Flashcards in Glacial Erosion Different Landforms Deck (22)
What is an arete?
A steep sided ridge.
How is an arete formed?
When 2 glaciers flow in parallel valleys.
The glaciers erode the sides of the valleys, which sharpens the ridge between them.
Give an example of an arete.
Striding Edge, Lake District.
What is a pyramidal peak?
A pointed mountain peak with at least three sides.
How is a pyramidal peak formed?
When 3 or more back-to-back glaciers erode a mountain.
Give an example of a pyramidal peak.
What are truncated spurs?
Cliff like edges on the valley side.
How are truncated spurs formed?
When ridges of land (spurs) that stick out into the main valley are cut off as the glacier moves past.
What are hanging valleys?
Valleys formed by smaller glaciers that flow into the main glacier.
What are smaller valleys called?
What happens in hanging valleys?
The glacial trough is eroded much more deeply by the large glaciers.
When the glaciers melt the valleys are left at a higher level.
What are glacial troughs?
Steep-sided valleys with flat bottoms.
How do glacial troughs start off?
As V-shaped river valleys but change into u-shape.
When do glacial troughs change into a u-shape?
As the glacier erodes the sides and bottom making it deeper and wider.
Give an example of a glacial trough.
Nant Ffrancon, Snowdonia.
What are ribbon lakes?
Long thin lakes.
How are ribbon lakes formed?
After a glacial retreat.
They form in hollows where softer rock was eroded more than the surrounding hard rock.
Give an example of a ribbon lake.
Windermere. Lake District.
How do corries begin?
As hollows containing a smaller glacier .
What happens during corries?
Ice moves by rotational slip.
Erodes the hollow into a steep sided armchair shape with a lip at the bottom end.
What is left in corries?
When the ice melts it can leave a small circular lake called a tarn.