P1C 08Glacial Features Caused by Deposition

Front

What role do glaciers play in sediment transport?

Back

Glaciers act as massive transport systems for sediment, functioning as 'large-scale sediment conveyor belts.' They carry sediment to the 'toe' (terminus) of the glacier, where it accumulates.

Front

What happens to sediment when glaciers retreat or melt?

Back

As glaciers retreat or melt, they deposit the material they carried, creating distinctive landforms such as moraines, erratics, and eskers.

Front

What is till in the context of glacial deposition?

Back

Till is a glacial deposit formed when a glacier reaches a warmer area and melts, leaving behind a mixture of clay, sand, rocks, and boulders.

Front

What are moraines and how are they formed?

Back

Moraines are long ridges of unsorted rocks, sand, and clay carried by a glacier and left behind when it retreats. They include terminal, lateral, and medial moraines.

Front

Describe a terminal moraine.

Back

A terminal moraine is a crescent-shaped ridge of unsorted stones, boulders, and clay dumped by the glacier at the furthest point (snout) it reached before retreating.

Front

What is a lateral moraine?

Back

A lateral moraine is debris that fell from valley side slopes onto the edges of the glacier, forming a narrow ridge along the outside of the glacier.

Front

How is a medial moraine formed?

Back

A medial moraine is formed when two glaciers flow together, merging their lateral moraines in the middle of the new enlarged glacier.

Front

What are erratics in glacial terms?

Back

Erratics are enormous rocks moved over long distances by a glacier and deposited where the glacier melted. They often have scratches from movement and differ from surrounding rocks.

Front

What are eskers and how do they form?

Back

Eskers are long, winding ridges of sand, gravel, and other sediments deposited by meltwater streams flowing within or beneath a glacier, left behind as raised landforms when the glacier retreats.

Front

What determines whether a glacier is advancing or retreating?

Back

The balance between snow accumulation and ice ablation (melting, sublimation) determines whether a glacier is advancing or retreating.