Find Your Clues
There are clues which tell us if a glacier has been over certain landscapes.
Think About It
Imagine a landscape of mountains, trees, and wildflowers. Up in the mountains a glacier has been growing for some time and now begins to creep and flow over the land. What do you think happens?
Here’s a Hint
Imagine a bulldozer going over mountains, trees, and flowers. The bulldozer would definitely leave a mark and probably tear out the trees. Think of a glacier as a natural bulldozer.
Glaciers are Sculptors
Glaciers sculpt and carve away the land, transport material, and create glacial landforms. A landscape can be dramatically re-shaped from a glacier’s passing. When glaciers carve and sculpt they are eroding the landscape. Eroding means to move dirt, rock, or other material from the ground. Boulders, broken rocks, and debris can be carried in and on the glacier ice and deposited far from their original locations. Sometimes the debris is even pushed ahead of a glacier and then left behind in mounds, or, rocks found at the end of a glacier may have come from the beginning.
Glacial landforms are clues to let us know where glaciers have been.
Glacier Landforms
Glacier movement can result in many different landforms.
Glaciated Valleys
Valleys with a U-shape, often with steep vertical cliffs. Sometimes entire mountains have been removed to create a U-valley.
Fjords
Long, narrow coastal valleys with steep sides and rounded bottoms. They were originally carved below sea level by their glaciers. After the glaciers left, sea water entered and covered the valley floors.
Cirques
Steep-sided basin-shaped depressions on a mountainside, carved out by a glacier.
Aretes
Sharp, narrow ridges formed by a glacier on a mountain.
Drumlins
Smooth rounded mounds of glacial till (rock, dirt, and debris) deposited under a glacier.
Kames
Steep-sided hills of sand and gravel deposited by glacial streams or in crevasses.
Horns
Steep-sided peaks, shaped like pyramids, formed when cirque glaciers erode on three or more sides of a mountain.
Tarn
A small lake filling a hollow which was eroded out by ice or dammed by a moraine. Frequently found with cirques.