Glacial landscapes
Features of a glacial landscape
You will see in the diagram below some features of a glacial landscape.
Match the following features to the numbers on the diagram: arête, A smaller valley which is located high above the main U-shaped valley., corrie, U-shaped valley, A fan-shaped deposit of material built-up by streams that flow over a hanging valley., pyramidal peak, corrie loch (or tarn), A small river occupying the floor of a u-shaped valley., ribbon lake, truncated spur, A build-up of broken rock fragments at the bottom of a mountain..
Answer
- is a pyramidal peak because it has steep, triangular faces divided by sharp ridges or arêtes.
- is an arête, because it is a sharp ridge between corries.
- is a corrie, because it is an armchair shaped hollow with steep back and sides.
- is a corrie loch, or tarn, has a body of water which has gathered in the hollow in the corrie floor.
- is an Alluvial Fan, because it is a fan shaped pile of rock remains (alluvium) washed down by the stream and piled up where the steep valley side meets the valley floor.
- is a ribbon lake, because it is a long narrow lake in a part of the valley cut deeper by the glacier.
- is a truncated spur, because the ridge has been cut off sharply by the ice that flowed down the main valley.
- is a misfit stream, is so-called because it is far too small to have cut the valley.
- is a hanging valley, because the valley floor is much higher than the floor of the main valley.
- is a U-shaped valley, because it has steep sides and a nearly flat floor. The other side of the valley is missing in this cut-away diagram.
Questions
Question
Describe the formation of a corrie. You may use diagrams to illustrate your answer.
- Snow collects in hollows.
- Snow compacts to ice.
- Ice moves under The force of attraction between all objects. The more mass an object has, the larger the force of gravity it exerts., lubricated by melt water.
- Ice rotates to lip.
- Abrasion deepens corrie.
- Plucking steepens back and sides.
- Corrie loch may fill hollow.
Question
Describe the formation of a pyramidal peak. You may use diagrams to illustrate your answer.
- Three or more corries are eroded backwards into the same mountain.
- The ice steepens the back walls through plucking.
- Abrasion deepens the hollows.
- Freeze-thaw weathering creates a jagged peak.
- Where corrie sidewalls meet they form arêtes (knife-edge ridges).
- With a pyramidal peak in the middle.
Question
Describe the formation of a U-shaped valley. You may use diagrams to illustrate your answer.
- A glacier flows in an earlier 'V'-shaped river valley.
- The glacier plucks rocks from the sides of the valley making it steeper.
- It also abrades the floor of the valley making it wider and deeper.
- The interlocking spurs have been cut-off by the ice and changed to truncated spurs.
- When the ice melts the valley has changed from a ‘V’ shape to U-shape.
- It has very steep sides and a fairly flat floor
- Any later rivers are called 'misfit streams' because they are far too small to have cut the valley.