Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Geography - Physical Paper > Coasts > Flashcards

Coasts Flashcards

You may prefer our related Brainscape-certified flashcards:
U.S. Geography flashcards World Geography flashcards
1
Q

What are coasts shaped by

A

The sea and the action of waves. The processes that take place are erosion, transportation and deposition.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is fetch

A

The distance in which the wind has blown

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are waves caused by

A

The transfer of energy from the wind

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What does a waves energy depend on

A

It’s fetch, the strength of the wind blowing,, the length of time over which the wind has blown.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

How do waves break

A

A prevailing wind causes waves to start out sea and have a circular orbit, as waves approach the shore friction slows the base of the wave. This causes the orbit to become elliptical until the top of the wave breaks over. Water swashes up the beach and water from previous Wave returns to the sea as back wash.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is a constructive wave

A

Waves Created in calm weather that build up the beaches

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is a destructive wave

A

A wave formed in stormy conditions that erodes the beach.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Height of a constructive wave

A

Under a metre

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Height of destructive wave

A

Over a metre

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Shape of constructive wave

A

Long in proportion to its height

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Shape of a destructive wave

A

High in proportion to its length

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the swash and backwash like in a constructive wave

A

Swash is strong and backwash is weak

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the swash and backwash like in destructive waves

A

Swash is weak but backwash is strong

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

How many constructive waves could occur per minute

A

Under 11

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How many destructive waves could occur in a minute

A

Over 13

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Season in which constructive waves are more common

A

Summer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Season in which destructive waves are more common

A

Winter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is a headland

A

A cliff promontory which juts out into the sea such that it is surrounded by water on 3 sides

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is a bay

A

A crescent shaped indention in the coastline found between two headlands. It usually has a beach which may be composed of sand or shingle.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Formation of headland and bays

A

Waves erode the les resistant rock and the more resistant rock. The less resistant rock erodes due to rapid erosion such as that of abrasion, hydraulic action and some solution.
Once the bay has formed the headlands are left sticking out so sea where their hard rock has been resisted of erosion.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Where and when will the rate of erosion be higher?

A

Coastline is exposed to a large fetch.
Strong winds blow for a long time creating destructive waves.
An area with no beach to act as a buffer between sea and cliffs.
Areas of soft rock.
A rock has many joints.
Waves converge on a headland (wave refraction) and gain height and erosive energy.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is wave refraction

A

Their energy is concentrated Around headlands but reduced around bays.
Waves then tend to approach the coastline parallel to it, and their energy decreases as water depth decreases.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is a cliff

A

A steep or vertical face of rock often found at the coast.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Formation of cliffs

A

Formed by weathering which weakens the top of the cliff whilst the sea attacks and waves erode the base which creates a wave cut notch. The notch increases in size causing the cliff to collapse, the backwash Carries the rubble towards the sea and it is repeated again.
Wave cut notch-undercut at base

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What is a wave cut platform

A

A wide gently sloping surface at the foot of a cliff, left behind when cliff retreats- exposed at low tide.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Formation of wave cut platform

A

The wave cut notch created, size gradually increases. As there is now nothing to support the cliff face above the force of gravity weakens the rock which is then broken off and eroded by attrition in the sea. The cliff retreats and leaves a wave cut platform, from where the cliff used to be. An area of flat rock is left at the base of the new cliff. This process is repeated resulting in wider wave cut platforms.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Characteristics of wave cut Platform

A

Slopes gently down to the sea at a 3-5* angle.
Bare rock, smoothed in places by attrition
Deep cracks in some places
Covered at high tide and exposed at low tide
An oval pitted appearance of bare rock interspersed with rock pools.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Formation of caves, arches, stacks and stumps.

A

A large crack opened up by hydraulic action.
The crack grows into a cave by hydraulic action and abrasion.
The cave becomes larger.
The cave breaks through the headland forming a natural arch.
The arch is eroded and collapses.
This leaves a tall rock stack.
The stack is eroded forming a stump.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What is a beach

A

A landform of coastal deposition that lies between the High and low tide levels.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q 
Describe the characteristics of a sandy beach 
Referring to its ...
Gradient 
Dominant wave
Distance stretched inland 
Back of beach
A

A sandy beach is generally shallow and flat, it’s dominant wave is constructive.
It’s distance stretching inland is a long way and at the back of the beach you will find sand dunes (sometimes).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Low tide In a sandy beach what is formed

A

Small water filled depressions called runnels form. These are separated by small sandy ridges running parallel to shore. The wet sand may have a rippled appearance.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q 
Describe the characteristics of a pebble beach
Referring to its...
Gradient 
Dominant wave
Distance inland 
Back of beach
A

The gradient on a pebble beach is generally steep, the dominant wave is destructive and the distance inland is not far.
At the back of the beach you can find large pebbles, pebble size increases towards the back of the beach.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

How do sandy beaches form

A

In shelters bays, low energy constructive waves transport material onto the shore. The swash is stronger than the backwash,so sediment is slowly but constantly moved up the beach.
Once the tide has gone out, there is more material on the beach than before.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

How do pebble beaches form

A

In Exposed beaches where there is large fetch.
Destructive waves plunging nature along with their stronger backwash means that pebbles are not moved far up the beach, which makes the beach profile steep.
A storm beach may form when there is wind, stormy weather and waves hurl boulders and large pebbles at the back of the beach.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Why and how do beach profiles change in winter

A

In winter destructive waves are present as the waves excavates material from the beach creating a concave profile. The beach will become much narrower, steeper and smoother.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Why and how do beach profiles change in summer

A

The beaches experience constructive waves, sand will slowly return to the beach and berms and sand dunes typically recover, as the sediment isn’t lost by offshore. The key change is the berm as it changes the most seasonally which affects the shape the most.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What is a berm and how is it formed

A

A step like landform (terrace) on a beach that has formed in the back-shore, above the water level at High tide.
They are formed as sand or shingle slowly ,cover up a beach by successive (one after another) income tides.
Common In shingle beaches.

38
Q

What are runnels/&ripples and how are they formed

A

They only form on beaches with a shallow gradient. They form as a simple drainage route for tides. Typically found on sandy beaches.

39
Q

What are sand dunes

A

Large heaps of sand, form on dry backshore of a sandy beach.

40
Q

What do sand dunes need to form

A

They need a
Large flat beach
Large supply of sand
A large tidal range so there is time for sand to dry.
An onshore wind to move sand to the back of the beach
An obstacle such as drift wood for the sand dune to form against.

41
Q

Describe the formation of sand dunes

A

Sand continues to move up the windward slope
Height Builds up until the structure becomes unstable
The sand then slips down the leeward slope (side protected by the wind by an elevation)

42
Q

Characteristics of Sand dunes

A

Gentle slope on windward side
Crests
Unstable steep slope on leeward side

43
Q

Name the 6 types of dune in order from start

A 
Embryo dune 
Fore dune 
Yellow dune
Grey dune 
Dune slack 
Mature dune
44
Q

What is a dune slack

A

Where there is a trough of low point in a line of dunes

45
Q

What is the leeward slope

A

Slope facing away from wind

46
Q

What is the windward slope

A

Slope facing the wind

47
Q

Name the 3 processes in which moves sand particles for sand dunes to form

A

Suspension
Saltation
Creep

48
Q

What is suspension

A

Sand is picked up and carried by wind

1%

49
Q

What is saltation

A

Grains of sand bounce along in the wind as they are alternately raised and dropped
(95%)

50
Q

What is creep

A

Sand grains collide with eachother and push other grains along
(4%)

51
Q

What is deposition (COASTAL)

A

Coastal deposition takes place in areas where the flow of water slows down. Sediment can no longer be carried or rolled along so has to be deposited.
It most commonly takes place in bays, where the energy of water is reduced when entering bay.

52
Q

What is longshore drift

A

The transportation of sediments along the coast parallel to the shoreline.
The direction is determined by the prevailing wind e.g. A prevailing wind blowing from southwest causes a drift in an easterly direction.
Longshore drift travels the load in a zig zag fashion.

53
Q

What is a spit

A

An area of sand or shingle which either extends at a gentle angle out to sea or which grows across a river estuary.

54
Q

Requirements for a spit to form

A

Longshore drift moves large amounts of material along the beach
A sudden change in direction of the coastline
The sea relatively shallow and becomes progressively more sheltered.

55
Q

Formation of a spit

A

Material is carried via longshore drift, a change in direction of coast line (from headland to bay) causes a sheltered area to form, the water at foot of headland is shallow so waves lose their energy and deposit material.
A prevailing wind causes the spit to curve inward forming a hook.
Behind spit in sheltered area forms a salt marsh

56
Q

How does a bar form

A

A bar is formed when Lsd continues to deposit material onto spit as a result the spit extends across a bay joining up two headlands

57
Q

How does a tombolo form

A

When a spit extends outwards into sea and connects to an offshore island forming a tombolo.

58
Q

What is an offshore bar

A

Submerged or partly exposed ridges of sand or coarse sediment that is build by waves offshore from a beach.

59
Q

How does an offshore bar form

A

When waves approach a gently sloping coast, friction between the waves and the sea bed causes the waves to break at some distance from the coast. Over time, more material are built up parallel to the coast to form a ridge of sand called offshore bar.

60
Q

What are mudflats

A

Coastal wetlands that form when mud is deposited as water loses its energy as it gets closer to the coast. They are typically found in areas where the tidal waters flow slowly and somewhere that is sheltered e.g. Bays

61
Q

What are saltmarshes

A

Area of coastal grassland and wetland that are flooded and drained by salt water brought in by the tides. Salt marshes form behind spits; the zone behind the spit becomes a sheltered area. The land is covered by water 2 times a day due to high and low tides.

62
Q

Why do some cliffs collapse.

A

Marine processes, sub Ariel processes and mass movement.

63
Q

What are marine processes

A

Hydraulic action and abrasion which erodes the base of the cliff, this results in the cliff face becoming steeper.
Undercutting the cliff also makes it unstable at the top

64
Q

What are sub Ariel processes

A

Weathering such as freeze thaw action this weakens and fragments the rock

65
Q

What is Mass movement

A

Loose rocks fall, slide or slump because of gravity

66
Q

What is meant by rocks to “slide”

A

Large chunks of rock slide down slopes without any warning. This can be dangerous for people below cliff

67
Q

What is meant by rocks that “slump”

A

Common when cliffs are made of clay, the clay becomes saturated during heavy rainfall and oozes down towards the sea as part of a mud or debris flow.

68
Q

What are chemical processes

A

Includes solution. This occurs when water reacts with the calcium carbonate in rocks like limestone and chalk, the calcium carbonate dissolve and is washed away in solution

69
Q

Mechanical processes

A

Freeze thaw action
Temperatures drop below freezing during the night and rise in the day. Any water held in cracks in the rock freezes, expands and then thaws again.
This is repeated till rock is weakened and fragments break away

70
Q

What is cliff recession

A

Wave cut notch is formed and increases over time, this causes the cliff to collapse. The cliff retreats and a wave cut platform is left.
This is repeated

71
Q

List some hard engineering strategies for protecting the coast

A

Sea wall
Groynes
Rock armour
Gabions

72
Q

List some soft engineering strategies for protecting the coast

A 
Beach nourishment 
Beach re profiling
Sand dune regeneration 
Managed retreat 
Marsh creation
73
Q

Define what is meant if the strategy beach nourishment is used

A

Adding sand and shingle from somewhere else to the beach

74
Q

Define what is meant if the strategy beach re profiling is used

A

Reshaping of a beach using existing materials e.g. Moving shingle back up the beach

75
Q

Define what is meant if the strategy sand dune regeneration is used

A

Creating or restarting sand dunes by either nourishment or planting vegetation to stabilise sand

76
Q

Define what is meant if the strategy managed retreat is used

A

Removing all existing defences and allowing land behind it to naturally flood

77
Q

Define what is meant if the strategy marsh creation is used

A

Breaking up of the waves and reducing their speed and erosive power

78
Q

Benefits and costs of beach nourishment

A 
Bigger beach - more room 
Safe and natural
Protects expensive properties 
BUT
during the process beach access is restricted for several weeks 
Expensive to create - £300K dredger
79
Q

Benefits and costs of beach re profiling

A

Cheap to maintain and easy to maintain
Natural
BUT
Bull dozers when created restrict access to Bach
Can be expensive e.g. £200,000 in West Sussex

80
Q

Benefits and costs of sand dune regeneration

A 
Help maintain and create habitats 
Picnic areas 
BUT
has to be checked twice a year with fertilisers
Expensive
Unstable
81
Q

Benefits and costs of managed retreat

A 
Encourages development of beaches 
Cheap 
Natural 
BUT 
People need to be compensated for loss and damage of land or buildings 
Unsafe
82
Q

Benefits and costs of marsh creation

A 
Cheap 
Low damage to environment 
BUT
High maintenance
Cheaper housing may be flooded to protect expensive ones 
Communities split up
83
Q

Define what is meant if the strategy sea walls are used

A

Wall made out of hard material to reflect waves- concave shape

84
Q

Define what is meant if the strategy groynes are used

A

Wooden or stone fences that are built to trap beach material transported by longshore drift

85
Q

Define what is meant if the strategy rock armour is used

A

Boulders or large rocks that are piled up, usually as back of beach or in front of sea wall

86
Q

Define what is meant if the strategy gabions is used

A

Wire meshed rocks and pebbles which can be stacked to form a wall like barrier at the back of the beach

87
Q

Costs and benefits of using sea walls

A 
Promenade on top 
Long lasting 
BUT 
£5000 a metre are expensive 
Not strong enough In some cases- a railroad on top of a sea wall once collapsed and cost £35 million in repairs
88
Q

Costs and benefits of using groynes

A 
Cheap 
Last up to 40 years 
BUT 
act like barriers which impede walking
Trap sediments which restricts sediment down drift- uneven beach
89
Q

Costs and benefits of using rock armour

A 
Cheap
Quick to build 
Long lasting 
BUT 
Restrict easy access to beach 
Regular maintenance if storms occur 
Eye sore
90
Q

Costs and benefits of using gabions

A 
Cheap 
Easy to construct 
BUT 
if damaged can be a danger to human and animal 
- birds caught in wire from cages 
Easily destroyed
High maintenance costs

Geography - Physical Paper (5 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions