location

Antarctica is the 5th largest continent, 25 per cent larger than Europe.

This single continent covers an area of approximately 14 million sq km. It is also the world’s highest continent, with an average land height of 2,300 metres.

During the winter, much of the water surrounding Antarctica freezes. This sea ice nearly doubles the size of Antarctica.

The South Pole is on Antarctica and the Southern Ocean surrounds the continent. From here, everywhere else in the world is north. No one lives in Antarctica permanently, though many scientists stay for long periods of time to carry out research. Countries have claimed ownership of parts of Antarctica.

The Antarctic Treaty was agreed in 1961 to help control human activity in the location and also to resolve disagreements over territory. It has been agreed that:

  • Countries who have signed up to the treaty are free to carry out scientific experiments and must share their results.

  • The environment must be conserved.

  • There must be no dumping of nuclear or radioactive waste.

  • The land is to be used for peaceful purposes only – no military activity is allowed.

  • Any new activities must be properly assessed for their environmental impact. Any impact must be minimised.

 

Climate change, the ozone layer and mineral extraction

Climate change

Studying the Antarctic ice cores has given scientists much information about how the climate has changed in the past. Each section of an ice core contains details of the atmosphere and environment over thousands of years.

Scientists are concerned about the thinning of the ice sheets. In 2002, one ice sheet collapsed into the sea. If the ice sheets melt then global sea levels could rise. The world’s population who live on low-lying land are threatened because of this.

 

The ozone layer

Studies in Antarctica revealed how the ozone layer is very thin above the Antarctic. The ozone layer protects us from the harmful rays of the Sun. Internationally, agreements were made to ban CFCs – a chemical linked with the reduction of the layer. These agreements have led to a reduction in the amount of ozone-depleting gases in the atmosphere. These changes in the atmosphere show how sensitive the atmosphere is to pollution and the different gases that are released because of human activity.

Mineral extraction

Extracting oil from Antarctica has been too expensive to consider in the past. However, as more land is exposed, building pipelines on the land is becoming a more viable option. As the price of oil increases and the availability of oil decreases, countries look to Antarctica as a possible location for supply.

Extraction of oil and minerals is banned for 50 years through the Antarctic treaty.

Potential resources in Antarctica

A resource is something that exists within the environment. It has the potential to have value. The Antarctic treaty has banned the exploitation of extracting resources for 50 years. However, global issues still place pressure to exploit these resources.

There are many resources in Antarctica, which include:

  • Mineral and energy resources – most is currently covered by snow, including the world’s largest known coalfield.

  • Fresh water extraction from icebergs (70 per cent of the world’s fresh water is in Antarctica).

  • Resources from the sealife – eg farming of fish and krill.

  • Scientific resources – scientists can study weather patterns, ecosystem adoptions and the past climatic and geological changes.

Tourism also offers potential because of the attraction of this unique wilderness.

The map below shows where resources are in Antarctica.

 

Ecosystems in Antarctica

The ecosystem of Antarctica has adapted to the harsh climatic conditions. These harsh conditions limit the complexity of thefood web.

  • On land, there are no trees or shrubs, and very few flowering plants. Mites and midges are at the top of the food chain (excluding the Antarctic sub-islands). Organisms are small, with a low total biomass.

  • Penguins, seen on land, rely on food in the sea for their energy and so are part of the marine ecosystem.

Unlike the land, the waters surrounding Antarctica are rich in life. The cold temperatures increase the movement between surface water and deeper water, encouraging the phytoplankton to photosynthesise. The food webs in the oceans are more complex than on the land, and contain more biomassincluding both whales and penguins.

 

Climate

Antarctica can be called a desert because of the low levels of precipitation. Antarctica has the coldest land temperature recorded on the earth of -89.2°C. The average annual temperature is around -50°C.

The precipitation in Antarctica is mainly snow. In coastal regions about 200 mm can fall annually. In mountainous regions and on the East Antarctica plateau the amount is less than 50 mm annually. is not as high as other desert regions because it is so cold, so the snow gradually builds up year after year. There are also strong winds, with recordings of up to 200 mph being made.

Antarctica’s seasons are opposite to the seasons that we’re familiar with in the UK. Antarctic summers happen at the same time as UK winters. This is because Antarctica is in the Southern Hemisphere, which faces the Sun during our winter time.

Why is it so cold and dry?

  • The angle of the Sun is low in the sky. This means the energy from the Sun spreads out over a large area.

  • The area has 24 hours of darkness for some of the winter. Therefore, there is no sunlight for long periods of time.

  • The surface of Antarctica has a high albedo. This means that a lot of the energy received from the Sun is reflected back into space.

  • The high altitude of the land. Temperatures decrease approximately 1°C for every 100 m increase in height.

  • Cold air cannot hold as much water vapour as warm air, so precipitation is less likely.

  • Oceans store heat so they often create milder temperatures and increased rainfall. However, as Antarctica is such a large land mass, only the very edges of the continent experience this effect.

The ice in Antarctica

The ice in Antarctica is on average 2.5 km thick.

Nearly 99 per cent of Antarctica is covered by an ice sheet. The ice sheet moves by gravity downhill. A few mountain peaks may be seen above the ice sheet. These are called Nunataks.

How icebergs are formed:

  • Glaciers are formed within the ice sheet.

  • As these glaciers move, the ice within them cracks, creating largecrevasses.

  • When the glacier flows into the sea, an ice shelf is formed.

  • The ice shelf floats on the water. The largest ice shelf in Antarctica is the Ross Ice Shelf.

  • If the blocks of ice break free from the glacier, a process called ‘calving’ forms icebergs.

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