Coastal landscapes

Question 1

Physical weathering

Answer 1

Water gets into cracks in the rock.When the temperature falls below freezing, the water will expanded it turns into ice This expansion puts pressure on the rock around it fragments of rock break off

Question 2

chemical weathering

Answer 2

Rain water contains weak acids that can react with certain rock types. Carbonate in limestone are dissolved by weak acids and this causes the rock to break off or disintegrate.

Question 3

Biological weathering

Answer 3

Seeds that fall into cracks in the rocks will start to grow when moisture is present. The roots of the young plant force their way in and in time can break up rocks.

Question 4

Mass movement

Answer 4

When material moves down a slope due to the pull of gravity

Question 5

Slumping

Answer 5

Large area of land moving down a slope. When it rains the water runs into cracks and is absorbed until the rock becomes saturated. This weakens the rock and due to the pull of gravity it slips down the slope

Question 6

Abrasion

Answer 6

Material carried in the river is thrown against the river bed and banks by the force of the water,breaking of rocks.

Question 7

Hydraulic action

Answer 7

The pressure of the water against the river bed.

Question 8

Solution

Answer 8

Chemical reaction between certain types of rocks and minerals,wearing it away.

Question 9

Attrition

Answer 9

Rocks in the water hit each other and break into smaller pieces.

Question 10

Traction

Answer 10

Large rocks and boulders are rolled along the river bed.

Question 11

Saltation

Answer 11

Small pebbles and stones are bounced along the river bed.

Question 12

Suspension

Answer 12

Fine light material is carried along the river.

Question 13

Solution [deposition]

Answer 13

Minerals are dissolved in the water and carried along in solution.

Question 14

Longshore drift

Answer 14

• The transport of sand and pebbles along the coast is called longshore drift.
• The prevailing wind causes waves to approach the coast at an angle.
• The swash carries the sand and pebbles up the beach at the same angle (usually 45º). The backwash, however carries the material back down the beach at right angles (90°) as this is the steepest gradient.

Question 15

What type of rocks erode more quickly?

Answer 15

Rocks that are well jointed or have many faults (such as limestone) erode quicker than rocks that have few joints as the waves exploit the lines of weakness.

Question 16

What type of cliffs erode more slowly?

Answer 16

Cliffs made from resistant rock (granite) will erode more slowly than cliffs made from less resistant rock (clay)

Question 17

Concordant coastline

Answer 17

• Have rocks that lie parallel to the coastline.
• They have alternate layers of resistant and less resistant rock.
• The hard rock acts as a barrier to the erosive power of the sea
• If the sea erodes through the had rock it will quickly erode the soft rock behind.

Question 18

Discordant coastline

Answer 18

• Have alternating layers of hard and soft rock that are perpendicular to the coast.
• Because the soft rock is exposed, it is erodes faster than the hard rock.
• This differential erosion creates headlands and bays along discordant coastlines.

Question 19

Destructive waves

Answer 19

• Most important agent in coastal erosion
• Backwash is stronger than swash and can carry pebbles & sand away from the shore
• Steep beach

Question 20

Constructive waves

Answer 20

• Responsible for deposition
• Swash is more powerful than backwash and so deposits sediment on beaches
• Gently sloping beaches

Question 21

How does the UK’s seasonality of weather and climate affect the rates of erosion?

Answer 21

-In the winter, the differences between day and night time temperatures can cause freeze thaw weathering on cliff faces

Question 22

How does the UK’s storm frequency affect the rates of erosion?

Answer 22

• Storms have an impact on the landforms of the coastline as storms waves are powerful agents of erosion
• The human coastal landscape such as sea defences are constantly in need of repair due to the increasing regularity of storms

Question 23

How does the UK’s prevailing wind affect the rates of erosion?

Answer 23

• The prevailing wind in the UK is from the SW
• The coastlines of cornwall and devon experience winds that may have blown for several thousand kilometres over the Atlantic ocean
• These winds have a long fetch: the longer the fetch, the stronger the wind and the more powerful the wave and the faster the rate of erosion

Question 24

What landforms are created by coastal erosion?

Answer 24

• Headlands and bays
• Cliffs and wave cut platforms
• Caves, arches, stacks and stumps

Question 25

Headlands and bays

Answer 25

- Headlands are formed when the sea attacks a section of coast with alternating bands of hard and soft rock. - The bands of soft rock,(sand and clay), erode more quickly than those of more resistant rock,(chalk). - This leaves a section of land jutting out into the sea called a headland. - The areas where the soft rock has eroded away, next to the headland, are called bays.

Question 26

Cliffs and wave cut platforms

Answer 26

- When the sea moves against the base of the cliff,using abrason or hydraulic action, it undercuts the cliff and forms a wave cut notch - An overhang will form above this notch which in time, will fall into sea due to the pressure of its own weight and pull of gravity - The sea will continue to attack the sea, forming another wave cut notch and causing the cliff to retreat as it becomes higher and steeper - The remains of the ciff rock ,now below sea level at high tide, form a rocky wave cut platform

Question 27

What landforms are created by coastal deposition?

Answer 27

- Beaches - Spits - Bars

Question 28

What is a beach?

Answer 28

A beach is an area of land between the low tide and storm tide marks and is made up of sand,pebbles and in some places mud and silt

Question 29

Formation of a beach

Answer 29

- They are formed by constructive waves, often in bays where the waves have less energy due to the gently sloping sea bed and as a result deposit material - They can be formed along straight stretches of coastline where longshore drift occurs

Question 30

What is a spit?

Answer 30

-A spit is a long narrow stretch of pebbles and sand that is attached the and at one end, with the other end tapering into the sea

Question 31

Formation of a spit

Answer 31

- Normally, longshore drift transports beach sediment along a coastline. - When the shape of the coastline changes substantially however, longshore drift continues to transport material in the same direction rather than following the coastline. - This transports the material out to sea. - As the strength of the drift weakens away from the coastline, the sediment is deposited. - Deposition can be brought about earlier near estuaries. The flow of water into the sea at an estuary is stronger than the drift, forcing the sediment to be deposited. - The deposition of sediment forms a spit

Question 32

Formation of a bar

Answer 32

-These form in the same way as a spit initially but bars are created where a spit grows across a bay, joining two headlands. Behind the bar, a lagoon is created, where water has been trapped

Question 33

How has urbanisation/industry affected coastal landscapes?

Answer 33

- As settlements grew the coastal landscape changed - Original wetland areas were drained to ensure the settlements were not flooded, meaning that wading birds and animals lost their habitats - Harbours were built to give shelter to fishing boats which involved the building of jetties into the cliff - Large ports developed to import materials; these were usually on estuaries,which had a major visual impact on the area as well causing environmental changes.

Question 34

What are the effects of coastal recession on people?

Answer 34

- If a recession is occurring where there is a settlement, then its effects on the people will be the greatest - If people lose their homes it will have a major impact on their finances because they would have lost the money they had invested in their homes - It affects transport networks, making it difficult for people to go to work or go about their daily lives - It could affect farmers who lose their land to sea. This could impact on the viability of their farm as it loses fields where crops were once grown

Question 35

What are the effects of coastal recession on people?

Answer 35

- If a recession is occurring where there is a settlement, then its effects on the people will be the greatest - If people lose their homes it will have a major impact on their finances because they would have lost the money they had invested in their homes - It affects transport networks, making it difficult for people to go to work or go about their daily lives - It could affect farmers who lose their land to sea. This could impact on the viability of their farm as it loses fields where crops were once grown

Question 36

What are the effects of coastal recession on the environment?

Answer 36

- The environmental effects of coastal erosion also relate to the loss of land - An example of this is the National Trust area called 'Golden Cap'; the cliff there has receded 40 metres in the past 20yrs - This means that animals and birds are losing their breeding grounds

Question 37

What are the effects of coastal flooding on people?

Answer 37

- Damage to people's homes and belongings from water - Loss of life from drowning - The contamination of fresh water supplies by sewage water - Bridges and roads can be washed away - Disruption to gas and electricity supplies

Question 38

What are the effects of coastal flooding on the environment?

Answer 38

- loss of land to sea, loss of habitats - Trees and vegetation washed away - Crops lost due to inundation by seawater

Question 39

Hard engineering

Answer 39

- Method of coastal management which involves major construction work - sea walls - groynes - rip rap

Question 40

soft engineering

Answer 40

- Method of coastal management which attempts to wok with the natural processes occurring on the coastline - beach nourishment - offshore reefs

Question 41

Advantages of sea walls

Answer 41

- Effective for many years - Very visible, making residents feel safe - Stops coastline receding by interfering with natural processes occurring on the coastline - Reflects and absorbs wave energy

Question 42

Disadvantages of sea walls

Answer 42

- Ugly- puts tourists off - Cost- £6000 per linear metre - Can cause wave scouring if not positioned correctly

Question 43

Formation of a cave, arch and stack

Answer 43

- Caves occur when waves force their way into cracks in the cliff face. - The water contains sand and other materials that grind away at the rock until the cracks become a cave - The cave is continually eroded until a hole is cut through the headland and an arch is formed. - Further erosion of the arch causes it to collapse , leaving behind the stack which is a left standing in the sea.