Wind
- Created by air moving from areas of high pressure to low pressure.
- Storms – pressure gradient is high and so strong winds.
- Generate powerful waves.
Waves
- Created by the wind blowing over the surface of the sea.
- Friction gives its circular motion.
- Height is affected by wind speed and fetch.
- High wind speed and long fetch results in more powerful waves.
- Friction on the sea bed slows the waves and makes their shape more elliptical; the crest collapses.
- Swash- water washing up the beach.
- Backwash- water washing back down the beach.
- Constructive waves: low frequency (6-8 per minute); low and long; elliptical cross profile; powerful swash, weak backwash.
- Destructive waves: high frequency (10-14 per minute); high and steep; circular cross profile; powerful backwash, weak swash.
Tides
- Periodic rise and fall of the ocean surface.
- Caused by the gravitational pull of the moon and the sun.
- They affect the position at which waves break on the beach.
- Between maximum high tide and minimum low tide is where most landforms are created and destroyed.
Currents
- General low of water in one direction.
- Caused by wind or by variations in water temperature and salinity.
- Move material.