glaciation

• freeze-thaw weathering

  1. water fills a crack in a rock
  2. the water freezes and the crack is made wider/more cracks form
  3. the rock breaks into several pieces from pressure.

  • step 2 can lead back to step 1 as more cracks form for water to fill
• abrasion = material being created by a glacier will rub against the valley sides and bottom as the glacier moves, it will wear the rock away like sandpaper ( also breaks larger bits off )

  abrasion helps WEAR AWAY, SANDPAPER
• plucking = glaciers tear away chunks of (bed)rocks - as it freezes to them - from the land beneath as it moves down the valley.

  plucking helps STEEPEN
• aretes = a sharp ridge in a glaciated landscape that is between two corries and often leads to a pyramidal peak
• pyramidal peak = sharply pointed peak/mountain formed when the heads of 3+ glacial valleys come together or 2+ aretes join at a point. glaciers within the valley carve away at the mountain creating it and when the lacier is still at work the peak is sharper and more significant
• u - shaped valleys:

  • a wide, deep, steep-sided landform that runs through an area that has been created by glaciers.
  • glaciers alter v-shaped valleys to u-shaped valleys when they move down and pluck rocks from beneath and those rucks rub against eachother eroding it more. the front of a glacier shifts, removes soil and plucks rock. mention abrasion
• misfit streams :

  • small within a vast landscape
  • the result of water running off the valley sides and collecting at the lowest point, flows downhill
  • cant erode valley on their own, formed in the valley after glaciation carved out the u-shaped valley
• ribbon lakes :

  • long and thin, found within u-shaped valleys
  • doesn't go all the way through the valley
  • collects rain water and melt water after glacier has melted
  • glacier erodes some parts of the valley more than others so water fills where the valley was eroded the most
• hanging valley :

  • smaller valley, found above u-shaped valleys
  • have a waterfall coming out
  • withing glaciers there are tributary glaciers (smaller, less mass and moraine so erodes valley less) and main glaciers (wider, deeper, more mass and material to erode valleys more)
• accumulation zone:

  • where inputs are greater than outputs
  • there is more ice and snow entering than water leaving so glacier grows
• ablation zone :

  • where outputs are greater than inputs
  • there is more ice lost through melting than snow falling and so the glacier shrinks
• inputs = precipitation(snow), avalanche
• outputs = evaporation, meltwater
• store = ice