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Coastal (Coastal transportation and deposition (transportation (long shore…

- - - - small particles - silt, clay carried by water
    - - pebble hopping on sea bed
    - - soluble mats dissolve in water
    - - boulder rolling on sea bed
    - - waves follow direction of prevailing wind
      - usually hit coast at oblique angle ie not right angle
        
        swash carries mat up beach in same direction as waves
        
        backwash carries down beach at right angles
        
        over time mat zigags along coast
  - - - spit joins two headlands together
        
        bar cuts off bay from sea
        
        lagoon can form
    - - beaches that stick into sea
        
        formed by longshore drift
        
        form at sharp bend in coastline
        
        sheltered area behind spit protected from waves
        
        material accumulates here
        
        plants can grow
        
        1 more item...
        
        strong winds/waves can curve end
        
        recurved end
        
        long shore drift transports sand/shingle past bend
        
        deposits in sea
        
        eg at river mouth
    - - on coasts between high water and low water marks
        
        constructive waves
        
        deposit shingle
        
        steep and narrow
        
        particles large, weak backwash cannot move down beach
        
        shingle particles build up
        
        1 more item...
        
        deposit sand
        
        particles small, weak backwash can move down beach
        
        creates long, gentle slope
        
        flat and wide
  - - - coasts built up when amount deposition greater than erosion
        
        deposition increased when:
        
        lots transportation material into area
        
        lots erosion elsewhere on coast
        
        lots material available
- - - - 1 type affects coasts: freeze thaw weatheirng
        
        temp alternates above and below 0
        
        water gets into cracks in rocks (eg granite)
        
        water freezes, expands, puts pressure on rock
        
        thaws contracts, releases pressure
        
        repeated freezing thawing widens cracks and causes rock break up
    - - carbonation
        
        happens in warm and wet conditions
        
        rainwater has carbon dioxide in it - weak carbonic acid
        
        carbonic acid reacts with rock that contains calcium carbonate
        
        eg carboniferous limestone
        
        rock dissolved by rainwater
  - - - shifting of rocks and material down a slope as one
        
        gravity on slope greater than force supporting it
        
        cause rapid retreat of coasts
        
        more likely when material full of water
        
        water acts as lubricant
      - slide
        
        material shifts in straight line
      - slump
        
        material shifts with rotation
    - - waves
        
        destructive waves
        
        high frequency (10-14 waves/minute)
        
        high and steep
        
        backwash stronger than swash
        
        material removed from coast
      - 4 processes of erosion
        
        solution
        
        weak carbonic acid in seawater
        
        dissolves rocks like chalk and limestone
        
        attrition
        
        eroded particles smash into each other
        
        break into smaller fragments
        
        edges get rounded off
        
        abrasion
        
        eroded particles in water
        
        scrape and rub against rock
        
        remove small particles
        
        hydraulic
        
        waves crash against rock
        
        compress air in cracks
        
        repeated compression widens cracks
        
        bits rock break off
      - coastal landforms caused by erosion
        
        wave-cut platforms
        
        eroded from cliffs
        
        waves most erosion at foot of cliff
        
        forms wave-cut notch
        
        rock above notch becomes unstable
        
        1 more item...
        
        headlands and bays
        
        alternating bands of resistant and less resist rocks
        
        less resistant (eg clay) eroded quickly
        
        forms a bay
        
        resistant rock eg chalk eroded slowly
        
        is left jutting out, forming headland
        
        headlands have steep sides
        
        caves, arches and stacks
        
        headlands have weakenesses eg cracks
        
        waves enlarge cracks
        
        repeated erosion/enlargement of cracks forms caves
        
        erosion deepens cave
        
        1 more item...
- - - - Melting ice
        
        melting of ice on land causes water that's stored as ice to return to the oceans
        
        e.g. Antarctic ice sheet
        
        this increase the volume of water, causing sea level to rise
      - Heating ocean
        
        Increased global temp causes the oceans to get warmer and expand
        
        this increase the volume of water, causing sea level to rise
  - - - Economic
        
        loss of tourism- many coastal are popular destinations
        
        Flooding can cause tourist attractions to close
        
        can put tourists off visiting
        
        damage repair
        
        repairing is very expensive
        
        Loss of agricultural land
        
        seawater has a high slat content
        
        salt reduces soil fertility
        
        Crop production can be affected for years after a flood
      - Social
        
        Deaths- coastal floods have killed thousands of people in past
        
        Water supplies affected
        
        Floodwater can pollute drinking water with salt and sewage
        
        loss of housing
        
        many people are made homeless because of flooding
        
        Loss of jobs
        
        coastal industries may be shut down
        
        because of damage to equipment and buildings
      - Environmental
        
        Ecosystems affected
        
        Seawater has a high slat content
        
        increased salt levels can damage or kill organisms in an ecosystem
        
        vegetation killed by water
        
        The force of flood water uproots trees and plants
        
        Standing flood water also drowns some trees and plants
        
        increased erosion
        
        a large volume of fast water can erode lots of material and damage the environment
      - Political
        
        The Gov has to make policies to reduce the impacts of future flooding
        
        Can do things like building more or better flood defenses
        
        Manage the use of ares that might flood
        
        e.g. by stopping people live there
- - - - What is it
        
        A wall made out of hard material that reflects waves back to sea
      - Benefits
        
        it also acts as a barrier to prevent flooding
        
        It prevents erosion of the coast
      - Disadvantages
        
        Creates a strong backwash which erodes the wall
        
        very expensive to build and maintain
    - - What is it
        
        Boulders that are piled up along the coast
      - Benefits
        
        fairly cheap
        
        absorb wave energy and so reduces erosion and flooding
      - Disadvantages
        
        Boulders can be moved around by strong waves
        
        therefor need to be replaced
    - - What is it
        
        Wooden of stone fences that are built at right angles to the coast.
        
        they trap material transported by long shore drift
      - Benefits
        
        groynes create wider beaches which slow waves
        
        This gives greater protection for flooding and erosion
        
        Fairly cheap
      - Disadvantages
        
        Narrower beaches don't protect the coast as was, leading the greater erosion and floods
        
        Starve beaches further down the coast of sand, making them narrower
  - - - What is it
      - Benefits
      - Disadvantage