Article Series

Series: Glacier Ice Features

Active glaciers often have distinct features that are associated with the flowing, melting ice. You can see many of these features in parks with glaciers.

  • Chapter 1: Crevasses

    The highly-crevassed surface of the Guyot Glacier (Wrangell-St Elias National Park, AK)

    Crevasses are cracks that form in glacier ice when flow is too fast for the ice to deform by creeping. Read more

  • Chapter 2: Ice Falls

    Stairway Icefall (Wrangell-St Elias National Park, AK)

    Ice falls in a glacier are like water falls in a river. They form in steep sections of the glacier and are characterized fast flow that can cause the ice to break into seracs. Read more

  • Chapter 3: Seracs and Icebergs

    Icebergs from the Bear Glacier (Kenai Fjords National Park, AK)

    Seracs and icebergs are blocks of ice that have detached from the main glacier. Read more

  • Chapter 4: Glacier Ice Caves

    Blue ice frames the view from inside a glacier ice cave in Glacier Bay National Park (AK)

    Sometimes, melting at the margin of a glacier may cause small caves to form within the ice, between the ice and the bedrock, or between the ice and the sediment beneath it. Read more

  • Chapter 5: Tarns

    The colorful tarn in front of Schoolroom Glacier (Grand Teton National Park, WY)

    Tarns are lakes that form in glacially-carved cirques. They are often dammed by moraines. If they are still associated with moving glaciers, tarns are often full of tiny, glacially-ground sediment that scatter light and can make the water appear colorful. Read more

  • Chapter 6: Jökulhlaups

    The source lake for the Bear Glacier outburst floods (Kenai Fjords National Park, AK)

    Jökulhlaups (an Icelandic word pronounced yo-KOOL-lahp) are glacial outburst floods. They occur when a lake fed by glacial meltwater breaches its dam and drains catastrophically. Read more