Glacial Processes

Question 1

Describe the process of abrasion

Answer 1

As the glacier moves downhill, the rocks that have been frozen into the base and sides of the glacier scrape the bedrock like sandpaper leaving scratches called striations behind

Question 2

Describe the process of plucking

Answer 2

As the glacier moves it plucks out loose rock that has frozen into the glacier from the bedrock and carries these rocks downhill with it.

Question 3

Describe Freeze-thaw Weathering

Answer 3

During slightly hotter periods of time, water melts from the glacier and seeps into cracks between rocks underneath the glacier. When the temperature drops again the water freezes and when doing so expands by about 9%. This makes the crack larger eventually breaking pieces of rock off from the bedrock

Question 4

What is BASAL SLIP and ROTATIONAL SLIP

Answer 4

Basal slip is the process of lubrication (from meltwater) between the glacier and rock allowing the glacier to slide down hill. Rotational slip is when this process occurs higher up in the valley causing a more curved movement.

Question 5

What is bulldozing in glaciers

Answer 5

The forceful transportation of loose debris within or in front of a glacier

Question 6

What is the process of deposition

Answer 6

Deposition occurs when the ice melts, as the glacier retreats it leaves behind fragments of rock called till. Ahead of the glacier meltwater carries sediment away, known as outwash.