Glaciation Enquiry q 2
- Created by: MiaSudbury
- Created on: 18-11-19 11:39
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- Processes within glacier systems
- Mass balance
- Accumulation: Input of precipitation
- Snow, avalanche
- Loess deposits
- Winds move snow & deposit them in nivation hollows
- Ablation: Output of meltwater
- Meltwater, evaporation
- Calving
- Chunks of ice that break off glaciers and fall into water
- Line of equilibrium/ Firn line: Point in the glacier where ablation = accumulation
- Positive feedback mechanism: The Albedo Effect
- More ice coverage = More of sun's radiation reflected by ice = Earth's temperature decreases = More ice formed...
- Accumulation: Input of precipitation
- Processes - Variation & rates
- Polar
- Do not move via basal slip as cannot reach PMP
- Instead move internally via internal deformation
- Ice particles within the glacial structure slip & slide over each other & deform
- Instead move internally via internal deformation
- Found at high latitude
- Do not move via basal slip as cannot reach PMP
- Temperate
- Pressure melting point (PMP)
- Due to ice and surrounding air temperature/s, the ice (notably the base of the glacier) can reach pressure melting point, resulting in basal slip
- At 0 degrees C
- Do not move via basal slip as cannot reach PMP
- Instead move internally via internal deformation
- Ice particles within the glacial structure slip & slide over each other & deform
- Instead move internally via internal deformation
- Found at high altitude
- Pressure melting point (PMP)
- Types of movement
- Regelation slip
- Melting of basal ice under higher pressure on the upstream side of bed obstacles, and refreezing of this ice in the lower pressure regime on the lee side of these obstacles
- Basal slip
- Creep
- When glacier encounters a blockage
- Regelation slip
- Melting of basal ice under higher pressure on the upstream side of bed obstacles, and refreezing of this ice in the lower pressure regime on the lee side of these obstacles
- Regelation slip
- Deformation of glacier ice in response to stress, by a process involving slippage within and between ice crystals. The rate of creep is dependent on both stress and temperature
- When glacier encounters a blockage
- Internal deformation
- Regelation slip
- Factors affecting rate of movement
- Altitude, slope, lithology, size, variations in mass balance
- Polar
- The glacier landform system
- Glacial processes
- Erosion
- Deposition
- Transport
- Entrainment
- Scales of landforms
- Macro, meso, micro = large. medium, small
- Areas
- Sub-glacial, marginal, proglacial and periglacial
- Distinctive landscapes
- Upland
- Corrie
- Arete
- Pyramidal peak
- Corrie
- Lowland
- Drumlins
- U-shaped valley
- Truncated spurs
- Hanging valleys
- Ribbon lakes
- Misfit streams
- Upland
- Glacial processes
- Mass balance
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