A diagram illustrating cirques, arêtes, and horns.
Glaciers are powerful agents of erosion and have created many unique features on the Earth. Some of the landforms produced by the eroding action of ice include:
- Cirques: A cirque is a deep, bowl-shaped depression that has been scooped out by a valley glacier at high elevation.
- Arêtes: An arête is a sharp, steep ridge that is formed between two cirques.
- Horns: A horn is a steep, pyramid-shaped mountain that is formed when three or more cirques erode around a central peak.
The Matterhorn in Switzerland is a well-known example of a horn.
- U-Shaped Valleys: As a glacier moves down a V-shaped valley, ice scrapes and gouges the sides of the valley. A U-shaped valley results from this erosion on the valley walls.
- Fjords: A fjord is a U-shaped valley that has been submerged by the ocean.
Sognefjord in Norway stretches 205 km (approximately 130 miles), and is Norway’s largest fjord.
- Hanging Valleys: Small glaciers in tributary valleys often flow into a large glacier in the central valley. When the main glacier recedes, the small tributary U-shaped valley above the main valley floor is known as a hanging valley.
The Yosemite Valley exhibits both a U-shape as well as a hanging valley above Bridal Veil Falls.
Did You Know?
Take a Load Off
During the last ice age, continental crust under the advancing glaciers became depressed because of the heavy burden of ice on it. The crust, however, has started to rebound with the end of the last ice age, and the removal of the heavy ice burden. In Canada’s Hudson Bay, this rebound has caused the continental crust to lift by as much as 330 meters (approximately 1,100 feet) within the last 8,000 years.
Word Link
Cirque: This word entered the English language in 1601. It is taken directly from the French word cirque which was itself based on the Latin word circus. The Latin word circus referred to an oval-shaped arena.
Arête: This word entered the English language in 1601. It is taken directly from the French word arête which was itself based on the Latin word arista. The Latin word arista referred to an ear of corn.
Try This!
A U-shaped valley in Banff National Park.
U Explore
U-Shaped Valleys: Although glacier carved U-shaped valleys are common in many parts of the world, few places illustrate this feature better than the many, long, classic U-shaped valleys of Banff National Park in Alberta (Canada).
- Click here to see the classic U-shape of a glacier formed valley near the town of Banff.
- Change your position and locate and explore at least 2 other U-shaped valleys near Banff. (Hint: Click here, and here if you need suggestions for valleys to investigate.)
Other Glacial Features: Glaciers produce many other prominent features in addition to U-shaped valleys.
- Click here to visit the glaciated landscape of the McGee Creek Valley in the Sierra Nevada Mountains in California. Examine the glacier carved U-shape of the valley.
- Zoom in on the mountain ridge at the end of the valley and locate at least two examples each of a horn, an arête, and a cirque. (Hint: Click here if you need help in zooming in on an area that illustrates these glacial features.)
An annotated view of glacial features (i.e. horn, arête, and cirque) of the McGee Creek Valley.