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The UK's evolving physical landscape - Coasts Topic 4, GCSE Geography

- - - - As skeletons fall, they crush those beneath, eventually squeezing out water and compacting them into rock
      - CaCO3 crystallises around the fragments; this cements them together and even preserves some fossils intact
  - - - Convection currents beneath the plate uplifted rocks from below the sea - becoming land
      - During uplift, some rocks snapped and moved along the faults in a series of earthquakes over thousands of years - each movement distributed the strata so they tilted
        Sometimes the faults form a steep edge called a fault scarp where uplift has raised some parts more than others
      - The plate on which the UK sits shifted, away from the tropics!
  - - - Altering river valleys, making them deeper and widening them into U-shaped troughs
      - As they melted they left features like Malham Cove with a spectacular waterfall!
- - - - Formed when sediments eroded and deposited by rivers
        Some are resistant yet some crumble easily
      - Examples:
        
        Carboniferous limestone
        Created in the Carboniferous period through compression in rock strata
        Permeable, with underground rivers, passages and caves; generally resistant
        
        Clay
        Formed from muds deposited by rivers or at sea
        Soft and crumbly; when compacted it becomes shale; generally weak
        
        Sandstone
        Formed from sand grains compacted together
        Slightly porous; less than 100mya are weak; more than 300mya are resistant
        
        Millstone grit
        Sandstone which has been firmly cemented and compacted
        Very resistant
        
        Chalk
        A purer, younger form of limestone
        Very porous; medium resistance - stronger than most clays and younger sands
    - - Sedimentary rocks that were heated and compressed during igneous activity
        Heating and compression harden and make them resistant
      - Examples:
        
        Slate
        Formed from heated muds or shale
        Very resistant
        
        Schist
        Formed by the further metamorphosis of slate, where it partially melted and solidified
        Very resistant
        
        Marble
        Formed by heated limestone
        Very resistant
    - - Earth's oldest rocks
        Formed from lavas and deep magmas
        Once moten, then cooled and crystallised
        Most are resistant to erosion
      - Examples:
        
        Granite
        Formed from magma cooling deep underground
        Contains crystals of quartz, feldspar, mica; very resistant
        
        Basalt
        Formed from lavas rich in minerals
        Almost black, and heavy; very resistant
  - - - Older rocks
        More resistant igneous and metamorphic
        More faults, where uplands were uplifted by tectonic activity
    - - Younger rocks
        Weaker sedimentary rocks - easily eroded
- - - - When it hooks around and joins to another place
    - - When the spits connect to another island
    - - When the sediment is deposited by L.S.D
- - - - Long wavelength - short height
      - Shallow gradient waves
      - Weak backwash
      - Strong swash
      - Beach built up by deposition of material bought up by swash
      - Unfrequent
      - Wide Gently sloping Beach
      - Less violent
    - - Weak swash
      - Strong backwash
      - Strong wavelength - tall height
      - Steep gradient waves
      - Beach erosion
      - Frequent
      - Steep Narrow Beach
      - More violent
- - - - Hard Rock Coasts consist of resistant rocks ie. granite, limestone. E.g: Lulworth Cave (Devon) & Flamborough Head (East Yorkshire).
      - Soft Rock Coasts consists of less resistant rocks i.e. clays,shales. E.g: Holderness Coast (East Yorkshire), Christchurch Bay (Dorset/Hampshire) and North Norfolk Coast.
- - - - Small particles dissolved in river due to chemical reactions between the salt water and rock
    - - The force of water forces the air into the cracks; air eventually causes the rock to expand and explode
    - - Material carried by river smashes into each other and break into smaller, smoother pieces
    - - Sea's load (rocks and sand) is thrown against the base of the cliff eventually eroding it
  - - - Bounced along the river or sea bed
    - - Materials carried in suspension along the sea bed
    - - Heavy boulders get carried along the sea/river bed
    - - Chemical reaction between rocks and salt water; rocks are dissolved and are now carried in solution
- - - - Companies in London cannot afford rent cost
      - Popular with younger workers
    - - People working in London cannot afford housing there
      - Good place for retirement
  - - - Risen sharply
- - - - Rapid cliff collapses are dangerous for those on cliff and beach
      - Infrastructure gets destroyed
      - Erosion makes living here unattractive
      - Houseowners lose their homes to the sea; house values fall with insurance impossible to get
- - - - £5000 per m
      - Steps dissipates wave energy; bullnose throws waves back to sea
    - - Breaks up incoming waves
      - Restricts beach access; looks ugly
      - £1000 per m
      - Can be distroyed by big storms
    - - Reflects waves back into sea
      - Prevents easy access to beach
      - Suffers wave scour
      - £2000 per m
    - - Absorbs wave energy as they are permeable
      - Cheap type of sea wall
      - Not very strong
      - £100 per m
    - - Easy to build
      - Expensive if built in sea
      - £300 per m
      - Dissipates wave energy and looks 'natural'
    - - £2000 per m
      - Prevents longshore drift, trapping sand/ shingle
      - Larger beach dissipates wave energy
      - May increase erosion downdirft
  - - - Use sea defenses to move coast further into sea; very expensive
    - - Gradually let the coast erode and move people/buisnesses from risky areas; may include financial compensation when homes are lost
    - - Use sea defenses to stop erosion, so coast stays where it is; expensive
    - - Take no action, let mother nature take her course
  - - - £500-£1000 per sq m; sand is pumped onto beach to increase its size
    - - £20-50 per sq m; plants are used to make cliff more stable
    - - £2000 per m; built using rip-rap, forcing waves to break before the beach
    - - Variable; pipes reduce water pressure an prevent saturation