Glaciers reshape the land as their heavy, moving ice scrapes, crushes, and scours rock. This lesson explores the erosional landforms produced by that movement and some striking features found in glaciers themselves.
As snow and ice accumulate, their weight presses a glacier against the ground. Moving ice can abrade bedrock with sediment carried at its base, while also crushing and scouring the surface. The resulting marks and landforms can reveal how glaciers shaped an area.
All flashcards
Glacial striations
Grooves or indentations scratched into bedrock by sediment dragged beneath moving ice; their orientation can indicate ice-flow direction.
Cirque and tarn
A cirque is a bowl-shaped mountainside hollow commonly associated with a mountain glacier's starting area; a lake occupying it is a tarn.
Arête and horn
An arête is a sharp ridge between glacially eroded areas; a horn is a sharp peak shaped by erosion from several directions.
Fjord
A U-shaped glacial trough valley flooded by the sea.
Glacial till and fluvioglacial deposits
Till is generally unsorted sediment deposited directly by ice; fluvioglacial deposits are deposited or reshaped by meltwater and are generally more sorted.
Quiz questions
What is a cirque?Answer: A bowl-shaped mountainside hollow commonly associated with a mountain glacier's starting area.
What feature may form when erosion cuts through an arête?Answer: A col, which is a pass or spillway through the ridge.
A tributary valley remains above the floor of a main glacial valley, often with a waterfall where its stream descends. What is this feature?Answer: A hanging valley.
How can successive recessional moraines create a paternoster lake system?Answer: They can dam a stream at successive points, creating a chain of lakes.
What does the proposed glacial buzzsaw effect describe?Answer: The idea that glaciers level elevated landscapes.
Based on the Wikipedia article Glacial landform, licensed CC BY-SA 4.0. Adapted into a summary, flashcards and quizzes.