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-