Glacial troughs, or glaciated valleys, are long, U-shaped valleys that were carved out by glaciers that have since receded or disappeared. Troughs tend to have flat valley floors and steep, straight sides.
Fjords, such as those in Norway, are coastal troughs carved out by glaciers. Once the glaciers receded, seawater covered the floor of the trough-shaped valleys to create fjords.
Geirangerfjord in Norway exhibits the deep “U” shaped trough common to many fjords. —Credit: David Wilkinson
Leh Valley in Ladakh, northwestern India, is a glacial valley. Leh Valley Glacier is visible at the far end of the valley. —Credit: Dan Hobley
Zêzere glacial valley in Portugal shows the characteristic “U” shape carved by a glacier. —Credit: Michael Clarke
This photograph was taken from Glacier Point in Yosemite National Park. The park’s famous Half Dome forms one side of a deep glacial valley. —Credit: Hillary Hartley