Coastal landscapes in the UK-Coastal Processes

Question 1

When the wind blows over the sea, it creates waves. The size and energy of the wave depends on certain factors:

Answer 1

the fetch - how far the wave has traveled
the strength of the wind
how long the wind has been blowing for

Question 2

There are two different types of wave -

Answer 2

constructive and destructive

Question 3

Swash

Answer 3

When a wave reaches the shore, the water that rushes up the beach is known as the swash.

Question 4

Backwash

Answer 4

The water that flows back towards the sea is known as the backwash.

Question 5

The characteristics of a destructive wave are:

Answer 5

weak swash and strong backwash
the strong backwash removes sediment from the beach
the waves are steep and close together

Question 6

The characteristics of a constructive wave are:

Answer 6

strong swash and weak backwash
the strong swash brings sediments to build up the beach
the backwash is not strong enough to remove the sediment
the waves are low and further apart

Question 7

Types of weathering

Answer 7

Freeze-thaw weathering
Biological weathering
Chemical weathering

Question 8

Freeze-thaw weathering

Answer 8

Freeze-thaw weathering occurs when rocks are porous (contain holes) or permeable (allow water to pass through).

Water enters cracks in the rock.
When temperatures drop, the water freezes and expands causing the crack to widen.
The ice melts and water makes its way deeper into the cracks.
The process repeats itself until the rock splits entirely.

Question 9

Biological weathering

Answer 9

Plants and animals can also have an effect on rocks. Roots burrow down, weakening the structure of the rock until it breaks away.

Plant roots can get into small cracks in the rock.
As the roots grow, the cracks become larger.
This causes small pieces of rock to break away.

Question 10

Chemical weathering

Answer 10

Rainwater and seawater can be a weak acid. If a coastline is made up of rocks such as limestone or chalk, over time they can become dissolved by the acid in the water.

Question 11

Types of mass movement
Another way material can be moved on the coastline is through mass movement.
Mass movement is the downhill movement of sediment that moves because of gravity.
There are four different types of mass movement

Answer 11

Rotational slip
Rockfall
Landslide
Mud flow

Question 12

Rockfall

Answer 12

Rocks fall off the cliff face forming scree at the bottom.

Bits of rock fall off the cliff face, usually due to freeze-thaw weathering.

Question 13

Mudflow

Answer 13

Saturated soil slides down the bedrock forming a lobe at the bottom with a stream running through.
Saturated soil (soil filled with water) flows down a slope.

Question 14

Landslide

Answer 14

Rocks detach off the slide plane and slide down to the bottom.
Large blocks of rock slide downhill.

Question 15

Rotational slip

Answer 15

Soil slides down a curved slip plane. The top is called the head, the bottom the foot. The soil collects at the toe. The wall of the curved slip plane is the scarp.
Saturated soil slumps down a curved surface.

Question 16

Erosion
Erosion is the wearing away of rock along the coastline. Destructive waves are responsible for erosion on the coastline. There are four types of erosion:

Answer 16

Hydraulic action -
Abrasion - .
Attrition -
Solution - .

Question 17

Hydraulic action -

Answer 17

Hydraulic action - this is the sheer power of the waves as they smash against the cliff. Air becomes trapped in the cracks in the rock and causes the rock to break apart.

Question 18

Abrasion -

Answer 18

this is when pebbles grind along a rock platform, much like sandpaper. Over time the rock becomes smooth.

Question 19

Attrition -

Answer 19

this is when rocks that the sea is carrying knock against each other. They break apart to become smaller and more rounded.

Question 20

Solution -

Answer 20

this is when sea water dissolves certain types of rocks. In the UK, chalk and limestone cliffs are prone to this type of erosion.

Question 21

Transportation

Beach material can be moved in four different ways. These are:

Answer 21

Solution -
Suspension -
Saltation –
Traction –

Question 22

Solution -

Answer 22

when minerals in rocks like chalk and limestone are dissolved in sea water and then carried in solution. The load is not visible.

Question 23

Suspension -

Answer 23

small particles such as silts and clays are suspended in the flow of the water.

Question 24

Saltation –

Answer 24

where small pieces of shingle or large sand grains are bounced along the sea bed.

Question 25

Traction –

Answer 25

where pebbles and larger material are rolled along the sea bed.

Question 26

longshore drift.

Answer 26

Sediment is carried by the waves along the coastline. The movement of the material is known as longshore drift.

Waves approach the coast at an angle because of the direction of the prevailing wind. The swash will carry the material towards the beach at an angle. The backwash then flows back to the sea, down the slope of the beach. The process repeats itself along the coast in the zigzag movement.

Question 27

Factors leading to deposition include:

Answer 27

waves starting to slow down and lose energy
shallow water
sheltered areas, eg bays
little or no wind

Question 28

.Deposition

Answer 28

When the sea loses energy, it drops the material it has been carrying. This is known as deposition. Deposition can occur on coastlines that have constructive waves.