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Earth Science
7.1 Glaciers
Ice Age
A period of time when much of Earth’s land is covered by glaciers
Glaciers
A thick mass of ice origination on land from the compaction and recrystallization of from snow that slows evidence of past or present flow
Snowline
Lowest elevation in a particular area that remains covered in snow all year
Valley Glaciers
A glacier confined to a mountain valley, which in most instances had previously been a stream valley; also known as an alpine glacier
Ice Sheet
Are enormous ice masses that flow in all directions from one or more centers and covered everything but the highest land
Glacial trough
The once narrow V-shaped valley is changed into U-shaped
Till
Sediment of different sizes deposited directly by glacier
Stratified drift
Is sediment laid down by glacial meltwater
Moraine
A ridge of unsorted sediment left by a glacier
Key Concepts
What types of glaciers exist, and where is each type found?Valley GlaciersIce Sheets
How do glaciers move?Plastic FlowBasal Slip
What distinguishes the various types of glacial drift? Weight of overlying ice and the associated
pressureWhat landscape features do glaciers
form?Glaciated ValleysCirquesAretes and Horns