Glacial troughs

Glaciers cut distinctive U-shaped valleys with a flat floor and steep sides. The glacier widens, steepens, deepens and smoothes V-shaped river valleys, eg Great Langdale Valley in the Lake District. The images below show the difference between a U-shaped valley and a V-shaped valley.

U-shaped valley in Hola Valley, Norway
U-shaped glacial valley
V-shaped valley on Vilcanota River, Peru
V-shaped river valley

Just like rivers, glaciers have tributaries. As the main glacier erodes deeper into the valley, the tributary is left higher up the steep sides of the glacier. U-shaped valleys ending with a waterfall at the cliff-face are called hanging valleys.

When a river erodes the landscape, ridges of land form in its upper course which jut into the river. These are called interlocking spurs. A glacier cuts through these ridges leaving behind truncated spurs.