Coasts 3 Coastal Landscape Development

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Characteristic Coastal Landscapes

  • Coastal landscapes have features that depend on the interactions between:
    • Coastal geology
    • Climate
    • Nature of waves and tides
  • Classification of coastlines:
    • Concordant/discordant
    • Cliffed/flat/graded shorelines
    • Emergent/submergent coastlines
  • Characteristics depend on:
    • high/low energy coast
    • Dominated by erosion/deposition
    • More or less intensely managed by people

Origin and Development of Landforms of Coastal Erosion

Headlands and Bays: 

  • Likely to occur along discordant coastlines
  • Depends on the geology of the rocks
  • components:
      • Wave refraction
    • Erosion of the headland
    • Deposition in the bay

Cliffs and Wave Cut Platforms: 

  • Erosion is concentrated at the base of the cliff causing a wave-cut notch and the cliff would collapse
  • The cliff line will retreat causing a wave cut platform 

Geos, Caves, Blowholes, Arches, Stacks and Stumps: 

  • geo: along a joint in a cliff, the sea will cut inland, widening the crack to form a narrow, steep-sided inlet
  • cave: the cliff is under cut
  • blowhole: the cave is extended to the top of the cliff
  • arch: if the cave is on a headland,  the cave will extend across the headland
  • stack: the arch will collapse, due to gravity
  • stump: the stack that is eroded

Origin and Development of Landforms of Coastal Deposition

  • Occurs when material is accumulated faster than it is removed
  • Usually where there is low wave energy or where rapid erosion provides an abundant supply of material

Beach Characteristics:

  • beaches: 
    • where land meets the sea and represent the accumulation of sediment deposited between low spring tides and the highest point reached by storm waves
  • berms: 
    • Beach terraces marking the successively lower high tides as the cycle goes from spring to neap tides
  • cusps: 
    • semi-circular shaped depressions which form

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