Coastal landscapes in the UK

Question 1

How do waves form

Answer 1

By wind blowing over the sea

Friction with the surface of the water causes ripples that develop into waves

Question 2

Features of a constructive wave

Answer 2

Formed by storms hundreds of kilometres away - common in summer

low waves with crests far apart

gently sloping wave front

push sand and pebbles up the beach

deposit material

Question 3

Features of a destructive wave

Answer 3

Formed by local storms close to the coat - common in winter

Waves are close together

High waves and steep wave front

Breaking waves plunge onto beach with little forward swash

Strong backwash erodes material

Question 4

What is mechanical weathering and an example

Answer 4

The breakdown of rock without changing its chemical composition

eg freeze thaw weathering
(expansion and thawing of ice repetitively in rock)

Question 5

What is chemical weathering and an example

Answer 5

The breakdown of rock by changing the chemical composition

e.g Carbonation (acid rain dissolving alkaline rocks such as limestone)

Question 6

What is biological weathering and an example

Answer 6

Caused by the actions by flora and fauna

e.g plants growing in cracks in rocks or animals borrowing into weak rock

Question 7

What is mass movement

Answer 7

The downward movement of weathered material under the influence of gravity

Question 8

What are the types of mass movement

Answer 8

Rockfall - rock breaks away often due to freeze fall on a steep cliff face

Landslide - blocks of rock slide downhill

Mudflow - saturated soil and weak rock flow downhill

Rotational slip - slump of saturated soil and weak rock along a curved surface

Question 9

Types of coastal erosion

Answer 9

Solution - dissolving of soluble chemicals in rock

Corrasion - rock fragments picked up by the sea are thrown at the cliff and scrape away the rock

Abrasion - The ‘sandpapering’ effect where

Attrition - rock fragments carried by the sea knock against each other becoming more rounded

Hydraulic power - the water is forced into cracks in the cliff and eventually break it up

Question 10

How is sediment transported

Answer 10

Solution - dissolved chemicals

Suspension - particles carried in the water

Traction - large pebbles rolled along the seabed

Saltation - a hopping or bouncing motion of particles to heavy to be suspended

Question 11

What is deposition and why does it happen

Answer 11

Deposited sediment and occurs when waves lose their energy

Question 12

What is a discordant coastline

Answer 12

Vertical bands parallel to the direction of waves

Question 13

What is a concordant coastline

Answer 13

Horizontal bands of rock perpendicular to the direction of waves

Question 14

What kind of coastlines are headlands and bays formed on

Answer 14

Discordant

Question 15

How do stacks form

Answer 15

Hydraulic power erodes the rock
Cave forms

Repeated erosion deepens the cave until it breaks through the headland to form an arch - eg. Durdle Door

Erosion continues to wear away at the arch until it eventually collapses

Forms a stack - e.g Old Harry in Dorset

Question 16

How do cliffs erode

Answer 16

Erosion creates a wave cut notch
This then collapses
The cliff retreats
A new wave cut notch is formed

Question 17

What are sand beaches

Answer 17

Created by low energy waves
Flat and wide
Long gentle slope

Question 18

What are shingle beaches

Answer 18

Created by high energy waves
Steep and narrow
Steep slope

Question 19

How is a spit formed

Answer 19

LSD deposits material past a bend

The area behind can become a salt marsh

Question 20

How is a bar formed

Answer 20

When a spit joins 2 headlands together

Lagoon formed behind

Question 21

How are sand dunes formed

Answer 21

When LSD deposits material up the beach by wind

Obstacles decrease wind speed so sand is deposited

Colonised by plants - eg. marram grass - this stabilises the sand and allows foredunes and mature dunes to form

Question 22

What is the Dorset coast made of

Answer 22

Bands of hard and soft rock
eg. Chalk and clay

Question 23

Where is Old Harry

Answer 23

Swanage Bay

Question 24

Types of hard engineering for coastal areas

Answer 24

Sea Wall - physical wall that reflects waves back out to sea

Gabions - wall of wire cages filled with rocks

Rock Armour - boulders that are piled up on the coast to dissipate some wave energy

Groynes - traps sediment transported by LSD

Question 25

Types of soft engineering for coastal areas

Answer 25

Beach nourishment - adding sand from elsewhere

Beach reprofiling - moving sand around

Dune regeneration - planting vegetation and more sand

Question 26

What is the term for doing nothing to coastal areas

Answer 26

Managed retreat

e.g in Lincolnshire to protect 400 k homes from floods and attract more species of birds and wildlife

Question 26

Why does Lyme Regis need protecting from erosion

Answer 26

Much of the Eastern side of the town is built along the edge of cliffs

3600 population and 50 k tourists each year

Local economy depends on tourism

1km of coast already has hard engineering strategies

Question 27

Current defences in Lyme Regis

Answer 27

4 phase plan began in 1990 and finished in 2015

£19.5 million

390m of sea walls and rock armour

Question 28

Pros and cons of the current defences in Lyme Regis

Answer 28

Pros:
Increase trade by 20%
People feel more secure in Lyme Regis

Cons:
More traffic and pollution because of tourism
Expensive for a ‘shorter term’ solution