Glacial Landforms

Revision booklet

Drumlins

A Drumlin is a smooth, egg-shaped hill commonly about 10m in height and a few hundred metres in length. Moulded and shaped by the moving ice it is made of moraine. Drumlins usually have a blunt end which faces down-valley. This shows the direction of glacial flow. A group of Drumlins are known as a swarm or a basket of eggs. They are formed at the bottom of a u-shaped valley.

Hanging Valley

Hanging valleys are valleys formed by smaller glaciers (tributary glaciers) that flows into the main glacier. The glacial trough is eroded much more deeply by the larger glacier so when the glaciers melt the valleys are left at a higher level (some have waterfalls)

Ribbon Lakes

Ribbon Lakes are long, thin lakes that form in hollows where softer rock was eroded more than the surrounding rock. They are fed by a misfit stream ( a stream that is too small to have eroded away.

Corries

Large, hollowed out depressions found on the upper slopes of glaciated valleys. They are armchair shaped with a steep back wall and a raised lip at the front. Today they often contain a lake called a tarn e.g. Red tarn in the Lake District.

Glacial Trough

A glacial trough is a steep-sided valley with a flat bottom. They start off as a V-shaped valley river valley but change to a u-shaped valley as the glacier erodes the sides and bottom making it deeper and wider.

Truncated Spur

Truncated spur are cliff like edges on the valley side formed when ridges of land (spurs) that stick out into the main valley were cut off as the glacier moves past.

Aretes

An arête is a knife-edged ridge often found at the back of a corrie. They are formed when two corries are back to back and eroding at the head of the wall; causing them the land in between them to narrow.

Pyramidal Peak

If three or more corries are eroding backwards towards each other a pyramidal peak is formed (e.g. Matterhorn, Pennine Alps.)