Constructive and destructive waves.
Find out more about constructive waves and destructive waves.
The distance a wave has travelled.
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Weak swash, strong backwash.
Find out more about destructive 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.
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Destructive waves
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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.
The wearing away of land by the sea.
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Abrasion occurs as breaking waves, concentrated between the high and low watermarks, which contain sand and larger fragments wear away the base of a cliff or headland. It is commonly known as the sandpaper effect. This process is particularly common in high-energy storm conditions.
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.
Corrasion, abrasion, hydraulic action, attrition and corrosion/solution.
Find out more about the processes of 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.
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.
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Weathering is the breakdown of rock in situ by the action of rainwater, extremes of temperature, and biological activity.
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Mechanical weathering is the breakdown of rock without changing its chemical structure (composition).
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Beach material is suspended and carried by the waves.
Find out more about coastal tansportation.
The movement of sediment and beach material through wave action.
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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.
Traction – large pebbles and boulders are rolled along the seafloor.
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Coastal transportation involves material being transported by the sea being deposited or dropped.
Find out more about coastal deposition.
