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geomorphic processes in glaciated landscapes - Coggle Diagram
geomorphic processes in glaciated landscapes
weathering
- the in situ breaks down of rocks exposed at, or near, the land surface by physical, chemical and biological processes
chemical
carbonation
hydration
solution
hydrolosis
oxidation
biological
tree roots
organic acids (chelation)
physical/mechanical
frost-shattering:Water trapped in pore spaces inside rock freezes and expands.
Small particles are separated from the rock.
Granular disintegration
Happens in porous materials (they expand and contract)
Influence of flows of materials
Water flowing into pore spaces in the rock
Movement of rock as it breaks off
influence of flows of energy:thermal energy because of the temperature changes
kinetic energy because of the movement of joints in the cracks of the rock
pressure release:Bedrock expands and cracks as an overlying mass of rock, ice or water is removed.
influence of flows of energy:
kinetic energy → rocks fall
thermal energy → ice has to melt for that to happen
Influence of flows of materials:
water in its solid state converting to liquid in solid state → flows away
movement of rock as it breaks off
freeze-thaw: Occurs in jointed rocks where temperatures regularly fluctuate around freezing point.
Pressure is exerted on joints as water freezes.
Results in block disintegration, rock break off and fall into the glacier
influence of flows of energy:thermal energy because of the temperature changes
kinetic energy because of the movement of joints in the cracks of the rock
Influence of flows of materials
when weathering occurs, bits of rock falls off
water flows into the crack in the rock in order for the process to happen.
mass movement
rock fall
influence of flows of materials
influence of flows of energy
slide
linear
influence of flows of materials
influence of flows of energy
rotational
influence of flows of materials
influence of flows of energy
erosion
plucking: when meltwater seeps into joints in the rocks of the valley floor/sides. this freezes and becomes attached to the glacier. as the glacier advances it pulls pieces of rock away
influence of flows of energy:
thermal: plucking is effective at the base of the glacier as the weight of the ice mass above may produce meltwater due to pressure melting
kinetic: glacier advances and retreats
influence on flows of material
rocks become frozen into the bottom and sides of the glacier. as the glacier moves downhill it 'plucks' the rock frozen into the glacier from the ground.
abrasion: the glacier moves across the surface, the debris embedded in its base/sides scours the surface rocks, wearing them away
influence of flows of energy:
influence of flows of materials: - the coarse material will scrape, scratch and groove the rock, finer material will tend to smooth and polish to rock. glacial debris is also worn down by the process, forming a finer rock flour
as the glacier moves downhill, rocks that have been frozen into the base and sides of the glacier scrape the rock beneath. the rocks scrape the bedrock like sandpaper, leaving scratches behind
depositional landforms - occurs when capacity of glacier to transport material has been reduced
during retreat/deglaication due to abaltion
also possible during advance
influence of flows of energy
influence of flows of material
morraines
transportation
sources of debris carried by glaciers:
rockfall
avalanches
debris flows
aeolian deposits (
wind
)
volcanic eruptions
plucking
abrasions
supraglacial debris
: debris being carried on the surface of a glacier, most often comes from weathering and rockfall
englacial debris
: debris within the ice, may have been supraglacial material that has been covered by further snowfall, fallen into crevices or sunk into the ice due to localised pressure melting
subglacial debris
: debris embedded in the base of the glacial which may have derived from plucking and abrasion or that has continued to move down through the ice as former englacial debris.
depositions - the laying down of sediment transported by rivers, waves, glaciers and winds, as energy levels decline
landform types
how they help to change a landscape
nivation - range of processes
erosion of the ground beneath and at the sides of a snow bank, mainly as a result of alternate freezing and thawing.
