Flashcards in Antarctica Deck (63)
Antarctica is the driest continent because...
Its' annual precipitation is 50mm- polar desert
Antarctica is the windiest continent because...
Smooth Antarctic surface allows for fast winds not slowed by surface friction
Antarctica is the coldest continent because...
Average temperature is -49oc (feels colder due to wind chill)
Opposite of accumulation
Processes that remove snow, ice, and water from a glacier or snowfield
(i.e. evaporation, melting of snow, ice running off a glacier, removal of snow by wind)
An exposed, often rock element of ridge, mountain or peak not covered with ice or snow within (or at the edge of) an ice field or glacier
Antarctic Convergence Zone
A natural boundary separating 2 distinct hydrological regions, areas of distinct climate, areas of distinct wildlife
Why does the Antarctic Convergence Zone vary seasonally?
Due to the expansion and contraction of sea ice
Salt water moving along gradients creates the global thermohaline circulation
Water moves from hot to cold (convection)
Changes in salinity accelerate these changes
2 main factors that have increased the threat Antarctica faces
Technology- we can now get there
Greater demand for resources- exploiting Antarctica is now economically viable
What are the 4 main threats Antarctica faces?
Fishing and Whaling
Tourism and Scientific Research
Climate Change: Which parts of Antarctica are cooling?
Which parts aren't?
East cooling- not near the coastal parts (ocean a radiator)
West melting- likely the East will grow as the West melts
Climate Change: What is the melting of the Antarctic Peninsula causing?
Positive dieback- loss of ice shelves has caused ice to speed up in land
Climate Change: How many tonnes of ice have been lost each year since 1993?
By how much have global sea levels increased as a result?
100 billion tonnes each year
Increased global sea levels by 0.2mm a year
Climate Change: What will partly offset the increase in the rate of ice melt?
Increased snow fall
Climate Change: By how much has Southern Ocean temperatures increased since 1995?
Climate Change: What impacts has the Southern Ocean warming more quickly that the oceans globally had?
Changed distribution of penguin colonies
Krill populations fallen by up to 80% in last 40 years
Melting snow = increased plant colonisation
Climate Change: Although the melting of ice shelves doesn't contribute to sea level rise, how do they cause it?
Rate of flow of glaciers behind the ice shelves increases
These glaciers melt = sea level rise
Climate Change: Why might sea ice be expanding on the eastern side of Antarctica?
More snow and rain layering Southern Ocean with a cooler, denser top
More storms = local waters less salty, raises temp. of ice formation
Melting of continental land ice = icebergs- contributes to sea ice formation
Climate Change: What is the problem with the carbonic acid that would be created with increased atmospheric carbon dioxide?
Oceans would become a little more acidic
Could potentially corrode unprotected shells and skeletons- problems with food chain
Climate Change: Why would some argue global trade/ globalisation was responsible for climate change?
Global trade has increased movement of goods- increased fossil fuel consumption
(Antarctica doesn't benefit from this trade at all, it is instead impacted by the pollution and waste generated from the trade)
Fishing and Whaling: Why are krill so heavily fished around Antarctica?
Fishing restrictions implemented in Northern Hemisphere
2007, catch allowance increased by nearly 600%
Fishing and Whaling: Problems with over fishing of krill?
Impacts food chain
Fishing and Whaling: When did whaling begin in this area?
Fishing and Whaling: Where was the whale processing station located?
Fishing and Whaling: When was commercial whaling banned?
Mineral Exploitation: Where is there a large amount of coal?
On the coast and in the mountains
Mineral Exploitation: How many barrels of oil do the Ross and Weddell Seas combined hold?
50 billion barrels of oil
Mineral Exploitation: Demand for minerals could cause global ____ in the future
Many countries already put in claims as safeguard measures
Tourism and Scientific Research: How many permanent scientific bases are there?
Means resources have to be flown or shipped in