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Hint
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Answer
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When lateral moraines of 2 merging glaciers converge - ridge of material in centre, found in lines parallel to ice flow
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Medial moraine
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Builds up at furtherest point of advancing glacier
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Terminal moraine
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Found in lines behind terminal moraine, when retreating glaciers experience stability
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Recessional moraine
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Small ridges produces by minor advances in subaqueous settings
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Push moraine
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Steep slopes with deep enclosed depressions and meltwater channels - results from thinning of ice as blocks of ice may squeeze debris realised from ice into crevasses
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Hummocky moraine!!!
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Oval shaped hills made of glacial till aligned in direction of flow, occur in large clusters - formation a mystery!
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Drumlin
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Glacier transported rock fragment that differs from local bedrock
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Erratic
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When large section of glacier detaches and melts - suspended bedrock is deposited and form large plain of unsorted till
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Till plain
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When a solid turns to a gas with no liquid stage
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Sublimation
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Moving glaciers spread this onto valley beneath the ice - rounded material of varying size
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Lodgement till
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Deposited at snout where ablation occurs, angular debris a glacier drops as it melts
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Ablation till
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A layer of soil, sediment or rock below the surface that is permanently frozen
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Permafrost
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Where 90% of the ground is frozen and temp is below -5 degrees
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Continuous permafrost
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Fragmented layer of permafrost where 50-90% of ground area is frozen and it has been below 0 degrees for 2 years
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Discontinuous permafrost
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Where 10-50% of ground area is frozen and- patches as it relies on micro climatic conditions
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Sporadic permafrost
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Less than 10% frozen
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Isolated permafrost
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Thawed permafrost
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Talik
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There is permafrost between talik and water
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Closed talik
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There is not permafrost between talik and the lake
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Open talik
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When snow melts and retains heat due to dark surface - thaws permafrost
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Thaw lake
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Permafrost is impermeable so when the active layer melts, the meltwater cannot drain away so soil becomes waterlogged and heavy. The soil will flow easily, especially on a gradient
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Solifluction
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Water under the rocks or ground freezes and expands which forces the mass upwards
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Frost heave
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Processes of snow turning to ice causing erosion
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Nivation
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Snow gathers in a small depression and erodes it into a hollow
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Nivation hollow
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Strong winds break loose till and weaken features, fine material is carried and deposited in glacial areas
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Aeolian / wind erosion
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In permafrost soil, low temps cause the ground to contract which leads to cracks in the permafrost. Temp increases and active layer thaws. The water freezes and expands the cracks
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Ice wedges
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Where stones are arranged on permafrost surface in circles, polygons or strips. This is cause by frost contraction where ground cracks and fills with stones. Then frost heave occurs which forces stones up and then they roll down mounds formed
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Patterned ground
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Conical hill with core of ice, discontinuous permafrost. Ground water is forced up through gaps in permafrost and freezes = ice lens
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Open Pingo
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Conical hill w core of ice, continuous permafrost. No lake=permafrost advances and water collects and freezes. Lake=unfrozen under lake
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Closed Pingo
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Large area filled with wind blown sediment. Strong winds blow eroded slit material across a plateau. Improves soil
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Loess field
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Erosion or deposition caused by meltwater from glaciers
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Fluvioglacial
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Hole in the surface of the ice
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Moulin
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Orientation of rocks, shows power of stream if perpendicular
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Imbrication
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Pro-glacial, layer of gravel, sand and clay that forms in front of where the snout used to be. Meltwater slows out carrying sediment in it
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Outwash plain / sandur
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Form in front of glaciers when terminal moraines dam the flow of meltwater streams
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Pro-glacial lake
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Pro-glacial, meltwater steams form them through erosion
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Meltwater channel
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Pro-glacial, blocks of ice left behind by glacier are covered my deposition from meltwater. Ice melts and leaves a depression - often filled with water
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Kettle hole
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Sediment deposited on the ice when meltwater streams flowing into pro-glacial lakes slow down
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Delta
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Stratified mounds of sorted sand and gravel on valley floor near snout
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Kame
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Distinct layer of silt lying on top of a layer of sand, deposited annually in lakes near glacial margins. Thicker = more melting
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Varve
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Long, winding ridges of sand and gravel. Stratified and run in same directional of glacier. Deposited by meltwater in sub glacial tunnels
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Esker
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Crossing outlast plains are braided where variations in volume of meltwater leads to streams becoming choked with coarse material
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Meltwater streams
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Piles of deposit left by valley walls, laid down by steams occupying the trough between the ice and valley side. Narrow and flat topped, in sorted layers
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Kame terrace
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Arranged into layers, fluvioglacial deposits are
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Stratification
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