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Coasts - Coggle Diagram
Coasts
Costal defence
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Sea Walls: A structure made of conrete or similar materials that is curved outwards so that when waves crash into it they are pushed back out to sea
Rock Armour: Large boulders placed at a coastline to absorb impacts from waves and reduce coastal erosion
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Longshore Drift
Waves hit the beach at an angle due to prevailing wind, and the backwash, under the force of gravity
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Costal Erosion
Hydraulic Action: When waves crash into the face of a cliff, pushing air and water into the cracks, until eventually the cracks grow and bits of the cliff fall away
Abrasion: Rocks that fall down from the cliff are picked up by waves and smashed into the cliff face, eroding the cliff away
Attrition: As the rocks bang into the cliff and eachother, they begin to break up. Overtime, the rocks will become smaller, smoother and more rounded.
Solution: Soluble rock particles can be dissolved by seawater aided by acids, which break down the calcium carbonate in the tiny rocks.
Coastal Features
Caves
When waves push through cracks, forming a tunnel/cave in the rock face
Arches
When waves go through both sides of a cave, hollowing it out and creating an arch
Stacks
When Arches collapse, leaving behind pillar-like pieces of rock
Stumps
Over time, a stack is undercut at its base by the waves until it collapses, leaving behind a (much) smaller stump
Tides
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Tides are certain points when the water is very high, or very far/low down from the coast
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Headlands & Bays
Headlands are harder pieces of land, and erode slowly
Bays are softer bits of lands, which get eroded quicker
Certain parts of rock are weak, due to faults and cracks, even though Headlands & bays are made of Limestone
Fetch
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The further the distance, the greater the fetch and the greater the wave size
How waves are formed
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The wind pushes some parts of the water down, which then pushes other parts of the water up, and it begins to spin in a cycle, forming a wave
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Erosion
The loss or displacement of land (like rock) due to waves, currents, tides, or impacts from storms
Happisburgh
An extremelt small costal city that is experiencing mass rates of erosion causing people to lose their homes. The government is not taking any action as it only cares about historical or densley populated areas, like London.
Storm Surges:
An extremely powerful tsunami like flood that brings extreme weather and can destroy cities or ruin peoples lives. For this reason, coastal defences are implemented.
The difference creates a pattern of bays, cliffs, etc
The sea will first attack the soft rock, and then go for cracks in the harder rocks
