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EMS Geography GCSE Revision FLASH CARDS:Unit 2 – Coastal Landscapes

EMS Geography GCSE Revision: Question(s) Answer(s)COASTAL LANDSCAPES

Define the key terms: a. Fetch b. Backwash c. Swash

Fetch – The distance over which wind has blown to form a waveBackwash – the movement of water back down a beach Swash – the movement of water up a beach


Describe and explain how waves form

- Wind blows over surface of water – creates friction - Frictional drag causes water particles to begin to rotate and energy is transferred forward in the form of a wave - As a wave reaches shallow water, friction increases between the sea bed and the base of the wave – causes the wave to slow down - Top of the wave – unaffected by the friction – becomes steeper – eventually breaks - When it breaks – water moving up the beach in the swash and the water moving back down the beach in the backwash


Outline the main characteristics of constructive waves

- Height: Low <1m - Energy: Low - Frequency: Low (<10/min) -Wave Shape: Elliptical- Strong Swash; Weak Backwash - Coastal Process: Deposition


Outline the main characteristics of destructive waves

- Height: Higher >1m - Energy: Higher- Frequency: Higher (>10/min) -Wave Shape: Orbital (round)- Strong Backwash; Weak Swash - Coastal Process: Erosion



Describe 3 factors which will affect the strength of a wave

- Strength and speed of wind – faster the wind – more energy transferred – bigger wave produced - Duration of the wind – length of time for which the wind has blown – longer the wind blows for, the more energy is transferred to the wave. - Fetch – the distance over which the wind has blown (i.e. how far the wave has travelled) – longer the fetch the stronger the wave.


Define these sub-aerial processes: (a) weathering(b) mass movement

Weathering – ways that rocks are broken down in situ.

Mass movement – material moves down a slope, pulled by gravity.


Explain the terms: (a) Physical weathering(b) Biological weathering(c) Chemical weathering

Physical weathering is when water gets into a crack in a rock, freezes & expands, forcing the rock to crack and eventually splitBiological weathering is when a seed gets into a crack in a rock & germinates, with roots growing, causing the rock to crack and fall apartChemical weathering is when slightly acidic rain reacts with alkaline rock such as limestone and dissolves at the surface.


Explain these types of mass movement:(a) slumping(b) soil creep

Slumping – erosion at base of cliff may lead to rotational slipping of cliff above – particularly on clay cliffs – during dry periods the clay contracts and cracks and will become saturated during wet periods – moving downslope due to gravity.

Soil Creep – very slow downslope movement of soil particles due to gravity. Heavy rainfall causes slightly faster movement. Ripples in slope develop called terracettes. Usually associated with chalk cliffs.



Name and outline four examples of erosion processes operating at the coast

- Abrasion – where sands in the wave are flung against the cliff face - Hydraulic action – waves break against cliff face – pressure of the breaking wave compresses air in cracks – ‘mini-explosions’ force the rocks apart - Corrosion – occurs where slightly acidic sea water is able to slowly dissolve alkaline rock (e.g. limestone or chalk cliffs gradually weakened). - Attrition – pebbles or small boulders carried by the waves – hit against each other and gradually wear down


Describe 3 factors which affect the rate of coastal erosion / recession

Geology - Resistance of Rocks – limestone / chalk and granite – more resistant - whereas clay = less resistant rocks = erode faster Shape of the Coastline – where discordant coastline (bands of rock at right angles to coast) – outcrops of hard and soft rock – resulting in differential erosion Strength of the Waves – longer the fetch the stronger the winds – greater the rates of cliff recession Coastal defence – rates of cliff recession are slower where coastal defence techniques are used.


Name 4 examples of erosion landforms found at the coast

- Headlands and Bays - Wave Cut Platform - Cliff - Cave - Stack and Stump - Arch


Explain the formation of cliffs and wave-cut platforms

- Cliff formation – sea erodes base of cliff by hydraulic action and abrasion- Over time this creates a wave-cut notch and overhang- Lack of support (gravity) of overhung cliff creates pressure / cracks and subsequent collapse- Action of sea compacting rock into wave-cut platform which protects coast at low tide e.g. Flamborough Head, Yorkshire- Formation of steep cliff which over time recedes



Explain the formation of headlands and bays

- Headlands and bays are formed in areas of hard and soft rock (discordant coastline)- Erosion is greater on the soft rock e.g. Clay (Swanage Bay, Dorset) – as these are less resistant to wave processes such as hydraulic action and abrasion- Headlands are more resistant – therefore erodes more slowly – protruding into the sea e.g. Limestone (Peveril Point, Swanage, Dorset)- The exposed headland eventually becomes more vulnerable to erosion from destructive waves.


Describe and explain the erosion of a headland

- The sea attacks base of cliff – erodes weaknesses such as joints / cracks in e.g. chalk - by processes such as hydraulic action and abrasion.- Cracks get larger – form into small caves - Further erosion widens the cave – where the fault line runs through the headland – eventually forms arch which passes through the headland - Further wave attack at base of arch and weathering of roof of arch (e.g. Durdle Door, Dorset) – weakens structure – roof of arch eventually collapses – leaves a stack (free standing column of rock) e.g. Old Harry, Purbeck, Dorset- Stack eventually collapses forming stump (covered at high tide) e.g. Old Harry’s Wife, Purbeck, Dorset


Give 3 main sources of beach material- Rivers – where fine muds and gravels and deposited at the river mouth - Longshore drift (bringing material from elsewhere along the coast) - Constructive Waves (bringing material up the beach from the sea) and from cliff erosion



Describe and explain the process of longshore drift

- This is the movement of material along the coastline. - Material is moved up the beach by the swash at an angle controlled by the prevailing wind. - The backwash then carries materials back down the beach at right angle to the coastline under the influence of gravity. - Gradually the material is moved along the coastline in a zig-zag movement - its direction controlled by the prevailing wind.


Explain the formation of beaches

- Made of sand and pebbles - Found on straight coastlines where longshore drift is happening- Also found in bays where the sea is shallower so the waves lose their energy and deposit what they are carrying – constructive waves (Strong swash, Weak backwash)


Explain the formation of:(a) Spits(b) Bars

(a) Spit (E.g. Spurn Head, Holderness Coast)- Spit formed by movement of material along a coastline due to longshore drift- Occurs where there is a change in direction of the coastline and builds out beyond headland.- May form re-curved end due to change in wind / wave direction.- Formation of salt marsh behind spit as sheltered from wave attack.

(b) Bar (as above + below)- Bars are spits which go across a bay- This is only possible if there is shallow water and no river entering the sea.- A lagoon is formed behind the bar E.g. Slapton Sands, Devon



Explain the effects of coastal recession on: (a) people and(b) the environment

Exam hint: This can be a 6 mark question and may focus on (a) people or (b) the environment or both! You MUST know a RANGE of EXAMPLES

(a) people- Since 1995, 25 properties in Happisburgh, Norfolk have been lost to the sea. The lives of the villagers are totally dominated by their struggle against the sea.- Since 1975, Barton on Sea (Hampshire) has lost a seaside café & Manor Lodge – demolished before becoming too dangerous.

(b) the environment- The Tower at Walton on the Naze could soon be lost to the sea if the cliff continues to erode at its present rate of 1.5 metres a year. - The area around the Tower is used for recreational purposes and is not deemed worthy of coastal protection.


Explain how the effects of coastal flooding can be reduced through prediction and prevention

Exam hint: This is a common 4 or 6 mark question where you could be asked specifically about either prediction or prevention or both! Make sure you have plenty of PLACE-SPECIFIC examples.

Prediction: - Forecasting: MET office predicts likelihood of coastal flooding – public news broadcasts and weather forecasts advise the public on being proactive – and advice put on the Environment Agency website. - Storm Tide forecasting service provides the Environment Agency with forecasts of coastal flooding. Prevention:- Education: Gov’t gives advice on website on how to protect homes and what to do if a flood occurs.- Bangladesh has flood warning system + King’s Lynn, Norfolk has flood siren and people employed by council to warn and help people prepare.- Building design: In Bangladesh, one- to two-storey buildings must have an external staircase to the roof. In Malibu, nr. Los Angeles, houses are built on stilts to protect against storm tides.- Planning: Planning permission needed before building.In Bangladesh – Coastal Embankment project built 12 sea-facing flood walls and 500 flood shelters.In London – Thames Flood Barrier completed in 1982 – by 2010 the Environment Agency had also installed new flood walls to protect London area from coastal flooding (should last until 2100).



What are the differences between hard and soft engineering in coastal management ?

Hard engineering involves the construction of man-made defences to control the natural processes (e.g. groynes and sea walls) whereas;Soft Engineering works with natural processes, not involving construction. It is usually visually unobtrusive and considered more environmentally friendly


Explain how effective hard engineering techniques are in controlling coastal erosion in the UK

(A) = advantages (D) = disadvantages

Revetments: slatted wooden structures built at the base of the cliff and run parallel to the coastline. (A) Can be cheap compared to other techniques. (D) Can make the beach inaccessible for tourists.Rip-rap: Large rocks placed in front of the cliff. (A) Effective for many years. (D) Unattractive.Recurved seawall: usually made of concrete; modern ones have a recurved face. (A) Very visible – make residents feel safe. (D) Can cause wave scouring (erosion of the beach) if not positioned correctly.Groynes: wooden fences which run at right-angles to the coastline. (A) Keep beach in place for tourist industry. (D) Stops longshore drift - narrows beach and increases erosion down-drift.Gabions: Wire cages filled with stones to reduce erosion (A) Rock cages absorb wave energy. (D) Wire cages can break – need to be securely tied down.Offshore reefs: large concrete blocks and boulders are sunk offshore to alter wave direction. (A) Waves break offshore and therefore reduce their erosive power (D) Difficult to install.


Explain how effective soft engineering techniques are in controlling coastal erosion in the UK

(A) = advantages (D) = disadvantages

Beach replenishment: Placing sand and pebbles on a beach. (A) Looks natural. (D) Needs constant maintenance – lost sand through longshore drift.Cliff regarding: The cliff is cut back and given a new slope to stop it slumping. (A) Covered in ecomatting to encourage vegetation growth and stabilise slope. (D) Not effective alone – needs other defences at cliff foot.Managed retreat: Allowing the sea to gradually flood land or erode cliffs. (A) Cheap & creates new habitats (D) Upsetting for landowners who lose land.



For a named example, explain how the coast is being managed.

(H) = hard strategies (S) = soft strategies

Exam hint: This is a common 4 or 6 mark question. Make sure you have plenty of PLACE-SPECIFIC examples & explain why they were used.

Walton-on-the-Naze, Essex: defended due to longshore drift and the rock type (London Clay – less-resistant rock).1977:(H) Groynes built to stop longshore drift movement from south to north. (S) Cliff regraded and drainage channels installed to produce more gentle, stable slopes.(S) Slope planted with gorse and nettles to stop people climbing on the cliff.(H) Seawall built to protect the soft London Clay at the bottom of the cliff.1998:(H) 300 tonnes of Leicester granite placed around the Tower breakwater.1999:(S) Beach replenished with sand and gravel from Harwich Harbour (work with nature & looks natural)

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