Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Geography > Coasts > Flashcards

Coasts Flashcards

(81 cards)

Start Studying
1
Q

inputs

sediment and energy

A

sediment: rivers, sea level rise, erosion, crushed shells, waves/tides/current transport sediment from offshore deposits
energy: winds, waves, tides, currents

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

outputs

A

sediment can be washed out to sea or deposited further along the coast

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

stores

A

landforms such as beaches, dunes and spits

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

flows/transfers

A

erosion, weathering, transportation and deposition

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

positive feedback

A

amplifies a change

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

negative feedback

A

counteracts a change

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

dynamic equilibrium

A

inputs and outputs of a system are balanced

small variations but remains balanced on average

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

sources of energy

wind

A

created by air moving from areas of high pressure to low pressure
pressure gradient between high and low stronger during storms
strong winds generate powerful waves
prevailing winds (constantly blowing in the same direction) cause higher energy waves

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

sources of energy

waves

A

created by wind blowing over the surface of the sea
friction between wind and surface creates circular motion
wave height = wind speed and fetch
friction between waves and sea bed slows them and makes their shape more elliptical
crest of wave rises then collapses
swash = up
backwash = down
constructive: low frequency, low and long, deposits sediment
destructive: high and steep, high frequency and circular cross profile, removes material from the beach

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

currents

A

general flow of water in one direction
caused by wind, variations in water temperature or salinity
move material along the coast

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

tides

A

periodic rise and fall of ocean surface caused by gravitational pull of the moon and the sun
affect the position at which waves break of the shore
area between max high tide and min low tide is where most landforms are created and destroyed

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

low energy coasts

A

low inputs of energy in the form of small gentle waves
caused by gentle winds, short fetches or gently sloping offshore zones
reef/island offshore which protects coast from full power of the waves
often have salt-marshes/mudflats
rate of deposition is higher than erosion

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

high energy coasts

A

high inputs of energy from large powerful waves
caused by strong winds, long fetches and steeply shelving offshore zones
sandy coves and rocky landforms
rate of erosion higher than deposition

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

sediment sources

A

rivers carry material from inland
sea level rise can flood valleys and form estuaries
sediment eroded from cliffs
sediment formed from crushed shells
waves tides and currents transport sediment from offshore deposits

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

sediment cells

A

(littoral cells)

lengths of coastline between two headlands that are self contained

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

sediment budget

A

the difference between the amount of sediment that enters and leaves the system
more enters = positive and builds
more leaves = negative and retreats

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

geomorphological processes
weathering
salt weathering

A

caused by saline water
saline water enters pores/cracks in rocks at high tide
tide goes out and rocks dry/water evaporates forming salt crystals. as the salt crystals form they expand exerting pressure on the rock which causes pieces to fall off

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

geomorphological processes

mass movement

A

the shifting of material downhill due to gravity
more likely to occur when cliffs are undercut by wave action, causing an unsupported overhang which is likely to collapse
can also move gradually by soil creep
unconsolidated rocks are prone to collapse as there is a little friction between particles to hold them together
heavy rain can saturate unconsolidated rocks further reducing friction and making them more likely to collapse
run off can erode fine particles and transport them downslope

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

geomorphological processes

erosion

A

a process where natural forces like water, wind, ice, and gravity wear away rocks and soil

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

geomorphological processes

transportation

A

the process of eroded material being moved

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

geomorphological processes

deposition

A

when material being transported is dropped on the coast
when sediment load exceeds the ability of the water or wind to carry it, either because sediment load increases or because wind/water slows down due to friction increasing or flows becoming turbulent

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

coastal processes
marine
solution

A

soluble rocks e.g. limestone and chalk get gradually dissolved by sea water

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

coastal processes
marine
attrition

A

bits of rock in the water smash and grind against each other and break into smaller bits

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

coastal processes
transportation
traction

A

very large particles e.g. boulders are pushed along the sea bed by the force of water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
coastal processes transportation suspension
very fine material such as silt or clay particles s whipped up by turbulence and carried along in the water most eroded material is transported this way
26
coastal processes transportation solution
substances that can dissolve are carried along in the water e.g. limestone is dissolved into water that's slightly acidic
27
coastal processes transportation saltation
larger particles such as pebbles/gravel are too heavy to be carried in suspension. instead the force of the water causes them to bounce along the sea bed
28
longshore drift
swash carries sediment up the beach parallel to the prevailing wind and backwash carries sediment back down the beach at right angles to the shoreline when there's an angle between the prevailing wind and the shoreline a few rounds of swash and backwash move sediment along the shoreline
29
geomorphological processes mass movement types
slides: material shifts in a straight line slumps: material shifts with a rotation rockfalls: material breaks up and falls mudflows: material flows downslope
30
geomorphological processes weathering freeze thaw weathering
occurs in areas where temperatures fluctuate above and below freezing water enters joints and crevices in rocks temp drops below 0, water in cracks freezes and expands overtime repeated freeze thaw action weakens the rocks and causes pieces to fall off
31
coastal processes transportation deposition
when material being transported is dropped on the coast when sediment load exceeds the ability of the water or wind to carry it, either because sediment load increases or because wind/water slows down due to friction increasing or flows becoming turbulent
32
run off
the flow of water that occurs when excess stormwater, meltwater, or other sources flows over the Earth's surface. the primary agent in soil erosion by water
33
landforms of erosion | headlands and bays
formed on discordant coastlines where there are bands of alternating hard rock and soft rock and right angles to the shoreline soft rock is eroded quickly forming bays and the harder rock is eroded less and sticks out as a headland
34
landforms of erosion | blow holes
sea caves along the shore can have an opening in the ground above. when waves enter the sea cave with sufficient force, water can travel upward with great pressure and escape through the opening
35
landforms of erosion | caves, arches and stacks
cliff profile features weak areas in rocks are eroded to form caves caves on opposite sides of a narrow headland may eventually join up to form an arch when an arch collapses it forms a stack
36
landforms of erosion | cliffs and wavecut platforms
cliffs form as the sea erodes the land and over time they retreat due to the action of waves and weathering weathering and wave erosion cause a notch to form at the high water mark, this eventually turns into a cave rock above the cave becomes unstable with nothing to support it and collapses wave cut platforms are flat surfaces left behind when a cliff is eroded
37
landforms of deposition | beaches
form when constructive waves deposit sediment on the shore
38
landforms of deposition spits simple
tend to form when the coast suddenly changes direction longshore drift continues to deposit material across the river mouth leaving a bank of sand and shingle sticking out into the sea
39
landforms of deposition | offshore bars
bars are formed when a spit joins two headlands together across a bay or a river mouth a lagoon forms behind the bar offshore bars form off the coast when material moves toward the coast and may remain partly submerged by the sea
40
landforms of deposition | barrier islands
long narrow islands of sand/gravel that run parallel to the shore and are detached from it, tend to form in areas where there's a good supply of sediment, a gentle slope offshore, powerful waves and a small tidal range
41
landforms of deposition | sand dunes
formed when sand deposited by longshore drift is moved up the beach by the wind sand trapped by driftwood/berms is colonised by plants/grasses, the vegetation stabilises the sand and encourages more to accumulate there overtime oldest dunes migrate inland
42
estuarine mudflats and saltmarshes
formed in sheltered, low energy environments silt and mud are deposited by the river or tide mudflats develop mudflats are colonised by vegetation that can survive high salt levels and long periods of submergence plants trap mud and silt and build upwards to create an area of saltmarsh that remains exposed for longer and longer between tides
43
eustatic sea level change
caused by a change in the volume of water in the sea or by a change in the shape of the ocean basins global effects main causes: 1) climate change (increase or decrease in temp causes melting/formation of ice) 2) tectonic movements that alter the shape of ocean basins, e.g. sea floor spreading increases volume of basin so decrease sea level
44
isostatic sea level change
caused by vertical movements of the land relative to the sea downward movement of land causes sea level to rise locally whilst uplift of land causes sea level to fall effects are local causes: 1) uplift/depression of earths crust due to accumulation/melting of ice sheets or accumulation of sediment, 2) subsidence of land due to shrinkage after abstraction of groundwater, 3) tectonic processes e.g. one plate forced under another
45
major sea level change in the last 10,000 years
last glacial period (110,000 to 12,000 years ago) water was stored in ice sheets so sea level was lower than present, last glacial maximum sea level was 130m lower than present temps began to increase 12,000 years ago ice sheets melted and sea level rose rapidly and reached its present level around 4000 years ago over last 4000 years has fluctuated around present value but been rising since about 1930
46
coastlines of emergence
when sea level falls relative to the coast, new coastline emerges from the sea this creates different landforms: raised beaches: when the fall in sea level leaves beaches above the high tide mark. over time beach sediment becomes vegetated and develops into soil. wave cut platforms relict cliffs: cliffs no longer eroded by the sea and slowly covered by vegetation wave cut notches, caves, arches and stacks within relict cliffs e.g. falmouth
47
coastlines of submergence | rias
formed when river valleys are partially submerged gentle, long cross profile wide and deep at the mouth becoming narrower and shallower further inland
48
processes create and alter landforms and landscapes over time
individual landforms combine to form landscapes coastal landscapes can be dominated by processes of deposition or erosion but most are formed by both processes can change/create landforms which means coastal landscapes change over time e.g. a change in one factors can lead to a change in others e.g. a change in wave direction may increase deposition and eventually change a landscape dominated by erosive landforms to one dominated by depositional landforms and 2) relict landforms can still experience coastal processes coastal landscapes therefore often made up of a mixture of active and relict landforms that reflect different periods of change changes occur over a range of temporal and spatial scales
49
recent physical and socioeconomic impacts of climate change on coasts
2mm sea level rise each year
50
predicted physical and socioeconomic impacts of climate change on coasts
8-6mm rise per year by 2100 frequent and intense storms more frequent and severe coastal flooding submergence of low lying islands e.g. maldives changes in the coastline e.g. bangladesh lost contamination of water sources and farmland, saline water damage ecosystems and crops and make water unsuitable for use increase coastal erosion
51
human causes of climate change
deforestation and burning of fossil fuels increasing the greenhouse effect
52
physical causes of climate change/sea level change
global warming = melting of ice sheets thermal expansion
53
four options for coastal management
hold the line advance the line do nothing managed retreat
54
hard engineering | sea walls
reflects waves back out to sea preventing erosion barrier to flooding expensive to build and maintain creates a strong backwash which erodes under the wall
55
hard engineering | revetments
slanted structures built at the foot of cliffs absorb wave energy expensive to build, cheap to maintain create a strong backwash
56
hard engineering | rip rap
boulders piled up along the coast absorb wave energy fairly cheap can shift in storms
57
hard engineering | gabions
rock filled cages cheap ugly
58
hard engineering | groynes
fences built at right angles to the coast that trap beach material transported by longshore drift which gives protection to flooding and erosion quite cheap starve down drift beaches of sand
59
hard engineering | barrages
dams built across river estuaries to generate electricity very expensive disrupt sediment flow
60
soft engineering | beach nourishment
sand and shingle added to beaches from elsewhere | creates wider beaches and reduces erosion of cliffs
61
soft engineering | dune regeneration
where sand dunes are created or restored by nourishment or stabilisation of the sand absorbs wave energy creating barrier between land and sea
62
soft engineering | marsh creation
planting appropriate vegetation which stabilises sediment which reduces the speed of waves which reduces erosive power and flooding
63
soft engineering | land use management
important for dune regeneration to keep vegetation in tact | wooden walk ways and fenced off areas
64
sustainable management strategies | shoreline management plans
plan devised for each sediment cell with the aim of protecting important cites without causing problems elsewhere in the cell can hold, advance, retreat the line or do nothing all local authorities in one call cooperate
65
sustainable management strategies | integrated coastal zone management
considers all elements of the coastal system aims to protect the coastal zone in a natural state while allowing use and development integrated: environment viewed as a whole, different uses are considered and local, regional and national levels of authority all have input dynamic strategy
66
geomorphological processes weathering wetting and drying
when rocks containing clay get wet the clay expands and the pressure caused by this breaks fragments off the rock
67
geomorphological processes weathering chemical weathering
the breakdown of rock by changing its chemical composition e.g. carbon dioxide in the atmosphere dissolves in rainwater forming a weak carbonic acid. this acid reacts with rock that contains calcium carbonate e.g. limestone so the rocks are gradually dissolved
68
coastal processes marine hydraulic action
air in cracks in cliffs is compressed when waves crash in | the pressure exerted by the compressed air breaks off rock pieces
69
coastal processes marine wave quarrying
the energy of a wave as it breaks against a cliff is enough to break pieces off
70
coastal processes marine corrasion/abrasion
bits of rock and sediment transported by the waves smash and grind against rocks and cliffs, breaking bits off and smoothing surfaces.
71
coastal processes marine cavitation
as waves recede the compressed air expands violently, again exerting pressure on the rock and causing pieces to break off
72
landforms of deposition spits compound
occasional changes to the dominant wind and wave direction may lead to a spit having a recurved end overtime several recurved ends may be abandoned as the waves return to their original direction, a spit with multiple recurved ends is called a compound spit
73
landforms of deposition beaches shingle
steep and narrow made up of larger particles which pile up at steep angles
74
landforms of deposition beaches sand
formed from smaller particles, wide and flat
75
landforms of deposition beaches berms
ridges of sand and pebbles about 1-2m high found at high tide marks
76
landforms of deposition beaches runnels
grooves in the sand running parallel to the shore formed by backwash draining to the sea
77
landforms of deposition beaches cusps
crescent shaped indentations that form on beaches of mixed sand and shingle
78
landforms of deposition | tombolos
a bar that connects the shore to an island | e.g. st ninians isle in the shetland islands is joined to a larger island by a tombolo
79
coastlines of submergence | fjords
drowned glacial valleys straight and narrow steep sides shallow mouth but very deep further inland
80
coastlines of submergence | dalmatian coastlines
where valleys lie parallel to the coast, an increase in sea level can form a dalmatian coastline the valleys are flooded leaving islands parallel to the coastline e.g. croatia
81
landforms of deposition spits behind the spit
behind the spit is sheltered from waves and often develops into mudflats and saltmarshes

Geography (11 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions