Glaciers are extremely slow moving, but perfectly transport material from one area to another. They do this in several ways:
Freeze-thaw weatheringcauses large pieces of rock to break off and fall onto the glacier. Once there, these rocks are transported to different areas.
As glaciers move downhill, they can “pluck” rocks from their surroundings. These rocks then travel downhill along with the glacier, within the icy flow.
Debris in front of the glacier is pushed downhill by the force of the moving ice in a process called bulldozing. Imagine a bulldozer clearing a path, but in this case, it’s a glacier pushing material ahead of it.
The materials that are moved and deposited by a glacier are called moraines. These are accumulations of debris deposited by glaciers. There are several types of moraines, including:
Terminal Moraine: This is a mound or ridge made of debris that marks the farthest point a glacier reaches. Think of it as a line that shows how far the glacier stretched. Terminal moraines typically have a crescent shape and you can find them at the end of a valley or basin.
Lateral Moraine: These are elongated mounds or hills of debris that form along the sides of a glacier. As the glacier moves, it gathers material like rocks and dirt along its edges, creating these moraines which run parallel to the glacier.
Medial Moraine: When two glaciers come together, the debris along their edges can merge to form a medial moraine. This looks like a dark stripe or line running down the middle of the new, larger glacier.
Ground Moraine: This is the layer of debris and sediment left behind by a retreating glacier. As the ice melts and pulls back, it deposits a layer of material over the land it once covered. Ground moraines typically have a blanket of debris covering the ground, creating a surface that is mostly flat or has gentle hills and dips.