EQ2 Coasts 14.5.19
EQ2: How do characteristic coastal landforms contribute to coastal landscapes?
Wave types and erosion processes are important in terms of the production of coastal
landforms.
Sediment transport and deposition processes produce coastal landforms, often stabilised by
plant succession.
The sediment call concept shows how coasts operate as holistic systems,
Weathering and mass movement subaerial processes are important on some coastlines.
Marine processes and waves
Waves are caused by friction between wind and water transferring energy from the wind
into the water. The force of wind is sustained. In open sea:
- Waves are simply energy moving through water.
- The water itself only moves up & down, not horizontally.
- There’s some orbital water particle motion within the wave, but no net forward
particle motion.
Wave size depends on:
- The strength of the wind.
- The duration the wind blows for.
- Water depth.
- Wave fetch.
Waves break as the water depth shallows towards a coastline.
- At a water depth at approx. half the wavelength, the internal orbital motion of the
water within the wave touches the sea bed.
- This creates friction between the wave and the sea bed, and this slows down the
wave.
- As waves approach the shore, wavelength decreases and wave height increases, so
waves ‘bunch’ together
- Wave crest starts to move much faster forward than the wave trough.
- Eventually the wave crest outruns the trough and the wave topples forward.
Key concept: tides
- Tides are formed by the gravitational pull of the Moon acting on water on the Earths
surface.
EQ2: How do characteristic coastal landforms contribute to coastal landscapes?
Wave types and erosion processes are important in terms of the production of coastal
landforms.
Sediment transport and deposition processes produce coastal landforms, often stabilised by
plant succession.
The sediment call concept shows how coasts operate as holistic systems,
Weathering and mass movement subaerial processes are important on some coastlines.
Marine processes and waves
Waves are caused by friction between wind and water transferring energy from the wind
into the water. The force of wind is sustained. In open sea:
- Waves are simply energy moving through water.
- The water itself only moves up & down, not horizontally.
- There’s some orbital water particle motion within the wave, but no net forward
particle motion.
Wave size depends on:
- The strength of the wind.
- The duration the wind blows for.
- Water depth.
- Wave fetch.
Waves break as the water depth shallows towards a coastline.
- At a water depth at approx. half the wavelength, the internal orbital motion of the
water within the wave touches the sea bed.
- This creates friction between the wave and the sea bed, and this slows down the
wave.
- As waves approach the shore, wavelength decreases and wave height increases, so
waves ‘bunch’ together
- Wave crest starts to move much faster forward than the wave trough.
- Eventually the wave crest outruns the trough and the wave topples forward.
Key concept: tides
- Tides are formed by the gravitational pull of the Moon acting on water on the Earths
surface.
