Coasts

Question 1

What is Hydraulic Action?

Answer 1

This is the force of the water hitting the cliff and squeezing air into the cracks in the rock

Question 2

What is Abrasion?

Answer 2

Abrasion is where the force of the bits of rock carried in the water blast into the cliff, therefore eroding it.

Question 3

What is Attrition?

Answer 3

Attrition is the process of rocks hitting each other and breaking into smaller rocks.

Question 4

What is Corrosion?

Answer 4

Corrosion is a chemical reaction between the sea water and minerals in the rocks. it is an acid and alkali reaction.

Question 5

What is solution?

Answer 5

Where the rocks dissolve in to the water. These are very fine pieces of rock as they have to be able to fit in the gaps between the liquid particles. When they are dissolved, it forms a solution.

Question 6

What is suspension?

Answer 6

Very fine and smaller particles that are held in water.

Question 7

What is traction?

Answer 7

Large boulders rolling across the sea bed.

Question 8

What is saltation?

Answer 8

Saltation is when pebbles bounce along the sea bed.

Question 9

What is Weathering?

Answer 9

Weathering is the breaking down of rocks, soils, and minerals as well as wood and artificial materials.

Question 10

What is the Fetch?

Answer 10

The fetch of a wave is the area where the winds blow over and it is also the distance a wave travels. It is an uninterrupted area. The size of a wave depends on its fetch. The greater the fetch, the larger the wave.

Question 11

What is the effect of wind on waves?

Answer 11

Wind has an effect on the size of waves because the stronger the wind, the larger the wave.

Question 12

What is deposition?

Answer 12

Deposition is the geological process where material is added to a land (or a landform). In deposition, wind and water may lay down grains of material that might have been eroded and transported from another place.

Question 13

How are bays formed?

Answer 13

Cliffs along the coastline do not erode at the same pace. When a stretch of coastline is formed from different types of rock, headlands and bays can form.
Bands of soft rock such as clay and sand are weaker and therefore they can be eroded quickly. This process forms bays. A bay is an inlet of the sea where the land curves inwards, usually with a beach.
Bays are sheltered with constructive waves which deposit sediment to form a beach.

Question 14

How are headlands formed?

Answer 14

Hard rock such as chalk is more resistant to the processes of erosion. When the softer rock is eroded inwards, the hard rock sticks out into the sea, forming a Headland.

Question 15

How do caves, arches, stacks and stumps form?

Answer 15

1. Caves, arches, stacks and stumps are erosional features that are commonly found on a headland.
2. Cracks are formed in the headland through the erosional processes of hydraulic action and abrasion.
3. As the waves continue to grind away at the crack, it begins to open up to form a cave.
4. The cave becomes larger and eventually breaks through the headland to form an arch.
5. The base of the arch continually becomes wider through further erosion, until its roof becomes too heavy and collapses into the sea. This leaves a stack.
6. Wave-cut platform is exposed at low tide. The stack collapses into a stump. The stack is undercut at the base until it collapses to form a stump.

Question 16

What is a stack?

Answer 16

It is an isolated column of rock. They are formed by an arch’s roof becoming too heavy and collapsing, leaving a headland and a stack.

Question 17

What is a stump?

Answer 17

It is a stack that has collapsed down because of erosion and weathering

Question 18

What is a cave?

Answer 18

Caves are natural openings in the earth. They are caused by waves continuing to grind away at the crack and it eventually turns into a cave because so much of it has been cracked away.

Question 19

What is a wave cut platform?

Answer 19

A wave-cut platform is a wide gently-sloping surface found at the foot of a cliff. The sea attacks the base of the cliff between the high and low water mark. A wave-cut notch is formed by erosional processes such as abrasion and hydraulic action - this is a dent in the cliff usually at the level of high tide.

Question 20

What is a Spit?

Answer 20

A spit is an extended stretch of beach material that projects out to sea and is joined to the mainland at one end. Spits are formed where the prevailing wind blows at an angle to the coastline, resulting in longshore drift.

Question 21

What is a tombolo?

Answer 21

A tombolo is formed when a spit connects the mainland coast to an island. The process of longshore drift occurs and this moves material along the coastline.

Question 22

What are the properties of constructive waves?

Answer 22

It has a strong swash and a weak backwash. The backwash moves little sediment.
The gentle and wide beach builds the sand.
It has a low wave in proportion to the length which is very wide.

Question 23

What is Longshore Drift?

Answer 23

Longshore drift is the movement of material along the shore which is done by waves. The waves approach the beach at an angle. The swash carries material up and along the beach while the backwash carries material back down at a right angle.

Question 24

What are the properties of destructive waves?

Answer 24

It has a weak swash and a strong backwash. Weaker swash moves sediment up the beach.
It has a high wave in proportion to the length which is very short. These waves are more frequent and are caused by large storms.

Question 25

How are spits formed?

Answer 25

1. Sediment is carried by longshore drift.
2. When there is a change in the shape of the coastline, deposition occurs. A long thin ridge of material is deposited. This is the spit.
3. A hooked end can form if there is a change in wind direction.
4. Waves cannot get past a spit, therefore the water behind a spit is very sheltered. Silts are deposited here to form salt marshes or mud flats.

Question 26

What is a bar?

Answer 26

Sometimes a spit can grow across a bay to join two headlands together. This landform is known as a bar. Bars can trap shallow lakes behind the bar - these are known as lagoons. Lagoons do not last forever and may be filled up with sediment.

Question 27

Where is the Holderness Coast and why is it easy to erode?

Answer 27

The Holderness Coast is on the east side of the UK and it is located in Lincolnshire and Yorkshire. However, Hull and Grimsby are very close. It runs from Flamborough Head to Spurn Head. It is easy to erode because it has a large fetch between this and Norway. The beaches are very narrow so the waves reach the coastline very easily. There is also very little coastal protection and there are lots of storms hitting it from the North Sea. Furthermore, it is made from boulder clay which is not a very strong substance.

Question 28

Why do we protect the coast?

Answer 28

We protect the coast because some people will be affected by coastal erosion. Stakeholders are people who are affected by coastal erosion. This might be because their factory is close to the coast or their house is for example.

Question 29

What are types of hard engineering?

Answer 29

Sea walls are concrete walls that are placed at the foot of a cliff to prevent erosion. They are curved to reflect the energy back into the sea.
Advantages
Effective at protecting the base of the cliff.
Sea walls usually have promenades so people can walk along them.
Disadvantages
Waves are still powerful and can break down and erode the sea wall.
Expensive - approximately £2,000 per metre.
Groynes are wooden or rock structures built out at right angles into the sea.
Advantages
Builds a beach - which encourages tourism.
They trap sediment being carried by longshore drift.
Disadvantages
By trapping sediment it starves beaches further down the coastline, increasing rates of erosion elsewhere.
They look unattractive.

Question 30

What are types of soft engineering?

Answer 30

Rock armour/rip rap are large boulders placed at the foot of a cliff. They break the waves and absorb their energy.
Advantages
Cheaper than a sea wall and easy to maintain.
Can be used for fishing.
Disadvantages
They look different to the local geology, as the rock has been imported from other areas.
The rocks are expensive to transport.
Beach nourishment is when sand is pumped onto an existing beach to build it up.
Advantages
Blends in with the existing beach.
Larger beaches appeal to tourists.
Disadvantages
Needs to be constantly replaced.
The sand has to be brought in from elsewhere
Reprofiling
A bulldozer moves sand up the beachA bulldozer moves sand up the beach
The sediment is redistributed from the lower part of the beach to the upper part of the beach.
Advantages
Cheap and simple.
Reduces the energy of the waves.
Disadvantages
Only works when wave energy is low.
Needs to be repeated continuously.
May cause a navigation hazard.
Can create an eyesore at low tide.
Can disrupt the recreational use of the beach, for example the use of jet skis.