Kettles

Reflections in a shallow kettle pond in Lamar Valley (Yellowstone National Park). Photo from 1966.

NPS Photo/John Good

As a glacier recedes, sediment is washed out from the glacier and deposited in a flat area below, forming an outwash plain. Depressions, known as kettles, often pockmark these outwash plains and other areas with glacial deposits.

Kettles form when a block of stagnant ice (a serac) detaches from the glacier. Eventually, it becomes wholly or partially buried in sediment and slowly melts, leaving behind a pit. In many cases, water begins fills the depression and forms a pond or lake—a kettle. Kettles can be feet or miles long, but they are usually shallow.

New kettle lakes form in front of the Kennicott Glacier as the ice recedes and melts (Wrangell-St. Elias National Park, Alaska)

NPS Photo/Jacob W. Frank

To learn more about glaciers, glacier features, and glacial landforms, see the Glaciers & Glacial Landforms Page.

Related Links

• NPS—Geoscience Concepts
• NPS—Geologic Tour
• NPS—Geodiversity Atlas
• NPS—Geology