S-Cool Revision Summary

S-Cool Revision Summary

  • Just as a river could be seen as a system of inputs, outputs, transfers and storage, so can a glacier.
  • Glaciers originate from heavy snowfalls over a prolonged period of time.
  • During a single year a valley glacier may well both grow and retreat, depending on the rate of accumulation compared to the rate of ablation. This is called the ice budget or glacial budget.
  • In general glaciers around the world are retreating at the moment as the climate slowly warms up and they melt slightly every year.
  • Glacial erosion occurs through three main processes
  • Plucking involves the ice picking up boulders by freezing around them
  • Abrasion is the scouring of the rock on the valley floor by rocks being carried by the glacier.
  • Freeze-thaw occurs where water freezes and expands in cracks in the rock
  • Glaciers carry a huge amount of material. These rocks are called moraine and can be carried great distances by a glacier.
  • Glaciers will always reach a point when they will start to melt, mainly due to the rise in temperature as they descend in height down the valley. As the ice melts it cannot carry as much material and so this is deposited.
  • The main erosional features of a glacier include aretes, corries, glacial troughs, hanging valleys, pyramid peaks, ribbon lakes, truncated spurs, and the distinctive U-shaped valleys.
  • The main depositional features of glaciers are boulder clay, drumlins, erratics and moraines (terminal, lateral, medial, ground and recessional).
  • Human uses of glacial areas include agriculture, tourism, recreation and hydro-electric power schemes.
  • Management is needed in glacial areas to cope with many demands and pressures.