Brainscape's Knowledge GenomeTM

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


See full index

Geography Alevel AQA > Coastal ecosystems > Flashcards

Coastal ecosystems Flashcards

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

What is abrasion

A

Where loose material in the waves hits and breaks down the walls, floors of the river, cliff or glacier

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

What is backshore

A

The upper beach closest to the land, including any cliffs or sand dunes

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

What is beach morphology

A

the surface shape of the beach

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

What is coastal recession

A

The retreat of a coastline due to the erosion, seallevel rise or submergence

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

What is a concordant coastline

A

A coastlne where bands of alternate gelogu run parallel to the coast (same type of rock however alternation as erodes)

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

What is a dalmation coast

A

A concordant coastline with several river valleys running perpendiculer to the coast. They becme flooded to produce parallel long islands

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

DEFRA’s 1:1 Cost-benefit Analysis

A

The evaluation of a coastal town’s economic value compared to the cost of the management required

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

What is a discordant coastline

A

a coastline whee bands of alternate geology run perpendiculer to the shore

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

What is dynamic equlibrium

A

Where a natural system tries to archive a balance by making coastal change in response to a constantly changing system

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

What is an emergent coastline

A

A coastline that is advancing relative to the sea level at the time

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

What is Eustatic sea level change

A

Global changes to sea levels

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

What is foreshore

A

The lower part of the beach overed twice a day at high tide (the part of the beach that receives the most reguler wave action)

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

What is freezethraw weathing

A

A form of physical sub-ariel weathering where water freezes in the cracks of a rock, expands and enlarges the crack, therefore weakens the rock

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

What is geology

A

The structural arrangement of the rock

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

What is glacial erosion

A

The removal of loose material by glacier ce, involving plucking, abrasion, crushing and bsal meltware (necessary in the formation of fjords)

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

What is grading

A

The layering of sediments based on their size

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

What is a high energy environment

A

A coast where wave action is predominantly large destructive waves, causing much erosion. The rate of erosion exceeds the rate of deposition

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

What does impermeable rock mean

A

A rock that does not allow rainwater to pass through

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

What is Isostatic sealevel change

A

A change in local coastline or land height relative to the sea level

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

Littoral Cell

A

A section of the coast, whin which involves much sediment movement. A littoral cell is not a closed system

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

What does permeable rock mean

A

A rock that allows rainwater to pass through it

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

What is plant succession

A

Change to a plant community due to growling conditions adapting (e.g. sand dunes and salt marshes)

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

What are subariel process

A

A combination of mass movement and weathering that affects the coastal land above sea level

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

What is a submergent coastline

A

A coast that is sinking relative to the sea level at the time

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

What is a till

A

Deposits of aguler rock gragments in a fine medium

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

What causes a submergent coastline

A

Ethier Eustatic change from rising sea levels or isostatic change possibly from glacial ice

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

What is a sediment cell

A

The concept of a sediment cell is that coasts are split up to sections and bordered by prominent headlands.

Within each cell there are smaller sub cells.

This means the movement of sediment is almost contained so the sediment has dynamic equilibrium.

The sediment cell has inputs such as wind, waves, pollution and outputs such as rip tides and ocean currents.

Sediment cells also have stores such as beaches, spits, cliffs. These stores are transferred throughout

The sediment cell through processes such as longshore drift

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

What is the littoral zone

A

The littoral zone is the area of land between the cliff’s or dunes on the coast and the offshore
area that is beyond the influence of the waves .

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

Describe the process of the formation of a wave - start to finish

A

Winds move across the surface of the water, causing frictional drag (resistance to the
wind by the water) which creates small ripples and waves . This leads to a circular orbital
motion of water particles in the ocean
● As the seabed becomes shallower towards the coastline, the orbit of the water particles
becomes more elliptical, leading to more horizontal movement of the waves
● The wave height increases, but the wavelength (distance between two waves) and
wave velocity both decrease
● This causes water to back up from behind the wave until the wave breaks (collapses)
and surges up the beach

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What factors affect wave energy

A

Strength of the wind
Duration of the wind (how active the wind is)
Size of the fetch (the distance over which the wind blows)

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

What are the features of a constructive wave: (formation, wavelength, frequency, wave and swash characteristics and effects on beach)

A

Formation: Formed by weather systems that operate in the open ocean
Wavelength: Long wavelength
Frequency: 6-9 per minute
Wave characteristics: Low waves, which surge up the beach
Swash characteristics: Strong swash, weak backwash
Effects on beach: Occurs on gently slopped beaches

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What are the features of a Destructive wave: (formation, wavelength, frequency, wave and swash characteristics and effects on beach)

A

Formation: Localised storm events with strong winds operating close to the coast
Wavelength: Short wavelength
Frequency: 11-16 per minute
Wave characteristics: High waves, which plunge onto the beach
Swash characteristics: Weak swash, Strong backwash
Effects on beach: Occurs on steeply slopped beaches

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

The types of waves in a coastal environment vary depending on the time of year. Explain how

A

In the summer constructive waves dominate but in the winter destructive waves dominate.
Constructive waves may become destructive waves if a storm begins
Climate change may increase the storm frequency within the UK
Coastal management may affect the type of waves that occur

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

What is a form of negative feed back in beaches and waves

A

The presence of contructive waves cause deposition on the beach which lead to the beach becoming steaper and favouring formation of destructive waves. The destructive waves erode the beach and reducing the beach profile which favours and leads to the formation of constructive waves

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

What is spring tide

A

The highest high tide and the lowest low tides occur when the mood and the sun are in alignment as their gravitational force effectively pul the oceans towards them

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

What is neap tide

A

The lowest high tide and the highest low tide, this occurs when the sun and the moon are perpendicular to each other. Both of their gravitational forces act against each other, so the overall pull is minimised at high tide, but therefore creates a higher low tide. The neap tide creates the smallest tidal range possible

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

What is a low-energy environment

A

Waves are predominelty constructive and tends to occur in sheltered areas. They tend to be fairly sandy areas. The rates of deposition exceed the rate of erosion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

What is wave refraction

A

The process by which waves turn and lose energy around a headland on uneven coastlines. The wave energy is focused on the headland, creating erosional features. The energy is dissipated in bays

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

What are the marine erosion processes

A

Corrasion, Abrasion, Attrition, Hydraulic Action, Corrosion

40
Q

What is abrasion

A

The process by which rocks and other material carried by the sea are picked up by strong waves and thrown against the coastline

41
Q

What is attrition

A

Wave action causes rocks and pebbles to hit against each other, wearing each other down which causes them to become rounded over time and eventually smaller.

42
Q

What is hydraulic action

A

As waves crashes onto rocks or cliff faces, they force air in cracks, joints an faults within the rock. The high pressure causes cracks to force apart and widen. This causes the rock to fracture. Can lead to cavitation where bubbles in the water explode.

43
Q

What is corrosion

A

The midly acidic sea water can cause alkaline rock such as limestone to be eroded.

44
Q

Factors affecting erosion

A

Wave (rate of waves and type)
Beaches
Sub-ariel process (landslides - weakens cliff)
Rock type (Sedimentary - weak, Indigenous/metamorphic - strong)
Rock faults (Increased surface area)
Rock lithology

45
Q

What is longshore drift

A

Waves hit beach at angle due to prevailing wind. Waves push sediment in wind direction up the beach as swash.
Due to gravity the wave then carries the sediment down the beach as back wash

46
Q

What is flocculation

A

Clay particles clump together due to chemical attraction and then dink due to high density.

47
Q

What is weathering

A

Weathering is the breakdown of rocks over time, leading to the transfer of material into the littoral zone, where it becomes input into the sediment cells

48
Q

What is mechanical weathering

A

the breakdown of rocks due to exertion of physical forces without chemical changes taking place

49
Q

What is is freeze-thaw

A

Water entering the cracks of rocks and then the water freezes and expands by 9% which increases the pressure acting on the rock, causing cracks

50
Q

What is salt crystallisation

A

Salt water enters the cracks of the rock, and as seawater evaporates, salt is left behind. The salt crystals grow over time, exerting pressure on the rock, and causing cracks

51
Q

What is chemical weathering

A

The breakdown of rocks through chemical reactions

52
Q

What is carbonation

A

Rainwater absorbs carbon dioxide from the air which creates a weak carbonic acid which reacts with calcium carbonate in rocks to calcium bicarbonate which can be easily dissolved. This happens with limestone

53
Q

What is oxidation

A

When minerals gets exposed to oxygen and become oxdisd which increases volume .

54
Q

What is biological weathering

A

The breakdown of rocks by organic activity

55
Q

How do plant roots cause erosion

A

Roots by growing into the cracks of rocks, which cause pressure and split the rocks apart

56
Q

How do animals cause erosion

A

Animals such as rabbits burrowing

57
Q

What is mass movement

A

The movement of material down a slope under the influence of gravity. Act as input to littoral zone

58
Q

What are the mass movements

A

Rotational slide, Rock falls, Landslide, Mudflows

59
Q

Salt marshes

A

Notes

60
Q

Sand dunes

A

Notes

61
Q

What are emergent coastlines

A

Where the land has been raised in relation to the coastline

62
Q

What are submerged coastlines

A

Where sea level rises or the coastline sinks in relation to the sea

63
Q

What are rias

A

Rias are formed when rising sea levels flood narrow winding inlets and river valleys. They are deeper at the mouth of the inlet, with the water depth decreasing further inland

Example: Camel trail, Padstow

64
Q

What are Fjords

A

Fjords are formed when rising sea levels flood deep glacial valleys to create natural inlets and harbours.

65
Q

What are Dalmatian coasts

A

This type of coastline occurs when valleys running parallel to the coast become flooded as a result of sea level change. This leaves a narrow long series of rugged islands

Example: Croatia’s Adriatic coast

66
Q

What is the dune structure (backwards)

A

Embryo dune, yellow dune, grey dune, dune slack, heath and woodland (climatic cliamax)

67
Q

Where do mudflats and saltmarshes tend to form

A

where flow of water from the river meets with incoming tides and waves from the sea, causing water flow to virtually cease. This can also occur in low-energy areas such as behind a spit. then floculation and pioneer species etc

68
Q

What are the risks to coastal environments

A

Storm surges, human activity

69
Q

What are storm surges

A

they are the result of low pressure created by significant weather events (such as tropical storms) causing the sea level to rise dramatically and overwhelm sea defensives.

70
Q

What are the impacts of storm surges

A
  • Removing natural vegetation (mangroves can limit this though) as it destroys plant sucessions and destroys coastal landforms. Increasing risks of rock falls and other mass movements
  • they are more likely to happen due to climate change and to be more intense
71
Q

What are the consequences to communities on the coastline

A

reduced house prices as the areas is prone to natural disasters
Leading to economic loss for homeowners and local economies

72
Q

What are the impacts of coastal flooding

A

Environmental refugees, over 1 billion people live on the coast that are at risk of coastal flooding. 75% of all the world’s large cities are coastal.

73
Q

What is coastal management

A

There are 2 types: Hard enginerring and soft engineering . It follows ‘erosion is occurring in this area so lets build a beach or a sea wall to reduce erosion’

74
Q

What is hard engineering

A

It involves man-made structures with the aim of preventing erosion. They are very effective at preventing erosion however they are high cost and have a significant environmental impact due to concentrate and other man-made materials.

75
Q

What are the hard engineering methods to stop erosion

A

Offshore Breakwater, Groynes, Sea Wall, Rip Rap (rock armour), revetments

76
Q

What is soft engineering

A

soft engineering aims to work with and complement the physical environment by using natural methods of coastal defence

77
Q

What are the soft engineering methods to stop erosion

A

Beach Norishments, CLiff regading and drainage, Dune stabilisation, Marsh creation

78
Q

What is Offshore breach water, pros and cons

A

Rock barrier which forces waves to breack before reaching shore.
Pro: Effective at reducing waves’ energy
Con: Visually unappealing
Navigation hazard for boats
Can interfere with Longshore-drift

79
Q

What are groynes, pros and cons

A

Wooden or rock protrusions that trap sediment from LSD
Pro:Builds up beach, protecting cliff and increasing tourist potential
Cost effective
Con: Visually unappealing
Terminal groyne syndrome (deprives other areas of sediment)

80
Q

What are sea walls, pros and cons

A

Contrete structures that absorb and reflect wave energy, with curved surfaces
Pro:Effective erosion prevention
Promanade has tourism benefits
Con: visually unapealing
Expensive to construct/maintain
Wave energy erode elsewhere as reflected

81
Q

What are Rip Rap (rock armour) pros and cons

A

Large rocks that reduce wave energy, but allow water to pass through
Pro: Cost effective
Con: Rocks are sourced from elsewhere, so do not fit with local geology
Pose a hazard if climbed upon

82
Q

What are Revetments, pros and cons

A

Wooden or concrete ramps that help absorb wave energy
Pro: Cost effective
Con: Visually unappealing
Can need constant maintenance which creates extra cost

83
Q

What is beach nourishment, pros and cons

A

Sediment is taken from offshore sources (stores) to build up existing beach
Pro: Builds up beach protecting cliff and increases tourist potential
Cost effective and looks natural
Cons: not a long-lasting solution and dredging may have consequences on local coastal habitats

84
Q

What is cliff regrading and Drainage, pros and cons

A

Reduces the angle of the cliff to help stabilise it.
Pro: cost-effective
Con: cliff may collapse suddenly as the iff is drier,
may look unnatural

85
Q

What is dune stabalistion, pros and cons

A

Marram grass planted, the roots help bind the bunes, protecting the land behind
Pro: cost-effective and creates an important wildlife habitat
Con: planting is time consuming

86
Q

What is marsh creation, pros and cons

A

Type of managed retreat allowing low-lying areas to flood
Pro: creates and important wildlife habitat
Con: Farmers lose land and may need compensation as a result

87
Q

What is cost-benefit analysis

A

A process carried out beofre any form of coastal management takes place. It takes into account the expended cost of construction, demolition and maintenance etc and compres it to expected benefits of a scheme which may included value of land, business. Benfits have to out way costs (DEFRA’s 1:1)

88
Q

What are hostile stratergies

A

it is recognised that all of the different coastline are interlinked and function together as a whole.

89
Q

What are ways to manage coasts sustainably

A

Managing natural resoruces
Education communities
Monitoring coastal changes

90
Q

What is the Integrated Coastal Zone Management (ICZM)

A

It is a method of sustainable coastline management, it represents the idea that large sections of coastline are managed with one integrated strategy.

91
Q

What does the ICZM recognise about coastal management

A

sediment eroded in one lackted may form a protective beach elsewhere and therefore a decision to protect one coastal community may not outwight the disadvantages of explosion another community to increased erosion

92
Q

What are shoreline management plans (SMPs)

A

They have been created for each sediment cell in the UK to help with coastline management. And consider them to be closed systems (though they not in reality)

93
Q

What are examples of SMPs

A

Hold the line: defences to maintain current position of shore line
Managed retreat: allowing the coastline to advance inwards to create its own natural defences using enginerring/defensives
Advance the line: defences are build to to more the shoreline outwards
No active intervention: let nature take its course

94
Q

What factors are consider when choosing a SMP

A

The economic value of assets
Technical feasibility of engineering solutions
Ecological and cultural value

95
Q

What are negative impacts of coastal management

A

Sea wall just refelcts wave energy down drift to increase erosion elsewhere also causes less sediment where needed

96
Q

How are wave-cut platforms formed

A

The erosion process (hydraulic action and abrasion etc) takes place on the foot of the cliff. This erodes inwards. This causes the cliff to become more and more undercut as erosion continues. it will then eventually collapse. This process repeats and the cliff slowly retreats inland. Leaving a gently sloping wave-cut platform. Only a small distance as waves no longer break on a cliff due to the platform

Example: Southerndown, Wales.

97
Q

How are raised beaches formed

A

due to the isostatic sea level change. caused by glacial rebound. Post-glacial elasticity as the crust rebounds to lift the beach which exposes wave-cut platforms and degraded cliffs.

Example: Isle or portland

Geography Alevel AQA (35 decks)

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