Flashcards in Antarctica (a global common) Deck (32)
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1
what is ablation
the opposite of accumulation, refers to all processes that remove snow, ice or water from a glacier or snow field
2
what is a nunatak
is an exposed, often rocky element of a ridge, mountain or peak not covered with ice or snow within an ice field or glacier
3
what is the Antarctic convergence zone
a natural boundary separating two distinct hydrological regions/areas of distinct climate/areas of distinct wildlife
4
what is the global thermohaline circulation (explain it)
water wants to move from where it is warm to where it is colder - but when water becomes colder it sinks. in the oceans this is accelerated further by changes in ocean salinity. these changes in temperature and salinity and the desire of water to move along gradients create the global thermohaline circulation
5
where does surface flow for the global thermohaline circulation come from
the tropics (warmest water)
6
where does bottom flow for the global thermohaline circulation come from
Antarctica (coldest water)
7
where is Vostok
is a south pole station- is isolated in the middle of the continent- in the coldest part of Antarctica
8
in which months is Antarctica warmest
October, November and December (temperature peak is in December and January)
9
main 4 threats to Antarctica
climate change
fishing and whaling
search for minerals
tourism and scientific research
10
Krill: there is a NEGATIVE feedback on
species that eat krill (as there is less krill in the oceans)
11
Krill: there is a POSITIVE feedback on
species that are eaten by krill
12
what impact has climate change has on Antarctica
parts of Antarctica are cooling and accumulating ice
the Antarctic peninsula has lost several large ice shelves causing a speed up of ice inland (positive dieback)
13
how many birds breed along the coast of Antarctica
100 million (from 35 species)
14
how many permanent scientific bases are there in Antarctica
40
15
example of an organisation that regulates tourism in Antarctica
International Association of Antarctic Tour Operators (compromised of 99 companies from 16 countries- membership is voluntary)
16
economic pressures on Antarctica: fishing and whaling
already an issue as Antarctica is rich in fish stock
number of krill dropped in the 1970s
increase in allowance of catch - to reduce pressure elsewhere
17
where are fishing restrictions
in the north sea- so people have gone to the south sea
18
when was whaling banned and by who
banned in 1904 by the IWC. but still allowed to for scientific purposes
19
mineral exploitation in Antarctica
need for fuels. coal found on the coast and on mountains
20
how many barrels of oil can be extracted in the Ross Sea area
50 billion- but no one is allowed to as it could cause conflict
21
negative impacts of scientific research
limited breeding space for penguins due to research
risk of oil spills and accidents from supply ships
22
research impacts: argentina 1989
in 1989 an argentine ship released 250,000 gallons of oil into the sea- affecting species of krill and sea birds
23
how many tourists come to Antarctica every year
1000
24
issues of tourism in Antarctica
more vessels on seas around Antarctica
little policing and management in place (no quarantine)
25
how much does it cost a tourist to go to antarctica
£4,500 to see it
£15,000 to get on land
26
how much has the temperature of Antarctica increased by
3 degrees celcius (faster than anywhere else- 5X the mean rate of global warming)
27
how much has the population of emperor penguins declined by in some areas
50% - breed on sea ice which is retreating
28
since the 1950s how many km2 of ice shelf has been left
28,000 km2
29
what species will be affected by the decline in krill numbers
whales, seals and penguins
30
