Coasts Flashcards
What causes the most erosion along the coast
Waves
What’s the fetch
The fetch is the distance the wave has travelled to reach land
What are destructive waves
Waves that take sediment away, and that have a stronger backwash than swash
How much energy do destructive waves carry
A lot, held at the top of the wave and when it breaks the energy is released
What are constructive waves
They place sediment, and have a stronger swash than a backwash
What is needed for a sand dune
A large flat beach, tidal range, onshore wind and an obstacle to form against
What’s a tidal range
The distance between where the tide comes in and retracts
What’s a wave length
The distance between the top of continuous waves
What’s wave crest
The top of a wave
How does sand move
Mainly saltation, the suspension and creep
What’s the definition of weathering
The breaking down of rock through the weather, animals or plants
What comes with weathering
little or no movement
Name 4 costal processes
Deposition, mass movement, transportation and erosion
What’s windward side
The side of the dune that gets hit by the wind
What’s a crest
The top of the dune
What’s a slip slope
The actual slope where all the sand has fallen down
What’s the leeward side
The opposite side to the windward side, also know as the slip slope
What is the angle that sand becomes unstable
34-36 degrees
What happens to sand when it reaches 34 degrees
It collapses onto the slip side
What are the types of weathering
Mechanical and chemical
What are some properties of the windward side
Long and shallow
What are some properties of a slip/leeward side
Short and steep
What do dunes do
Migrate
What types of erosion are there
Attrition, corrosion, hydraulic action and corrasion
Name 3 types of mass movement
Land sliding, slumping and rock falls
What’s happens during dune migration
Sand is collected off the last dune, and moves until it hits another obstacle
What is the obstacle in dune making
Plants or grass
What factored influence costal change
Human activity, fetch length, hard and soft rock
What’s chemical weathering caused by
It is caused by a chemical reaction when rainwater hits rock and decomposes it
What is carbonation
It’s when carbonic acid in rainwater reacts with calcium carbonate in limestone to form calcium bicarbonate
How do dunes change as they move away from the beach
They get taller as there is more vegetation and more sand to pick up
What’s the water table
A natural level of water in the world
What’s hydrolysis
When acidic rainwater breaks down the rock causing it to rot
What’s mechanical weathering
Rocks being disintegrated rather than decomposed
What does mechanical occur in
Extreme of temperatures
What is a type of mechanical weathering
Freeze thaw
What are headlands
Hard rocks which are left jutting out into the sea
What’s a bay
An area of soft rock which has been worn away more than the headland, usually having a sandy beach
What’s the most common feature of a coastline
Cliff
How are cliffs shaped
Through a combination of erosion and weathering
Name some example soft rocks
Sand and clay
Name some examples of hard rock
Chalk
What kind of slopes do hard and soft rock create
Hard=steep
Soft=gently sloping
How is a Wave cut notch made
The sea erodes using attriction and make a cut in the rock
What is a wave cut platform made
The slab of rock fallen from a wave cut notch
What’s a stack
A tall piece of hard rock protruding from the ground
How are stacks formed
A crack forms in the cliff/headlands side, water entered the weakness and starts to break it up using hydraulic action. A cave forms, but the back gets eroded away by attrition and abrasion, making an arch. The arch becomes weak due to weathering so it collapses, creating a stack. The stack is then eroded by acid rain, turing it into a stump
What’s the definition of coastal deposition
When the sea loses energy and drops the sand,rock particles and pebbles it has been carrying
What is formed due to costal deposition
A beach, spit or bar
What waves enter bays
Constructive
What’s the difference between sandy and pebble beaches
Sandy=long and flat
Pebble=short and steep
What’s slack
Slow moving water
What causes slack to drop sediment
The lack of energy
What comes with a bar
Lagoon
What comes with a spit
A salt marsh
What are the 3 types of soft engineering
Beach nourishment, reprofiling and sand dune regeneration
How is beach nourishment done
A dredger replenishes sand
How is reprofiling done
The beach is reshaped with existing materials
What is the difference between reprofiling and nourishment
Reprofiling protects locals and nourishment effects tourists
Name 4 types of hard engineering
Sea walls, groynes, gabions and rock armour
What’s the pros and cons of gabions
They cost £100 per metre and provide seating and look pretty
Can be dangerous to animals and humans
What is built to prevent longshore drift
Groynes
What is costal management
The local authority trying to protect important, high-value buildings
Name some facts about the Holderness coast
North-East of the UK Cliff retreating at alarming rate Boulder clay Losing home and ruining businesses Habitats are being destroyed
