1
Q
What are models in geography?
A
simplification of reality to allow comparison between countries/places/situations
2
Q
What are systems in geography?
A
an assemblage of interrelated parts that work together
3
Q
What are elements of a system?
A
parts
4
Q
What are attributes to a system?
A
characteristics
5
Q
What are relationships in a system?
A
connections
6
Q
Are coasts an open or closed system?
A
open
7
Q
Why are coasts an open system?
A
- fluvial
- sub-aerial
- coastal
- marine
8
Q
What are some inputs into the coastal system?
A
- tides/waves/currents
- sediment cells
- rivers
- sea level fluctuations
- sediment from erosion/weathering
9
Q
What are some outputs in the coastal system?
A
- sediment washed out to sea
10
Q
What are some flows/transfers in the coastal system?
A
- erosion
- weathering
- transportation
- deposition
11
Q
What are some stores in the coastal system?
A
- landforms e.g. beaches, spits, dunes
12
Q
What is the most important agent in shaping coastal landforms?
A
waves (input)
13
Q
How are waves created?
A
winds blow over a smooth sea surface causing ripples known as waves
14
Q
What is the fetch of a wave?
A
the distance of open sea which wind blows, it effects the size of the wave
15
Q
What will happen if the wave has a longer fetch?
A
more energy –> more erosion
16
Q
What are the two types of waves?
A
constructive and destructive
17
Q
What are prevailing winds?
A
winds blowing in the same direction consistently
18
Q
Characteristics of a constructive wave:
A
- usually in the summer
- long wavelength
- formed by weather systems
- 6-9 per minute
- low waves, surge up the beach
- strong swash
- creates gently sloped beaches
19
Q
Characteristics of a destructive wave:
A
- usually in the winter
- localised in storm events
- short wavelength
- 11-16 per minute
- strong backwash
- high waves, erode beach
- create steeply sloped beaches
20
Q
What is the normal atmospheric pressure?
A
1012
21
Q
Are coasts high or low energy?
A
high and/or low
22
Q
What are the characteristics of a coast that is high energy?
A
- long fetch
- strong winds
- sandy coves & rocky landforms
- rate of erosion higher than deposition
23
Q
What are the characteristics of a coast that is low energy?
A
- short fetch
- gently sloping off shore (due to a reef or islands)
- deposition rate is higher than erosion
24
Q
What is a landform?
A
a single feature, formed by erosion, transportation or deposition
25
What is a landscape?
a collection landforms linked
together and interrelated, as part of a system
26
What is a concordant coastline?
horizontal bands of hard & soft rock
27
What is a disconcordant coastline?
vertical bands of hard & soft rock
28
What is erosion?
The breaking down of sediment through processes such as hydraulic action, attrition, abrasion and solution.
29
What is transportation?
A group of processes where material is transferred between stores or in/out of the system.
30
What is deposition?
This occurs when energy is low in an area of the sea and therefore material can no longer be suspended.
31
What is weathering?
This is the gradual break down of rock by agents such as ice, salt, plant roots and acids.
32
What is mass movement?
This is the gradual or rapid movement of material down a slope occurring on the cliff.
33
What is tidal range?
the difference between high and low tides
34
What are tidal bores?
extra large (unusual waves)
35
How many tides are there per day in the UK?
2 x high
2 x low
36
What is the time lag between high tides?
12 hrs 25 mins
37
How are tides formed/created? (generalised)
- gravitational pull of the sun or moon changes the water levels of the seas and oceans
- Tides affect erosion and lead to the formation of different coastal landforms.
38
When do the highest high tide and the lowest low tides occur?
- when the sun and the moon are in
alignment.
- Both of their gravitational forces combine to effectively pull the oceans towards them
- On the other side of the planet, this creates the lowest
possible low tides
- This is a spring tide
- creates the largest possible tidal range.
39
When do the lowest high tide and the highest low tides occur?
- when the sun and the moon are
perpendicular to each other
- Both of their gravitational forces act against each other
- This is a neap tide
- creates the smallest possible tidal range.
40
What is a current?
the general flow of water in one direction caused by winds or variation in water temperature/salinity
41
How are currents formed?
- Wind pushes surface waters
- while the density differences created by temperature and salinity drive the slower, global movement of deep currents.
42
What is refraction?
the 'bending' of the wave fronts
- when it approaches an irregular coastline
- energy is concentrated on the headland (low or high energy waves)
- increases erosion
43
What are rivers (in terms of coasts)?
they account for the vast majority of coastal sediment, especially in high rainfall environments where active river erosion occurs (source)
44
What is cliff erosion?
extremely important locally in areas of soft or unconsolidated rock (source)
45
What is littoral drift?
(LSD) sediment is transported from one stretch of coastline (output) to another (input) (transportation)
46
What is wind & sand dunes?
wind blows sand which is deposited in coastal regions
- this creates sand dunes which are features of the coast (sink)
47
What are glaciers?
in some parts of the world, such as Alaska, Greenland and Antartica, ice shelves calve into the sea, depositing sediment, which gets trapped in the ice
48
What are inputs?
sources of sediment
49
What are transfers?
transportation of sediment
50
What are stores?
sinks of sediment
51
What are sediment cells?
a stretch of coastline usually boardered by 2 prominant headlands, where movement of sediment is more or less contained
52
How many sediment cells are in England & Wales?
11
53
What are sediment budgets?
the balance between sediment being added to and removed from the coastal system (dynamic equilibrium)
54
What are marine processes?
operating on the coast and are directly connected to the sea (waves/wind/tides) - erosion, transportation, deposition
55
What are sub-aerial processes?
operating on the land but affect the shape of the coast - weathering & mass movement
56
What is geomorphology?
'physical geography' - study of the land
57
What is cauitation? (HA)
force of the waves pushes air into the cracks at massive pressures, forcing out parts of the cliff face
58
What is wave quarrying?
action of the waves breaking against unconsolidated materials like gravel and sand, waves scoop up the loose material
59
What is corrasion? (abrasion)
waves pick up sand and pebbles from the seabed, hurle it at the cliff foot which chips the rock
60
What is corrosion? (solution)
weak acids in sea water dissolve alkaline rocks (limestone and chalk)
61
What is attrition?
gradual wearing down of rock particles by impact and abrasion as they are moved by waves/tides/currents
62
What is mass movement?
the downhill movement of material under the influence of gravity
63
What is weathering?
breaking down of rocks
64
Types of mechanical weathering:
- freeze-thaw (water freezes in cracks)
- salt crystallisation
- wetting & drying (rocks expand when wet)
65
In freeze-thaw weathering, what % does water expand by?
10%
66
What is biological weathering?
the breakdown of rocks caused by living organisms like plants, animals, and microbes. This process involves both physical and chemical actions, such as plant roots growing in rock cracks and widening them, animals burrowing, and organisms like lichens releasing weak acids that dissolve minerals.
67
What is chemical weathering?
the process where rocks break down due to chemical reactions - oxidation, carbonation, solution
68
What is carbonation?
rain absorbs CO2, forming calcium biacarbonate
69
What is oxidation?
reaction of rock minerals with oxygen
70
What is solution?
dissolving rock materials
71
What 2 factors does mass movement depend upon?
range in speed e.g. 1cm per year or landslides and weight of rainfall / how the geology copes with that
72
What is soil creep?
- the slow, downhill movement of soil and rock material on a slope under the force of gravity.
- It happens almost imperceptibly on gentle slopes and is caused by processes like freezing and thawing, or wetting and drying, which cause soil particles to move downhill in minute, continuous steps.
- zig zag direction
73
What are mudflows?
- a rapid downhill flow of water-saturated soil, mud, and debris that moves like a viscous fluid down a slope.
- It occurs when heavy rainfall saturates the ground, causing it to become unstable and lose cohesion, making it flow downhill, sometimes at high speeds.
74
What are landslides?
the movement of a large mass of rock, earth, or debris down a slope, caused by gravity down a planar surface
75
What is rockfall?
where fragments of rock break away from a cliff or steep slope and fall freely under gravity. This is often caused by weathering, such as freeze-thaw cycles, which widen cracks in the rock, eventually leading to fragments becoming detached.
76
What is slumping?
- where a section of land moves down a slope along a curved, rotational slip plane.
- This typically happens after heavy rain saturates weaker, permeable rock that overlays impermeable rock, making the material heavy and unstable.
- The upper part of the slope sinks and may tilt forward, creating a series of steps and leaving behind a curved, indented scar
77
What is soliflucation?
cold periglacial environments, sodden soil moves downhill by a combination of heave and flow
78
What does unconsolidated mean?
'loose earth'
79
What is traction?
rolling of large material along the sea floor by the waves
80
What is saltation?
bouncing of slightly lighter material along the sea floor
81
What is suspension?
small particles of material carried by the water
82
What is solution? (transportation)
material that is dissolved and carried by the water
83
How is a wave-cut platform formed?
- When waves erode a cliff, the erosion is mostly concentrated around the high-tide line .
- The main processes of hydraulic action and corrasion create a wave-cut notch.
- As the notch becomes deeper (and sub-aerial weathering weakens the cliff from the top)
the cliff face becomes unstable and falls under its own weight through mass movement.
- This leaves behind a platform of the unaffected cliff base beneath the wave-cut notch
- Over time the same processes repeat leading to a wave-cut platform to be formed, which
is normally exposed at high-tide
84
How are headlands and bays formed?
- discordant coastlines
- Bands of soft rock such as clay and sand are weaker therefore they can be eroded quickly.
- Hard rock such as chalk is more resistant to the processes of erosion. When the softer rock is eroded inwards, the hard rock sticks out into the sea, forming a
headland.
85
How are caves, arches, stacks and stumps formed?
- Initially, faults in the headland are eroded by hydraulic action and abrasion to create
small caves
- The overlying rock in a cave may collapse , forming a blowhole. The blowhole spurts
water when a wave enters at the base, forcing sea spray and air out of the top.
- Marine erosion widens faults in the base of the headland , widening over time to create a
cave
- The cave will widen due to both marine erosion and sub-aerial processes , eroding
through to the other side of the headland, creating an arch
- The arch continues to widen until it is unable to support itself, falling under its own weight
through mass movement, leaving a stack as one side of the arch becomes detached from
the mainland
86
How are spits formed?
- Sediment is carried by littoral drift.
- When there is a change in the shape of the coastline, deposition
occurs.
- A long thin ridge of material is deposited. This is the spit.
- A hooked end can form if there is a change in wind direction.
- Waves cannot get past a spit, therefore the water behind a spit is very sheltered.
- Silts are deposited here to form salt marshes or mud flats.
87
What is floculation?
when salt clings onto sediment particles in rivers, increasing weight and causing them to drop to the bottom of the esturary
88
What is a bar?
a spit that joins two headlands, with a lagoon forming behind
89
What is a tombolo?
deposited materials beet an offshore island, connecting the island to the mainland
90
What is an offshore bar?
- An offshore region where sand is deposited , as the waves don’t have enough energy to carry
the sediment to shore.
- They can be formed when the wave breaks early, instantly depositing its
sediment as a loose-sediment offshore bar.
- Waves may pick up sediment from an offshore bar,
which then provides an important sediment input into the coastal zone . - They may also be
formed as a result of backwash from destructive waves removing sediment from a beach.
91
What is the 1st theory of a barrier island?
formed at the end of the last ice age, ice melted which meant sea levels rose. This meant that rising water flooded the land behind beaches and transported sand offshore, deposited it, which formed islands
92
What is theory 2 of a barrier island?
they were once bars, and eroded in sections causing the ends/breaches to cut it off from the headland
93
Example of a barrier island?
Long Island (NYC)
94
What are mudflats?
- rising tides create a buffer with the river flow
- decreases velocity which means deposition occurs (mud)
- covered at high tide
- exposed at low tide
95
What are saltmarshes?
- flat areas
- slity sediment
- sheltered areas
- salt & fresh water (esturaries)
- no strong tides or currents
96
Are mudflats/saltmarshes low or high energy environments?
low
97
How do sand dunes form?
- prevailing winds blow sediment to the back of the beach and
therefore the formation of dunes requires large quantities of sand and a large tidal range.
- This allows the sand to dry, so that it is light enough to be picked up and carried by the wind to the back
of the beach.
- Frequent and strong onshore winds are also necessary
98
What are the types of dunes in order?
- embryo dunes
- fore dunes
- yellow dunes
- grey dunes
- sune slacks
99
Example of a mudflat:
Humber Esturary
100
Example of a saltmarsh:
Holkham, Norfolk
101
Vegetation succession in sand dunes:
- Pioneer species such as sea rocket are resistant and able to survive in the salty sand, with
its roots helping to bind the dunes together
- Decaying organic matter adds nutrients and humus (organic material comprised of
decaying plant and animal matter) to the soil allowing marram grass to grow
- Larger plants are able to colonise the area and the climatic climax occurs when trees are
able to colonise the area
102
Vegetation succession in mudflats & saltmarshes:
- eelgrass begins to colonise
- sea surface dries species such as sea asters colonise
- shrubs and trees will colonise (climatic climax)
103
What are halophytes?
salt tolerant species
104
What is a fully completed succession called?
halosere
105
How do beaches form?
- Beaches are made up from eroded material that has been transported from elsewhere and then deposited by the sea.
- For this to occur, waves must have limited energy, so beaches often form in sheltered areas like
bays
- Constructive waves build up beaches as they have strong swash and a weak backwash
- Sandy beaches are usually found in bays where the water is shallow and the waves have less energy. Pebble beaches often form where cliffs are being eroded and where there are higher energy waves.
- The beach profile has lots of ridges called berms. They show the lines of the high tide and the storm tides.
106
How does climate change impact sea levels rising?
as the Earth's climate warms, both naturally and due to human impacts, water stored on the surface as ice is released onto the oceans as it melts
107
What is thermal expansion?
hotter water occupies a greater volume of water as CO2 causes it to swell
108
How much do sea levels rise per year?
4/5mm
109
What is the prediction as to how much sea levels will rise by 2090?
18-59cm
110
Impacts of climate change on coastal areas:
- storms will become more frequent and intense
- damage coastal ecosystems and settlements
- frequent and more severe coastal flooding
- submergence of low-lying islands
- area of land is decreased
- contamination of water sources and farmland
- increased coastal erosion
111
What are eustatic sea levels?
a change in the amount of water in the ocean - GLOBAL
112
What are isostatic sea levels?
a vertical movement of the land compared to the sea - LOCAL - uplift/depression of the earth's crust
113
What are tectonic sea levels?
changes the shape of the basin, destructive plate margins cause sea levels to rise
114
Which one is more prominant currently? Eustatic or isostatic?
Eustatic
115
What is the process of glacial sea level impacts?
- climate is cool so rain falls as snow
- snow & ice are a store of water so sea level fall eustatically
- weight of the ice causes land surfaces to sink (isostatic)
- climate warms so ice melt and sea levels rise again (eustatic)
116
Isostatic change in the UK:
N/NW = sea levels falling due to isostatic recovery (emerging)
S/SE = sea levels rising due to isostatic sinking
117
What is isostatic subsidence?
ice sheets cover the land, weighs it down
118
What is isostatic readjustment?
ice melts, land rises
119
What is an emergent coastline?
a decrease in sea levels exposes the land previously covered by the sea
120
What is a submergent coastline?
an increase in sea levels floods the coast
121
What are submergent landforms/features?
- ria
- fjord
- dalmation coasts
122
What is a ria?
drowned river valley, as sea levels increase, they flood the river valley, leaving only high land visible
123
Example of a ria:
Falmouth, Cornwall
124
What is a fjord?
a drowned glacial, U - shaped, valley. As sea levels rise, U shaped valleys are submerged
125
Example of a fjord:
Loch Torndon, Scotland
126
What is a dalmation coast?
form in a landscape of ridges and valleys running parallel to the coast. When sea levels rise, the valley flood but the tops of the ridges remain exposed forming a series of offshore islands running parallel to the coast
127
Example of a dalmation coast:
Croatia
128
What are raised beaches?
areas of former wave-cut platforms and their beaches which are at a higher level than the present sea level
128
What are emergent features?
- raised beaches
- relict cliffs
129
What are relict cliffs?
an old cliff displaying features such as caves, arches, stacks and stumps
130
Example of a raised beach:
Isle of Arran, Scotland
131
What % of the world's population live within 100km of the coast?
44%
132
What does the International Panel for Climate Change predict will happen to sea levels by 2100?
rise between 40cm - 1m
133
Risks to coastal areas for a rise in sea levels?
- shoreline erosion and degradation
- amplified storm surges
- permanent inundation (submergence)
- saltwater contamination
134
What % of large cities are by the coast?
75%
135
What is traditional human intervention?
hard & soft engineering
136
What is sustainable human intervention?
intergreted approaches considers the entire coastal zone
137
What is 'cost-benefit' analysis?
carried out before a coastal management project is given the go-ahead, weighs up the tangible and intangible costs/benefits
138
What is a Shoreline Management Plan? (SMP)
- DEFRA recommends
- identifies natural processes, human activities & management decisions
- aims to protect sites with limited effects/impacts
- hold the line / advance / do nothing
- each sediment cell considered a 'closed cell'
- controlled by local authorities
139
What is an Intergrated Coastal Zone Management? (ICZM)
- all aspects of the coastal system
- aims to sustainably resolve SEE challenges
- national scale
- plan is dynamic
140
What are sustainable intergrated approaches to managing the coast?
- SMP
- ICZM
141
What does 'advance the line' mean?
move defence seaward
142
What does 'hold the line' mean?
hold the current defences / line
143
What does 'do nothing' mean?
no coastal defence system
144
What does 'retreat the line' mean?
let it flood, move it back
145
What are hard engineering strategies?
- sea walls
- reventments
- gabions
- groynes
- rip rap
- artificial reefs
146
What are soft engineering strategies?
- beach nourishment
- 'do nothing'
- zone management / red lining
147
What does accomodation mean?
working with natural processes
148
What does adjustment mean?
working to secure the future of a coastline
Physical geography
flashcards
Decks in class (19)
# Cards
-
Water cycles59
-
River Eden (case study W&C)16
-
Carbon Cycle29
-
Amazon Rainforest (case study W&C)23
-
Hazards - Hazards / disasters38
-
Hazards - Plate tectonics15
-
Hazards - volcanoes39
-
Hazards - Montseratt 1997 eruption12
-
Hazards - Seismic hazards43
-
Hazards - (seismic) Kashmir 200512
-
Hazards (seismic) - Tohoku, Japan 201128
-
Hazards - tropical storms28
-
Hazards - Hurricane Katrina 200513
-
Hazards - Wildfires39
-
Hazards - Black Saturday fires wildfires18
-
Hazards - multi hazardous environment29
-
Coasts149
-
Holderness Coastline - local - COASTS19
-
Sudarbans (Bangledesh) - COASTS22
