Corrie/ arete/ pyramidal peak

• Snow accumulates in north facing hollows when more snow falls in the winter than melts in the summer. North/north east facing slopes are more shaded so snow lies longer with accumulated snow compressed into neve and eventually ice.
• The glacier moves downhill due to gravity. Freeze-thaw weathering takes place at the top of the glacier, when water in the cracks in the rock freezes, expands and contracts weakening the rock until fragments break off.
• Bergschrund crevasseopens up at the back of the hollow. This allows meltwater and rock fragments to get to the base of the glacier, increasing the erosive power.
• Plucking takes place when ice freezes on to bedrock, pulling loose rocks away from the back wall. Rocks that fall into the glacier are aroded through the process of abrasion, when angular rock embedded in the ice frinds the hollow.
• The weight of the glacier pushes down causing rotational sliding, which overtime deapens the hollow. Friction causes the ice to slow down at the front edge of the corrie, allowing a rock lip to for which traps rain water.
• An example is Brown Cove
• An arete is formed when two corries form back to back. The back walls erode into each other by plucking creating a sharp knife ridge.
• A pyramidal peak is formed when three or more corries form back to back. Plucking takes place at the back and side walls creating a sharp peak and a jagged ridge.