Geography- Unit 1.2.1/ How do coasts change overtime?

Question 1

Constructive waves characteristics

Answer 1

-They have a stronger swash
-Long wavelength but low in height
-Break on the shore and deposit material
-Low frequency (less than 10 per minute)

Question 2

Destructive waves characteristics

Answer 2

-They have a stronger backwash
-Created in stormy conditions
-Created by a long fetch and high wave energy.
-Short wavelength but are tall
- High frequency (10-14 per minute)

Question 3

What is Mechanical weathering?

Answer 3

Any process that causes physical disintegration of material without changing the chemical composition. e.g temperature change from day to night causes ice in rocks to expand and contract, causing the rock to crack

Question 4

What is chemical weathering?

Answer 4

Disintegration of material through chemical reactions. e.g carbonation when acid rain reacts with limestone and causes cracks to form.

Question 5

What is biological weathering?

Answer 5

When living organisms cause the disintegration/ changing material. E.g Plants grow into cracks inside rocks and break them apart.

Question 6

Labelling a wave

Answer 6

1) Crest- top of the wave
2) Trough- Bottom of a wave
3) Backwash- water rus back down the beach
4) Swash- Wave breaks and washes up the beach
5/6) Destructive or constructive

Question 7

Why do waves form?

Answer 7

Waves begin in a circular motion, however friction causes the base movement of the wave to slow creating an elliptical movement. As the sea bed rises, more friction is applied, and the motion becomes so elliptical that the top of the wave breaks over.

Question 8

What is longshore drift?

Answer 8

Prevailing wind pushes constructive waves towards the shore at an angle, causing the swash to occur at an angle. The backwash moves at a 90 degrees angle back. This causes the mass movement of sediment up and down the beach, each time moving further along the coastline.

Question 9

How is a headland and bay formed?

Answer 9

The soft rock in a discordant coastline are eroded causing a bay, whilst the harder rock layers remain protruding out, as headlands. This is process is also called differential erosion.

Question 10

What is a concordant coastline?

Answer 10

Concordant coasts have alternating layers of hard and soft rock that run parallel to the coast/ it faces one type of rock then the other type of rock is behind it.

Question 11

What is a discordant coastline?

Answer 11

Discordant coastline is where the alternating layers of hard and soft rock run perpendicular to the coastline/ vertical.

Question 12

Why are there more constructive waves near bays?

Answer 12

Leading to bays, the sea bed rises, causing increased friction meaning the waves become smaller and more constructive.

Question 13

How are caves formed?

Answer 13

Hydraulic action causes large cracks, which ( by hydraulic action and abrasion) indents in the cliff and is thus a cave.

Question 14

How are arches formed?

Answer 14

By hydraulic action and abrasion, the cave breaks through the headland, created an arch shape

Question 15

How are stacks formed?

Answer 15

The rock forming the arch collapses, creating a stump situated next to another area of land.

Question 16

Ho are stumps formed?

Answer 16

The stack is weathered down to create a smaller structure, the stump.

Question 17

What is a wave cut platform?

Answer 17

-Bottomof cliff is eroded at sea level
-Without support, the top collapeses creating a 90 degree cliff
- This continuous, retreating the land and creating a platform

Question 18

How is a wave cut platform formed and why are cliff faces always verticle?

Answer 18

Waves erode part of the cliff just above sea-level ( most powerful waves hit there) , creating an indent called a wave cut notch. This leaves an overhang which eventually collapses, creating a vertical cliff face. This process repeats, causing the cliff face to retreat and leaving a flat piece of land called the wave cut platform.

Question 19

What and how was lulworth cove formed?

Answer 19

Lulworth cove is a near circular bay and is a great example of a concordant coastline.
Waves slowly eroded a small path through resistant rock such as portland, once through, easily eroded the weaker rock on the next layer. This weaker rock was eroded in every direction, creating the circular bay.

Question 20

Why does the south of the uk experience many destructive waves?

Answer 20

Because the waves have a large fetch as they have travelled over the atlantic ocean

Question 21

Famous uk arch

Answer 21

Durdle door in dorset.

Question 22

What is a beach?

Answer 22

A buffer zone between the sea and land, made from eroded material. This occurs when waves become less energetic,

Question 23

What is a spit?

Answer 23

A long narrow piece of land made from sand or shingle, attached to the mainland at one end, whilst the other protrudes out into the sea.

Question 24

Where is a famous uk spit?

Answer 24

Spurn point in yorkshire.

Question 25

Where is a spit generally formed?

Answer 25

At an embayment or estuary (mouth of a large river)

Question 26

How is a spit formed?

Answer 26

Through longshore drift, and the deposition of finer material further from the mainland, creating the long narrow shape. These can curve causing a hook, as secondary winds and shallow water change the angle from which the swash travels.

Question 27

What is and how is a bar formed?

Answer 27

It is a sand or shingle beach, connecting two areas of land or headlands together, with a shallow lagoon (once a bay) behind. This is caused by the elongate growth of a spit.

Question 28

What is another name for a bar?

Answer 28

A barrier beach

Question 29

What is and how is a tombolos formed?

Answer 29

It is a sand or shingle bar attaching the coastline to an island. Due to the shallow waters surrounding an island, the waves lose energy and deposit more material, causing a connection between the island and mainland.

Question 30

How are salt marshes formed?

Answer 30

They form behind a spit or in a river estuary as it is sheltered and therefore more material is deposited. Here in mud flats, vegetation develops and colonises overtime.

Question 31

How do plants survive in salt marshes?

Answer 31

-Plants must be adapted to suit saline conditions e.g salt grass.
- Withstand being submerged in water
-Use roots as an anchor, these also reduce the tidal flor and traps more material, creating a better habitat.

Question 32

How are sand dunes formed?

Answer 32

Saltation, sand blows dry wind back off the coastline and they pile together.

Question 33

Unconsolidated rock

Answer 33

A form of weak rock that has not been compacted, cemented or transformed into actual rock.

Question 34

How many villages have been lost in holderness coast?

Answer 34

29

Question 35

How much of holderness coastline is eroded annually?

Answer 35

2m

Question 36

Why does holderness coast erode quickly?

Answer 36

Physical:
GEOLOGY- Because the bedrock is made from unconsolidated till deposited by glaciers over 18,000 years ago.
FETCH- Waves travelling there have a large fetch.
Human:
DREDGING- removing material from the coast to build houses
MANAGEMENT- Built groynes that causes sediment causes more erosion further along the coastline. terminal groyne syndrome.
GLOBAL WARMING- heat causes water to expands and glaciers melt causing sea level rise.

Question 37

Where is the holderness coast and what are some surrounding towns and rivers ?

Answer 37

Is on the North- east coast of England, surrounded by towns such as kingston upon hull, grimsby and bridlington.
- North of River Humber