Coasts 🌊

Question 1

What is coastal erosion?

Answer 1

Coastal erosion is the process where coastlines are eroded by wave action, currents, and tides.

Question 2

What are discordant coasts?

Answer 2

Discordant coasts are characterized by alternating layers of hard rock and soft rock that are oriented perpendicular to the sea.

Question 3

What happens during wave refraction?

Answer 3

Wave refraction occurs when waves bend as they encounter different materials, changing their direction.

Question 4

What is the effect of soft rock on coastal features?

Answer 4

Soft rock erodes more quickly than hard rock, leading to the formation of indentations and features such as bays.

Question 5

How do destructive waves affect beaches?

Answer 5

Destructive waves hit the beach with force, causing them to lose energy and erode the coastline.

Question 6

What is the role of constructive waves in beach formation?

Answer 6

Constructive waves deposit sediment on the beach, contributing to its formation and stability.

Question 8

How are waves formed?

Answer 8

Waves are formed by the transfer of energy from wind moving over the sea, creating friction. The energy gained from a wave is determined by speed, time, and distance.

Question 9

What happens when a wave reaches the coast?

Answer 9

When the wave reaches the coast, friction at the base slows them down.

Question 10

What are constructive waves?

Answer 10

Constructive waves have a strong swash that carries water up the beach, low frequency, and low energy, depositing material on the beach.

Question 11

What are destructive waves?

Answer 11

Destructive waves have a strong backwash that removes material from beaches, are steeper, and have high energy.

Question 12

What factors determine the size of waves?

Answer 12

The size of waves depends on the strength of the wind, the duration the wind blows, and the distance over which the wind blows across open water.

Question 13

What is the power of waves?

Answer 13

The power of waves is a significant force in coastal change, created by wind blowing over the sea, generating friction and moving waves forward.

Question 14

What is the role of constructive waves in coastal areas?

Answer 14

Constructive waves are responsible for depositing sediment in coastal areas, with a strong swash that builds up the beach.

Question 15

What is the role of destructive waves in coastal areas?

Answer 15

Destructive waves are mainly responsible for coastal erosion and removing sediment away from coastlines, with a stronger backwash than swash.

Question 17

What is erosion?

Answer 17

Erosion is a natural process occurring when water hits the shore, taking sediment water to the sea and wearing into rock, causing it to erode.

Question 18

What factors increase the rate of erosion?

Answer 18

The rate of erosion increases when waves are powerful, such as in storms or high winds, and is influenced by climate change, sea level rise, and geology.

Question 19

What is coastal erosion?

Answer 19

Coastal erosion is the process by which soil and rock are removed by the action of the sea. Eroded material is then transferred and deposited in another location.

Question 20

What are the effects of erosion on coasts with hard rock?

Answer 20

Erosion of coasts with hard rock occurs over a longer time.

Question 21

What are the effects of erosion on coasts with soft rock?

Answer 21

Erosion of coasts with soft rock occurs over a shorter time.

Question 22

What are the four main types of erosion?

Answer 22

1. Hydraulic action: The sheer force of water hitting the surface forces air into cracks, breaking up the rock.
2. Abrasion: Stones in the water rub against the seabed and cliffs, wearing them away.
3. Solution: Acids in the sea dissolve certain rocks.
4. Attrition: Pebbles collide with each other, becoming smaller and more rounded.

Question 23

What factors affect how coastlines erode material?

Answer 23

1. Geology: Hard rock like granite erodes much slower than soft rock like sandstone.
2. Wave strength: Destructive waves cause more erosion than constructive waves.
3. Human interference: Human activity can prevent coastlines from being destroyed.
4. Type of erosion: Hydraulic action and abrasion are most significant, especially under storm conditions.
5. Rock types: The arrangement of different rock types impacts erosion.

Question 24

What is weathering?

Answer 24

Weathering is the breakdown of rocks at or near the surface, mainly caused by weather conditions such as changes in temperature. It occurs in situ, meaning no movement after the process.

Question 25

What are the three types of weathering?

Answer 25

1. Biological: Seeds grow in cracks of rock, and roots break around rock. 2. Chemical: Chemicals in rainwater, such as sulfur dioxide and nitric acid, can erode stone. 3. Physical: Freeze-thaw cycles cause water to expand as it freezes, breaking rocks.

Question 26

What is a coast?

Answer 26

A coast is where the land meets the sea. It can be regenerated through tourism and can also serve as a water and food source.

Question 28

What are the impacts of coastal erosion?

Answer 28

Increased risk of flooding in coastal areas, loss of agricultural land, reduced crop yields, relocation of schools, loss of cultural heritage, loss of major infrastructure, decline in property values, increased costs for coastal defense measures, and impact on local tourism.

Question 29

What is hard engineering in coastal management?

Answer 29

Building artificial structures aimed at controlling natural processes.

Question 30

What is a sea wall?

Answer 30

An artificial structure built along coastlines to protect against the force of waves, acting as a barrier to reduce flooding and property damage.

Question 31

What are the advantages of sea walls?

Answer 31

Provide reliable protection for a long period of time, give people a sense of safety and security, and are popular with tourists.

Question 32

What are the disadvantages of sea walls?

Answer 32

Can increase erosion of beach material, destroy habitats in the coastal environment, and are often very expensive to build and maintain.

Question 33

What can happen if waves breach a sea wall?

Answer 33

Flooding can occur, redirecting water's energy to nearby areas.

Question 34

What is the impact of coastal erosion on biodiversity?

Answer 34

Loss of biodiversity in agricultural land and reduced crop yields in coastal ecosystems.

Question 35

How do changes in sediment deposition patterns affect marine habitats?

Answer 35

They can negatively impact marine ecosystems.

Question 36

What financial investment was made for coastal defense in Dawlish, Devon?

Answer 36

The government invested €30 million for a new sea wall after the collapse of the main railway in 2014.

Question 38

What is soft engineering?

Answer 38

A sustainable approach to managing the coastline which uses the natural environment to provide protection. ## Footnote It is cheaper, has less impact on the environment, is more sustainable, but less effective than hard engineering.

Question 39

What is beach nourishment?

Answer 39

Putting back sand that has been taken away from the beach by destructive waves or longshore drift. ## Footnote It replenishes the sand and reduces erosion by acting as a buffer between the sea and land.

Question 40

How does beach nourishment protect buildings and cliffs?

Answer 40

The beach absorbs energy from the waves, thereby reducing their erosive power and protecting buildings and cliffs.

Question 41

How often does beach nourishment need to occur?

Answer 41

Beach nourishment has to happen every year as it isn't permanent; destructive waves and longshore drift continue to take sediment from or along the beach.

Question 42

What are the three types of beach nourishment?

Answer 42

1. Ships 2. Bulldozers 3. Sand can be brought to the beach from elsewhere to 'top it up'.

Question 43

Why do hotel owners prefer beach nourishment?

Answer 43

Guests come for scenery and views; sea walls would disrupt these views, leading to less income.

Question 44

What role do grass dunes play in erosion?

Answer 44

Grass dunes help with the problem of erosion as the roots of plants such as marram grass bind sands together, reducing beach erosion.

Question 46

What are the four types of transportation in coastal processes?

Answer 46

The four types of transportation are solution, suspension, saltation, and traction.

Question 47

What happens to material once it has been weathered?

Answer 47

Once material has been weathered, it will be transported to another area of the coastline by waves.

Question 48

What is suspension in coastal transportation?

Answer 48

Suspension refers to particles carried within the waves.

Question 49

When does most traction occur?

Answer 49

Most traction occurs during stormy conditions when there are more waves with large energy.

Question 50

Can granite be transported by solution?

Answer 50

No, granite cannot be transported by solution as it is not soluble.

Question 51

What happens during saltation?

Answer 51

During saltation, particles bounce and skip along the seabed.

Question 52

How do waves approach the beach?

Answer 52

Waves reach the coastline at an angle due to prevailing winds.

Question 53

What is the direction of backwash?

Answer 53

Backwash causes waves to retreat back up the ocean at a 90° angle to the coastline.

Question 54

What is longshore drift?

Answer 54

Longshore drift is the movement of sediment along the coastline in line with prevailing winds.

Question 55

What is a groyne?

Answer 55

A groyne is a man-made barrier designed to stop longshore drift.

Question 56

What happens to sediment at a groyne?

Answer 56

Sediment builds up on the side of the groyne where longshore drift stops.

Question 58

What is deposition?

Answer 58

Deposition is when eroded material is deposited by constructive waves. It occurs as these waves have less energy and are no longer able to carry material.

Question 59

When is deposition likely to occur?

Answer 59

Deposition is likely to occur when: → Waves enter an area of shallow water → Waves enter a sheltered area → There is little wind → There is a good supply of material

Question 60

What is a spit?

Answer 60

A spit is a long narrow ridge of sand that extends out into the sea.

Question 61

How is a spit formed?

Answer 61

A spit is formed when: • LSD moves a large amount of material along the beach • There is a sudden change in wind direction of the coastline • The sea becomes more sheltered and waves are constructive.

Question 62

What happens to a spit over time?

Answer 62

Over time, the material builds up forming a spit located across the estuary. The end of the spit will start to curve due to short changes in wind direction.

Question 63

What is a salt marsh?

Answer 63

A salt marsh will form behind the spit as sediment becomes trapped. Plants start to grow as their roots stabilize the sediment.

Question 64

What is a bar?

Answer 64

A bar is similar to a spit as it deposits material and is a thin strip of land off a headland.

Question 65

How does a bar differ from a spit?

Answer 65

A bar differs from a spit as it: • Goes all the way across the bay (as there is no river) • Has no hooks, no river • Forms a lagoon on the inside of the bar instead of a salt marsh.