Contrasting Coasts

Question 1

What two types of rock do hard rock coasts contain?

Answer 1

Resistant rocks (e.g. granite) and sedimentary rock (e.g. limestone).

Question 2

Give two examples of hard rock coasts.

Answer 2

Flamborough Head and Lulworth Coast.

Question 3

What two materials are soft rock coasts made of?

Answer 3

Clay and shale.

Question 4

What are two examples of soft rock coasts?

Answer 4

Christchurch Bay and the North Norfolk Coast.

Question 5

Describe how a crack in the coastline can become a stump?

Answer 5

1) Hydraulic action creates a crack in the coast.
2) The crack grows until it becomes a cave.
3) The cave breaks through the headland to form an arch.
4) The arch is eroded until it collapses leaving a stack.
5) The stack is eroded until it leaves a stump.

Question 6

What are the three ways erosion happens on the coastline?

Answer 6

• Hydraulic Action
• Attrition
• Abrasion

Question 7

What is hydraulic action?

Answer 7

Air is compressed into cracks in the cliff face by water. When the wave retreats the air explodes out.

Question 8

What is attrition?

Answer 8

When small pieces of sediment are knocked into each other.

Question 9

What is abrasion?

Answer 9

When small pieces of sediment are picked up by waves and slammed into the cliff face.

Question 10

What is a concordant coastline?

Answer 10

A coastline where the strata run parallel to the sea. This means the coastline is made of one type of rock.

Question 11

What is a discordant coastline?

Answer 11

A coastline where the strata are perpendicular to the sea. This means the coastline is made up of lots of different types of rock.

Question 12

At what type of coastline are coves formed?

Answer 12

Concodrant

Question 13

Describe how coves are formed.

Answer 13

1) Erosion breaks through the first layer of rock at a coastline, revealing less resistant rock behind it.
2) The waves erode the softer rock forming a cove.
3) The cove stops widening when it hits harder rock again.

Question 14

At what type of coastline are headlands and bays made?

Answer 14

Discordant

Question 15

How are headlands and bays made?

Answer 15

The rocks at discordant coastlines erode at different speeds. The softer rock erodes faster forming bays whereas the harder rocks form headlands.

Question 16

What coastline is a good example of headlands and bays?

Answer 16

The South-West Irish coast.

Question 17

How are waves formed?

Answer 17

Wind blows across the sea create friction which becomes waves.

Question 18

What three factors affect the size of a wave?

Answer 18

• The strength of the wind
• The duration of the wind
• The fetch of the wind

Question 19

What is the fetch of a wind?

Answer 19

How far the wind has travelled.

Question 20

What type of waves do we get in the summer?

Answer 20

Constructive waves

Question 21

What are constructive waves like?

Answer 21

• Strong swash
• Long wavelengths
• Low amplitudes

Question 22

What effects do constructive waves have on sediment on the beach?

Answer 22

They transport sediment up the beach.

Question 23

What type of waves do we get in the winter?

Answer 23

Destructive waves

Question 24

What are destructive waves like?

Answer 24

-•Strong backwash

• Short wavelengths
• Larger amplitudes

Question 25

What effects do destructive waves have on sediment on beaches?

Answer 25

* They erode and making the beach steeper. | * Some sand is carried offshore and form an offshore bar.

Question 26

Describe longshore drift.

Answer 26

•The prevailing winds push waves to shore. 2) The swash pushes sediment up the beach in the direction of the prevailing wind. 3) The sediment falls back with the backwash at a 90 degree angle.

Question 27

How are sand dunes formed?

Answer 27

Onshore winds blow sand inland forming sand dunes parallel to the shore.

Question 28

How are bars formed?

Answer 28

When there's a sudden change in the shape of the landscape, longshore drift continues to deposit sediment until it reaches land again.

Question 29

What do you call the body of water on the other side of a bar?

Answer 29

A lagoon

Question 30

How is a spit formed?

Answer 30

At a river mouth, longshore drift continues until it is stopped by river flow. The sand continues to build up forming a spit.

Question 31

How does a spit get a recurved end?

Answer 31

The movement of water during the changing of the tides forces the spit back on itself.

Question 32

What does the water behind a recurved end become?

Answer 32

A salt marsh?

Question 33

What three adaptions do plants require to survive in depositional landforms?

Answer 33

* Long roots to stop them being uprooted in strong winds. * Tough, waxy leaves to stop them being sandblasted. * They need to be able to survive being sprayed by salt water.

Question 34

Why are plants useful on depositional landforms?

Answer 34

They help to stabilise it.

Question 35

How much is the sea level predicted to rise by by 2100?

Answer 35

1m

Question 36

What could three effects of the sea rising 1m be on global geography?

Answer 36

* 15% of !Bangladesh would flood. * London and Essex would flood completely. * Small coral islands like the Maldives could disappear.

Question 37

What is a storm surge?

Answer 37

When a spring tide combines with an area of low pressure to form huge waves.

Question 38

What is an example of a storm surge?

Answer 38

Storm Sandy.

Question 39

When did Storm Sandy happen?

Answer 39

October 2012

Question 40

Where did Storm Sandy hit?

Answer 40

New York and New Jersey.

Question 41

How tall were the waves made by Storm Sandy?

Answer 41

4m

Question 42

How many people lost electricity because of Storm Sandy?

Answer 42

5 million

Question 43

How many people died in Storm Sandy?

Answer 43

100

Question 44

What was the total value of damage done to property because of Storm Sandy?

Answer 44

$50 billion

Question 45

What is a marine reason why cliffs collapse?

Answer 45

The base of the cliff is eroded by hydraulic action and abrasion.

Question 46

What are three sub-aerial causes of cliffs collapsing?

Answer 46

* Mechanical (i.e. Freeze thaw action) and chemical (i.e. Solution) weathering. * Rain runs down the cliff face. * Permeable rock absorbs rain making it heavier.

Question 47

What is a human cause of cliffs collapsing?

Answer 47

Humans build on top of cliffs.

Question 48

What is an advantage of hard engineering?

Answer 48

Very effective.

Question 49

What are two costs of hard engineering?

Answer 49

It is very ugly and expensive.

Question 50

What do sea walls do?

Answer 50

Reflect waves back into the sea.

Question 51

What does a sea wall with steps and bullnose do?

Answer 51

It dissipates the waves before throwing it back into the sea.

Question 52

What do revetments do?

Answer 52

Break up incoming waves.

Question 53

What are gabions?

Answer 53

Cheaper, permeable sea walls.

Question 54

What are rip rap?

Answer 54

Large boulders that dissipate sea waves.

Question 55

What do groynes do?

Answer 55

Trap sediment and dissipate waves.

Question 56

How much are the cliffs eroded at Christchurch Bay without intervention?

Answer 56

2m a year

Question 57

Give four effects of rapid cliff erosion at Christchurch Bay.

Answer 57

* Homeowners could lose their homes to the sea. As such insurance is impossible to get. * Mass movement is dangerous for those above and below the cliffs. * Roads could be destroyed. * Erosion makes area less attractive to tourists.

Question 58

What do the residents and business owners of Christchurch think needs to be done?

Answer 58

They are in favour of doing whatever it takes - although they are mindful that engineering could deter tourists.

Question 59

What do the councillors and MPs of Christchurch think needs to be done?

Answer 59

They don't take a stance as to not polarise the public.

Question 60

What do the residents of towns near Christchurch think needs to be done?

Answer 60

They hunk that it should be a cheap option as they will have to pay for the engineering works with their taxes.

Question 61

What do the environmentalists of Christchurch think needs to be done?

Answer 61

They think the solution is either to do nothing or use soft engineering.

Question 62

What do those living downdrift from Christchurch think needs to be done?

Answer 62

They fear that hard engineering will have a knock-on effect on them so prefer soft engineering.

Question 63

What do the fishermen of Christchurch think needs to be done?

Answer 63

Whatever the solution is, they need easy access to the sea.

Question 64

Why might the government choose not to save somewhere from coastal erosion?

Answer 64

* The land value could be smaller than the cost of protecting it. * Protection of the area may increase erosion elsewhere.

Question 65

What is an ICZM?

Answer 65

Integrated Coastal Zone Management is planning whether or not to protect a shoreline.

Question 66

What is an SMP?

Answer 66

A Shoreline Management Plan is the type of management chosen for each shoreline. There are four options.

Question 67

What is meant by "hold the line"?

Answer 67

Use sea defences to keep the shoreline where it is.

Question 68

What is meant by "advance the line"?

Answer 68

Use sea defences to move the coast further into the sea.

Question 69

What is meant by "strategic realignment"?

Answer 69

Gradually letting the sea erode the coastline and relocate homes and businesses.

Question 70

What is meant by "do nothing"?

Answer 70

Letting the sea erode the coastline with no intervention.

Question 71

What is soft engineering?

Answer 71

Coastline management that is cheap and aims to preserve the coast using natural processes.

Question 72

What are three examples of soft engineering?

Answer 72

* Planting vegetation. * Beach nourishment. * Offshore breakwaters.

Question 73

What is an offshore breakwater?

Answer 73

A wall of rip rap that breaks up incoming waves.