Pyramidal Peak

• 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.
• The weight of the glacier pushes down causing rotational sliding, which over-deepens the hollow
• A pyramidal peak is formed when three corries erode back towards each other.
• Frost shattering can make a sharp summit form.
• An example is Mt Everest.