Antartica Flashcards
Physical features
Only polar land mass
Nearly 60 times the size of the UK
98% covered by ice and snow 4 1/2 feet thick
Coldest continent with an average temperature of -49 degrees celcius
Earths biggest desert
Average altitude is 2,300M
Life in Antartica
Very few terrestrial plants or animals can survive due to low air temperatures and long winters
The sea is much warmer than the land at -1.8 to +3.5 degrees celcius
The upwelling of nutrient rich water around the Antartic convergence supports a rich food web
Example food web
Phytoplankton eaten by zooplankton
Zooplankton eaten by krill, squid, small fish
Krill eaten by albatross, adelie penguin, emperor penguin, crabeater seal, baleen whale
Squid eaten by ross seal, weddel seal
Small fish eaten by ross seal, weddel seal, large fish, albatross
Crabeater seal eaten by orca, leopard seal
Emperor penguin eaten by leopard seal
Adelie penguin eaten by leopard seal
Large fish eaten by orca
Weddel seal eaten by orca
Ross seal eaten by orca
Leopard seal eaten by orca
Albatross and orca not eaten
Importance of Antartica
Unique features
Last pristine environment on earth
Maintains conditions for the rest of the planet
If all the ice on Antartica were to melt, sea levels would rise 75M
High albedo reduces global temperatures
Krill faeces falls to the bottom of the ocean and acts as a carbon sink
Threats to Antartica
Global climate change Ozone depletion Tourism Overfishing Future mineral extraction Scientific research
Global climate change
Temperature rise melts the land ice.
The resulting water lubricates glaciers, making them enter the water quicker
Krill feed on plankton on the underside of ice so a reduction in ice reduces the food web
Ozone depletion
Plankton is sensitive to UV light, so an increase could lead to reduced populations.
Tourism
Tourism in Antartica is rising rapidly
Most visit via ship.
Waste disposal, oil spills, wildlife disturbance are all risks of tourism
There are worries of diseases being transmitted from humans to wildlife
Most tourists land in the same areas, increasing impact in those areas
There have been proposals to limit the number of tourists allowed
Overfishing
Harvesting krill threatens the dependent species eg baleen whales
Overfishing of the patagonian toothfish threatens the food supplies of the sperm whale and elephant seal.
Long lining for toothfish kills many albatrosses as they get caught on the hooks
Future mineral extraction
Below the ice is many deposits of oil, coal, iron ore and other minerals
Pressure to exploit these deposits increase as reserves elsewhere run out
Scientific research
Fuel spills, waste management, building impacts are all threats associated with research
These have all been minimised by careful management
Case study- British Antarctic Survey (BAS)
BAS operates in 4 stations
Carries out research on climate change, geology, biodiversity, marine exploitation, sustainability
Environmental impact reduced in various ways
Oil tanks have secondary containment to reduce spills
Marine oil gas is used since its less persistent than other fuels
All waste except sewage and food is stored and removed
Dogs are no longer used to reduce the spread of disease
Abandoned bases are cleaned ad wastes removed
Conservation of Antarctica
Antarctic treaty signed in 1959
Military personnel only allowed for research or civilian activities
Scientific research must continue with free transfer of information and personnel
Nuclear explosions and radioactive waste disposal is banned
Commercial exploitation of minerals is banned
Conservation of living organisms including marine life
Monitored environmental impact of tourism
