Glacial Landforms Flashcards
List all erosional landforms ?
Corries
Arêtes
U- shaped valleys
Truncated spurs
Hanging valleys
Roches moutonnées
Knock and lochan
Crag and tail
Pyramidal peak
Ribbon lake
What is a corrie ?
Corries are armchair-shaped and often N or NE facing in the northern hemisphere as this direction will receive the least sunlight.
They are in the lee of prevailing winds, causing the snow to accumulate for longer.
Size varies but they are often around 0.5km in diameter with a back wall up to 1000m in height.
What is an arête ?
As corries develop, they eat back into the mountain mass in which they have developed.
When several corries lie close to one another, the divide separating two corries may become progressively narrowed until it is reduced to a narrow precipitous ridge called an arête.
How is a u-shaped valley formed ?
How is truncated spurs formed ?
How are hanging valleys formed ?
How are roches moutonees formed ?
What is a pyramidal peak ?
If glaciers in corries continue to erode away at the mountain from three or more sides, the result is the formation of a sharp pyramidal peak, sometimes called a horn.
What is a ribbon lake ?
Glacial flow is uneven and where erosion has over-deepened a section of the valley (e.g. where there is softer rock which is more easily eroded) it forms a rock basin.
These rock basins often fill with water post-glaciation, forming a ribbon lake.
What is a U-shaped valley ?
develop where glaciers flow into pre-existing V-shaped river valleys.
Glaciers widen and deepen the original valley making it steep sided with a wide, flat base.
Glaciers tend to straighten the valley, cutting off spurs and leaving cliffs called truncated spurs.
At the upper end of the valley where the glacier has entered the valley from the corries above, there is often a steep wall called the trough end.
