Constructive wave

Find out more about constructive 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.

Waves are caused by the transfer of energy from the wind to the sea due to the friction of the wind on the water’s surface.

Find out more about waves.

Swash

Find out more about waves.

Constructive and destructive waves.

Find out more about constructive waves and destructive waves.

Attrition is when waves cause rocks and pebbles to bump into each other and break up.

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.

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.

Coastal erosion is the wearing away of the land by the sea.

Find out more about the processes of coastal erosion.

The wearing away of land by the sea.

Find out more about coastal erosion.

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.

Mechanical weathering is the breakdown of rock without changing its chemical structure (composition).

Find out more about weathering.

Weathering is the breakdown of rock in situ by the action of rainwater, extremes of temperature, and biological activity.

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Recently weathered rock can be seen at the foot of chalk and limestone cliffs and is easily identified because it is angular.

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Chemical weathering is the breakdown of rock through changing its chemical composition.

Find out more about weathering.

Coastal transportation involves material being transported by the sea being deposited or dropped.

Find out more about coastal deposition.

Littoral drift

Find out more about longshore drift.

Material is dissolved and carried by the water.

Find out more about coastal transportation.

Solution, suspension, saltation and traction.

Find out more about coastal transportation.

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.