Land formations and Wave defenses

Wave Cut Platform

Cliffs are shaped through a combination of erosion and weathering

Weather weakens the top of the cliff. The sea attacks the base of the cliff forming a wave-cut notch. The notch increases in size causing the cliff to collapse. The backwash carries the rubble towards the sea forming a wave-cut platform. The process repeats and the cliff continues to retreat.

Rock Armour

Rock armour is rock or other material used to armor shorelines, streambeds, bridge abutments, pilings and other shoreline structures against scour, water or ice erosion.

Waves and Coasts

Transportation - Longshore Drift

Longshore drift is the transport of sand and rocks along a coast at an angle to the shoreline, which is dependent on prevailing wind direction, swash and backwash.

Erosion

Erosion is the process of weathering and transport of solids (sediment, soil, rock and other things) in the natural environment or their source and deposits them elsewhere.

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Coasts And Waves

Destructive waves

 

•Destructive waves are created in storm conditions.

•are created from big, strong waves when the wind is powerful and has been blowing for a long time.

•occur when wave energy is high and the wave has travelled over a long fetch.

•tend to erode the coast.

•have a stronger backwash than swash.

•have a short wave length and are high and steep.

Coasts And Waves

Constructive waves

 

•Constructive waves are created in calm weather and are less powerful that destructive waves.

•break on the shore and deposit material, building up beaches.

•have a swash that is stronger than the backwash.

•have a long wavelength, a low height.

Coasts And Waves

Arches, Caves, Stacks, and Stumps.

 

•Caves occur when waves force their way into cracks in the cliff face. The water contains sand and other materials that grind away at the rock until the cracks become a cave.

•If the cave is formed in a headland, it may eventually break through to the other side forming an arch.

•The arch will gradually become bigger until it can no longer support the top of the arch. When the arch collapses, it leaves the headland on one side and a stack (a tall column of rock) on the other.

•The stack will be attacked at the base in the same way that a wave cut notch is formed. This weakens the structure and it will eventually collapse to form a stump.

•All of the rock types are linked together.

Coasts and Waves

How are waves formed

 

•Waves are formed by wind. The wind usually comes from the south west so the coast on the south west get better waves because the wind pushes the waves further and higher. This is called the fetch.