- Created by: rchapman99
- Created on: 19-01-18 12:42
Antarctica has a unique environment and climate:
It covers and area about 14 million km^2.
It contains 90% of all the ice on Earth; around 70% of all the Earth's fresh water.
Part of the global commons.
There's very little available water in Antartica for plants to grow. The inland areas receive less than 166 mm of precipitation per year.
The average temperature is -49 degrees C. And there is little sunshine in winter.
Very few plants and animals survive and the ones that do have adapted.
The lack of water, warmth and sunlight in Antarctica means that the terrestrial ecosystem is very fragile; easily damaged.
At the Antarctic Convergence, there's upwelling of nutrient-rich cold water. Microscopic phytoplankton thrive here, which provide plenty of food for krill and form the basis of the whole Southern Ocean food chain.
There's abundant sea life, birds which survive on the sea life. The marine ecosystem is also fragile; if the population of one species decreases, it affects other species.
There are four main threats to Antarctica:
- Past 5 decades - west coast has warmed by 3 degrees C.
- Warming has cuased ice shelves to melt.
- Species of penguin that are adapted to sea ice, have declined as the ice has melted.
- Antarctic krill depend on the environment the sea ice provides. The krill population has declined by 80% since the 1970s.
- Global sea levels have risen by 3mm a year since the 1990s.
- Ocean acidification - when carbon dioxide in the air reacts with saltwater, it creates carbonic acid, which depletes the amount of calcium carbonate in the water.
Fishing and whaling:
- Over-fishing threatens many species. Reduced fish and krill populations disrupt food chains.
- Legal limits on how much fish can be cuaght per year to keep stocks at a sustainable level.
- Whaling was common in the mid-20th century, but has declined since 1982 when regulations were brought in to ban all commercial whaling.
- Significantly decreased the population, which is now slowly recovering.
Search for minerals:
- A lot of minerals in Antarctica; coal and iron ore.
- Large reserves of oil.
- Mining is currently banned, but conditions aren't favourable.
- However, this may change in the future due to increasing demand for minerals and oil as supplies are depleted elsewhere. Mining would damage the environment.
Tourism and research: