Constructive waves
Find out more about constructive waves.
Constructive wave
Find out more about constructive waves.
Destructive waves
Find out more about destructive waves.
A wave is a disturbance on the surface of the sea or ocean, in the form of a moving ridge or swell.
Find out more about waves.
Swash
Find out more about waves.
Attrition is when waves cause rocks and pebbles to bump into each other and break up.
Find out more about coastal erosion.
The wearing away of land by the sea.
Find out more about coastal erosion.
Corrasion is when destructive waves pick up beach material (e.g. pebbles) and hurl them at the base of a cliff. Over time this can loosen cliff material forming a wave-cut notch.
Find out more about coastal erosion.
Coastal erosion is the wearing away of the land by the sea.
Find out more about the processes of coastal erosion.
Waves hitting the base of a cliff causes leads to air compression in cracks, joints and folds in bedding planes, causing repeated changes in air pressure. As air rushes out of the crack when the wave retreats, it leads to an explosive effect as pressure is released. This process is supported further by the weakening effect of weathering. The material breaks off cliffs, sometimes in huge chunks. This process is known as hydraulic action.
Find out more about coastal erosion.
When rainwater hits rock it decomposes it or eats it away. This is known as carbonation. This occurs when slightly acidic (carbonic) rain or seawater comes into contact with sedimentary rock, such as limestone or chalk, it causes it to dissolve. A chemical reaction occurs between the acidic water and the calcium carbonate and forms calcium bicarbonate. This is soluble and is carried away in solution. Carbonation weathering occurs in warm, wet conditions.
Find out more about weathering.
Mechanical weathering is the breakdown of rock without changing its chemical structure (composition).
Find out more about weathering.
Freeze-thaw weathering occurs when rocks are porous (contain holes) or permeable (allow water to pass through). Water enters the rock and freezes. The ice expands by around 9%. This causes pressure on the rock until it cracks. Repeated freeze-thaw can cause the rock to break up.
Find out more about weathering.
Salt weathering is when salt spray from the sea gets into a crack in a rock. It may evaporate and crystallise, putting pressure on the surrounding rock and weakening the structure.
Find out more about weathering.
Recently weathered rock can be seen at the foot of chalk and limestone cliffs and is easily identified because it is angular.
Find out more about weathering.
The movement of sediment and beach material through wave action.
Find out more about coastal transportation.
Longshore drift
Find out more about longshore drift.
Littoral drift
Find out more about longshore drift.
Any three from:
- Waves enter an area of shallow water/waves enter a sheltered area, eg a cove or bay
- There is little wind
- A river or estuary flows into the sea reducing wave energy
- There is a good supply of material and the amount of material being transported is greater than the wave energy can transport.
Find out more about coastal deposition.
Material is dissolved and carried by the water.
Find out more about coastal transportation.
