Glaciation

Question 1

How is a Glacier Formed?

Answer 1

Snow builds up during the winter in hallows at high altitudes and latitudes. Particularly on colder, north facing slopes. The snow is compressed into ice forming a neve.

Question 2

Glacial Erosional Processes

Answer 2

Inputs - snow and rain. Processes - plucking and abrasion. Outputs - melt water and moraine.

Question 3

Freeze-thaw

Answer 3

water enters joints in the rock. Water freezes in the crack as temperatures fall at night on increase of 9% in volume put pressure on the cracks.

Question 4

Plucking

Answer 4

Plucking is when rocks and stones become frozen to the base of the glacier and are plucked from the ground as the glacier moves. Ice continues to flow down slope. A piece of the ground is plucked up by the glacier.

Question 5

Abrasion

Answer 5

Rocks and stones, picked up by the glacier and are rubbed against the bed rock at the bottom and sides of the glacier, deepening and widening.

Question 6

Perfect Answer - With the aid of a diagram, explain the processes involved in the formation of a corrie.

Answer 6

Snow collects in the north facing hollow of a mountain and the bottom layers turn into ice. as more snow collects and compresses into glacial ice, it freezes onto surrounding rock that was weakened by freeze thaw. The glacier begins to move under its own weight and gravity. The rocks losesended by frost shattering stick onto the glacier and pull free as the glacier moves, this is known as plucking. Rocks froze on to the bottom of the ice wearing away at the base of the hollow, this is known as abrasion. The ice melts leaving a loch or a corrie loch.

Question 7

Arete

Answer 7

An arete is a ridge that results when two corries are formed back to back or side by side by side on a mountain. The ice in the corries erodes the hollows using plucking and abrasion. The back walls of the corries erode backwards, towards each other. As each glacier erodes both corries in either side of the ridge, the edge becomes steeper and the ridge becomes narrow. The ridge is jagged as it has been exposed to freeze thaw weathering.

Question 8

Pyramidal Peak

Answer 8

A pyramidal peak is formed when three or more corries meet back to back. Narrow ridges, called aretes, separate the corries. As glaciers erode backwards the corries get bigger; this produces a steep-sided peak. Freeze thaw weathering erodes the top of the mountain and creates a pointed peak