Active cirque and headwall. Kluane National Park, Yukon Territory, Canada.
Glacial Erosional Features
Active cirque and headwall. Kluane National Park, Yukon Territory, Canada.
Cirques are the bowl-shaped regions at the head of a glacier--they're bowl-shaped because the glaciers scour the underlying bedrock and erode the mountain sides behind them into cliffs called headwalls. Peaks that are surrounded by cirques are called horns; ridges between cirques are called aretes. Both tend to be steep and jagged.
Most glaciated areas in the conterminous United States no longer contain glaciers--but they show the characteristic features. Below are some examples. Click on any of the images for a larger view.
Comparison of actively glaciated region and previously glaciated one: SE Alaska and Sierra Nevada, California.
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Cirques, Headwalls, Horns.
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V- and U-shaped Valleys.
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Glacial Striations!
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