Coastal Zone

Question 1

What are the impacts on the environment due to cliff collapse on the Jurassic Coast?

Answer 1

20m of South West Coastal Footpath gave way - lead to an estimated 400 tonnes of mud and rock fall onto the beach, hugely alters the shape of the landscape
There are concerns that continued erosion and cliff collapse will cause iconic arch, Durdle Door, near Lyme Regis in Dorset to collapse

Question 2

What factors affect mass movement?

Answer 2

Geology
Precipitation
Antecedent (previous) weather conditions
Human activity

Question 3

What is hard engineering?

Answer 3

Building artificial structures such as sea walls, aimed at controlling natural processes

Question 4

What are the fauna adaptations in the Essex salt marshes?

Answer 4

To get food supply deep in the mud and water the Curlew bird has a long, curved bill
To keep their bodies dry Redshanks and Oystercatchers have long legs
To prise open mussels and cockles Oystercatchers have a perfectly shaped bill for this

Question 5

What is weathering?

Answer 5

The breakdown of rocks in situ

Question 6

What 3 factors affect the SIZE of waves?

Answer 6

Wind speed
Wind duration e.g. succession of storms
Fetch

Question 7

Dune regeneration: what it is, benefits, costs

Answer 7

Dune regeneration is creating or restoring sand dunes by nourishment or by planting vegetation to stabilise the sand
Benefits: sand dunes are a barrier between the land and sea, absorbs wave energy, stabilisation is cheap
Costs: protection is limited to a small area, nourishment is very expensive

Question 8

Describe the difference between sand and shingle beaches.

Answer 8

Sand beaches are flat and wide - sand particles are small and the weak backwash can move them back down the beach, creating a long, gentle slope

Question 9

What are discordant coastlines?

Answer 9

Coastlines where the geology alternates between hard rock and soft rock

Question 10

What is traction?

Answer 10

Heavy particles and big rocks roll along the sea floor.

Question 11

What is attrition?

Answer 11

The knocking together of pebbles, making them gradually smaller and smoother

Question 12

What are the flora adaptations in the Essex salt marshes?

Answer 12

To withstand the effect of wave action and water movement the Spartina plant has a double root system, attaching it to the surface and 2m deep into the sediment below
To adapt to the low oxygen content the Spartina and Glasswort plants have aerenchyma, which supply oxygen to submerged parts of the plant
To adapt to the high salt content in the water the Spartina and Glasswort plants are halophytes with special glands to excrete the salt
To tolerate the dry conditions Glasswort plants are xerophytic which concentrates salt into their roots to lower water potential, allowing osmosis to take place

Question 13

Explain the formation of beaches

Answer 13

Beaches form when there is a build up of material so that deposition outweighs any erosion that would remove material. Often, there is a clear source of sediment nearby e.g. a soft cliff. Deposition of sand and shingle occurs in sheltered areas where waves are not powerful and where the waves are constructive with a strong swash, forming the beach

Question 14

What is longshore drift

Answer 14

The transport of sediment along a stretch of coastline, caused by the waves approaching the beach at the same angle as the prevailing wind.

Question 15

Why do waves break at the coast?

Answer 15

The sea becomes shallower, so friction against the sea bed slows the bottom of the wave. The top of the wave is not slowed by friction, causing the wave to become increasingly elliptical closer to the shore. It begins to appear as ‘curved’. The top of the wave is moving much faster than the bottom so the wave breaks. Water rushes up the beach as awash and back down the beach as backwash due to gravity.

Question 16

How are wave cut platforms formed?

Answer 16

A wave-cut platform is a wide, gently sloping rocky surface at the base of a cliff.
Waves erode the base of the cliff by the processes of hydraulic power This creates a wave cut notch as the cliff has been undercut. The top of the cliff becomes unstable. This overhang will collapse into the sea providing more material for corrasion. The cliff has now retreated. This process of corrasion will continue. Because there is no corrosion below low tide a rock platform is left called a wave cut platform.

Question 17

What are beaches?

Answer 17

Beaches are found on coasts between the high water mark and the low water mark. They are formed by constructive waves depositing material like sand and shingle.

Question 18

Location of the Jurassic coast and brief sentence about why it is vulnerable to cliff collapse

Answer 18

The Jurassic Coast is a 95 mile stretch of the south coast from Exmouth in Devon to Studland in Dorset. It is vulnerable to cliff collapse because of its differential rates of erosion on the discordant coastline

Question 19

Location of Holderness

Answer 19

The Holderness coastline is 61km long stretching from Flamborough Head (a headland) to Spurn Head (a spit).

Question 20

What is a vegetation succession?

Answer 20

A sequence of vegetation species colonising an environment

Question 21

Why are some areas of the Jurassic Coast susceptible to undercutting by the sea and collapse?

Answer 21

Differential rates of erosion due to different geology e.g. Limestone at Lyme Regis and Chalk at Studland - these are sedimentary rocks and the less resistant geology (e.g. chalk) will be susceptible to erosion and undercutting by the sea, therefore mass movements are common.

Also, these sedimentary rocks contain pore spaces (which make up almost 30% of the rock) - when it rains (esp when there is heavy rainfall like in 2012 in Devon and Dorest), these pores hold water and thus increase the mass of the cliff making it unstable and susceptible to mass movement

Rotational slip on the Jurassic Coast occurs when sandstone and/or limestone are interbedded with clay along a concave pane. Heavy rain saturates the ground and the earth slumps.

Question 22

What problems have the hard engineering strategies at Holderness caused? (costs)

Answer 22

1) Groynes cause narrow beaches to form further down the coast - this increases erosion there e.g. Cowden Farm (south of Mapleton) is now at risk of falling into the sea
2) The material produced from the erosion of Holderness is normally transported south into the Humber Estuary and down the Lincolnshire coast - reducing this amount of material increases the risk of flooding in the Humber Estuary, because there’s less material to slow the floodwater down
3) The rate of coastal retreat along the Lincolnshire coast has increased, because less new material is being added
4) Spurn Head is at risk of being eroded away because less material is being added to it
5) Bays are forming between the protected areas and the protected areas are becoming headlands which are being eroded more heavily - this means maintaining the defences in the protected areas is becoming more expensive

Question 23

When drawing a diagram of LSD what do you need to draw?

Answer 23

DRAW
Sea
Arrows representing swash and backwash
A pebble showing where the sand moves
LABEL
direction of LSD
direction of prevailing wind (same direction as swash)
Sea
Land/Coast

Question 24

What is hydraulic action?

Answer 24

When waves crash against rock and compress the air in the cracks, putting pressure on the rock. Repeated compression widens the cracks and causes bits of the rock to fall off

Question 25

What is a salt marsh?

Answer 25

A low-lying coastal wetland mostly extending between high and low tide that is periodically flooded

Question 26

What is abrasion?

Answer 26

The 'sandpapering' effect of pebbles grinding over a rocky platform, often causing it to become smoother

Question 27

What are the four types of mass movement?

Answer 27

Fall Slide Flow Slip/slump

Question 28

How do waves form?

Answer 28

Waves form as wind passes over the surface of the water Energy from the wind is transported into the topmost layers of water (via friction and pressure) These forces develop a disturbance (ripples) that are transported through the sea water and develop into waves WAVES MOVE NOT WATER

Question 29

Why does Holderness need coastal management?

Answer 29

The average rate of erosion at Holderness is about 1.8m/year The main reasons for its rapid erosion is that most of the cliffs are made from boulder clay, it has naturally narrow beaches and has powerful waves

Question 30

Groynes: what they are, benefits, costs

Answer 30

Groynes are wooden fences placed at right angles to the coast that trap material transported by LSD Benefits: create wider beaches so slows the waves and is good for tourism, not too expensive (£10,000 each) Costs: the problem is shifted, creating narrower beaches further down the coast, unattractive

Question 31

What is mass movement?

Answer 31

The downhill movement of material under the influence of gravity

Question 32

Managed retreat: what it is, benefits, costs

Answer 32

Managed retreat is removing an existing defence and allowing the land behind it to flood Benefits: over time the land will become marshland - creates new habitats, flooding and erosion reduced by marshland, fairly cheap Costs: people may disagree over what land is allowed to flood e.g. flooding farmland would affect the livelihood of the farmers

Question 33

General political impacts of coastal flooding

Answer 33

Government has to make policies to reduce impacts of future flooding by: building more and better flood defences managing the use of areas that might be flooded e.g. by stopping people living there/relocating

Question 34

What are the impacts on people's lives due to cliff collapse on the Jurassic Coast?

Answer 34

Property loss and damage - mass movement at Monmouth beach cause damage to £200,000 beach huts Death - threat of death due to mass movements in 2012, July 2012, Charlotte Blackman was buried by tonnes of rock following cliff collapse Local economy - because of the threat on people's lives, they had to shut down beaches, affect tourism and jobs§

Question 35

Explain the problem of thermal expansion.

Answer 35

As global temperatures rise due to climate change the water in the ocean expands and takes up more space. Thermal expansion occurs due to an increase in volume of the water. This happens because as the water temperature rises the molecules gain more energy and move around more thus taking up more space. The volume of the sea increases and sea levels rise.

Question 36

Explain why deposition occurs at certain places along the coast

Answer 36

Deposition occurs in areas when there is too little energy to transport material so it is left behind. It occurs in places which are sheltered because there is less wind so less energy in the wave. Also in areas with more constructive waves because they have less energy. Areas where there is a lot of material in the water as the water has reached its carrying capacity e.g. And the end of a river. Also where groynes are placed

Question 37

Explain the process of freeze thaw weathering

Answer 37

Water enters a crack in the rock The water freezes when the temperature goes below 0 degrees Expansion of the water as ice exerts pressure on the cracks and they are enlarged When the temperature rises above 0 the ice melts and this process repeats This causes the rock to eventually break off when the cracks break

Question 38

Facts about rates of coastal erosion on the Jurassic Coast

Answer 38

Rates are expected to increase Differential rates of erosion occur due to different geology on the Jurassic Coast East of the cliffs at Burton Bradstock there has been a noticeable change in the line of the cliff top and also in the width of the beach below - in recent years there have been a number of cliff collapse events in the area

Question 39

What is Slide?

Answer 39

Material blocks of consolidated earth slide downhill along a straight plane e.g. A landslide when blocks of rock slide downhill

Question 40

What is Slip/slump?

Answer 40

The slumping of unsaturated or saturated soil and weak rock along a curved surface e.g. Rotational slip

Question 41

What is solution? (transportation)

Answer 41

The transportation of dissolved chemicals in the water.

Question 42

How is a cave/arch/stack/stump formed?

Answer 42

*Define one asked Waves crash into headlands and enlarge cracks in the rock, mainly by the processes of hydraulic action and abrasion Repeated erosion and enlargement of the cracks causes a CAVE to form Continued erosion deepens the cave until it breaks through the headland, forming an ARCH Erosion continues to wear away the rock supporting the arch until it finally collapses, leaving behind a STACK Over time, more weathering and erosion can cause the stack to collapse, forming a small STUMP, that is covered at high tide by the sea

Question 43

Political impacts of Maldives sea level rise

Answer 43

Maldivian Government had to ask Japan for $60mn to build a 30m high sea wall to protect the capital city of Male Changes to environmental policies - they have become more carbon neutral and are encouraging other countries to do the same Changes to long term plans - thinking of buying land in India and Australia, so Maldivians can move there before the islands become uninhabitable

Question 44

Beach nourishment: what it is, benefits, costs

Answer 44

Beach nourishment is when sand and shingle from elsewhere is added to beaches Benefits: prevents erosion, creates bigger beaches, aesthetically pleasing Costs: needs constant maintenance, taking material from the seabed can kill organisms, very expensive

Question 45

What is the strategy for managing Wallasea Island? Describe its characteristics

Answer 45

Managed realignment - turning 746ha of arable farmland into 320ha of mudflats, 160ha of saltmarsh, 96ha of shallow saline lagoons, 64ha of brackish grazing marshland and 129ha of pasture. It will cost approx £500,000 for design engineering studies followed by £12m to carry out the project. Breaches in the sea wall will be created, recreating an intertidal habitat. The landscape will be used for tourism and recreation as well as wildlife e.g. bird watching, walking, cycling, painting, photography. 15km of new and improved access routes and eventually a range of visitor facilities will also be provided.

Question 46

Explain how a spit is formed

Answer 46

A spit is a long, narrow piece of land that is attached at one end to the mainland and then protrudes out into the sea, a landform of deposition. Longshore drift transports material along the coastline at the same angles as the prevailing wind. Where the coast changes direction, the material is deposited and builds up to form a long, narrow spit. Deposition occurs when the waves have less energy so they leave material behind e.g. in sheltered areas. A spit often has a curved end because of a second most dominant wind blowing in a different direction, changing the direction of longshore drift, causing deposition to occur in a different direction.

Question 47

Social impacts of Maldives sea level rise

Answer 47

Houses damaged and destroyed | Less fresh water available - polluted with salty water, may have to rely on rainwater or expensive desalination plants

Question 48

What is soft engineering?

Answer 48

A sustainable approach to managing the coast without using artificial structures

Question 49

General environmental impacts of coastal flooding

Answer 49

Ecosystems affected (salt can harm and kill organisms) Vegetation killed by water (floodwater uproots and drowns trees) Increased erosion

Question 50

Marsh creation: what it is, benefits, costs

Answer 50

Marsh creation is planting vegetation in mudflats along the coast Benefits: vegetation stabilises mudflats and helps to reduce the speed of the waves - prevents flooding and erosion, creates new habitats for organisms Costs: it isn't useful where erosion rates are high because the marsh can't establish itself, fairly expensive

Question 51

What are characteristics of a constructive wave?

Answer 51

``` 1m high Limited energy Strong swash Flat and low Form gentle beaches ```

Question 52

What are the hard engineering strategies that have been put in place in Holderness?

Answer 52

1) Bridlington is protected from erosion and flooding by a 4.7km long sea wall as well as wooden groynes 2) At Hornsea there's a sea wall, wooden groynes and rock armour that protect the village from erosion and flooding 3) At Withernsea there are groynes to create wider beaches and a sea wall - some rock armour was placed in front of the wall after it was damaged in severe in 1992 4) At Mapleton, defences including two rock groynes were built in 1991 - they cost £2m and were built to protect the village and a coastal road from erosion and flooding 5) The eastern side of Spurn Head is protected by groynes and rock armour - this also protects the Humber Estuary behind Spurn Head * These strategies have all been locally successful (benefit)

Question 53

General social impacts of coastal flooding

Answer 53

Deaths Water supplies affected (floodwater pollutes drinking water) Loss of housing and jobs

Question 54

Social impacts of Maldives sea level rise

Answer 54

In Kiribati 2005 126 people does because of floods due to sea level rise. Eventually everyone will be forced to evacuate. In 2007 a hospital in male flooded and the patients had to be evacuated. MADE UP FACT PLEASE ADD SOME XXX Flooding contaminates water, locals have to rely on rain water.

Question 55

How did people worsen the situation of cliff collapse on the Jurassic Coast in 2012

Answer 55

Tourists ignored warming signs and continued to attempt to reach areas of the cliff/beach - caused smaller rockfalls and landslips People searching for newly exposed fossils at the base of recently collapsed cliffs and Lyme Regis - putting their lives at risk * however, this did attract tourists to the area, which is famous for its fossils

Question 56

What is suspension?

Answer 56

Lighter particles floating in the sea water.

Question 57

What is saltation?

Answer 57

A hopping movement of small pebbles along the seabed.

Question 58

Rock Armour: what it is, benefits, costs

Answer 58

Rock armour is boulders piled up along the coast that absorb wave energy Benefits: quite cheap (£1000-4000/m), provides interest to coast Costs: expensive to transport, don't fit in with the local geology, can be moved by strong waves

Question 59

When do salt marshes form?

Answer 59

Low energy, gentle waves enter sheltered areas behind a spit and deposit finer material such as silt and mud. This builds up to form a feature which is then colonised by vegetation.

Question 60

What is chemical weathering?

Answer 60

The decomposition of the rocks is caused by a chemical reaction within the rock e.g. Acid rain - rainwater

Question 61

Describe and explain the process of longshore drift

Answer 61

Waves follow the direction of the prevailing wind They usually hit the coast at an oblique angle The swash carries material up the beach in the same direction as the waves (and prevailing wind) The backwash then carries material down the beach at right angles, back towards the sea Over time, material is transported in zigzags along the coast

Question 62

What is chemical weathering?

Answer 62

The decomposition of the rocks is caused by a chemical reaction within the rock e.g. Acid rain - rainwater has CO2 dissolved in it, which makes it a weak carbonic acid. This reacts with rock that contains calcium carbonate so the rocks are dissolved by the rainwater

Question 63

What is cliff collapse?

Answer 63

This occurs when steeply sloping or vertical parts of the coast fall onto beaches or the sea below. Unstable cliffs may slide or slump as they fall

Question 64

How do salt marshes form?

Answer 64

They often develop in the shelter of spits because this is an area of low energy waves with little wave action. The waves deposit the finer material such as silt and mud that builds up to form a feature which is then colonised by vegetation

Question 65

Explain the formation of headlands and bays

Answer 65

A headland is a promontory of land jutting out into the sea and a bay is a broad coastal inlet often with a beach. Headlands form by differential erosion on discordant coastlines. Differential erosion occurs on discordant coastlines because of the alternating geology. The softer rock is less resistant to the power of the waves and therefore erodes at a faster rate than the hard rock, which is more resistant. The hard rock left is the headland and in the areas between the headlands, where the soft rock has been eroded, bays form. This is because deposition occurs here as it is a sheltered area and the waves have less energy.

Question 66

Environmental characteristics of the Essex salt marshes

Answer 66

Mixture of winding shallow creeks, drowned estuaries, mudflats and large expanses of marshland with some sand and shingle beaches The meandering creeks dividing up the salt marshes look cerebral The marshes are situated between high and low tide and are therefore flooded at high tide, meaning the water there is saline. They are one of the most valuable habitats for wildlife in Britain with a wide range of plants, birds and animals hat are adapted to the saline conditions.

Question 67

What are concordant coastlines?

Answer 67

Coastlines with the same type of rock

Question 68

Location of Essex salt marshes (intro sentence to 8 mark Q)

Answer 68

One example of a coast habitat is a salt marsh. A salt marsh is a low-lying coastal wetland. The Essex salt marshes are found in the South-East of England along the River Thames

Question 69

What are the four processes of erosion

Answer 69

Hydraulic Action Abrasion Attrition Solution

Question 70

What are revetments?

Answer 70

Wooden or concrete barriers built at an angle at the back of the beach Waves break against them dissipating energy, protects the cliff face 30-40 year lifespan, £1000-£2000/m

Question 71

General economic impacts of coastal flooding

Answer 71

Loss of tourism Damage repair Loss of agricultural land (due to salty seawater)

Question 72

Environmental impacts of Maldives sea level rise

Answer 72

Loss of beaches - destroys habitats, exposes land behind to blooding, affects tourism Loss of soil - most soil is shallow (20cm deep or less), if the soil layer is washed away plants can't grow

Question 73

What is solution (erosion)?

Answer 73

When weak carbonic acid in seawater dissolves rock like chalk and limestone

Question 74

How is a bar formed?

Answer 74

*formation of spit* | A bar is formed when a spit joins two headlands together, trapping the bay behind it. A lagoon forms behind the bar.

Question 75

What is physical/mechanical weathering?

Answer 75

Disintegration of rock without a chemical change e.g. Freeze thaw

Question 76

Describe the difference between sand and shingle beaches.

Answer 76

Sand beaches are flat and wide - sand particles are small and the weak backwash can move them back down the beach, creating a long, gentle slope Shingle beaches are steep and narrow - shingle particles are large and the weak backwash can't move them back down the beach. The shingle particles build up and create a steep slope.

Question 77

What are characteristics of destructive waves?

Answer 77

3-4m high High energy Strong backwash Creates steep beaches

Question 78

What is the Wallasea Island Wild Coast project and what are its aims?

Answer 78

A landmark conservation and engineering scheme for the 21st century, began in 2012 and likely to be completed by 2019 The aim is to combat the threats form climate change, coastal flooding and sea level rise by recreating the ancient wetland landscape of mudflats and saltmarsh, lagoons and pasture It will also help to compensate for the loss of such tidal habitats elsewhere in England

Question 79

How will the Wallasea Island Wild Coast Project allow sustainable use of the area?

Answer 79

Managed realignment schemes seem to be the best management option as they greatly benefit the environment - greater habitats for fish, which may also benefit local fishing economies - increase in bird life, increasing the beauty and attraction of the area to tourists esp bird watchers Although tourism makes up a large part of the local economy (£2.9bn in total to the Essex economy), strategies must minimise damage to the environment in order to prevent littering, trampling, water pollution etc. Dykes, dams and other hard engineering strategies should not be implemented as they disrupt the natural supply of sediment to the marshes, restrict the natural water flow and may cause coastal squeeze.

Question 80

What is erosion?

Answer 80

When the rocks are broken down and carried away

Question 81

Economic impacts of sea level rise in the Maldives

Answer 81

Loss of tourism - biggest industry in the Maldives, the main airport could not work anymore Disrupted fishing industry - fish is the Maldives' largest export, damage to fish processing plants

Question 82

Why does cliff collapse occur?

Answer 82

1) the power of the waves eroding the base of the cliff, undercutting it and making it unstable. The overhang eventually collapses 2) heavy rainfall can add weight to the rock, especially if the rock is soft and porous, which can cause landslides or slumps

Question 83

Sea Wall: what it is, benefits, costs

Answer 83

A sea wall is a wall made out of hard material such as concrete, that reflects waves Benefits: prevents erosion and is a barrier for flooding, long lifespan (up to 50 years) Costs: can be obtrusive and ugly, very expensive (£6m/km), high maintenance

Question 84

Why do the Essex salt marshes need to be conserved?

Answer 84

They are key habitats of specialised fauna and flora They are disappearing due to the development pressures of tourism, industry, recreation and hard engineering flood management strategies

Question 85

What is the name of the island that needs protecting in the Essex marshes and what is happening to it?

Answer 85

Wallasea Island This land is being claimed by agriculture and enclosed sea defences Consequently the marshes are diminishing by 100ha/year and this is certain to increase with the acceleration of sea level rise