Key Terms in Glacial Erosion and Landforms

Abrasion

Erosion caused by rocks and boulders embedded in the base of a glacier acting like sandpaper, scratching and scraping the rock below.

Arête

A sharp, knife-like ridge formed between two corries due to erosion and freeze-thaw weathering.

Bulldozing

The process where ice pushes material of all shapes and sizes as it moves slowly forward.

Conservation

Managing the environment to preserve, protect, or restore it.

Corrie (or Cirque)

An armchair-shaped hollow on a mountainside formed by glacial erosion, rotational slip, and freeze-thaw weathering. When the ice melts, it may leave a circular lake called a tarn.

Drumlin

An oval or elongated hill made of glacial till, shaped by the movement of a glacier. The long axis runs parallel to the direction of ice flow.

Erratics

Large rocks transported and deposited by a glacier, found far from their source area.

Freeze-thaw Weathering (Frost-shattering)

Occurs when water enters cracks in rocks during warmer temperatures and freezes at night. As the ice expands, it breaks the rock apart.

Glacial Trough

A U-shaped valley formed by the erosive action of a glacier, replacing the original V-shape of a river valley.

Hanging Valley

A tributary valley left higher than the main glacial trough, often featuring a waterfall where it joins the main valley.

Land Use Conflicts

Disagreements between different users or stakeholders over how land should be used.

Moraine

Accumulations of rock and debris (till) transported and deposited by a glacier. Can form various landforms such as terminal or lateral moraines.

Outwash

Sorted and rounded material (like sand or gravel) deposited by meltwater streams in front of or under a glacier.

Plucking

A type of glacial erosion where meltwater freezes onto rock, and as the glacier moves, it pulls pieces of rock away.

Pyramidal Peak

A sharply pointed mountain peak formed when several corries erode back towards each other.

Ribbon Lake

A long, narrow lake in a glaciated valley, formed where the glacier eroded more deeply due to softer rock or added ice from a tributary glacier.

Rotational Slip

The circular movement of ice within a corrie that helps erode and deepen the hollow into a bowl shape.

Till

An unsorted mixture of materials like sand, clay, and boulders deposited by a glacier as ground moraine.

Truncated Spur

A former river valley spur that has been cut off (truncated) by the action of a valley glacier, forming steep, cliff-like edges.