AQA AS Geography Coasts: Mindmap 2
- Created by: jennywoolcock
- Created on: 15-10-16 16:42
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
- Strength of the wind (controlled by the pressure gradient)
- 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.
- Closer to the coast, the water becomes shallower and the water particles' circular orbit elongates, becoming elliptical.
- Circular motion of the water particles begins.
- Wind blows over the surface of the water, creating tiny ripples.
- 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
- HIGH ENERGY
- 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.
- Factors that determine the energy of a wave
Comments
No comments have yet been made