T4 - Coasts

Question 1

What is erosion?

Answer 1

The land wearing away over time by waves, wind and water and the removal of material.

Question 2

Explain cave, arch, stack, stump

Answer 2

1) A crack opens due to hydraulic action
2) Widens and becomes a cave
3) Breaks headland forming an arch
4) Arch is eroded and collapses to form a stack
5) Stack is eroded and forms a stump

Question 3

Hard rock coasts

Answer 3

• consist of resistant rocks
• igneous ex. granite
• sedimentary ex. limestone and chalk
• Lulworth Cove, Dorset, East Yorkshire

Question 4

Soft rock coasts

Answer 4

• less resistant rocks
• sedimentary ex. clays
• Holderness coastline, Christchuch Bay

Question 5

Concordant coastlines

Answer 5

• rocks are parallel
• one type of rock
• forms coves
  ex. Lulworth Cove

Question 6

Discordant coastlines

Answer 6

• rocks are perpendicular
• many types of rock
• forms headlands and bays
  ex. Holderness Coastline

Question 7

What causes waves?

Answer 7

Caused by wind dragging on the surface of the water

Question 8

What is the fetch?

Answer 8

Length of water the wind blows over

Question 9

Swash

Answer 9

Water that rushes up the sand when a wave breaks

Question 10

Backwash

Answer 10

Water runs down the sand after a wave breaks

Question 11

What are tides?

Answer 11

Result of rise and fall in sea level

Question 12

Two types of coastline

Answer 12

Concordant and discordant

Question 13

Two types of waves

Answer 13

Destructive and constructive

Question 14

Constructive waves

Answer 14

• small spilling waves
• long wavelengths and low amplitudes
• strong swash
• sand is deposited

Question 15

Destructive waves

Answer 15

• tall, plunging waves
• short wavelengths and large amplitudes
• strong backwash
• sand is eroded

Question 16

Headlands

Answer 16

Hard rocks have a high resistance to erosion, eroded slowly

Question 17

Bays

Answer 17

Soft rocks have low resistance to erosion, eroded quickly

Question 18

What is longshore drift?

Answer 18

• sediments being transported along a coastline
• when waves break at an angle

Question 19

What factors make coastal flooding worse?

Answer 19

• climate change
• building
• shape of sea
• geology

Question 20

What is hard engineering?

Answer 20

Man made structures to control the flow of the sea, reduce flooding and erosion

Question 21

What is soft engineering?

Answer 21

Natural methods to reduce effects of flooding and erosion

Question 22

Groynes

Answer 22

• placed at right angles to trap sand from longshore drift
• can cause erosion further down the coast
• ugly and expensive

Question 23

Sea walls

Answer 23

• concrete walls that absorb wave energy and protect cliffs
• reflect waves back to sea
• can create strong backwash
• expensive

Question 24

Rip rap/ rock armour

Answer 24

• large boundaries absorbs wave energy
• relatively cheap
• natural looking

Question 25

Gabions

Answer 25

- steel mesh cages with boulders - cheap - ugly

Question 26

Beach replenishment

Answer 26

- sand is added to replace washed away sand - beach absorbs wave energy - have to do regularly - cheap

Question 27

Dune stabalisation

Answer 27

- roots of plants bind to sand and dunes develop - cheap if maintained

Question 28

What is climate change?

Answer 28

A significant change in Earth's climate over a long period

Question 29

Evidence that earth's temperature has changed

Answer 29

- ice cores - tree rings - historical sources

Question 30

Impacts

Answer 30

- changes weather patterns wet areas get wetter and dry areas get drier - storms. floods, droughts

Question 31

Contributing factors to climate change

Answer 31

- forest fires - melting polar ice caps - deforestation - combustion

Question 32

What are greenhouse gases?

Answer 32

Gases in the earth's atmosphere that trap heat

Question 33

Examples of greenhouse gases

Answer 33

- carbon dioxide - methane - halo carbons

Question 34

What is the greenhouse effect?

Answer 34

Energy from host star heats planet but greenhouse gases prevent from the heat returning back to space which results in a warmer planet

Question 35

What is a storm surge?

Answer 35

Rising of sea as a result of wind, waves and low pressure - atmospheric pressure changes due to a storm

Question 36

What is storm frequency?

Answer 36

Climate change results in them becoming more frequent Storms give water more erosional power

Question 37

Rising sea levels

Answer 37

- low-lying coastal areas - increasing high tides -> more floods - increase in erosion - beaches more narrow

Question 38

Case study: Holbeck Hall

Answer 38

- cliff collapsed in Scarborough, North Yorkshire, 1993 - geology: sedimentary - 1M tonnes of land displaced less tourism, loss of livelihoods Don't build on land nearby sea

Question 39

Christchurch Bay

Answer 39

- on UK's south coast - big waves + mass movement - cliff collapses, unsafe, loss of homes, insurance is impossible, expensive

Question 40

Spits

Answer 40

- sharp bends - LD transports sand and shingle past bend and deposits into sea - strong winds and waves can curve the end - material accumulates - mud flat/salt marsh

Question 41

Bars

Answer 41

- when a spit joins two headlands together - bar cuts off bay from the sea - lagoon forms behind bar

Question 42

Sand dunes

Answer 42

- when sand deposited by LD moved up by wind - obstacle changes wind speed - colonised by plants - sand accumulates