Module 3: Antartica Flashcards
Location
-southern most continent and site of South Pole.
-closest to continent South America
-population: 1000-5000.
Human characteristics of Antarctica, what do humans do there
-commercial fishing for a variety of species
-increasing tourist population
-population are scientists
-permanent human settlements but not human habitation
Physical characteristics
-almost completely covered by ice sheet
-beneath the sheets are hidden landscapes of mountain, villages and plains
-annual mean temp -16.9 degrees
Facts about Antarctica
-5.4million square miles
-less then 2inches rain per year
-98% covered by thick sheet of ice
-70% of worlds fresh water
-no one owns it but 7 nations have announced territorial claims
What is ablation
All processes that remove snow, ice, or water from a glacier or snowfield and erosion of snow
What is a nun attack
Very few areas of Antarctica are free from ice. An exposed often rocky element of a ridge, mountain, or peak not covered with ice or snow within an ice field or glacier
What is AC2
-a natural boundary separating two distinct hydrological regions (hot and cold water)
-step1: sea water that has cooled dramatically around the Antarctic continent and so become heavier, starts to flow northwards along the sea bed
-step2: it meets deep warmer south flowing water from equatorial regions at the Antarctica convergence which results in an upwelling of the deep waters to the surface
-step3: upwelling of water brings dissolves nutrients with it which acts like fertiliser for the southern ocean and is the reason that the seas around Antarctica are so surprisingly productive despite the cold temperatures
Process of movement of ocean warm and cold water
-water moves along gradients it wants to move from where it is warm to cold
-as the water becomes colder it becomes more dense and sinks
-in the oceans there is accelerated further by Changes in north Ayer salinity
-these changes to water temperature and salinity and the deduce of water to move along gradient of each creates a global circulation
What are the threats to Antarctica
-global climate change
-mining valuable metals
-increase in whaling
-increase in fishing for krill, squid and fish
-extraction of oil
-construction of land based hotels for tourists
-tourism bring in invasive species
-territorial claims
What are the 5 main threats to Antarctica
-climate change (ENV)
-fishing and whaling (ECON)
-tourism (ENV/ECON)
-the search for minerals (ECON)
-scientific research
What are the scientific pressures on Antarctica
-scientific research has been carried out in Antarctica since 1898
-there has been a rapid increase in bases established in Antarctica. 1000-5000 scientists
-brings environmental issues
What are the problems scientists bring to Antarctica/ what has changed since they have been there
-40 permanent bases
-26 airports
-53 heliports
-50 summer staff and 15 winter staff
-bases occupy areas of land of breeding space for penguins
-oil spills, Bahia Paraiso spilt 250,000 gallons of fuel in the sea
-most populations of species have seen a mortality rates less than 20%
-1995, 21000 gallons of oil was spilt
-Australia considered using their airport for tourism
What are the environmental pressure on Antarctica: krill
-krill are the lifeboat of the food web in Antarctica
-1999: 100,000 tones
-2012: 210,000 tones
-rich source of protein and fatty acid which are under development as human food and dietary supplements
What are the issues of overfishing krill
-disastrous impacts on larger predators
-penguin population could drop by 1/3
-krill feed in Marine algae which remove co2 resulting in an increase of co2
-global krill industry to grow by 12%
-spills of oil
-krill population has dropped by 80% since 1970
What is being done about the overfishing of krill
-a global campaign has been launched to turn a huge tract of Antarctic seas into ocean sanctuaries banning all fishing
-Ross sea in 2016 became a 1.8million sq/km sanctuary
-commission for the conservation of Antarctic marine living resources include 24 national government and tHe EU
-green peace
What is the doomsday glacier and why is it melting quicker then the east ice burgs
-120km ice berg along western Antarctica
-air and water temp is increasing. East Antarctic ice sheet is higher above the sea level with less underwater. Western Antarctica is majority under sea level, only thing that stops the ice sheet melting is the ice cap on the land creating a barrier between once sheet and ocean. (Tipping point)
What is happening to the Thwaites glacier and why is this a potential doomsday scenario
-3m added to sea level of melted
-moved back 14km since 1992
-contributes to 4% of sea level rise already
-it reaches into central Antarctica which would cause more melting resulting in.
What are the environmental pressures on Antarctica
-in last 50 years the peninsula warmed by 3 degrees, 3x higher then the global average of 0.9 degrees.
-distribution of penguins colonies has changed
-melting of perennial snow and ice covers has resulted in increased colonisation by the plants
-long term decline in the abundance of Antarctic krill in the SW
-glaciers retreating