6AIII- Suggest reasons for the retreat of a glacier• Caused by less precipitation (less snow) in the zone of accumulation which could lead to a decrease in snow and ice. (2 marks)• Rising temperatures (caused by global warming) at lower altitudes in the zone of ablation could lead to it’s retreat to higher altitudes. (2 marks)
Describe Characteristics of the Glacier• The glacier is white and has accumulated the whole of the valley. (1 mark)• The valley it’s housed in is a u-shaped valley formed through abrasion. (1 mark)• The glacier is carrying small and large pieces of debris (lateral and medial moraines) (1 mark)
6C- Explain the formation of a glacial trough• A glacial trough is a u-shaped valley. (1 mark)• The mass of snow and ice made its way down the valley, it would slowly abrade and erode away the edges and bottom. This consequently formed a u-shaped valley. (3 marks)
6D- Explain why avalanches occur• Avalanches are a sudden fall and dislodgement of snow that tumbles down a mountain at vast speeds. (1 mark)• This can be caused by natural events or man made events and actions. (1 mark)• Excessive snow can cause an imbalance in the existing snow on the cornice.• Volcanic or earthquakes activity can cause vibrations in the snow.• Deforestation, e.g. for ski slopes. Can lead to avalanches as the trees act as a barrier that can support the snow and prevent it from sliding.• Winter sports like skiing can cause vibrations that can cause the snow to dislodge, causing an avalanche.