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Coastal Landscape Exam Questions Year 10 Intervention
Coastal processes that shape the coastline
Weathering – the break down of rocks (disintegration) in its original location.
Weathering weakens the coastline speeding up rates of erosion. There are two
types of weathering.
1. Mechanical weathering or freeze thaw weathering. Water enters a crack in
a rock, at night time when the temperature drops this water freezes and
expands by 9-10% exerting pressure on the side of the rock. This then
melts or thaws and the process continues. Eventually the rock will break
up.
2. Chemical weathering involves a weak carbonic acid dissolving the outside
layer of rock. This usually takes place under warm and wet conditions.
Mechanical weathering changes the size of the rock whereas chemical weathering
changes the shape and colour. Chemical weathering changes the chemical
composition of the rock. Mechanical weathering does not.
Erosion – the wearing away of the land by the sea
Hydraulic power – water and air is blasted into cracks in cliffs widening these over time and causing
parts of the cliff to break off
Abrasion – sediment within the water is thrown at the cliff face. This wears down the outer later of
rock and has a sandpapering effect. Rock is often left smoother as a result of this.
Attrition – does not affect cliffs but rocks themselves. Rocks and pebbles will bang into each other
becoming smaller, smoother and rounder.
Transportation – long shore drift
Sediment is moved along the coastline in a process called long shore drift. Sediment is moved up the beach in
the swash, usually at an angle driven by the prevailing winds. Sediment is then carried back down the beach at
a right angle under the force of gravity in the backwash. This process continues creating a zig zag pattern that
results in sediment being moved from one end of the beach to the other. If groynes are in place this process
may be interrupted.
Exam Questions
(i) Outline the process of slumping.
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(ii) State one impact of slumping on the coast. (1)
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Exam Mark scheme
i) Slumping – a rotational movement of land at the coast (1) triggered by saturation
(1). Allow simple statements about water in cracks and downward movement of
land. Credit explanations at 1 mark
ii) Loss of land (1) Destruction of property (1) loss of animal habitats (1)
Deposition – the dropping of sediment by the sea. This happens when the waves do not have enough
energy to transport sediment. This can happen under the following conditions
Constructive waves – strong swash washed sediment up onto the beach. The weaker backwash can
not drag it back and so the sediment is deposited on the beach.
Next to a groyne – when a wave hits a groyne it loses energy. Long shore drift is prevented and
sediment is deposited next to the groyne where it accumulates.
In an estuary – where a river meets the sea the fast slowing river is forced to slow down as it meets
the sea, at the meeting of the two types of water sediment is deposited.
Near to cliffs that are easily eroded – the more sediment in the sea the more deposition that is
likely to take place as the sea won’t have the energy to transport all of the sediment.
Mass movement – when large amounts of sediment or material move downhill under the force of
gravity (cliff collapse)
Sliding/landslides – a very fast sudden movement. Large amounts of material moves suddenly
downhill at the same time. Happens as a result of erosion at the base of the cliff and weathering on
the surface
Slumping – a curved slower movement. Sediment starts to creep slowly downhill, only a short
distance. Usually happens when cliffs are made of softer material like clay and become saturated
after heavy fall.
Rockfalls – individual pieces of rock move freely away from the cliff. This can happen after freeze
thaw weathering has helped to loosen and dislodge pieces of rock.
Study Figure 1b. It shows erosion rates at four sites (A–D) along a coastline. Each site has a different type of coastal management.
(i) Describe the changes in erosion rate along the coastline shown in Figure 1b. Use erosion rate data (cm/year) in your answer.
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Rates of erosion have fallen at A, C and D (1).
But risen at site B (1)
Greater rate of decrease at site C (1)
Smallest decrease at site D (1)
Use of data – data is cm/yr erosion data (1)
(iii) Physical weathering can affect the landforms shown on Figure 1a. Explain the process of physical weathering.
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Freeze thaw – diurnal changes in temperature around 0 degrees (1). Water in crack widened due to freezing (1), 9% volume increase (1) thawing leaves crack prized open – removes water (1), process repeats (1)
Could also refer to animal burrowing/plant action.
Describe the differences between constructive and destructive waves. (4)
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Mark Scheme Maximum of 3 marks for answers which do not use comparative language ‘whereas, however, in comparison’
Constructive waves have a greater swash than backwash whereas destructive waves have a greater backwash than swash (1)
Destructive waves are higher energy waves in comparison to constructive waves which are low in energy (1)
Constructive and destructive
waves
Constructive waves are waves that surge up
the beach with a powerful swash. They carry
large amounts of sediment and ‘construct the
beach’, making it bigger. They deposit
material. They appear less often than
destructive waves
Destructive waves are so named because
they ‘destroy’ the beach. Destructive waves are
closely spaced and often interfere with each
other, creating a chaotic swirling mass of
water. There is little forward motion when a
wave breaks (swash) but a strong powerful
backwash that erodes the beach.
Destructive waves remove sediment from the beach whereas constructive waves build up the beach (1)
Destructive waves break more frequently than constructive waves (1) for example, destructive waves break 13-15 times per minute whereas constructive 5-9 times per minute (1)
Study Figure 1a. It shows a constructive wave.
Using Figure 1a, state one feature of a constructive wave.
(1) ..............................................................................................................................................
State two other features of a constructive wave.
(2)
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Landforms of costal erosion
1. Headlands and bays
Headlands and bays 1. Coastlines are made of alternating bands of soft
rock and hard rock (more resistant and less resistant)
2. Less resistant rock such as clay is eroded more quickly, this retreats back forming a bay
3. More resistant rock such as granite is eroded more slowly. This protrudes (sticks out) forming a headland.
Explain the formation of headlands and bays.
.............................................................................................................................................. ............................................................................................................................................. .............................................................................................................................................. ............................................................................................................................................. .............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. Mark Scheme Max 3 marks without a process or full sequence. Max 3 without reference to headland and bays.
Differential erosion due to perpendicular geology (reference to hard and soft geology which is perpendicular to the coast).
Harder rock is more resistant therefore forms land which sticks out into the sea (headlands).
Softer rock is eroded (hydraulic action/abrasion/corrosion) at a quicker rate to form a bay. An extension to sequence could refer to development of headlands into stacks/stumps or
beaches within bays
2. Caves, arches, stacks and stumps
Caves, arches, stacks and stumps 1. A weakness in a headland will be eroded until it
becomes wider forming a cave 2. Hydraulic actions and abrasion erode the cave
further until it breaks through to the other side of the headland forming an arch.
3. The roof of the arch is weakened at the base by erosion and on the top by weathering. Eventually this collapses leaving a stack.
4. The stack will be undercut by hydraulic action and abrasion. Eventually this will collapse resulting in a stump.
Explain the formation of a stack.
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Stacks begin as part of an eroding headland. Wave refraction causes waves to attack the side of the headland
Joints are exploited by erosion (named process e.g. hydraulic action, corrasion). Repeated erosion causes a cave, which becomes eroded through to become an arch. Pressure on the arch and force of gravity ultimately cause the collapse of the arch, leaving
a stack.
3. Wave Cut Platforms
Wave cut platforms This is a gentle sloping platform that sticks out from the base of a cliff 1. The sea erodes the cliff face at the high
water mark and the low water mark creating a wave cut notch
2. Hydraulic action and abrasion erode the notch further until it becomes bigger.
3. The top of the cliff above the notch will be unsupported as it is undercut and so eventually collapses
4. This process repeats and eventually the cliff retreats leaving a wave cut platform
5. Abrasion smooth’s this platform over time.
Study Figure 1b. It shows coastal landforms.
Describe the cliff and wave-cut platform. (4 marks) Use evidence from Figure 1b in your answer.
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The cliffs have a wave-cut platform in front of them (1)
Cliff overhangs the wave-cut notch. The cliffs are 30m high (1) The cliffs are vertical (1) Cliff / wave-cut platform made of chalk (1) Debris / rocks / on the wave-cut platform (1) Notch separates cliff from platform (1) The wave cut platform extends 20m from coast (1)
Explain how geology influences the formation of coastal landforms.
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Exam Mark Scheme
Landforms of deposition
Exam question
I) Draw an arrow in the box on Figure 1a to show the direction of long shore drift
iii) Identify landform X on Figure 1a.
Beaches Beaches form as the result of deposition. Constructive waves carry sediment onto the beach that is left behind by the weaker back wash. Beaches also form in bays. The bay is sheltered from the full power of the waves by the headlands. As the wave enters the bay it is slower, has less energy and therefore deposits sediment. The shallower the bay the more friction and so the more deposition.
Spits – form in sheltered areas of the coastline. Normally in estuaries 1. Longshore drift carries sediment along the
coastline driven by the prevailing wind. 2. As the coastline changes shape or next to a
headland, sediment will be deposited as there is a loss in energy. Here sediment starts to accumulate.
3. Over time this sediment builds up to form a narrow ridge made of sand called a spit
4. If the wind changes direction curved tips will form 5. Salt marsh forms behind the spit. Sediment
collects here from the river, over time grasses will start to grown on it forming a spit.
Describe the formation of a bar. (3 marks)
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Mark scheme List of words with no description max 1. Must describe the link of sediment across the bay to get maximum marks.
Bars form due to longshore drift often at bays (1)
The spit extends across the bay until it reaches the other side (1)
Sediment is moves by the action of swash and backwash (1)
If a spit extends from one side of the bay to the other it will form a bar (1)
A lagoon can form behind the bar once the bar covers the bay (1).
Bars – form across bays 1. Longshore drift carries sediment along the
coastline driven by the prevailing wind. 2. As the coastline changes shape or next to a
headland, sediment will be deposited as there is a loss in energy. Here sediment starts to accumulate.
3. Over time this sediment builds up to form a narrow ridge made of sand
4. This becomes a bar when the narrow ridge of sand joins two headlands together.
5. A lagoon is created where the bay once was.
The causes and effects of coastal erosion
Coastal areas provide economic (money/jobs), environmental (nature) and social (e.g. activities) opportunities which is why many people live near the coast. Coastal erosion and the threat of flooding is posing a threat to such communities.
Coastal erosion is the removal of material from the coast by wave action, causing the coastline to retreat (move backwards) inland. This results in loss of land, damage to buildings, roads and railways and can further increase the risk of flooding in the future.
How fast is the coast changing?
Depending on the reason, coastlines recede at varying rates.
Failure of coastal defences leads to the most coastal erosion
Landslides also lead to coastal erosion
Wave and storm damage lead to significant coastal erosion.
Rising sea levels
Sea levels along the English Channel has risen by about 12cm in the past 100 years. Levels are expected to rise by another 11-16cm by 2030 due to global warming. A warmer climate causes seawater to expand and causes the ice sheets and glaciers to melt, leading to increased sea levels as a result. The effects are as follows:
Cliffs that are currently being undercut and collasing will continue to retreat, the position of the wave cut notch and the level of the wave cut platform may change.
Areas of soft coastline (clay and gravel) may experience more erosion and retreat due to more frequent and stronger storm surges.
Storms and storm surges
A storm surge is a large scale increase in sea level due to gale force winds driving water towards the coastline. They can last hours to days and span hundreds of kilometres and cause significant damage and loss of life.
In 2013, the North Sea (to the east of England) experienced an enormous storm surge due to a storm. Due to the coastal defences and early warnings, flood related deaths and major damage was avoided. However, in January and February 2014, the jet stream (fast flowing currents of air) resulted in a depressions (low pressure system – rising air, cooling, condensing, forming convectional rainfall) leading to high winds and widespread damage.
Human causes of coastal erosion and their impacts
Human activities such as farming, urban and industrial development affect coastal processes and thus landscapes.
Causes
Strictures like groynes are built to trap sand, however, removing sediment from the system results in increased erosion along the coast
Dredging (removing material from the coastline) to build up other areas leaves the
coastline vulnerable to erosion as the material would have acted as a barrier.
If cliffs are protected from erosion, the supply of sediment that would have resulted from the natural erosion of the sea cliffs leads to a loss of sediment further up the coastline resulting in more erosion elsewhere.
Impacts
Settlements – over 20 million people in the UK live on the coast. In a place called Holderness, over 29 villages have been lost due to erosion in the last 1000 years.
Tourism – plays a major part in local economies for example jobs.
Infrastructure – roads, railways, oil refineries and ferry and shipping ports are located along the coast.
Agriculture – sea level rise and increase coastal erosion are leading to the loss of farmland.
An example of a section of coastline in the UK to identify its major landforms of
erosion and deposition.
Holderness is in east England in the country of Yorkshire. The Holderness coastline is 61km is length. To the north is Famborough Head made out of hard chalk. The coastline to the south of this headland is made from soft boulder clay. The coastline ends at the Humber Estuary,
Flamborough Head – landform of erosion Flamborough Head is made from more resistant hard rock (chalk) that is being eroded more slowly than the softer boulder clay surrounding it. As a result, it protrudes out forming the headlands.
Spurn Head – landform of deposition Spurn head is a coastal spit growing out across the Humber Estuary. Large amounts of sediment are transported south via longshore drift. As the coastline changes shape the sediment is deposited into the estuary in the shallower waters forming a spit.
Using examples, explain how coastal recession affects the human environment.
(6)
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Exam Mark Scheme
Explain the factors which affect the rate of coastal recession. (4)
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Could refer to coastal management (lack of it), geology or fetch. Affects can be an increase or a decrease in rate of erosion.
Coastal Management. A sea wall would provide a barrier to the waves (1) which absorbs wave energy (1) leading to a reduction in the rate of coastal erosion (1)
Increased fetch would lead to waves with greater energy (1) which would therefore be more destructive (1) causing more erosion.
More resistant geology such as Chalk /limestone/ igneous rock (1) can withstand greater impact from waves (1) therefore would erode less quickly
Coastal management
Hard engineering – man made structures, very expensive that help to hold back the sea
and protect the coastline
Strategy Benefits Costs (bad)
Groynes – stone
or wooden
structure that
sticks out at a 90
degree angle to the
beach
Stops longshore drift, sediment
is deposited next to groynes.
Helps to build a bigger beach
which provides a buffer to a sea
and protects the coastline
behind. Builds a bigger beach
which is popular with tourists.
Sediment is deposited next to
the groyne so cannot be carried
further down the coastline. This
can accelerate (speed up) the
rate of erosion further south of
the groyne.
Wood rots and so they need
replacing often.
Sea wall – a high
wall usually made
out of stone.
Sometimes curved
in shape.
Protects the coastline from the
sea as it is tall and made of
concrete so cannot be eroded
The sea wall can provide a
promenade (walkway) for
tourists
Very expensive costing millions
of pounds.
The sea can bounce back off the
sea wall with great force eroding
the beach in front
Can look obtrusive (ugly)
Rock armour –
large boulders
placed in front of a
cliff
Provide a buffer to the sea. The
rocks absorb the power of the
waves protecting the land
behind
Can provide a spot for fishing
Look very obtrusive (ugly)
Rock are often imported which is
very expensive
Gabions – metal
cages filled with
rocks that are piled
on top of each
other
Provide a buffer to the sea. The
rocks absorb the power of the
waves protecting the land
behind
Overtime vegetation may grow
on the gabions making them
look more natural.
Metal cages can rust easily which
could become dangerous. Looks
obtrusive and out of place
Soft engineering – working with the natural environment to provide a barrier to the sea. Less obtrusive and less expensive. Often better for wildlife and more sustainable.
Strategy Benefits Costs (bad)
Beach nourishment
and reprofilling –
sand or shingle is
dredged from
offshore and placed
onto the beach
Looks natural
Builds a bigger beach that is
popular with tourists
Relatively cheap
Larger beach provides a natural
buffer to the sea, absorbing the
power of the waves and
protecting the land behind
Sediment is easily eroded so
needs to be replaced regularly
which overtime can become
costly.
Does not provide a solid barrier
to the sea. Flooding is still
possible.
Will need to be used alongside
hard engineering to fully protect
the coastline.
Dune regeneration
– new sand dunes
are created by
planting marram
grass to help
stabilise the sand
and build bigger
dunes
New habitats are created
These are a popular feature
with walkers and nature
enthusiasts
The high sand dunes provide a
natural barrier to the sea
helping to protect the land
behind
Humans can trample of the sand
dunes so they will need
maintenance.
Large storms could destroy the
dunes.
Describe the advantages of the hard engineering. (3 marks) .............................................................................................................................................. ............................................................................................................................................. .............................................................................................................................................. ............................................................................................................................................. Mark Scheme Point marked Types of engineering e.g. rock groynes, gabions, sea wall.
Hard engineering is stronger (1) and more durable (1). The rock groynes help build beaches (1) which absorb the energy of the waves (1). They are cost effective in the long term (1).
Soft engineering is a way of managing the coastline. Outline the advantages and disadvantages of soft engineering techniques.
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Mark Scheme
Credit explanations at one mark. Max 3 with reference to only advantages or disadvantages
Advantages – cheaper than hard engineering (1). More sustainable to environment (1), and does not require quarrying of rock (1). Less visually obtrusive (1). Doesn't require as much maintenance.
Disadvantages – less effective than hard engineering (1) as it does not always stop erosion from occurring (1), cost of maintenance could be high in the long term (1) with repeated outlays due to annual upkeep (1)
Holderness Coastline: example of a coastal management scheme in the UK to show:
1. The reasons for management
2. The management strategy
3. The resulting effects and conflicts
In 1991 a £2 Million rock groyne was built to protect the village of Mappleton along the Holderness
coastline. This was built to protect the village as well as the B1242 coastal road, an important main road.
The cliffs are made of soft boulder clay. When not protected the average rate of erosion is 2m per year.
The groyne helped to trap sediment in front of Mappleton, building a bigger beach and slowing the rate of
erosion. Unfortunately, this accelerated the rate of erosion further south as sediment was no longer
being replenished.
Conflicts - further south
Colin and Josie of cliff house farm lost their business. Their farm became dangerously close to the sea.
They tried to sue the council and blamed the rock groyne at Mappleton for the accelerated rate of
erosion.
Grange farm and Cowden farm have been completely lost to the sea
House prices have decreased further south as the rate of erosion has increased
Explain the management techniques used to protect a named area of coastline.
(4)
Named area of coastline ............................................................
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