AQA AS Geography Coasts: Mindmap 2

?
View mindmap
  • Physical geography
    • Factors that determine the energy of a wave
      • Strength of the wind (controlled by the pressure gradient)
        • Wind moves from areas of high pressure to low pressure. The greater the difference in pressure, the faster the wind.
      • Duration of the wind
      • The fetch
    • Tides and currents
      • Rip currents: occur on some beaches and are strong, localised underwater currents. They normally form when a series of plunging waves causes a build up of water at the top of the beach.
      • Tides: tides are changes in the water level due to gravitational pull from the moon.
    • Formation of waves
      • Wind blows over the surface of the water, creating tiny ripples.
        • Circular motion of the water particles begins.
          • Closer to the coast, the water becomes shallower and the water particles' circular orbit elongates, becoming elliptical.
            • The wavelength and velocity then decreases due to friction along the seabed, increasing wave height.
    • Low energy and high energy coastline characteristics
      • HIGH ENERGY
        • Rocky coatline
        • streches of the atlantic facing coast wher wave are more powerful eg. Cornwall
        • Where erosion occurs mire than deposition
        • Lots of erosional landforms eg. headlands
      • LOW ENERGY
        • Sandy coastline
        • sheltered from large waves eg. bays of lincolnshire
        • Where deposition occurs more than eroison
        • Lots of depositional landforms eg. beaches and spits
    • Wave refraction
      • Wave refraction causes energy to be concentrated at headlands and dissipated at bays. This us why both erosional and depositional landforms form.
    • Sources of sediment
      • Rivers, glaciers, offshore, wind, cliff erosion, longshore drift
    • A sediment cell is a stretch of coastline, usually bordered by 2 prominent headlands, where the movement of sediment is more or less contained. A sediment cell contains...
      • Inputs
      • Outputs
      • Transfers
      • Sinks (stores)
      • Material in a sediment cell can be considered as a sediment budget with losses and gains. In principle, a state of dynamic equilibrium is attempted to be achieved through various gains and losses though this can be upset by events such as large river discharge.

Comments

No comments have yet been made

Similar Geography resources:

See all Geography resources »See all Coastal environments resources »