Warm and Cold Based Glaciers

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  • Created by: ionag
  • Created on: 10-04-18 12:03
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  • WARM BASED
    • Location
      • In places with high winter snowfall rates and spring and summer temperatures high enough to create rapid summer melt rates
    • Warm and Cold Based Glaciers
      • COLD BASED
        • Location
          • Areas of high latitude within the Arctic and Antarctic Circle
          • Areas with low precipitation rates, so receive little new snow each year and accumulation rates are low.
          • Little or no melting of ice in cold glaciers, so the ice can be very old, with ice at the base of some Arctic and Antarctic ice sheets dating  back around 100,000 years BP.
        • Development
          • 1. All ice, except the most upper surface layers that can be exposed to summer atmospheric temperatures of above 0 degrees Celsius, is below the melting point.
          • 2. There is little melt-water associated with these glaciers as atmospheric and sub-glacial heat sources are not great enough to reach melting point.
          • 3. The majority of ice loss is due to sublimation and the carving of icebergs/ blocks.
          • 4. Movement is much slower than in temperate glaciers as they are often frozen to their beds, thus most movement is due to internal flow
          • 5. Much less erosion, transportation and deposition occur
    • Development
      • The vast amounts of melt water act as a lubricant and allow he glacier to be far more mobile than cold based glaciers.
        • In places with high winter snowfall rates and spring and summer temperatures high enough to create rapid summer melt rates
      • The faster rates of glacial movement mean that warm based glaciers are ore likely to erode, transport and deposit material
      • 1. At the surface, the thin layer of more recent snow and firn is subject to seasonal temp fluctuations so melts rapidly at around 0 degrees Celsius in the summer melt.
      • 2. The surface layer of snow insulates the layers of ice beneath it.
      • 3. With increasing depth in a glacier, the ice is under ever increasing pressure from the surrounding ice, lowering the melting point of the ice (pressure melting point.)

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