U-shaped valley

geology

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July 14, 2026

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A U-shaped valley, also known as a glacial valley, is a stream valley that has been carved by a glacier. These valleys are characterized by their distinct U-shaped cross-section, which is a result of the glacier's erosive power.12

When a glacier moves through a valley, it widens and deepens the existing V-shaped stream valley. The U-shape is the most efficient form for a moving glacier due to minimal frictional resistance. Glaciers can scour the valley walls, leaving them steep and sometimes nearly vertical. The valley floor may be covered with glacial debris like till or moraines.1

Smaller tributary glaciers carve shallower troughs, which are left as hanging valleys high on the main valley walls when the ice melts. These can create waterfalls, such as Yosemite Falls. U-shaped valleys are common features in glaciated mountain ranges worldwide.13

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fjord
Glacial erosion produces U-shaped valleys, and fjords are characteristically so shaped. Because the lower (and more horizontally inclined) part of the U is far underwater, the visible walls of fjords may rise vertically for hundreds of feet from the water’s edge, and close to the shore the water…
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Glacial erosion produces U-shaped valleys, and fjords are characteristically so shaped. Because the lower (and more horizontally inclined) part of the U is far underwater, the visible walls of fjords may rise vertically for hundreds of feet from the water’s edge, and close to the shore the water…
Read More

glacial landform
Cirques, tarns, U-shaped valleys, arêtes, and horns
…assume a characteristic parabolic or U-shaped cross profile, with relatively wide and flat bottoms and steep, even vertical sidewalls. By the same process, glaciers tend to narrow the bedrock divides between the upper reaches of neighbouring parallel valleys to jagged, knife-edge ridges known as arêtes. Arêtes also form between two…
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…assume a characteristic parabolic or U-shaped cross profile, with relatively wide and flat bottoms and steep, even vertical sidewalls. By the same process, glaciers tend to narrow the bedrock divides between the upper reaches of neighbouring parallel valleys to jagged, knife-edge ridges known as arêtes. Arêtes also form between two…
Read More

glacial valley
…valley is converted to a U-shaped valley because the U-shape provides the least frictional resistance to the moving glacier. Because a glacier has a much greater viscosity and cross section than a river, its course has fewer and broader bends, and thus, the valley becomes straighter and smoother. The valley…
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…valley is converted to a U-shaped valley because the U-shape provides the least frictional resistance to the moving glacier. Because a glacier has a much greater viscosity and cross section than a river, its course has fewer and broader bends, and thus, the valley becomes straighter and smoother. The valley…
Read More