Glaciers Flashcards
(Causes of climate change)
What is Continental Drift?
- How long ago
- What was created
- Glacial or interglacial?
LONG TERM
3 million years ago, N + S American tectonic plates collided.
-Resulted in re-routed ocean currents so that warm carribean waters forced northwest creating the gulf stream.
-Glacial Period- more evaporation so moist air goes to poles.
(Causes of climate change) What is Eccentricity of the orbit? -How long does last? -what happens -glacial or interglacial
LONG TERM
Shape of the earths orbit varies from circular to elliptical over 100,000 year cycles.
-The earth recives less radiation in the elliptical orbit when the Earth is farthest from the sun. (position known as Aphelion)
-Glacial - less solar radiation
(Causes of climate change) What is Axil tilt? -How long does last? -what happens -glacial or interglacial
LONG TERM
-Tilt of earths axis varies between 21.5 degrees and 24.5 over 41,000 year cycles.
This changes the severity of seasons.
-Glacial=if we were tilted away= it would be slightly colder
-Interglacial=tilted towards sun more
(Causes of climate change) What is 'Wobble'? -How long does last? -what happens -glacial or interglacial
LONG TERM
-the earth wobbles as it spins on its axis, which means that the season during which the earth is nearest sun. (position known as perihelion varies)
-at the moment-> northern hemisphere winter occurs in perihelion milder conditions than previous winters in aphelion
-approx 21,000 year cycles changes intensity of seasons
-interglacial as gets closerto sun
glacial- further
(Causes of climate change) What are Variations in solar output? -How long does last? -what happens -glacial or interglacial
SHORT TERM
-dark areas on sun caused by intense magnetic activity in suns interior.
an increase in amount of sunspots give off more energy
-11 year cycles
-interglacial
(Causes of climate change) What are Volcanic causes -How long does last? -what happens -glacial or interglacial
large eruptions=more ash, sulphur dioxide,water vapour+carbon dioxide (volcanic aerosols) globally distributed by winds. blocks suns radiation cooling earth
- ash can settle after few months, sulphur dioxide lasts longer.
- Glacial, solar cant get in
example of a kame
Yellow stone national park, wyoming
example of a kame terrace
lower loch Etive, scotland
example of an esker
munra esker, canada
example of a sandur
glaciar bay national park, alaska
example of a kettle hole
higgens lake- florida
example of a proglacial lake
solheimjokull iceland
example of a meltwater channel
orkney meltwater channel
what are the environmental values of glaciated landscapes
- they support a fragile biodiversity eg polar bears, arctic foxes and whales
- hydrological cycle-sea level rise
- carbon locked away- Yamal peninsula large carbon sink stores 2x atmosphere amount
what has the rate of ice mass loss increased by
181 gigatonnes between 1992-2001
what are the economic values of glaciated landscapes
- farming-mostly livestockas crops difficult to grow in rugged soil. crops that are planted include quinoa, potatoes and beans
- tourism- guided walks and heli rides
- forestry- difficlut to use land for farming forestry commission in uk grow fast conifers as they tolerate acidic soil
- mining and quarrying- igneous and metamorphic rocks, lowland areas rich in sands and gravel for concrete
- hydroelectricity-
what % of bolivia live in the andes
70%
what % of Bolivias GDP is from farming in the Andes
30%
what % of bolivias pop live below poverty line
60%- many of this is in mountains indigenous Indians
how much of norway and new zealand electricity is from Hydroelec
90%- from either natural ribbon lakes or dam or reservoir in glaciated valley
how many hydroelectric power stations does switzerland have and what % of elec is this
500
70%
they have improved quality of life in many villages
examples of natural threats to active and relict glaciate landscapes
- avalanches
- glacial outburst floods
- thick unstable till deposits
- natural climate change
- fragile ecosystem
examples of human threats to active and relict glaciate landscapes
- footpath erosion
- water and air pollution as well as littering
- overfishing
- construction
- resource exploitation
- climate change
- deforestation
what % of greenland is ice cover
80%
who owns greenland
denmark- granted self-government by danish in 1979
what is the demographic of greenland
88% inuit 12%European danish descent
0.14 people per km2
what was the rate of ice loss in greenland between 1992 and 2001
how does this differ between 2002 and 2011
- 34 gigatonnes a year
- 215 gigatonnes a year
how much did melting greenland ice contribute to sea level rise
what if whole sheet melted
0.33mm per year between 1993 and 2010
if whole sheet melted 7m increase
which cities would be effected if there was a sea level rise
which countries would dissapear
boston, new york, london, shanghai, LA
maldives, bangladesh and US state of florida
how does greenland play a vital role in global climate
-feedback cycles
high ice albedo reflects solar radiation
however ice loss is decreasing surface albedo increasing amount of solar absorbed which leads to positive feedback mechanism
how has inuit lifestyle changed
- live in towns, modern homes w/ appliances and work in mining and tourism
- still utilise glacial and periglacial landscapes to maintain traditional lifestyle of hunting and fishingand herding
what are the threats to inuit culture and lifestyle
-modern culture, conservationists and climate change
what is the economic value of greenland
meltwater hydroelectric - has worlds largest unexploited hydroelectric cacpacity
- as ice retreats also exposes deposits of rubies and gold
- tourism of cruises, peaks in summer
what are the threats to greenlands landscape
as well as ice loss and climate change
- increased industrial activity- oil and gas will bring in marine shipping and as ice retreats new commericial fishing routes in Arctic Northwest passage which leads to more pollution
- could be opened to large scale mining for uranium but there have been protests in 2014, fears of irreversible damage, waste would endanger fish
- political disputes -russia flag in 2007 created conflict with denmark and canada
describe the yamal peninsula environmental value
low biodiversity but global value particularly for birds, summer home for migratory birds
permafrost large carbon store and methane so if melts will increase vol of ghgs in atm
describe the yamal peninsula cultural value
nenets understanding of harsh conditions and fragile ecosystems has enabled them to live sustainably
reindeer as transport, clothing and hides for tents meats and income
nenets and reindeer migrate seasonally to avoid cold weather and overgrazing pastures
describe the yamal peninsula economic value
- reindeer support 10,000 nomad who herd over 300,000 domesticated reindeer in pastures of peninsula 80% is privately owned by herders.
- economic value of herding cant compete w/ natural resources underneath pastures as largets gas reserves under there1/4 of known reserves
- increasing investment to exploit
how much of world gas is in yamal peninsula
-1/4 (at risk of exploitation)
threats to yamal peninsula
-earlier spring melting and delays to freezing effect reindeer ability to cross tundra
-sinkholes caused by methane released by permafrost, change in carbon cycle will effect locals and biodiveristy
-infrastructure
-now controlled by gazprom will build 572km railway and pipelines evicted 160 reindeer herders
question if nenets can maintain their culture
benefits of gazprom in yamal peninsula
-build railways, kindergartens, hospitals, fisha nd venison factories, provide finacial compensation to nenets.
assess the value of one glaciated landscape
example can be others
cultural- greenland local people rely on fishing hunting ect but inuit lifestyle now threatened
- economically-tourism, glacier climbing cruises. threat to environment
- environment-ice stores 90% world freshwater, global warming increased sea level by 0.33 mm a year from greenland ice sheet
