Glaciation
Glaciers as a systems
Inputs in glacial system:
Nature and distribution of cold environments
Fragile cold environments
Fragile cold enviornment is an enviornmennt which needs to are be handled with care where the slightest of change can have significant effects and is not easily reversible
How plants have adapted to fragile cold enviornments:
cushioned structure e.g cushion plants, low growing compact plants therefor ware shielded from cold and windy conditions
helotropic which means they can track sunlight for maximum sun exposure for increased photosynthesis e.g arctic poppy which has snow buttercups
lichen does not need soil to grow, it grows very slowly and can withstand cold temperatures and survive underneath snow cover
Svalabard Case study
Location:
Svalabrd is a Norwegian territory in the Arctic Ocean
The most Northern permanently inhabited group of islands in the world
5 major islands and numerous smaller islands
Glaciated landcape from beyond the UK
Characterists of Svalbard
Svalbards population (2700) live in Longyearbyen
60% is currently covered in ice caps and glaciers, the rest is permafrost
30% barren ground, 10% vegetated
No arable land or trees
Wildlife include plankton, seals, whales, arctic fox's and polar bears
Challenges of Svalbard
Climate challanges:
Very low temperatures average below -5 degrees in the summer and -16 degrees in the winter, snow blizzards and snow on the ground for long periods
Population must have warm clothing to prevent hypothermia
Soils:
Soils are thin, stony and poor developed soils, steep slope and mountainous relief
Hard to grow crops from poorly developed soils and harder for communities to form as little produce can be made
Permafrost:
Active layer thaws in the summer
Permafrost exists all over Svalbard to a depth of 100m to 150m, 40% land area is permafrost
Climate characterists:
Very low temperatures of 5-6 degrees in the summer and between -16 degrees in the summer
It has short growing seasons and summers
Opportunities
Tourism:
Coal mining:
Fishing:
The cold waters to the south of Svalbard have the richest fishing grounds this means there is an opportunity for locals to export high quality fish for fish for high prices which will benefit local economy.
Norway and Russia have strict sustainable fishing method which ensure the ecosystem is protected - this means fishing is sustainable and fish populations aren't depleted and have protection from overfishing in the long-term.
Potential for continued economic growth as fishing industry can continue
In 2013 70,000 people visited Longerybyen
Extreme tourism has become increasingly popular from attraction of the natural environment or study its historical development
Tourism has increased by 30,000 a year through increased accessibility through flights and connection is easier through processes of globalisation
Tourism is a major employment sector more employment opportunities for locals and benefit economy for locals
300 people have jobs in this indutry
Cruises proved education on conservation of arctic environment i.e., clean up Svalbard schemes to encourage litter pickups.
Has large coal reserves
It was the main economic activity provided 300 jobs
Environmentalist and political powers have meant price of coal has declined and new investment in renewable energy
Challenges
Fishing:
Always room for exploitation and pollution of seas as global population increases, more demand for food so more need to match future population
Risk of pollution from tourism boats which can impact fish ecosystem to small extent
The regulations only ensures outer limits of Svalbard are proptected, therefore protection of fishing on extends local scale
Tourism:
Small litter disruption to ecosystem
Cruise ships are source of pollution which can impact marine wildlife
In the future as temperatures increase, more ice melts which can mean cruise ships are able to access larger parts around the island - potential for future impact
Challenges for constructive and infastructure:
The ground is mainly permafrost which previously provided solid foundations for construction
As temperatures are warming the permafrost is thawing which has meant the ground is unstable where grounds are beginning to sinks and become waterlogged
Human activities
Coal mining, fishing, tourism and scientific exploration
All have spacial and temporal impact and will continue to have an impact in the future
large industry with most present day mining occurring in Sveagrama, 50km south-east of Longyerbyen
State-owned mining company employs a third of all workers on svalbard
Impact of human activities on physical landscape and natural enviornment
Coal mining
Impact on physical environment at local scale - mining requires drilling of rock and the use of heavy machinery to dig up the ground - results in potential for permafrost being broken and thawing due to heat generated by machinery
large scale impact as Svalbard becomes less glaciated - thawing releases CO2 and methane which enhances greenhouse effect, increasing temperatures and introduced positive feedback loop and more permafrost melting
Whilst coal mining still employs 200 residents number has decreases but 400 since 1990
Decreases demand for coal and falling oil prices, mines were closed only 7 functioning mines - as mines close there's less of impact on physical environment and impact on natural environment both specially and temporary is limited
Toursim
Large industry in Svalbard visiting the ascherpelago or cruise ships as early as 1820
Tourism has largely incresed, especially since airport opened in 1975
Increased access to Svalbard due to increased globalisation links like transport results in shifting flows In the area - more flights, more CO2 emissions into the atmopshere
Building on airport would have resulted in destruction of natural enviornment
Cruise ships create pollution as CO2 is released from their engines, increased risk of oil spills which destroy marine wildlfie
Fishing
Cold Barents Sea south of Svalbard have richest fishing grounds
Potential for mass fishing to occur, potential for more emissions from boats and increased oil spills - long term impact on hydrosphere
Potential for overfishing which would decrease fish population and marine and land animals which rely on fish for food
Norway and Russia have controls and monitors fishing practices to enable sustainability which limits large scale impacts
Systems and proccesses
Warm based glaciers
Occur in temperate regions
Temp at base is pressure melting point
Heat generated by earth increases melting
meltwater assists movement of glacier
Active erosion and transporting
Basal sliding
Cold bases glaciers
Occur in high latitudes
Ice temp below pressure melting point
Little meltwater which means movement is very slow and moves by internal deformation
Little erosion due to less erosion
Pleistocene era:
Began from 2.6 million years ago till 11,700 years ago
Epoch, at one point sheets of ice has covered all parts of Europe and South America, climate was much colder since most of the earth's water was frozen and global tempaertires were 5 to 10 degrees
18,000 years ago there was glacial max was reached, this was when ice was at its greatest extent and much of Northern hemisphere was buried under extensive ice
Laurentide ice sheet extended from the Arctic with its southern margin reached New York
Ice covered 75% of Canada, reached thickness of 4km
Scandanavia ice sheet extended across North Sea to the British Isles and reached London
In the northern hemisphere water was locked up in glaciers
Tectonic activity
Convection currents travelling around the equator were cut off by North and South America colliding
Warm water Brough moisture into northern hemisphere which meant more formation of snow and ice cover
Significant event in onset of Pleistocene era 2.6 million years ago
Glacial budget - balance between accumulation and ablation
Mer de Glace
Located in Chamonix in the French Alps
French Alps have lost a quarter of their area since the 1970s
Largest glacier is the Alps
Lost 70 metres in thickness at Montenevers Station from 1995 to 2005
12km long
during little ice age the glacier extended to the floor of the Valle de Chamonix to 1000m
Since little ice age its retreated 2300m
Gulkana Glacier
Located in Alaska range USA
In 2011area of 16.7 km
Erosinal and depositional landforms
Corries
Glacial troughs
Hanging valleys
Rouche mountonees
Morains
Till plains
Fluvioglacial landforms
Esker
example Kippit Hills Esker Aberdeenshire
Long sinus ridge of deposited glacial material
Water travels through sub and englacial channels
High hydrostatic pressure allows meltwater to carry heavy material
When stream reaches snout, pressure decreases and meltwater looses its energy and deposits material
Continuously retreating snout leads to linear deposits of material
Kames
steep sided mound of sand and gravel deposed by a melting ice sheet
Two types kame delta - flat topped, elongate deposit formed between between an ice margin and glacier
Crevasse kame - ice melts on deposited on valley floor forming small hummocks
Outwash plain
Extensive area of deposited material
At the end of glacial period when the glacier is retreating, large amounts of water is released which is carrying glacial material
Basal sliding - meltwater flowing beneath glacier facilitates movement and erosion process and the base of the glaciers
Accounts for 75% of movement within a warm based glacier
Fluvioglacial proccess
Meltwater carries lots of sediment inside, on top and underneath the glacier
Fluvioglacial deposits are sorted
Periglacial proccesses
Permafrost permanently frozen ground. Active layer can melt in the summer, 20-25% earth's surface is permafrost
Discontinous permafrost - mean annualn temperature below 0 degrees for at least two years
Continous permafrost - mean annual temp below -5
Mass movement (solifluction) - when summer temperatures rise enough to melt active layer where huge amounts of water is held, downward movement of material by gravity
frost creep- mass movement characterised by heave
solifluction - mass movement characterised by flow
Managment of fragile cold enviornments
How companies avoid oil spills
Pipeline pigs, computers for data, stilts, safety equipment
Trans Atlantic pipeline
1.2km in diameter and 1200km long
Pipeline runs through Alaskan country side from the bay to port of Valdez
Aims to satisfy economic and and environmental demands - the pipelines are insulated and raised on stilts to prevent the warm oil melting underlying permafrost
Pipeline operators to maintain and mintor pipelines from within, monitoring movement of petroleum within the pipes if a leak were to occur they could control the amount of spill to the enviornment
successful protection (9700) barrels have been spilt which Is small amount
effective high technology to prevent large scale spillages
has prevented melting of permafrost successfully
Adaption strategies - Prudhoe bay oilfields reserves have started to decline and companies are considering alternate locations
Adaption - learning to live with change
Reaction - responding to an event once it has occurred e.g, cleaning up oil spills
Prevention - attempting to prevent harmful events occurring
Example of oil spill Exxon Valdez
11 million gallons of oil spilt
International treaties
Glacial
Polar
Alpine
Found at high altitudes an any latitude
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Delta kame formation
englacial streams loose their energy at the base of a glacier and deposit their load
Supraglacial streams loose their energy as they enter a static body of water
Kame terrace formation - different specific heat capacities of the valley glacier, leading to supra glacier streams which deposit material along the valley side