Glacial Landscapes

Weathering processes:

Freeze-thaw: in summer water flows into the cracks in the rocks and freezes during the winter. This expands the cracks causing the rock to break away. This shapes jagged glacial mountain landscapes, rocks are weak and eroded by glaciers and large angular rocks(scree) collect at the foot of the mountain.

Abrasion: sandpaper effect caused by the weight of the ice scouring the valley floor. Leaves a smooth, polished surface.

Plucking: meltwater beneath a glacier freezes and bonds the base of the glaciers to the rocky surface below. As the glacier moves loose fragments of rocks are 'plucked' away.

Rotational slip: in the summer, meltwater lubricates the glacier enabling it to slide downhill. In higher up areas, on the valley sides, the movement is more curved and moves in circular motions. Eroding and deepening hollows into a bowl shape on the mountainside. 

Bulldozing: rock fragments are transported by the glacier. Moraine can be transported on the ice, in the ice, and below the ice. As the glacier moves forward it pushes loose debris ahead, downhill. 

Deposition: occurs when the ice melts. Occurs mostly at the front, where the ice melts the most. As the glacier retreats, it leaves behind an unsorted mixture of sand, clay boulders, called till. Ahead of the glacier, meltwater rivers carry sediment away. Attrition makes the rocks smaller and more rounded. The finer material is carried, by meltwater streams metres away, this is called outwash.

Corries: large hollowed-out depressions found on the upper slopes of glaciated valleys. They have a steep back wall and a raised 'lip' at the front. May contain a tarn(lake). When an ice age occurs on north-facing slopes, winter snow builds up in hollows on the sides of the mountains and summits. The snow will slowly develop into ice, above and around the hollow, freeze-thaw will occur and will shatter the rock. The rocks will fall and be carried away as the accumulated ice overflows from the hollow, and moves off downhill into the valley. The back wall of the not yet completely formed corrie becomes steeper and rugged (caused by plucking). This also means the hollow will be cut back in towards the summit. The moving ice uses the plucked material, and weathered rocks to grind out and deepen the base of the hollow. (Abrasion).It forms an armchair shape with sharp edges. A lip develops for erosion is less because the ice tends to slip from underneath as it moves. When temperatures begin to increase, ablation rate increases and the ice retreats and disappears. The base of the Cirque will contain a lake as the ice melts and post-glacial precipitation occurs. These lakes are known as tarns. Screes develop around the sides and back of the corrie. The screes are a result of freeze-thaw during winter months or material simply falling off the mountainsides as there is no longer any ice to support it. This is called pressure release. 

Pyramidal Peak: Snow accumulates in a hollow on the north slope of…