Karteikarten
Cold Environments
Karten in diesem Stapel (95)
- 1Main reasons cold environments form. high altitudes- temp decreases with altitude, less Sun's energy reflected back from Earth is trapped at higher altitude, pressure higher so temp higher
.high latitude- less solar radiation
. continentality- land cools and heats quicker than the sea - 2What is a glacial environmentarea permanently covered in ice- glaciers or ice sheets
- 3Where do glacial environments form?high latitudes- Antarctic Ice Sheet
high altitudes (regardless of latitude)- Himalayan mountains - 4What is a periglacial environment?where temperatures constantly or frequently below freezing, not covered by ice. Instead have a layer of permafrost on or below the surface
- 5Where are periglacial environments found?high latitudes- N Asia
high altitudes- Tibetan plateau in Asia
interior land masses- central Asia - 6What are alpine environments?cold areas of land at an altitude above the tree line (limit trees can grow)
- 7Where are alpine areas found?always high altitudes- Himalayas, can exist at any latitude
alpine environments include periglacial and glacial conditions. Temp decreases as altitude increases- permafrost - 8What are the 2 polar environments?Arctic polar environment and Antarctic polar environment
- 9What are the similarities between the 2 polar environments?. cold due to high latitude
. most made up of sea ice, shrinks in summer and refreezes in winter - 10What does the glacial system have?. inputs- ice, snow etc
. outputs- ice can melt, evaporation etc
. stores- main store is ice, meltwater, debris - 11What is the glacial budget?balance between accumulation and ablation over a year- shows volume of water in the glacial system increased or decreased, whether snout advance or retreats
- 12What is equilibrium?when the accumulation and ablation are equal
- 13How does a glacier form?. snow settles, loose fluffy snowflakes
. weight of more snow turns snow denser, more granular kind called firn
. air squeezed out, particles of ice compressed together by continuing accumulation of snow and ice
. water also melts and refreezes in air spaces, making ice more dense - 14What is a warm based glacier?base is warmer than melting point of ice.
Happens because heat of friction caused by glacier moving, or geothermal heat.
Meltwater acts as a lubricant , easier for glacier to travel downhill.
Lots of movement= lots of erosion - 15What is a cold based glacier?base is well below ice's melting point so very little melting.
Ice frozen to base of the valley= little movement.
Hardly any melting on surface either.
Therefore very little erosion - 16What is basal sliding?use of meltwater under a glacier to slide over the ground
- 17Why is there more melting around protruding rock?more pressure on the ice, meltwater can refreeze downstream of the obstruction where there's less pressure, flow tends to be faster around the obstruction, slower downstream
- 18What is rotational flow?glaciers move in an arc shape when they're in a hollow
- 19What is internal deformation? What kind of glacier uses this the most?ice bends and warps to flow down hill like a liquid. Caused by ice crystals shifting past each other.
.cold based - 20Head of a glacier the valley is steep, so strong gravitational force pulling ice downwards, making the ice move v quickly. When it moves quickly more tension causing ice to fracture into thinner layers. What is this called?extensional flow
- 21Lower down the glacier ice moving slowly as valley less steep. Faster ice from head pushes down on slower ice and compresses it. High pressure causes ice to fracture into layers. What is this?compressional flow
- 22Main things determining speed of a glacier?. gradient of valley floor
. thickness of ice
. temperature of the base - 23What are crevasses?stressed and strains cause cracks, caused by extensional flow
- 24How is a begschrund formed?tension caused by glacier pulling away from ice attached to the back wall produces SEMICIRCULAR crevasse at the back
- 25What is plucking?ice in contact with rock surfaces can thaw slightly then refreeze around rocks protruding from valley sides and floor. When glacier advances it plucks rock away from the sides and floor
- 26What is abrasion?debris carried along by glacier scrape material off valley sides and floor
- 27What erodes and shaped the valley floorhuge quantities of meltwater make streams that are powerful enough to erode valley floor
- 28How is rate and amount of erosion increased?. less resistant rock
. glacier is thick
. moving fast
. lots of debris - 29What is frost shattering?breaks rock off back and side walls of valley. Meltwater from snow gets into cracks in walls and freezes and expands and exerts pressure.
- 30Three ways debris is transported in a glacier. subglacially- moved at the base
. supraglacially- on top
. englacially- within - 31What is glaciers debris called?it is unsorted material called till
- 32Different types of till. lodgement till- spread on valley floor beneath ice by MOVING glaciers
. ablation till- dropped by glaciers as it melts. Mainly at snout - 33What is till deposited as?landforms called moraines
- 34Formation of a corrie. snow collects in hollows turns into ice
. basal sliding with abrasion and plucking deepen the hollow into a corrie
. when ice in hollow is thick enough, flows over the lip and downhill as a glacier
. frost shattering and plucking steepen the back wall - 35Formation of an aretesteep sided ridge
. two glaciers flow in parallel valleys
. glaciers erode sides of valley, which sharpens the mountain ridge in-between them - 36Formation of a pyramidal peakpointed mountain peak with at least three sides
. three or more corries from back to back - 37Formation of U shaped valleysteep sided valleys with flat bottoms
. erosion of v shaped valley river valleys by glaciers, making it deeper and wider - 38formation of hanging valley. formed by tributary glaciers
. erode valley floor much less deeply as they're smaller
. when glaciers melt, valleys get left at a higher level than U shaped valley
. get water falls - 39Formation of truncated spurs. spurs that stick out into the main valley are chopped off as main valley glacier moves past
- 40Formation of valley steps. glacier erodes valley floor more deeply where another glacier joins or less resistant rock
- 41Formation of tarns. form in corrie after glacier retreated
- 42formation of ribbon lakes. after a glacier retreats
. form in dips caused by erosion of bands of less resistant rock - 43formation of fjordslong, deep inlets that
. form when a valley eroded by glacier is flooded by rise in sea level after ice has melted - 44formation of roche mountonneeresistant mass of rock on valley floor
. stoss side is smooth due to abrasion as glacier went over it
. lee side is steep and rough where glacier has plucked it - 45Four different types of moraine. lateral- deposited where sides of the glacier were
. medial- deposited in centre of valley where two glaciers converge (where two lateral moraines join together)
. terminal- builds at end of the glacier, deposited as semicircular hillocks of till
. recessional- moraine left when the glacier retreats - 46What are drumlins?half-egg shaped hills of till, up to 1500 m long and 100 m high.
Stoss side is wide and tall and lee side is narrow and low.
often found in groups e.g. Ribble Valley Lancashire - 47What are erratics?rocks picked up by glacier and placed in area of different geology
- 48What are meltwater streams?landforms that erode the landscape, more than a normal river because pressure of ice means meltwater streams flow very quickly so lots of material to erode the landscape
. Made from meltwater , especially from warm based ones. - 49How meltwater streams form. surface meltwater filters through glacier + flows through tunnels under glacier, before running to the snout.
. meltwater streams form deepened throughs called meltwater channels.
. lots of erosive power means channels are wide and deep
. after glacier retreated, deep meltwater channels are left with shallow streams - 50What are braided streams?many meltwater streams are braided- split into lots of mini streams that cross over each other because meltwater flowing slowly it can't carry its load- deposits sediement on ground, and splits to get around it
- 51Difference between fluvioglacial depositional features and glacial depositional features?. fluvioglacial depositional features are sorted
. glacial deposits are unsorted - 52What is an outwash plain?layer of gravel, sand and clay that forms IN FRONT of where the snout of the melting glacier used to be.
Meltwater flows out of glacier taking sediment with it - 53How are outwash plains' sediment sorted into layers?. gravel dropped first as heavier, bottom layer
. clay dropped last and carried furthest away from snout as lightest, top layer - 54Formation of kettle holes?.blocks of ice that've broken off from snout can surrounded and partially buried by fluvioglacial deposits.
. when blocks of ice melt, they leave holes in outwash plain called kettle holes - 55What are eskers?. long, winding ridges of sand and gravel running in same direction as glacier.
. deposited by meltwater streams flowing in tunnels UNDER glacier- when glacier retreats and stream dries, load remains as an esker.
. they show you where the tunnel used to be - 56What are kames?.mounds of sand and gravel found on valley floor.
. meltwater streams ON TOP of glaciers collect in depressions and deposit layers of debris
. when ice melts debris is dumped on valley floor - 57What are kame terraces and their formation?. piles of deposits left against valley wall by meltwater streams that run between glacier and valley side.
look like lateral moraine, but sorted into layers - 58Formation of delta kames?. proglacial lakes can form in front of glaciers e.g. meltwater dammed by terminal moraine
. as meltwater streams flow into proglacial lake, they slow and deposit sediment on the ice- deltas.
. when ice melts, these deltas are dumped on valley floor- kame delta - 59What is permafrost?found in periglacial environments
. permanently frozen ground with top layer than can thaw in summer- active layer
. 20-25% world's land surface permafrost
. can be continuous (all ground frozen) or discontinuous (only patches are frozen) - 60How does discontinuous permafrost form?mean annual temperature needs to be below 0 degrees for at least 2 years
- 61How does continuous permafrost form?annual mean temperature must be below -5 degrees
- 62Why does the active layer get water logged?permafrost impermeable, so if active layer thaws the water can't go anywhere.
This waterlogged means water will easily flows wherever there's gradient.
This is called SOLIFLUCTION - 63Formation of ice wedges?. temperatures drop very low in winter, ground contracts and cracks form in the permafrost. This is called FROST CONTRACTION.
. when temperature increases, active layer thaws and meltwater seeps into the cracks
. permafrost layer still frozen so water freezes in cracks - ice wedges
. ice wedge can widen if they're split and more water seeps in - 64Ground water freezes causing frost heave. Explain this.. water freezing in ground makes humps on surface
. when active layer freezes in winter, ice forms lens shape
. in fine-grained soil the ice lifts up surface layer of soil- frost heave - 65Where else can ice lens form?. underneath stones because stones lose heat faster than soil around them, so when temperature drop it's colder beneath stones
. as ice lenses expand, they push stones upwards towards surface.
. ice lenses underneath stones stop stones from slipping down.
. if ice thaws, fine material fills in the space where ice was, so stones don't fall
.eventually stones rise above surface of ground - 66What is patterned ground?stones of surface of the ground arranged in patterns e.g. circles, polygons or stripes.
formed either by frost heave of frost contraction - 67Frost heave method of patterned ground. frost heave pushes stones to surface
. once reached surface they roll down edges of the mounds formed, so form circles around them
. if mounds on a slope, stones roll downhill and form lines - 68Frost contraction method of patterned ground. causes ground to crack in polygon shapes
. cracks get filled with stones, forming that shape - 69Formation of a nivation hollow. snow get in hollow in the ground, increasing size of hollow
. temperatures in periglacial areas fluctuates around 0 degrees so a lot of freezing and thawing happens
. every time ice freezes, it expands, so frost shattering eventually breaks off bits of rock at base of hollow
. when snow melts, meltwater transports debris away
. slopes collapse as waterlogged and been eroded
. eventually hollow becomes deeper and wider
. known as process called nivation
. start of corrie - 70What is solifluction. waterlogged active layer of soil flows easily over frozen impermeable layer beneath .
. solifluction produces lobe formations where one section of the soil moving faster than soil around it e.g. steeper ground, so flows down further to create tongue shape - 71What is a pingo?conical hill with a core of ice
. can be 80m high and 500m wide - 72What is an open system pingo?. forms where there's discontinuous permafrost.
. ground water forced up through gaps between areas of permafrost
. water collects together and freezes, forming a core of ice that pushes ground above upwards - 73What is a closed system pingo?. areas of continuous permafrost where there's a lake at the surface
. lake insulates ground, so area beneath remains unfrozen
. when lakes dries, ground no longer insulated and permafrost advances around area of unfrozen ground
. causes water to collect in centre of unfrozen ground
. water eventually freezes and creates core of ice that pushes ground above upwards - 74What do cold environments contain that attract developmentValuable resources
. whales, seals, fish- N Russia hunted for skins and largest fishing industry
. minerals- gold in Canada + Alaska led to gold rushes for mining
. oil- Alaska lots of oil
. attractive scenery- tourism, Antarctica risen from 6700 in 1992 to 46000 2007/8
. hydroelectric power- Norway 99% electricity - 75Why cold environments fragile. struggle to recover from damage
. fragile because of harsh climate
. short growing season, don't have much time to recover if damaged
. plants and animals adapted to CE, so find it hard to survive if environment changes
. decay slow due to cold, pollution broken down v slowly - 76Where is the Tundra?found where too cold for trees to grow, either because high altitude or latitude.
Artic Tundra found in Greenland, N Russia, and Canada. Antarctic Tundra found in islands around Antartica. - 77How fishing in CE can damage ecosystems. disrupt food chains e.g. krill fishing in S Ocean depleting food supplies for whales
. overfishing of species severely deplete its population, Patagonian Toothfish in Antarctic is currently a concern
. bottom trawling catches fish by dragging nets along bed. Disrupts ecosystems and catches other species e.g. Gulf of Alaska, Greenland sea, Barents Sea - 78How oiling in CE can damage ecosystems. oils spills occur during transport e.g. 1989 huge oil spill off coast of Alaska when Exxon Valdez oil tanker crashed. 40 million litres spilt into ocean, 250000 fish and birds killed
. oil spills occur if pipe lines leak. 1977-1994 there were, on average, 30-40 spills a year from Trans-Alaska pipeline. Some caused by intentional attack and forest fires - 79How hydroelectric power production in CE can damage ecosystems. hydroelectric dams can block normal migratory path of fish, preventing them reaching spawning grounds, population may decrease
. hydroelectric dams also heat up water, can endanger fish that are used to colder temperatures - 80How tourism in CE can damage ecosystems. large cruise ships increase pollution in areas
. tourists and tourism developments disrupt wildlife and damage habitats leading to reduction in biodiversity - 81How mining in CE can damage ecosystems. can lead to ground and surface water contamination, by chemicals used during mining or materials being mined e.g. lead-zinc mine in Maarmorilik (Greenland) closed 1990 but lead and zinc still released, polluting fjords
. mining produces solid waste and waste water to be disposed of e.g. Red Dog Mine in Alaska, facilities aren't built to deal with quantities produced and waste released into environment - 82Who are Inuit people?group of tribes live in the tundra in N Canada, Greenland and Russia. Traditional way of life involves hunting and fishing
- 83How did newcomers from Europe and US in 17th century negatively affect people living in the tundra?. brought new diseases with them- infected and died e.g. late 19 C 90% of Canadian Inuit tribe killed by diseases
. increased whaling, sealing and fishing reduced numbers for Inuit people to catch - 84How has development in tundra (Canada) had big impact on lifestyle of the indigenous people?. aren't enough resources for Inuit tribes to support themselves by hunting and fishing so they find paid employment. Difficult as few job opportunities usually taken by more educated white people
. unemployment under 50% amongst some communities, rely on government
. change of employment led to Inuits living in permanent settlements - 85How can development in CE be made more sustainable?. National parks to allow tourism while protecting environment e.g. Denali NP in Alaska 1917 expanded in 1980, cars banned from park, travel by buses, some places have no road yet
. fishing quotas been introduced e.g. Barents Sea, limit number of fish caught and prevent overexploitation
. oil pipes automatic shut-off valves to minimise oil spills - 86Where is Antartica?. largest wilderness area on Earth- covers 14million km
. 90% world's ice, 70% fresh water - 87Why is it fragile?. slow rate of plant growth
. limited species
. fluctuations in energy in food chain
. if disturbed could take 50 years to return to original state - 88Use of the Southern Ocean. fishing- krill, affects food web
. seals for fur- over 3 year 30000 killed
. whaling- species dangerously low, 19 C 275000 in 1964 1000-2000 (after restrictions) more than 5000 whales left, international whaling conservation 1946 - 89How is the Antarctic protected?ANTARCTIC TREATY
. protocol for environmental protection since 1961
. 12 countries set aside who owns it and set laws in place to protect it
. many protocols and conventions that control/prohibit certain activities - 90Oil extraction and mining in Antartica?. currently banned due to possible huge environmental impacts
. Madrid Protocol (part of Antarctic treaty) in 1998, banning all mining and oil extraction- reviewed in 2048
. some feel ban should be lifted in 2048 due for need for minerals and oil - 91Whaling in Antartica?. whaling was allowed in the Antarctic, but caused decrease in whale populations e.g. estimated 250000 blue whales century ago, now fewer than 1000
. in 1994 whole Antarctic area was declared whale sanctuary and commercial hunting prohibited - 92Sustainable management for tourism in Antarctic. Antarctic treaty prohibits discharging oil/plastic from cruise ships
. tour operators stick to Antarctic treaty, most self-regulated by the IAATO. Imposes restrictions on tourist activity to reduce environ impact, e.g. no more than 100 passengers allowed on shore in 1 place at a time - 93Sustainable management for scientific research. Protocol on Environmental Protection (1998) part of Antarctic treaty.
. includes rules that protect Antarctica from damage caused by research e.g. scientists remove most waste from Antarctic, treat sewage before disposed - 94Sustainable management for fishing. Convention for Conservation of Antarctic Marine Living Resources(1982) part of Antarctic treaty
. includes quotas on fish such as krill - 95How many tourists visited Antarctic in 2007-8?46000
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- A Levels Geography (Sections ) Karteikarten am Cold Environments, erstellt von Alice Kimpton am 05/03/2016.
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