Mammoth Memory

Glacial Trough – Erosion by glaciers in a "U" shape

(Pronounced gley-shuhl troff)

To remember the meaning of the term Glacial Trough, use the following mnemonic:

The farmer preferred his glass trough (glacial trough) to the pig's trough. The farmer's trough was "U" shaped and more comfortable.


The farmer preferred his glass trough (glacial trough), which was "U" shaped.

A glacial trough is a valley widened and deepened by the erosive action of a glacier. The valley becomes U-shaped, rather than the V shape of a normal river valley. 

Diagram of a glacial trough within a glacial landscape

Stages of glacial trough formation

Glacial troughs tend to have steep, straight sides and flattish valley floors. As an example, the Norwegian Fjords are coastal troughs carved out by glaciers.

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