Coastal Zones

Coastal Zones

WEATHERING
1. Mechanical
  1. breakdown of rock without changing its chemical composition - freeze thaw weathering
    1. 1. temperature alternates above and below 0'C
    2. 2. Water gets into cracks
    3. 3. When water freezes it expands, puts pressure on the rock
    4. 4. When water thaws it contracts, releasing pressure
    5. 5. This process repeats and widens the crack causes rock to break up
2. Chemical
  1. break down of rock by changing chemical composition - carbonation weathering (warm and wet conditions)
    1. 1. Rainwater has carbon dioxide dissolved in it- makes it weak carbonic acid
    2. 2. Carbonic acid reacts with rock that contain calcium carbonate so rocks dissolve by rainwater (limestone)
MASS MOVEMENT
1. shifting of rocks and loose material down a slope.
  1. causes coasts to retreat rapidly
  2. more likely to happen when material is full of water
2. 2 types
  1. material shifts in a straight line
  2. material shifts with a rotation
PROCESS OF EROSION
1. Hydraulic Action - waves crash against rock, compress air in crack. Pressure on rocks- process repeats widens the crack, rocks fall off
2. Abrasion - eroded particles in water scrape and rub against rock, removing small pieces
3. Attrition - particles smash into eachother and break into smaller fragments - edges round off
4. Solution - particles dissolve in water
WAVES
1. Constructive
  1. carry and deposit material
    1. low and long
    2. swash is more powerful than the backwash
      1. material is deposited instead of taken away
2. Destructive
  1. carry out erosional process
    1. high and steep
    2. backwash is more powerful than the swash
      1. material removed from beach

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	Created by sophie.oke1810 over 8 years ago