What is a glacial trough?

A glacier trough is a U-shaped valley that forms after ice glaciers melt or drift. Glaciers move up to a few feet a day, and they remove the debris within the valley as they move, creating the U-shape.

The valley typically begins as a V-shape, but the scraping and erosion that occurs from the glacier deepens the ravine. Debris left from the glacial path is called the terminal moraine. Examples of glacier troughs include Glacier Point at Yosemite National Park and Leh Valley in India. When water penetrates an empty glacier trough, it becomes a fjord. A glacier forms with the accumulation of ice and snow around a mountain.