Coasts Flashcards
(216 cards)
1
Q
The coastal system is an … System
A
Open
2
Q
Inputs in the coastal system
A
Precipitation
Wind
Fluvial sediment
3
Q
Flows/processes in the coastal system
A
LSD
Erosion
Mass movement
Evaporation
4
Q
Stores and components of the coastal system
A
Beaches
Sand dunes
Spits
Bars
5
Q
Outputs of the coastal system
A
Headlands Bays Wave cut platforms Ocean currents Evaporation RIP tides
6
Q
Negative feedback of the coastal system
A
Mass movement decreasing cliff foot erosion
7
Q
Positive feedback in the coastal system
A
Coastal management increasing erosion elsewhere
8
Q
Terrestrial factors influencing the coastline
A
Tectonics Sun-aerial processes Glaciations Supply of sediment Fluvial processes
9
Q
Marine processes influencing the coastline
A
Bionic features eg reefs Wave shape/size Fetch Sea level change Wave direction Tides
10
Q
Human intervention factors influencing the coastline
A
Industrial and residential development Sea defences Conservation Tourism and recreation Global warming Pollution
11
Q
Atmospheric factors influencing the coastline
A
Winds Precipitation Temperature Solar energy Global warming
12
Q
Define dynamic equalibrium
A
A system in dynamic equalibrium has inputs and outputs of energy and matter that balance
13
Q
Dynamic equalibrium is affected by:
A
Supply of sand ie conservation
Energy of waves
Sea level change ie global warming
Location of the shoreline eg managed retreat
14
Q
Define landform
A
Individual features which are created by coastal processes eg stacks, wave cut platforms, and spits
15
Q
Define landscapes
A
The entire area of sea, coastline, and immediate land behind the sea front. Within the landscape are characteristic landforms
16
Q
Sources of coastal energy
A
Waves
Wind
Currents
Tides
17
Q
As with all Earth systems the initial energy input for the coastal system is…
A
From the sun
18
Q
How does the sun’s energy cause other forms of energy in the coastal system
A
It causes different air pressures (due to different rates of heating) which creates wind, this wind then generates waves which are the main form of energy
19
Q
How is wind formed
A
Air moving between areas of high pressure to low pressure (along a pressure gradient)
20
Q
How does the pressure gradient affect wind speed
A
The steeper the gradient the faster the wind moves
21
Q
How does the strength of the wind influence wave energy
A
The stronger the wind the bigger the wave
22
Q
How does fetch influence wave energy
A
The shorter the fetch the smaller the wave (less distance to gain energy)
23
Q
How does the duration of the wind influence wave energy
A
The longer the wind has been blowing , the longer time the waves have to gain energy
24
Q
How do waves form
A
Diagram look it up idk
25
Why are some areas of the uk subject to more powerful waves than other areas
Fetch is longest in South West and shortest in South East
South West prevailing wind
South West is a high energy coast
South West not heavily eroded due to rock type
26
Constructive wave components
Low wave
Long wavelength
Strong swash
27
What are the processes associated with constructive waves
Deposition and LSD
28
How are constructive waves formed
Distant weather systems
29
Landforms made by constructive waves
Beaches, spits, and bars
30
Which waves never reach the back of the beach (backshore)
Constructive
31
Destructive wave components
Tall in relation to length
Steep beach profile
Strong backwash
32
What are the processes associated with destructive waves
```
Erosion
Mass movement (cliff erosion and undercutting)
```
33
When are destructive waves most common
During winter storms
34
Features created by destructive waves
Wave cut platforms
Cave
Arch
Stack
35
What are tides
Periodic rise and fall in the level of the sea caused by the gravitational pull of the sun and the moon
36
Both the ... and ... of the tides change on a daily basis based on the position of the sun and the moon relative to the Earth
Time and size
37
Why are spring tides exceptionally high
The gravitational pull from the sun and moon is in the same direction which means there is more force
38
Why are neap tides very low
The sun and the moon are pulling in different directions
39
Why is knowledge of tides essential for coastal management
Tides could go over groynes or sea wall and make them useless
40
Which process is more evident in high energy coastlines? Erosion or deposition
Erosion exceed deposition
41
Which process is more evident in low energy coastlines? Erosion or deposition
Deposition exceeds erosion
42
Where in the Uk are high energy coastlines mostly found and why
Atlantic facing eg Cornwall because there is a large fetch so high energy waves
43
Landforms associated with low energy coastlines
Sheltered areas eg bays
| Beaches and spits
44
Landforms found in high energy coastlines
Cliffs and headlands
45
What is the tidal range
How long wave processes can act on a cliff face for
| Small range means more focused on the same area for longer and so more erosion
46
What is tidal current
The horizontal movement of water accompanying the rise and fall of tides
47
Flood current definition
The incoming tide along the coast and into the bays and estuaries
48
Define the ebb current
The outgoing tide
49
When do the strongest flood and ebb current occur
Before or near the time of the high and low tides when water levels are closest to their highest/lowest value
50
Slack tides definition
The weakest currents occurring between the flood and ebb currents
51
Where are currents strongest
Near estuary entrances, narrow straits, and inlets
52
What do large tidal ranges do
Provide energy via tidal currents and transport sediment
53
What do small tidal ranges do
Concentrated erosion at the cliff base
54
What are orthogonals?
They show the direction of energy
55
What causes wave refraction?
The shape of the sea bed means that the waves hit shallower water at different times, shallower water means slower waves
56
Where is the area of high wave energy? Headland or bay
Headland
57
Define sediment cell
A stretch of coastline within which sediment movement is more or less contained
58
Give an example of a sediment cell
Flamborough Head (eastern coast of England)
59
Sources of sediment
Rivers
Cliff erosion
Offshore sediment
Wind
60
Where does most of the sediment come from
Rivers
61
What type of rock does Cornwall have
Tough, igneous granite
62
Rates of cliff erosion along the Holderness Coast in Lincolnshire can be as high as...
10m/year
63
How is offshore sediment transported into the coastal zone?
Waves
Tides
Currents
Storm surges
64
Define geomorphological
Changing Earth - sub aerial and marine processes
65
What are geomorphological sub-aerial processes
Weathering
Run off
Mass movement
66
What are geomorphological marine processes
Erosion
Transportation
Deposition
67
How does geographical location determine the type and rate of weathering
Wildlife - burrowing animals so more physical
Climate
Rock type
68
Positive feedback example in weathering
If the rate of debris removal exceeds the rate of weathering and mass movement then the latter will increase
69
Example of negative feedback in weathering
If debris removal is slow more will build up so weathering and mass movement rates will decrease as cannot get to the cliff
70
Define mass movement
The downhill movement of weathered material under the force of gravity
71
Define biological weathering
The breakdown of rocks by organic activity I.e. plants, animals
72
Define chemical weathering
Involves a chemical reaction where salts may be dissolved
73
Define mechanical/physical weathering
Involves the break up of rocks without any chemical changing taking place
74
Give examples of biological weathering
Tap roots
Burrowing animals
Water running through decaying vegetation becomes acidic
75
Give examples of chemical weathering
Carbonation
Oxidation
Solution
76
Give examples of mechanical weathering
Frost shattering
Salt crystallisation
Setting and drying
77
What are the types of mass movement
```
Solifluction
Mudflow
Run off
Landslide
Rock fall
```
78
Factors affecting the rate of erosion
```
Lithology
Waves
Sea defences
Discordant/concordat coastline
Season
Tidal range
Geological structure
```
79
What are the methods of transportation
Saltation
Solution
Traction
Suspension
80
Define traction
Large particles like boulders are pushed along the sea bed by the force of the water
81
Define suspension
Small particles like silt or clay are carried along in the water
82
Define saltation
Pebble sized particles are bounced along the sea bed by the force of water
83
Define solution
Soluble materials dissolve in the water and are carried along
84
What determines the method of transportation of sediment
Size of particle
| Energy of waves/water
85
Another name for LSD
Littoral drift
86
Deposition in high energy coasts
Small particles are easily transported
| Larger material is deposited forming shingle beaches
87
Deposition in low energy coasts
Even the smallest material deposited forming mudflats and salt marshes
88
What are the processes of erosion
```
Hydraulic action
Wave quarrying
Abrasion/corrasion
Attrition
Solution/corrosion
```
89
Define hydraulic action
The impact on rocks of the sheer force of the water which exerts a lot of pressure on the rock and so weakening it
90
Define wave quarrying
A braking wave traps air in the cliff, air compressed, water retreats and pressure released so large areas removed
91
Define abrasion
Eroded material being thrown against the rock by waves (wave cut platforms)
92
Define attrition
Rocks which are carrying out abrasion are slowly worn down into smaller and rounder particles
93
Define solution
Dissolving of rocks
94
Concordant coastline
Parallel to the sea
95
Example of a concordant coastline
South Purbeck, Dorset
96
Discordant coastline
Perpendicular to the sea
97
Example of discordant coastline
East Purbeck, Dorset
98
What is the cliff profile
The gradient of the cliff
99
How do sedimentary rocks form
Layers of deposited sediment, either on the beds of ancient oceans or rivers
100
Sequence leading to stack
```
Headland
Line of weakness
Cave
Arch
Stack
```
101
Ridges in beaches
Accumulations of sand in lines where the sediment has been deposited
102
Swash alligned
Sediment moves up and down the beach with little lateral transfer
103
Drift alligned
LSD
104
What are the two types of spit
Compound
| Simple
105
Compound spits
Barbs or hooks on their landward side
106
Simple spits
Bars of sand without barbs or hooks
107
What are barbs and hooks?
Secondary wind directions cause different LSD direction
108
What are tombolos?
form in a similar way to spits but are unique because they join the main land to an offshore island via deposition
109
Name a famous tombolo
Angel road of Shodo Island, Japan
110
Name an UK example of a barrier beach
Slapton Sands
111
Name a non-UK example of a barrier beach
Jupiter Island, Florida
112
Name an UK example of barrier islands
Scolt Head Islands, Norfolk
113
Name a non-UK example of barrier islands
Alabama barrier islands, Mississippi
114
Name an UK example of offshore bars
Hordle Cliff offshore bar
115
Name a non-UK example of offshore bars
Gulf of Mexico has some
116
What are sand dunes
Accumilation of sand blown into mounds by the wind
117
What is an aeolian formation
Formed by the wind
118
Are sand dunes deposition landforms
Not officially because they are formed by deposition from the wind not the sea
119
What do sand dunes need to form?
Flat beach
| No secondary wind direction
120
Types of sand dune
```
Embryo dune
Fore dune
Main ridge
Grey dune
Dune slack
Dune health
Mature dune
```
121
What are human threats to sand dunes
```
Industrial pollution
Agricultural pollution
Dredging
Shipping
Grazing
```
122
What component are marshes within the coastal system
Stores
123
How are mudflats created
The deposition of fine salts and clays in sheltered low energy coastal environments such as esturies
124
What are salt marshes
Areas of coastal grassland that is regularly flooded by seawater
125
Required conditions for mudflats to form
```
Low energy
Deposition
Sheltered area
No strong tides or currents
Where salt and freshwater meet
```
126
Define pioneering species
The first plants to colonise an area e.g. eelgrass and cordgrass
127
Define flocculation
Mud deposited close to high-tide line, dropping out of the water by flocculation where tiny particles of mud stick together such that their combined mass enables them to sink to the sea bed
128
Define halophytes
Plants that tolerate salt water - have adapted
129
Eustatic change
A global change in sea level resulting from a fall or rise in the level of the sea itself
130
Isostatic change
Local changes in sea level resulting from the land rising and falling relative to the sea
131
Causes of sea level rise
Thermal expansion and melting land ice
132
Thermal expansion
Where the volume of water increases as it gets warmer
133
When did the last glaciation end?
10 000 years ago
134
What leads to a submergence coastline?
Land sinks and sea level rise
135
What leads to an emergence coastline?
Land rise and sea level fall
136
What is a rias?
A submergence coastline feature, submerged river valleys.
137
Give an example of a rias?
Dartmoor
138
What are marine platforms/terraces?
A wave cut platform which is higher than sea level and at the base of a relict cliff
139
Give an example of a marine platform/terrace
Examples found in Scotland
140
What are dalmation coasts?
A series of river valleys next to the coast which have been filled with water leaving parallel ridges as islands
141
What are relict/fossil cliffs?
Emergent coastline feature
Weathering affects it not coastal erosion
An old cave showing features of caves etc
142
Give an example of a relict/fossil cliff
Isle of Arran, Scotland
143
What are fjords?
When a glacier retreats and the sea fills the valley floor
| Submergence coastline feature
144
Give an example of a fjord
Sognefjord, Norway
145
What is a raised beach?
Emergent feature
| Former wave cut platforms and their beaches are higher than the present coastline
146
Give an example of a raised beach
Isle of arran, Scotland
147
What is subsistence?
Coastal areas sinking due to excess ground level extraction which has the effect of making the sea level higher
148
...% of the UK manufacturing industry lies close to the coast
40
149
...million people live within the coastal zone
16.9
150
Why does the coastline need managing?
Coastal erosion
Coastal flooding
Failure of former defences
151
What's a hold the line management strategy?
Maintain current defences or build new ones to ensure coastline stays where it is
152
What's an advance the line approach?
Build new defences seaward of existing
153
What's a retreat the line (managed retreat) approach?
Allow the coastline to retreat due to flooding and erosion but closely manage rate and location of this retreat
154
The do nothing approach
Low value areas lift to natural coastal processes as not deemed viable to spend on defences
155
Social things to consider when planning management strategies
Number of people directly impacted
History and culture
Employment/unemployment levels
156
Political things to consider when planning management strategies
Voter opinion/importance
Why pays? - local/national government
relationships with other areas
157
Economic things to consider when planning management strategies
Value of infrastructure and housing
Cost of businesses in the area
Cost of defences
158
Environmental things to consider when planning management strategies
Valuable ecosystem
Is the environment common? (salt marshes are rare)
Pollution the defences will cause
Will there be damage elsewhere
159
Hard engineering strategies
```
Sea walls
Groynes
Gabions
Revetements
Barrages
Offshore reefs
```
160
Soft engineering strategies
```
Beach nourishment
Dune regeneration
Managed retreat
Land-use management
Do nothing
```
161
What is a sea wall
At the foot of a cliff or at the top of a beach, usually have a curved face to reflect waves back at into the sea
162
Advantages of sea walls
Effective prevention of erosion
| They often have a promenade for people to walk along
163
What are groynes
Built at right angles to the coast, they trap sediment being moved up the beach
164
Advantages of groynes
Work with natural processes to build up the beach with increases tourist potential and protects the land behind it
Not too expensive
165
What are revetements
Sloping structures placed at the foot of the cliff or top of beach, they break up the waves energy
166
What are offshore reefs
A partly submerged rock barrier, designed to break up the waves before they reach the coast
167
What is a cost benefit analysis?
(Carried out before a coastal management project is given the go ahead) it’s where costs are forecasted and compared with the expected benefits
168
Define tangible costs
Where costs and benefits are known and can be given a monetary value
169
Define intangible costs
Where costs may be difficult to asses but are important eg visual impact
170
Historically, cost Benifit analysis were not conducted what issues may this have caused?
Other areas nearby may be affected
It could be a waste of money
Did not consider the intangible costs
171
Define soft engineering
Works with nature and natural systems to protect the coast
172
Define hard engineering
Making a physical change to the coastline using man made materials and/or structures
173
How many SMPs (shoreline management plans) did the government create and what does this number represent?
22 (number of sediment cells)
174
What is the purpose of SMPs?
Their purpose is to avoid affects further down the coastline when protecting one stretch
175
What are ICZMs?
Integrated coastal zone management (they focus on sustainability and desires of different stake holders)
176
What are the different stakeholder groups in ICZMs?
```
Coastal residents
Local council/government
National government
Conservation groups
Local businesses
Tourists
```
177
Why are ICZMs more sustainable?
Focuses more on the future (economic and environmental effects) and by collecting information they can adapt to any changes and can make improvements
178
What are some arguments for not protecting to coast at all?
Cost benifit analysis
Environmental impact now and future
Land may not be at risk
May impact other areas negatively
179
What local coastal environment did I study?
Slapton sands
180
What are the processes found at slapton sands?
LSD
Deposition
Erosion
181
Evidence of coastal processes at work in slapton sands:
```
Barrier beach
Beach
Stack/stumps
Cove
Wave cut platform
Headland/bay
```
182
What is the name of the barrier beach found at slapton?
Slapton sands
183
What is the name of the beach at slapton?
Beesands
184
What is the name of the headland/bay at slapton?
Start point and start bay
185
What is the name of the stacks/stumps at slapton?
Dancing beggars
186
What is the name of that the cove at slapton?
Redlap cove
187
What is the name of the wave cut platform at slapton?
Limpet rocks
188
What is the fat place study I did and why?
Odisha, India because it has unique characteristics and setting
189
Where is odisha?
East coast of India
| Boarding the Bay of Bengal
190
What type of climate does India have?
Seasonal ie monsoons
191
Odisha is India’s 9th largest state by...
Area
192
Odisha is India’s 11th largest state by...
Population
193
How long is odisha’s straight coastline?
480km
194
Describe odisha’s unique ecology:
Endangered olive ridley turtles
1435km^2 of mangrove forest (rare)
Chilika Lake which is salty but fresh in monsoons
195
What is the dominant process occurring at Odisha?
Deposition so it’s a low energy coast
196
How many rivers have mouths on the Odisha coastline?
6 so most of the sediment is fluvial
197
Risks/difficulties in protecting the odisha coastline:
Increased rates of erosion
Vulnerable to storms, tsunamis, and rising sea levels
14.4% stable
198
Why has there been increased rates in erosion in odisha?
Both natural and human factors (ie protecting infrastructure as many people live by the coast so rely on it)
199
Rewards/benefits of protecting odisha’s coastline:
Potential for offshore generating of electricity
35% of coastline has resources which can be sold (eg metal deposits)
Fishing and agriculture industry vital to locals
Chilika Lake Bird Sanctuary has 159 species of bird
200
How does planting of mangroves become a defence? (Odisha)
Make waves loose energy
| Roots hold sediment together which stabilises the coast from erosion etc
201
Why does a 14.4% stability in odisha’s coastline make it difficult to protect?
Difficult to decide which strategy
Long term investment is risky
Difficult to predict changes
202
Where is Slapton Sands
Devon
203
Length and age of seawall at Torcross
319 m it was built in 1979 rebuilt in 2000 by the environment Agency
204
Height and age of sheet piling topped with concrete rocks just north of Torcross
143 m and 1979
205
Where is the 795 meter revetment built in 1979
Between Torcross and the car park
206
What protects the a 379 Road at Slapton Sands
Rock armour
207
Why has beach nourishment not been used at Slapton Sands
£1.14 million to maintain so too expensive
208
What future defences could be used at Slapton Sands
Shingle recycling
209
How much of the odisha coastline is being eroded
36.8%
210
What is affected by the accelerated rates of erosion at odisha in recent years
Habitats and coastal agriculture
211
Hazards associated with the Odisha area
Tsunamis and tropical storms
212
What is the long-term threat to the Odisha coastline
Sealevel rise
213
What has been exploited in Odisha
Fish and minerals impacting the livelihoods of coastal populations
214
Why do Tourists go to odisha
For the beaches and wildlife sanctuaries
215
What sort of energy production is there a huge potential for at odisha
Wave offshore wind and tidal energy
216
Percentage of the Odisha coastline is laden with mineral and heavy metal deposits
35%
