Antarctica Flashcards
Where is Antarctica
On the south pole
How big is Antarctica?
14,000,000km² - 5th largest continent. Its 2 largest ice shelves (Ross and Rome) are larger than the British isle.
Southern Ocean
Introduced in 2000. Is located at 60° south of the equator, fully circling Antarctica.
Antarctic convergence zone
32-48km wide area of ocean where cold Antarctic water meets the warmer sub-Antarctic water. The colder Antarctic waters are denser so sink, allowing warmer water up, creating a zone of biological productivity.
Antarctic Circumpolar Current
An ocean current that flows clockwise around Antarctica, blocking warmer water travelling south.
Known as the West Wind Drift
Antarctic Divergence
A lesser ocean current around Antarctica.
Flows counterclockwise, blown by Easterly winds
What ice sheets make up Antarctica
East Ice sheet and West Ice sheet.
They are divided by the transantarctic mountain range.
The East sheet is bigger and thicker than the West sheet.
Together they make up the Antarctic Ice Sheet
How much of Antarctica is covered by the Antarctic Ice Sheet
98%
How much of the world’s surface fresh water does the Antarctic Ice Sheet hold?
90%
Average temperature of Antarctica
-49°c but can reach up to -89°c
Average windspeed of Antarctica
Mean annual wind speed is 50 miles per hour
Gales can reach 200mph
Average rainfall of Antarctica
Mean annual precipitation is low.
Interior has an average of less than 50 mm/year
Coastal areas can have 400-600+ mm/year.
Lack of rain means it can be called a polar desert
How are the ice sheets formed on Antarctica?
Formed from lots of small amounts of snow and frost building up over time instead of from heavy snowfall.
How diverse is Antarctica?
Marine life is very diverse.
Surrounding sea temperatures are warmer than the land and upwelling cooler water brings nutrients that phytoplankton feed on.
Why are phytoplankton important?
Phytoplankton provide food for other marine life and are the base of the marine food web.
What are the main threats to Antarctica?
Climate change
Fishing and whaling
Tourism and research
Exploitation of minerals and resources
How is climate change a threat to ice in Antarctica
Antarctic temperatures are rising 2-3 times faster than the global average, causing ice sheets and glaciers to melt.
Antarctica is losing 150 billion tons of ice per year
How is climate change a threat to animals in Antarctica
Changing temperatures can shift timing of natural events like migration and breeding of birds.
Melting sea ice can cause habitat loss and reduce feeding areas - Adelie penguins need stable sea ice for nests and to raise young.
As oceans absorb more CO2 they become more acidic which can cause a decrease in krill and phytoplankton.
How is fishing a threat to Antarctica
Unsustainable fishing causes species to become in risk of becoming endangered - toothfish
Overfishing can imbalance the food web, damaging marine ecosystems
Other species can be caught in fishing nets - dolphins, albatross.
How is whaling a threat to Antarctica
Commercial whaling started in Antarctica after whale numbers dropped in the Atlantic.
Whaling started in Antarctica, bringing some species close to extinction before whaling of blue whales was banned in 1965.
Some countries still hunt whales - Japan has killed 9,409 whales in the Southern Ocean in the name of ‘scientific research’.
How many research stations are there in Antarctica.
There are 82 research stations across Antarctica with populations ranging between 5000 in summer and 1000 in winter.
What was built to help with sewage management.
A waste treatment plant at Australia’s Davis station.
How is research a threat to Antarctica
Research activities such as drilling can disturb wildlife and disrupt feeding and breeding.
Transporting resources like fuel and supplies to research stations can cause pollution.
Sewage needs to be carefully managed so as not to impact Antarctica’s environment.
Scientists could also accidentally introduce invasive species.
How is tourism a threat to Antarctica
Tourists can disturb wildlife - tourist activities have changed penguins reproductive and social behaviours.
Tourists can damage the environment - littering.
Travelling to Antarctica has a high carbon footprint.
