Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

A level physical geography > the coastal system > Flashcards

the coastal system Flashcards

(105 cards)

Start Studying
1
Q

What kind of system is the coastal system?

A

open as it receives inputs from outside the system and transfers outputs away from the system and into other systems

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

What kind of system are sediment cells

A

They are closed systems as sediment is recycled within the sediment cell

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

What are the sources of energy in a coastal system?

A

wind
waves
tides
currents

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

what are the different types of waves

A

constructive
destructive

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

what is the effect of wind on waves

A

A high wind speed and long fetch creates higher and more powerful waves

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

What are the differences between constructive and destructive waves

A

Constructive waves have a powerful swash and weak backwash
constructive waves have a low frequency
constructive waves are low and long
constructive waves carry material up the beach and deposit it

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

Describe the action of tides

A

Tides are the periodic rise and fall of the ocean surface caused by the gravitational pull of the moon and sun
Tides affect the position at which waves break on the beach - at high tide they break higher up the shore
The land between maximum high and 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
8
Q

Describe the action of currents

A

A current is the general flow of water in one direction and can be caused by wind or by variations in water temperature and salinity

currents cause material to move along the coast

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

define sediment budget

A

The difference between the amount of sand that enters and leaves the system

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

How does the sediment budget affect the coastline

A

A positive sediment budget means more sediment enters than leaves the cell and overall, the coastline builds outwards

if the sediment budget is negative then the coastline retreats

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

How many sediment cells are there in the UK

A

11

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

what are the four types of erosion

A

abrasion
attrition
hydraulic action
solution

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

what are the four types of transportation

A

traction
saltation
suspension
solution

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

what is the difference between marine and aeolian deposition

A

Aeolian deposition is when sediment carried by wind is deposited and marine is when sediment carried by seawater is deposited

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

what are the 4 types of sub-aerial weathering

A

salt weathering
freeze-thaw weathering
chemical weathering
biological weathering

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

What are the 4 types of mass movement

A

slumping - material shifts with rotation
sliding - material shifts in a straight line
rockfall
mudflow

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

describe how cliffs and wave-cut platforms are formed

A

weathering and wave erosion causes a wave-cut notch to form at the high watermark and this eventually develops into a cave

the rock above the cave becomes unstable and with nothing to support it collapses

wave cut platforms are flat surfaces left behind when a cliff is eroded

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

describe how headlands and bays are formed

A

headlands and bays form when there are alternating bands of soft rock, and the soft rock is eroded quickly forming bays and the hard rock left over forms a headland

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

describe the formation of caves, arches, stacks and stumps

A

weak areas in rock are eroded to form caves and when caves on opposite sides join to form an arch

the arch continues to experience erosion and weathering and may collapse to form a stack

erosion of the stack will lead to a stump

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

Give an example of a stack

A

Loch Bracadale, Scotland

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

what are the erosional coastal landforms

A

cliffs and wave cut platforms
caves, arches, stacks, stumps
headlands and bays

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

Describe how a beach is formed

A

beaches form when constructive waves deposit sediment on the shore and they are a store in the coastal system

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

What is the difference between swash and drift aligned beaches

A

swash aligned beaches may have larger sediment and there is limited longshore drift, so sediment doesn’t travel far along the beach

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

what are some distinctive features of beaches

A

berms
cusps
runnells
larger sediment is found towards the top of the beach

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
what are berms
ridges of sand and pebbles found at high tide marks
26
what are runnels
grooves in the sand running parallel to the shore formed by backwash draining to the sea
27
what are cusps
small, curved dips in the beach where the swash comes in
28
what is a spit and how are they formed
they are a long, narrow strip of land which is formed when the coast suddenly changes direction and littoral drift causes the beach to extend to the sea and a salt marsh may form bhind the spit due to the sheltered environment
29
What is the difference between a simple and a compound spit
straight spits are simple Compound spits may have many recurved ends due to several periods of growth
30
Describe the difference between offshore bars and tombolos
bars are formed when a spit joins two headlands and a lagoon is formed behind it. A tombolo however, is when a spit joins to an island
31
describe barrier islands
they are long, narrow islands of sand or gravel that run parallel to the shore and are detached from it. They tend to form in areas where there's a good supply of sediment, fairly powerful waves and a small tidal range
32
describe the formation of barrier islands
it is not exactly clear how they form but scientists believe they probably formed after the last ice age ended when ice melt cause rapid sea level rise. The rising waters flooded the land behind beaches and transported sand offshore where it was deposited in shallow water forming islands
33
Describe the formation of sand dunes
sand dunes are formed when sand deposited by littoral drift is moved up the beach by the winds Sand trapped by driftwood or berms is colonised by plants and grasses stabilising the sand dune encouraging more sand to accumulate forming embryo dunes
34
What kind of sere is a sand dune
psamosere
35
What is a plagioclimax
when a climatic climax isn't reached due to human intervention such as a golf course
36
What are sand dunes an example of
Succesion
37
Describe the formation of mudflats and salt marshes
mudflats and saltmarshes form in low energy, sheltered environments e.g., behind spits as silt and mud are deposited by the river or tide mudflats develop and are colonised by vegetation that can survive halophytic conditions and long periods of submergence by the tide the plants trap more silt and sediment and gradually the mudflat builds upwards to create an area of saltmarsh that remains exposed for longer and longer between tides
38
Give 6 examples of depositional landforms
beaches spits tombolos and bars barrier island mudflats and saltmarshes sand dunes
39
define eustatic change
when the sea level itself rises or falls
40
deine iostatic change
when the land rises or falls relative tothe sea
41
Describe how eustatic change occurs
glacial melting or thermal expansion
42
describe how isostatic change occurs
isostatic recovery - when glacial ice melts and the land lifts to readjust due to the reduced weight of the ice on the land
43
What is the difference between isostatic and eustatic change
eustatic is global and is the change in water isostatic change occurs locally and is the change in the land relative to the sea
44
give evidence of sea level change
global sea level is rising by around 2mm each year increasing temperatures are likely to cause increases in sea level and sea level is predicted to rise by 8-16mm per year by 2100
45
How can eustatic change impact coastlines
submergence of low lying islands changes in coastlines - 8000km2 of Bangladesh will be lost increased coatal erosion
46
give examples of emergent coastlines
raised beaches sea-level fall can lead to exposed wave-cut platforms relict cliffs- cliffs above raised beaches are no longer eroded by the sea
47
Give examples of submergent coastlines
Rias - flooded river valley e.g., Milford Haven in Wales Fjords - drowned glacial valleys Dalmation coasts- valleys are flooded leaving islands parallel to the cast e.g., Croatio
48
What is the difference between rias and fjords
Rias are flooded river valleys whereas fjords are drowned glacial valleys Rias generally have a long and wide cross profile whereas fjords are narrow and straight sided Rias become shallower inland but fjords are very deep inland
49
what are the 4 options for coastal management
hold the line advance the line do nothing managed retreat
50
define hold the line
maintain the existing coastal defences
51
define advance the line
build new coastal defences further out to sea
52
define managed realignment
allow the shoreline to move but manage the retreat so it causes the least damage
53
what is the difference between hard and soft engineering
Hard engineering involves built structures whereas soft engineering involves coaxing natural processes along
54
describe how a sea wall works
the wall reflects waves back out to sea preventing erosion of the cast and flooding
55
What are the disadvantages of sea walls
they are expensive to build and maintain and create a strong backwash which erodes the under wall
56
describe how a revetment works
they are slanted structures built at the foot of a cliff and absorb wave energy preventing cliff erosion is relatively cheap to maintain
57
what are the disadvantages of revetments
expensive to build and creates a strong backwash
58
Describe how gabions work
gabions are rock-filled cages which absorb energy and are quite cheap
59
What are the disadvantages of gabions
ugly
60
describe how ripraps work
they are boulders piled up along the coast which absorb wave energy and are fairly cheap
61
What are the disadvantages of rip raps
they can shift in storms
62
Describe how groynes work
groynes are fences built at right angles to the coast and traps material deposited by littoral drift creating wider beaches and gives greater protection from floods and erosion and they are quite cheap
63
what are the disadvantages of groynes
they deplete further along the beach of sediment making it more prone to erosion and flooding
64
describe how breakwaters work
concrete blocks or builders deposited of the coast forcing waves to break offshore so theyre erosional power is less when they reach the beach
65
What are the disadvantages of breakwaters
they are expensive and can be damaged in storms
66
describe how earth banks work
They are mounds of earth that act as a barrier against flooding
67
What are the disadvantages of earth banks
expensive and can be eroded
68
Describe how tidal barriers work
Built across river estuaries and contain floodgates that can be raised to prevent flooding from storm surges
69
What are the disadvantages of tidal barriers
theyre very expensive
70
Describe how tidal barrages work
dams built across river estuaries and thier main purpose is to generate electricity and water is trapped behind it at high tide prevent flooding at storm surges
71
What are the disadvantages of tidal barrages(dams)
very expensive and can disrupt sediment flow
72
what are the 6 soft engineering defences
beach nourishment beach stabilisation dune regeneration land use management creating marshland coastal realignment - allowing the sea to flood the land and breaching the defence
73
Define SMP
shoreline management plan the coastline is split into stretches by sediment cells and for each cell a plan is devised for how to manage different areas with the aim of protecting important sites without causing problems elsewhere
74
Define ICZM
Integrated coastal zone management considers all elements of the coastal system such as economy water and people it is a dynamic strategy the environment is viewed as a whole and different uses are considered and levels of authority have an input to the plan It aims to protect the coastal zone in a relatively natural state whilst allowing people to use it and develop it in different ways
75
.what are the different types of wind action
surface creep wind rolls or slides sand along the surface saltation - where wind is strong enough to temporarily lift grains into the airflow to heights of up to one metre for long distances
76
what are some examples of chemical weathering
solution hydrolysis carbonation acid rain
77
what kind of waves do bays experience and why
they experience low -energy waves that allow sediment to accumulate because of refraction
78
what happens when waves are refracted
they become increasingly parallel to the coastline
79
What are the different types of current
longshore rip currents upwelling
80
what do tidal ranges determine
the upper and lower limits of erosion
81
what is the difference between a spring and a neap tide
spring tides are the highest and sun, moon and earth are in a straight line neap tides are 10-30 per cent lower than average and moon is perpendicular to earth and sun
82
what are the main inputs at a discordant coast
geology and lithology of the coast nature of waves approaching the coast direction and strength of prevailing wind
83
what are the processes at a discordant coast
differential rates of erosion at the coast wave refraction deposition in the bay erosion of the headland
84
what are the outputs at a discordant coast
the headland and bay erosional features of the headland depositional features in the bay
85
why is the size of a wave-cut platform limited
as the platform continues to grow the waves break further out at sea and have to travel across more platform before reaching the cliff line so there is a greater dissipation of energy
86
what is a geo
the sea will cut inland along a joint widening the crack to form a narrow steep sided inlet
87
why is shingle usually at the top of the beach
because water rapidly percolates through shingle so the backwash is somewhat limited in its ability to transport material back down the beach
88
at what kinds of coasts are swash-alligned beaches found
irregular coastlines where littoral drift is impeded
89
At what kinds of coasts are drift-alligned beaches found
where coastline is fairly regular or where wave direction is at an angle to the beach
90
What can occur as a spit matures
sand dunes can develop as deposited sand dries out and is blown landward side of the spit
91
What is the formation of a barrier beach thought to be
breaching of a spit or by constructive waves pushing a bar towards land
92
what are some factors that over time have helped to develop the coastline
local tectonic processes sea level change climatic change changing ocean currents and wave regimens human activity natural disasters
93
what are some inputs of a coastal sand dune
plentiful supply of sand strong onshore winds large tidal range obstacle to trap the sand vegetation growth to encourage further dune growth
94
describe how an embryo dune is formed
sand is moved inland mainly by saltation and where there is a large tidal range large amounts of sand are exposed at low tides sand may be trapped by obstacles such as seaweed and driftwood at the back of the beach possibly on the highest berm
95
Why are embryo dunes suitable for colonisation
accumulating wind blown sand is stabilised by grasses and low hummocky dunes are formed and the presence of plants adds organic matter increasing water retention
96
how are foredunes formed
upwards growth of embryo dunes raises the height of the dune so they are beyond the reach of all but the highest storm tides foredunes are originally yellow because they lack organic matter but as vegetation cover increases humus is added to the sand and they look grey in colour
97
What are dune slacks
depressions within fixed dunes where water table is on or near the surface
98
why are salt marshes not a permanent feature
changes in sea level wave action changes in discharge levels in river changes to tidal flows
99
describe the flows of water at a salt marsh
salt water from slow moving sea currents bring large amounts of fine sediments and meets the river which is also carrying its own fine silts and clays as two flows meet fine particles settle out of the suspension by flocculation where clay particles aggregate to form larger heavier particles that sink to the bed
100
what are the pioneer plants in a salt marsh
glasswort, sea-bite, spartina
101
when are raised beaches formed
when isostatic movement is faster then eustatic
102
how do dalmatian coasts differ from rias and fjords
the flooded valleys run parallel to the coast rather than at right-angles
103
what are changes in sea level a result of
increased volume of ocean subsidence of coast
104
how does rock strata influence coastlines
steepest cliffs tend to form in rocks that have horizontal strata or dip gently inland whereas rocks that dip towards the coast produce more sloping features
105
how can run off impact coastlines
may take in the form of a stream emerging in a bay and taking large quantities of load during times of flood stream cascading over cliff excavating v shaped groove presence will also assist with many mass movements

A level physical geography (3 decks)

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