Glacial Budget

Glacial Features

Fluvioglacial processes

Periglacial processes


Alaskan Pipeline

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1. First snow settles that has a loose fluffy snowflakey consistency at this point

2. The weight of more snow falling on top turns the snow into a denser, more granular kind of snow called firn

3. Air is squeezed out, and particles of ice are compressed together by the continuing accumulation of ice and snow

4. Water also melts melts and refreezes in the air spaces, making the ice more dense forming a glacier


Warm based glaciers - the base is warmer than the melting point of ice, its warmer because of heat from friction caused by the glacier moving or geothermal heat from the Earth. The ice of the bottom of the glacier melts and the meltwater acts like a lubricant making it easier for the glacier to move downhill. Lots more erosion

Cold based glaciers - base is cold so there is very little melting. The ice is frozen to the base of the valley so theres very little movement. There is hardly any melting and don't cause much erosion at all

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Glacial Budget

Inputs - Snow, Condensation, Sublimation of water vapour and bits of rock

Stores - Ice, Meltwater and debris

Outputs - Meltwater, snow evaporate, sublimation, snow blown away and ice bergs

Accumulation is the input of snow and ice into the glacial system, most accumulation is snow

Ablation - output of water from a glacier

Glacial budget is the balance between accumulation and ablation a year

If there is more accumulation than ablation over a year, the glacier advances

If there is less accumulation then then the glacier retreats

More ablation during the warmer times of the year as more ice melts, and more accumulation when it colder

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Glacial Landforms

Corries - circular hollow formed by rotational flow, abrasion and plucking

Arete - steep sided ridge formed when two glaciers flow in parallel valleys

Pyramidal Peak - pointed mountain peak formed when three or more corries form back to back

Glacial troughs - steep sided valleys with flat bottoms

Hanging valleys - formed by tributary glaciers, they erode the valley floor and can form waterfalls

Truncated Spurs - formed when spurs stick out the main valley are chopped off when main valley glacier moves past

Valley steps - steps in the glacial trough

Tarns - lakes that form in corries after glacier has retreated

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Glacial Landforms 2

Ribbon Lakes - long thin lakes that form after glacier retreats

Fjords - long deep inlets that form when a valley that has been eroded by a glacier is flooded

Roche Moutonne - resistant mass of rock on the valley floor

Lateral Moraine - deposited at the sides of the glacier

Medial Moraine - deposited at the centre of the valley

Terminal Moraine - builds up at the end of the glacier

Drumlins - half egg shaped hills of till, the stoss is wide and tall and lee is narrow and low

Erratics - rocks that have been picked up by a glacier or an ice sheet, carried along and dropped in an area of different rock type

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Fluvioglacial Processes

Fluvioglacial landforms are formed from meltwater. Meltwater streams erode the landscape.

Fluvioglacial deposits are sorted and glacial are unsorted

Outwash plains is a layer of gravel, sand and clay that forms in front of where the snout of the melting glacier used to be

Blocks of ice that have broken off from the front of the glacier can get surrounded and buried by fluvioglacial deposits. When the blocks of ice melt they leave holes in the outwash plain called kettle holes

Eskers are long winding ridges of sand and gravel that run in the same direction as the glacier

Kames are mounds of sand and gravel found on the valley floor. Kame terraces are piles of deposits left against the valley wall by meltwater streams that run between the glacier and the valley sides

Proglacial lakes can form in front of glaciers when the flow from meltwater streams gets dammed by terminal moraine

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Periglacial Processes

Permafrost - permanently frozen ground with a top layer that can melt in the summer. Can be continuous, discontinuous or sporadic

Ice wedges in permafrost soil - when temperatures drop very low in the winter the ground contracts and cracks form in the permafrost called frost contraction. When temperatures increase in the spring, the active layer thaws and meltwater seeps into the cracks

Frost Heave - water freezing in ground causing humps, when active layer freezes in winter and ice forms a kind of lens shape. In fine grained soil the ice lifts up the surface layers of soil called frost heave. Ice lenses form underneath stones because stones lose heat faster than soil around them. As they expand they push upwards and ice lenses stop the stones dropping back down

Patterned ground formed by frost heave and frost contraction. Stones can be pushed to the surface by frost heave, once they reach the surface they roll down to the edges of the mounds have formed so they form circles around them (polygons). Frost contraction causes the ground to contract in polygon shapes. The cracks get filled in with stones forming polygon patterns on surface.

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Periglacial Processes 2

Nivation hollows - when snow gets into a hollow in the ground, it can increase the size of the hollow. Every time the ice freezes it expands so frost shattering eventually breaks bits off the rock at the base of the hollow. When the snow melts, the meltwater carries the broken bits of rock away. Slopes collapse because theyre waterlogged and theyve been eroded. Eventually hollow becomes deeper and wider. The processes that cause this are collectively called nivation.

Solifluction - waterlogged active layer of soil flows easily over the frozen impermeable layer beneath. Solifluction produce lobe formations where one section of the soil is moving faster around

Pingos - conical hill with a core of ice. Open system pingos form where there is discontinous permafrost. Groundwater is forced up through the gaps between areas of permafrost. The water collects together and freezes, forming a core of ice that pushes the ground above it upwards. Closed system pingos form in areas of continous permafrost where there is a lake at the surface. The lake insulates the ground so the area beneath it remains unfrozen. When the lake dries up, the ground is no longer insulated and the permafrost advances around the area of unfrozen ground. Causes the water to collect in the centre of the unfrozen ground. The water eventually freezes and creates a core of ice that pushes the ground above it upwards

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History - Whaling, Sealing and Fishing

Tourism - camping trips, ship board visits and fishing. IAATO oversees the limits on the tourism in Antarctica

Antarctic Treaty - 1959 countries signed this to stop the resource exploitation

Tourists go over to see glacial landscapes, and wildlife. Go for the remoteness and isolation and to test themselves in adverse weather conditions. Interested in historic sites. Tourism is concentrated in southern summer period

Positive impacts of tourism; tourism is a well run industry, guidelines are accepted by operators and tourists, damage to vegetation is due to natural causes, no litter is attributed to tourists, no stress is caused to penguins, tourists who follow guidelines cause no impact, out of 200 sites only 5% showed wear and tear

Negative impacts of tourism; extremely fragile, summer tourist season coincides with peak breeding periods, land based installations in ice free locations, demand for fresh water is difficult to meet, visitor pressure on heritage sites, some evidence that planes caused stress to breeding colonies and unique legal status of Antarctica makes enforcement of any code of behaviour difficult

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Alaskan Pipeline

Situated in the Northern hemisphere and passes from Prudhoe Bay to Valdez. History:

  • 1968 - oil discovered in Prudhoe Bay, permission given to start construction
  • 1970 - conservationists delay pipeline
  • 1877 - oil flows along pipeline
  • 1989 - massive oil spill from ground tanker
  • 2001 - support for new exploration given


  • 8 billion dollars to build
  • 8 years to design and build
  • forced caribou to move away from sites
  • til 1986 there were 300 minor oil spills recorded
  • building it causes damage to the fragile tundra vegetation and wildlife
  • cause destruction of traditional lifestyles


  • provides oil for many countries
  • creates many job opportunities
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