Geography: Glaciation

Glacier Definition

A large, slow moving mass of ice formed from compacted snow

How does a glacier form

Accumulation, compaction, formation of glacial ice, movement and ablation

Process: Accumulation

snow accumulates and persists all year around

Process: Compaction

over time layers of snow builds up, weight of snow compresses lower layers

Process: Formation of glacial ice

accumulation + pressure = dense ice formed

Process: Movement

ice builds up → pressure. Base melts and moves downhill

Process: Ablation

ice melt > accumulation = looses mass

Glacier: Erosion

The glacier wears away rocks + land as it moves

Glacier: transportation

The glacier carries sediment + debris as it flows

Glacier: Deposition

The glacier drops the material carried as it melts

Created feature: Corries

snow accumulates in hollows, compacts into ice, back and base erodes, leaves rounded hollow

Created feature: Aretes

two corries erode back to back, leaves sharp ridge inbetween

Created feature: Pyramidal Peak

three or more corries erode different sides of mountain, leaves sharp peak

Created feature: U-shaped valley

glacier moves through V-shaped valley, plucking and abrasion on sides and bottom, leaves as wide, flat and steep

What is Freeze-thaw weathering?

the breaking of rock caused by water getting into cracks, freezing, expanding and melting repeatedly