The Coastal Zone.

Question 1

What is mechanical weathering?

Answer 1

Mechanical weathering is the breakdown of rock without changing its chemical composition.

Question 2

Describe the process of chemical weathering.

Answer 2

1) Rainwater has carbon dioxide dissolved in it, which makes it a weak carbonic acid.
2) Carbonic acid reacts with rock that contains Calcium Carbonate, so the rocks are dissolved by the rainwater.

Question 3

What is meant by mass movement? Give one example of mass movement.

Answer 3

1) Mass movement is the shifting of rocks and loose material down a slope like a cliff. It happens when the force of gravity acting on a slope is greater than the force supporting it.

Question 4

How do waves erode the coast by hydraulic power?

Answer 4

Waves crash against rock and compress the air in the cracks. This puts pressure on the rock. Repeated compression widens the cracks and makes bits of rock break off.

Question 5

What waves are associated with coastal erosion?

Answer 5

Destructive waves.

Question 6

Describe how a wave-cut platform is formed.

Answer 6

1) Waves cause most erosion at the foot of the cliff.
2) This forms a wave-cut notch, which is enlarged as erosion continues.
3) The collapsed material is washed away and a new wave-cut notch starts to form.
4) Repeated collapsing results in the cliff retreating.
5) A wave-cut platform is the platform that is left behind as the cliff retreats.

Question 7

Are headlands made of more or less resistant rock?

Answer 7

1) Headlands are usually made of resistant rocks that have weaknesses like cracks.

Question 8

Describe how erosion can turn a crack in a cliff to a cave.

Answer 8

1) Waves crash into the headlands and enlarge the cracks – mainly by hydraulic power and abrasion.
2) Repeated erosion and enlargement of the cracks causes a cave to form.

Question 9

By what process is material transported along coasts?

Answer 9

Long-shore drift.

Question 10

What is deposition?

Answer 10

Deposition is when material being carried by the sea is dropped on the coast.

Question 11

What waves are associated with coastal deposition?

Answer 11

Constructive Waves.

Question 12

Why is a sand beach flatter and wider than a shingle beach?

Answer 12

1) 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. Whereas a Shingle beach is steep and narrow – shingle particles are large and the weak backwash cannot move them back down the beach. The shingle particles build up and create a steep slope.

Question 13

Where is a beach formed on a coast?

Answer 13

Beaches are found on coasts between the high water mark and the low water mark.

Question 14

Name the transportation process that forms spits and bars.

Answer 14

Long-shore drifts.

Question 15

Where do spits form?

Answer 15

Spits form at sharp bends in the coast line e.g. at the river mouth.

Question 16

Why can’t cracks, caves and arches be seen on a map?

Answer 16

There is to much rock above caves and arches.

Question 17

How are cliffs shown on a map?

Answer 17

Cliffs are shown on maps as little black lines.

Question 18

On maps, what do speckles of yellow shading tell you?

Answer 18

That there is a beach there.

Question 19

Describe one effect of global warming that is causing the sea level to rise.

Answer 19

1 ) Melting ice: The melting ice on the land causes water that is stored as ice to return to the oceans. This increases the volume of water in the oceans and causes sea levels to rise.

Question 20

Give two economic impacts of coastal flooding.

Answer 20

1) There would be a loss in tourism, which is the largest industry in the Maldives. If the main airport can’t work properly because of coastal flooding the country would be cut off from international tourists. This will massively reduce the country’s income.
2) Disrupted fishing industry: Fish are the Maldives’ largest export. Coastal flooding may damage fish processing plants, reducing the fish exports and the country’s income.

Question 21

Give two social impacts of coastal flooding.

Answer 21

1) Houses could be damaged or destroyed – A severe flood could make entire communities homeless in the Maldives.
2) Less fresh water available – Supplies of fresh water are already low on many of the islands. If supplies are polluted with salty sea water during floods, then some islands will have to rely on rainwater or build expensive desalination plants to meet their water demands.

Question 22

Why is the risk of coastal flooding becoming greater in the Maldives?

Answer 22

1) The highest point of land in the Maldives is 2.4 metres high and due to rising sea levels, the Islands will be completely submerged within 50 to 100 years.

Question 23

Describe a political impact of coastal flooding in the Maldives.

Answer 23

The Maldivian government had to ask the Japanese government to give them $60 million to build the 3 metre high sea wall that protects the capital city, Malé.

Question 24

a) Give two main reasons for rapid erosion along a names coastline.
b) Describe three impacts on people’s lives that are caused by erosion of the same coastline.
c) Describe an environmental impact caused by erosion of the same coastline.

Answer 24

a) Easily eroded rock type – The cliffs are mostly made of boulder clay which is easily eroded. It is likely to slump when it is wet, causing the cliffs to collapse.
b) 1) Homes near the cliffs are at risk of collapsing into the sea.
2) Property prices along the coast have fallen sharply for those houses at risk from erosion.
3) Accessibility to some settlements has been affected because roads near the cliff tops are at risk of collapsing into the sea e.g. Southfield Lane which runs between Skipsea and Ulrome has been closed.
c) Some SSSI’s (Sites of Special Scientific Interest) are threatened – e.g. the Lagoons near Eastington are part of an SSSI. The lagoons are separated from the sea by a narrow strip of sand and shingle (a bar). If this is eroded, it will connect the Lagoons to the sea and they would be destroyed.

Question 25

Describe the difference between hard engineering and soft engineering coastal management strategies.

Answer 25

Hard engineering – Man-made structures built to control the flow of the sea and reduce flooding and erosion.
Soft Engineering - Schemes set up using knowledge of the sea and its processes to reduce the effects of flooding and erosion.

Question 26

Explain a disadvantage of using groynes as a coastal defence.

Answer 26

They starve beaches further down the coast of sand, making them narrower. Narrower beaches do not protect the coast as well, leading to greater erosion and floods.

Question 27

a) Name two soft engineering strategies.

b) Give one benefit of each strategy.

Answer 27

1a) Beach Nourishment
1b) Beach Nourishment creates wider beaches which slows the waves. This gives greater protection from flooding and erosion.
2a) Dune regeneration
2b) Sand dunes provide a barrier between the land and the sea. Wave energy is absorbed which prevents flooding and erosion. Stabilisation is also cheap.

Question 28

a) Give two examples of hard engineering used along a named coast line.
b) Describe two problems caused by the use of hard engineering strategies used along the same coastline.

Answer 28

1a) Sea wall.
1b) It creates a strong backwash, which erodes under the wall. Sea walls are also very expensive to build and to maintain.
2a) Rock Armour.
2b) Boulders can be moved around by strong waves, so they need to be replaced.

Question 29

a) Describe how two organisms are adapted to living in a named coastal habitat.
b) Describe two strategies for dealing with conflicts between land use and conservation in this coastal habitat.

Answer 29

1a) Marram grass.
1b) Has folded leaves to reduce water loss – sand dunes are windy and dry which increases transpiration. It also has long roots to take up water and to stabilise itself in the loose sand.
2a) Lyme Grass.
2b) Have waxy leaves to reduce water loss by transpiration.