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What is the coastline?
The zone where the land meets the sea.
What is swash?
The forward movement of the wave, up the beach.
What is backwash?
The backward movement of the wave, down the beach.
What is a destructive wave?
A tall powerful wave with a strong backwash that drags the sediment back into the sea.
What is a constructive wave?
A shallow wave that has a strong swash and deposits sediment.
What factors influence the size and energy of a wave?
The fetch
Weather/ Wind
The moon (tides)
What is fetch?
The distance a wave travels. The greater the fetch, the larger the wave.
What part of the UK receive waves with the biggest fetch?
South West
Cornwall
Wales
Explain why the coastline of the South Coast of the Uk is eroding.
Due to having a large fetch. Because the waves travel quite a far distance, the waves are destructive and erode the coast because waves have a strong backwash.
What is erosion?
The wearing away and removal of material (sediment) along the coast line, by the waves.
What is transportation?
The movement of eroded material along the coast by waves.
What is hydraulic action?
The force of water against the coast enters cracks (faults) in the coastline and compresses the air within the crack. This forces the cracks to widen.
What is abrasion?
The coast is worn down by the material carried by the waves. Waves throw these particles against the rock, rubbing away parts of the cliff. (sandpaper)
What is attrition?
Materials carried by the waves bump into each other and are smoothed and broken down into smaller particles.
What is solution?
Minerals in rocks are dissolved in the sea water and then carried in solution. The load is not visible.
What rock characteristics cause fast erosion?
Soft rocks (sands and clay)
Well-jointed rocks (lots of cracks)
What rock characteristics cause slow erosion?
Hard rocks (granite)
Unconsolidated rocks (boulder clay)
What wave characteristics cause fast erosion?
Destructive waves
Long fetch of the waves
What wave characteristics cause slow erosion?
Constructive waves
Short fetch of the waves
What weather characteristics cause fast erosion?
Winter storms
What weather characteristics cause slow erosion?
Calm sunny weather
What is weathering?
Breaking down of rocks in situ (where they are). It is caused by the day to day changes in the atmosphere such as temperature and precipitation.
What is mechanical weathering?
The breakdown of rock without changing its chemical composition such as freeze-thaw weathering.
What are the stages of freeze-thaw weathering?
water gets into cracks or holes (pores) of the rock (rain or sea water).
at night the temperature, when it falls to 0°, will cause the water to freeze and expand making cracks in the rock bigger.
when the temperature rises during the day, the ice thaws (defrosts/melts) water seeps deeper into the rock.
this process of freeze-thaw weathering is repeated -eventually the fragments (bits of) rock may break of and fall to the foot of the cliff, creating scree.
What is chemical weathering?
The breakdown of rock by changing its chemical composition such as carbonation weathering.
What are the stages of carbonation weathering?
water (H2O) reacts with the carbon dioxide (CO2) in the air creating a weak carbonic acid (H2CO3)
acid rain (H2CO3) reacts with rock that contains calcium carbonate (CaCO3) such as limestone.
this creates calcium bicarbonate (Ca(HCO3)2) which dissolves the rock. -Acid rain then evaporates back into the atmosphere.
What is mass movement?
The shifting of rock and loose material down slope under the influence of gravity.
Describe rock fall
Rockfall is the rapid free fall of rocks due to gravity. It creates scree due to the over time freeze-thaw weathering., that creates cracks in the in the cliff, that causes parts of the cliff to break off.
Describe landslides
Are caused when heavy rain infiltrates the soil and percolates down into the rock. It's weakened y weathering and falls/slides at a down hill movement at a 45 degree angle. Large amounts of rock, soil and mud.
Describe rotational slumping
Dry weather makes the clay crack allowing water to get into it. Material is rotated backwards into the cliff face as it slips as large pieces of rock are pulled downwards. A slump has a concave slip, creates a stir effect.
Describe the evidence of mass movement in the figure (3)
Generally, there is a downward movement of material evidencing mass movement in the figure. Specifically there is rotational slumping as there is a downward curve with grass on top. Additionally, there is loose rock, which is also known as rockfall.
Explain how weathering can affect a stretch of coastline (4)
Coastlines can b e affected by mechanical weathering. This is when rocks are broken down in situ without changing their chemical composition e.g freeze-thaw weathering. Freeze-thaw weathering can lead to mass movement e.g rockfall. This is when the cliff is weakened and parts of the cliff break off: rapidly falling downward to create a pile of scree at the bottom. The cliff will eventually move backwards/ retreat.
What is a headland?
A piece of hard rock (granite) jutting out into the sea.
What is a bay?
A section of soft rock (clay), eroded into the land between two headlands.
Explain the formation of headlands and bay changes over time (6)
At the coastline there are areas of more and less resistant rocks. The destructive waves come in and attack the less resistant rock, causing it to erode quicker by hydraulic action and abrasion. This process continues, resulting in the areas of softer rock to retreat, forming bays, whilst the more resistant rock will erode slower, forming headlands. Overtime, deposition will occur in the bays ans so forming beaches.
Describe the process of caves, arches, stacks and stumps
CRACK: Destructive waves attack and erode the base of the cliff through hydraulic action and abrasion on a headland. CAVE: The crack widens overtime due to hydraulic action and abrasion, forming a cave. ARCH: The back of the cave has been completely eroded away forming an arch. It erodes all the way through the headland. COLLAPSED ARCH: The arch grows and becomes unsupported forming a collapsed arch. STACK: Once the arch has collapsed, a stack is left unattached to the headland. STUMP: The waves erode away the bottom of the stack making oi unstable. This then collapses leaving behind a stump.
Explain how coastal processes have formed this land form (4)
Erosion has created this headland in the figure above. This is evidenced through the cracks, cave, arch stack and stump. When destructive waves attack the headland with their powerful force, this creates a weakness in the hard rock resulting in a crack. This is further eroded through hydraulic action and abrasion to form a cave and eventually an arch. With continued weathering, the arch becomes unstable . The unstable rock collapses into the sea because of freeze-thaw weathering and leaves behind a stack evidenced in the figure above.
How are wave cut platforms formed?
Destructive wave attack the coastline
Hydraulic action and abrasion erode the foot of the cliff forming a weak point/ crack.
This is further eroded leading to undercutting to form a wave cut notch.
The cliff is left unsupported as the foot has been eroded away. This leads to the cliff eventually collapsing and retreating backward.
During low tide, the sea goes out and a wave cut platform is left exposed.
What is undercutting?
The erosion of the base of the cliff leaving it unsupported.
Describe longshore drift
the prevailing wind is approaching the shore line at an angle
the swash approaches the beach at the same angle as the wind with the sediment
the backwash goes back out to sea due to gravity at a right angle to the beach
longshore drift transports the sediment along the coastline
What is suspension?
Small particles such as silts and clays are suspended in the flow of the water.
What is saltation?
Where small pieces of shingle or large sand grain are bounced along the sea bed.
What is traction?
Where pebbles and larger material are rolled along the sea bed.
What are the characteristics of sand beaches?
shallow and flat
gentle slope
constructive waves
long way inland
sand dunes found at back
What are the characteristics of pebble (shingle) beaches?
steep
destructive waves
not very far inland
larger pebbles found at back
Explain the formation of a beach (4)
Deposition is the main process responsible for the formation of a beach. For this to occur, waves must have limited energy and so beaches often form in open areas such as bays where wave is less than on exposed headlands. Here, waves are likely to be constructive where the swash is dominant and the backwash weaker so that material is left on the beach rather than being taken away by the waves.
What is a spit?
An extended stretch of beach material that points out to sea and is joined to the mainland at one end.
What is a salt marsh?
The zone behind a spit that is sheltered from the sea. Lots of material is deposited here and it is rich in wildlife.
How is a spit formed?
Longshore drift transports sand along the coast.
The coastline changes shape and the waves begin to loose energy.
Deposition starts to build up at the proximal end and the spit grows out into the sea. The spit is exposed to changes in wind and wave direction which cause the distal end to hook back towards the land.
A salt marsh forms behind the spit and material is deposited to low energy levels.
Sand dunes form along the spit and vegetation helps stabilise them
What is a bar?
When a spit grows and attaches to two headlands.
Explain the formation of a bar
a spit joins together two headlands
a bar cuts off the bay between the headlands from the sea
a lagoon can form behind the bar
Note 
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