Geography Landforms Flashcards
How is a corrie formed
Snow collects in the north facing hollow of a mountain and the bottom layers turn to ice (1); the ice begins to move and the hollow is eroded (1);
Rocks frozen on to the bottom of the ice scrape away at the base of the hollow (1) this is known as abrasion (1); ice plucking is when the glacier freezes on to loosened rock and pulls if free as the glacier moves (1); frost shattering may cause material to be incorporated into the ice (1); the ice melts leaving a tam or corrie loch (1)
How are U-shaped valleys formed
V-shaped valleys get filled by a glacier, the glacier will wear away at the valley sides and floor by abrasion AND plucking. Once the ice melts it’ll leave a valley with a flat, wide floor, and steep sides.
How is an arête formed
An arête is formed when two corries are created back to back or side by side and the rock between them has been plucked away to form a steep and narrow ridge. The ridge becomes narrower and is jagged from exposure to frost shattering.
How is a pyramidal peak formed
When three or more corries form back to back, the rock between them is plucked and weathered into a sharp point, usually the highest point in the area. This is known as a pyramidal peak.
