Coastal Zone Flashcards
(19 cards)
What are the 4 processes of erosion and explain them
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What are destructive waves?
Give some characteristics
Waves which carry out erosion all processes
High frequency
Steep/high
Backwash more powerful than swash- material removed from beach
How are wave cut platforms created?
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What is mass movement?
Name 2 different types
Shifting of rocks and loose material down a slope as the coerce of gravity is stronger than the force supporting it. Causes coasts to retreat rapidly, more likely to happen when the material is filled with water
2 types:
slides- material shifts in a straight line
Slumps- material shifts with a rotation
How do headlands and bays form?
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How does headland erosion work?
Old Harry Swanage
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How does longshore drift work?
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What are the 4 processes of transportation and explain them
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What are constructive waves?
Low frequency
Low and long. swash is powerful- builds up coast
Backwash is weak- less material carried to sea
What map symbols indicate stacks, shingle/sand beaches, cliffs and wave-cut platforms
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How do beaches form?
Deposition between high and low water marks
How do spits form?
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What is the difference between mechanical and chemical weathering?
Mechanical- brake down of rock without changing the chemical structure- freeze thaw weathering
Chemical- break down of rock changing the chemical composition- carbonation weathering- rainwater dissolves rocks
Give 2 ways sea level rises
Melting ice- stored ice returns to sea
Heating oceans- water gets warmer causing it to expand
Give an example of coastal flooding.
What is the population
What are the economic, social, environmental and political impacts?
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Give an example of coastal erosion
Give impacts on people and the environment
Holderness- spurn head
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Give examples of hard engineering on coasts and their benefits and disadvantages
Minehead
Sea walls £12 million
+ prevent erosion and flooding
- create a strong backwash which erodes the wall. Expensive
Rock armour boulders weighing 7 tonnes each
+ boulders absorb wave energy, cheap
- ugly, need to be replaced
Groynes
+ create wider beaches, protection from flooding and erosion, cheap
- starve beaches further down from sand
Give examples of soft engineering on coasts and benefits/disadvantages
Wallasea
Beach nourishment
+ wider beaches, slows down waves
- taking material from sea beds can kill organisms. Very expensive
Dune regeneration
+ wave energy is absorbed, prevents flooding and erosion
- protection is limited to a small area. Very expensive
Marsh creation
+ creates new habitats. Protects from erosion and flooding
Managed retreat
+ cheap. Land will become marshland, more habitats
- people may disagree what area can be flooded, affects farmers livelihood
Give an example of a salt marsh
How is it formed?
Hurst castle- south west coast of England, Keyhaven
SSSI- maintain biodiversity
The spurn head spit helped to accumulate sediment and for eel grass- helps to stabilise the area by trapping more sediment. Grass wort and sea blite help accumulate mudflats. Plants die and trap more sediment helping the salty marsh to grow and the process repeats itself
