Corrie

• Snow gathers in a north facing hollow and compacts to ice, creating a glacier
• The glacier moves downhill due to gravity.
• Plucking happens which is when ice freezes to rocks, the glacier moves and plucks the rocks out, steepening the back wall
• Abrasion happens which is when rocks stuck in the ice scrape the hollow, grinding it like sandpaper, deepening it.
• Frost shattering happens which is when water gets into cracks in the rocks, freezes, expands and breaks the rock.
• Bergschrund crevasse opens up at the back of the hollow. This allows meltwater and rocks to get to the base of the glacier, increasing erosive power
• The weight of the glacier pushes down causing rotational sliding, which over-deepens the hollow
• Friction causes the ice to slow down at the front edge of the corrie, allowing a rock lip to form which traps rain water
• An example is Red Tarn