Coasts - Systems and processes Flashcards
What are some of the sources of energy in the coastal system?
- Wind - strengthen, create and moves waves, e.g. fetch
- Waves - transfer energy, could deposit or erode
- Currents - transportation of sediment and erosion
- Tides - determine where waves hit + where beaches form
How does the wind provide energy?
- Strong winds move the water surface and create waves
- Winds with large fetches can transfer more energy
How is wind energy formed?
By air moving between areas of different pressure
How does wind strength impact waves?
The stronger the wind, the more power and energy the waves have and so the more powerful and potentially destructive they are
How do waves provide energy?
- Waves have powerful erosive energy, can destroy features
- Moves sediment around, creates as well as destroys
How do currents provide energy?
- Can move sediment on the sea floor
- Move material on and off coastline regularly, great force
How do tides provide energy?
- Moves sediment up the beach and down again, carries material
- Dictates where waves can get to, location of the energy
How does the sun provide energy?
It causes differences in air pressure due to different rates of heating, when then creates wind
How are powerful winds created?
The greater the difference in air pressure gradient, the faster the wind speed and the more powerful
What are the factors impacting the size of waves?
- Strength of the wind
- The fetch
- Duration of the wind
How are waves formed?
By energy passing through the water, causing it to move in a circular motion
What do waves transmit?
Energy, not water
What are wind driven waves caused by?
Frictional drag between the wind and the surface water
How do waves change as they approach the shore?
Disturbance to the circular motion beneath the surface leads to a more horizontal movement and the wave breaks
What terrestrial (land) factors influence the coastline?
- Supply of sediment
- Tectonics
- Fluvial processes
