Coastal Landscapes and Change Flashcards
1
Q
What is the littoral zone and what are its four subdivisions in order
A
The coastal zone in which sediments are moved around between the land, beach and sea
It consists of the offshore, the nearshore, the foreshore and the backshore
2
Q
What are the four types of coasts classified by advancing or retreating
A
Emerging Coast (Advancing Coast)
Submerging Coast (Retreating Coast)
Outbuilding Coast (Advancing Coast)
Eroding Coast (Retreating Coast)
3
Q
What the the following characteristics of high energy coasts?
Wave Characteristics: (1)
Processes: (3)
Landforms: (6)
General Location: (3)
A
- Wave Characteristics: Destructive
- Processes: Erosion and transport, mass
movement, weathering - Landforms: Cliffs, wave-cut platforms, caves, arches, stacks, stumps
General Location: Rocky landscapes, highland and lowland coasts, exposed to largest waves
4
Q
What the the following characteristics of low energy coasts?
Wave Characteristics: (1)
Processes: (2)
Landforms: (5)
General Location: (3)
A
- Wave Characteristics: Constructive
- Processes: Deposition and transport, longshore drift
- Landforms: Beaches, spits, bars, sand dunes, salt marshes
- General Location: Coastal plain landscapes, lowland coasts, sheltered from largest waves
5
Q
Name the 4 types of inputs of the coastal system
A
- Marine: Waves, tides, storm surges etc
- Atmospheric: Climate change, weather/climate
- Land: Rock type, tectonic activity
- People: Human activity, coastal management
6
Q
Name 5 main processes in the coastal system (Think GCSE)
A
- Erosion
- Weathering
- Mass Movement
- Transport
- Deposition
7
Q
What are the 3 factors affecting the energy of a wave
A
- Wind Speed
- Wind Duration
- Fetch (distance the wave has moved)
8
Q
Why do tides exist
A
The sea is affected by the gravity of the sun and the moon (mostly the moon as its closer) so the water is pulled towards the moon which depending on the position of the moon tides are either high or low
9
Q
What is a spring tide and what is a neap tide
A
A spring tide is the highest point a tide will go and occurs twice a lunar month when the sun earth and moon perfectly line up
A neap tide is the lowest point a tide will go and occurs twice a lunar month when the sun and earth moon perfectly form a right angle
10
Q
how long is a lunar month
A
Approximately 29.5 days
11
Q
Why do some places have such different tidal ranges compared to others
A
The shape of the coastline and its position on Earth can affect how much variation in tides there are
12
Q
Name one place with a low tidal range and one place with a high tidal range and the effect of the tides on their coastlines
A
A place with a low tidal range is the Mediterranean which causes there to be limited wave action and erosion
A place with a high tidal range is the UK which causes there to be much more coastal erosion
13
Q
What is a sediment cell
A
A section of a coastline where sediment moves between the beaches, cliffs and sea. Cells are usually divided by a physical barrier like a large headland which prevents most movements of sediment between cells
14
Q
How many major sediment cells are there in England and Wales
A
11 (with subsections eg 5d, 5e, 5f etc)
15
Q
Are sediment cells closed systems
A
Sediment cells are mostly closed systems but small amounts of sediment movement in or out is inevitable
16
Q
Give an example of a minor sediment cell around the UK
A
South Isle of Wight (sediment moves from the destructive Needles coastline to the constructive Sandown Bay coastline)
17
Q
Why do waves break (4)
A
- Waves usually move forwards in a circular motion (water at the top of the wave goes to the bottom and vice versa)
- When waves get close to the coastline they make contact with the seabed which exerts friction onto the wave
- This leads the wave to move from a circular motion to an elliptical one
- Over time the friction increases to the point where the crest of the wave tips over the front which is a wave breaking
18
Q
What is the difference between geology and lithology?
A
Geology is the study of the classification of rocks and their origion
Lithology is the study of physical properties of rocks, such as their texture or features
19
Q
What is Strata
A
Thin layers of (usually) sedimentary rock formed at the Earth’s surface which each have internally consistent characteristics which distinguish it from other layers
20
Q
What are Bedding Planes
A
Horizontal Cracks dividing rocks which signify a change in the depositional conditions which affect the formation of each distinct layer of sediment
21
Q
What is a possible depositional change that can occur and create bedding planes
A
Floods or severe storms
22
Q
What are Joints
A
Vertical cracks in rocks which often pull away from each other
23
Q
What are Folds
A
When layers of rocks or strata are permanently bent or curved as a result of pressure or tectonic activity
24
Q
What are Faults
A
A crack in the crust of the Earth; often form tectonic plate boundaries
25
What is the Dip of a rock
The angle at which the Strata lies (eg diagonally, horizontal, vertical)
26
What are the three main categories of mass movement
- Flows
- Slides
- Slumps
27
What are the 3 types of flows in mass movement
- Soil Creep (long term downhill movement of soil particles)
- Solifluction (In tundra areas where the ground is frozen, when the top layer of soil thaws but the rest doesn't, the top layer flows downhill over the rest of the soil)
- Earthflows/Mudflows (An increase in water, usually from rain, reduces friction which can make earth and mud flow downhill easier)
28
What are the two types of slides in mass movement
- Rock Fall (When weathering weakens a rock causing it to fall out of a cliff)
- Rock Slides (When rocks slide downhill as a result of rainfall reducing friction, more susceptible in rocks with joints or bedding planes)
29
What are slumps in mass movement
When soft material like clay or sands slide down harder rock like granite in a rotational movement
30
What is the different between flows, slides and slumps
Flows are unique as all the material is mixed and jumbled whereas in a slide or slump the material remains intact
Slumps are unique because it has a rotational movement
31
What are the three types of weathering
Biological, Chemical, Mechanical
32
Name the two categories of landforms that form as a result of coastal processes (aka the outputs in the coastal system)
- Erosional Landforms (eg caves)
- Depositional Landforms (eg beaches)
33
Give 3 fixed factors influencing the rate of erosion
- Geology
- Lithology
- Exposure
34
Give 3 variable factors influencing the rate of erosion
- Storms
- Wind Direction
- Season
35
Describe the formation of wave cut notches and wave cut platforms
Waves erode at the high tide line at the bottom of a cliff, breaking away a gap in the cliff called a wave cut notch.
Over time the wave cut notch will get larger until it causes the cliff above it to collapse.
The part of the cliff just under the wave cut notch will remain.
The process continuously repeats itself causing the cliff to retreat but leaving the platform under where all the wave cut notches are forming a wave cut platform which is usually only exposed at low tide
36
What type of coastline allows for the creation of headlands and bays and why
Discordant - it has alternating bands of hard and soft rock
37
Describe the formation of headlands and bays
Found on discordant coastlines with alternating bands of hard and soft rock. The soft rock erodes quicker causing coastline retreat while the hard rocks are more resistant which means they don't erode. This causes headlands to stick out and experience the bulk of wave power while bays often become tucked between headlands where they are often more sheltered from destructive waves
38
Describe the formation of caves arches stacks and stumps
Found on narrow peninsulas such as headlands. Erosion takes place on either side of a headland forming small caves on either side within the headland. Eventually, the caves meet up causing a hole to pass through the whole headland which creates an arch. Eventually the bridge over the top of the arch collapses, retreating the headland and leaving a stack which erodes over time until it collapses leaving a stump
39
What are the four methods of coastal transportation
- Traction (big rocks rolling across seabed)
- Saltation (small rocks bouncing across seabed)
- Suspension (small sediment which floats)
- Solution (dissolved into water)
40
What are the two types of deposition
- Gravity Settling: A decrease in energy causes water to drop the sediment
- Flocculation: When particles in suspension such as clay will coagulate or clump together over time until it is too heavy to carry so it is deposited
41
What direction is most longshore drift in the South UK and why
West to East
Longshore drift follows the direction of the prevailing winds which are usually the southwesterlies
42
What is a spit
When a coastline changes direction, longshore drift will still continue moving beach sediment in the same direction which causes it to extend out into the sea or a river estuary
43
What is a recurved spit
When a spit extends into a river estuary, once it reaches the actual flow of the river the spit can't go any further so it bends back on itself slightly
44
What is a bayhead beach
A beach formed in the innermost part of a bay by deposition
45
What is a barrier beach / bar
A spit that extends all the way across a gap which traps a lagoon behind it
46
What is a barrier island
When a barrier beach becomes detached from the mainland
47
What is a tombolo
A beach that stretches out into the sea to connect the mainland to an island
48
What is a cuspate foreland
A triangular shaped coastline where longshore drift happens in two directions causing sediment to be deposited at the point where the two longshore drift patterns meet up
49
What is the difference between concordant and discordant coastlines
concordant coastlines run parallel to the coast whereas discordant coastlines run perpendicular to the coast
50
Name two types of concordant coastline and an example of each
Dalmatian Coastlines - When tectonic activity creates folds in the land making valleys parallel to the coast, which become flooded by sea level rise creating the impression of islands running parallel to the coast (Croatia)
Haff Coastlines - Long sediment ridges often topped by sand dunes that over time act like a bar, trapping a parallel lagoon behind it (Kaliningrad)
51
Describe the formation of Coves
Formed on concordant coastlines where the nearest band of rock to the sea is hard rock. If there are any faults or joints exposed in the rock then the hard rock will be eroded until the coast reaches the soft rock in the layer behind. This layer will erode far quicker as it is less resistant, forming a large cove out of the soft rock with only a small and narrow hard rock entrance
52
Why are many depositional features unstable
They are usually made of sand and shingle and are therefore loose and easy to erode and transport
53
What are sand dunes and what is the sand dune stabilisation process called
A landform made of wind-blown sand
- it is stabilised by plant succession
54
Describe Plant Succession
1. Bare ground is gradually colonised by pioneer species such as Marram Grass who are capable of existing in such unstable environments
2. The pioneer species' roots bind the sand with their roots and add nutrients when they die creating humus making it more habitable for other species
3. Creeping plants which have leaves colonise the sand dune which helps keep moisture in the sand making it even more habitable
4. The new invaders are large enough to provide shade and improve the soil
5. As the sand becomes more and more habitable it allows more and more plants to grow until the plant succession stabilises
6. The final community to colonise the sand dune is called the climax community (trees)
55
What are the six "zones/stages" of sand dune succession
1. Embyro Dunes - Difficult to survive and only colonised by very few pioneer species such as Marram grass, otherwise yellow sand
2. Mobile Dunes - Many large areas of yellow sand but more Marram grass than before
3. Semi-fixed Dunes - Some sand (with a greyish tinge) but lots of plant coverage
4. Fixed Dunes - little Marram Grass but mostly been outcompeted by other thriving species. Almost full vegetation cover
5. Dune Slacks - Where the sand dips from erosion or wind blowouts which often forms a depression in the dune
6. Climax - Fixed Dunes and Dune Slacks reach the climax community when trees grow
56
As dunes age how does the humus and moisture content in the ground change?
It increases
57
As dunes age how does the ground pH change?
Becomes more acidic
58
What is a halosere
A plant succession in saline environments like salt marshes
59
What is a salt marsh
A coastal environment between land and open saltwater which is characterized by its salt resistant vegetation
60
What are the three prerequisites for the beginning of the formation of a salt marsh
- Minimal Wave Action/Protection from Waves (to create a calm environment)
- The right elevation to be submerged at spring tide and above water at neap tide
- A source of mud from either the sea or a river
61
Describe the halosere in a salt marsh
1. Over time, mud builds up from intake of sediment by rivers or the sea until it is at about the mean high tide level
2. This means it can stay above water for a few days at a time which gives it long enough for pioneer species such as Spartina to germinate and begin to colonise the mud
3. The roots of the pioneer species help bind and stabilise the mud while the top of the plants help trap more sediment (up to 10cm of mud a year) which further increases the mud height. These plants act as shelter and food for animals and when they die their roots remain in the mud keeping it binded
4. As the mud height increases, other pioneer species and some flowering plants begin to migrate to the area and all these species contribute humus to the ground.
5. The mud height reaches a point where the surface is out of the water long enough to allow new species such as Salt Marsh Grass to grow. Both the pioneer species and new species thrive and grow to cover more area
6. By this point the mud is high enough for a wide variety of new species which can be categorised into opportunistic species and equilibrium species - the pioneer species can't compete and die out
7. The new species compete with each other and eventually a few dominant species triumph creating ecological stabilisation - the mud height stops growing and is at the point where it is only flooded once or twice a year
62
What may some older salt marshes turn into
Scrubland or eventually woodlands
63
What is 'immersion' in relation to salt marshes
The process of the marsh being flooded
64
What is the difference between eustatic and isostatic
eustatic refers to a change in the sea level because of the sea itself
isostatic refers to a change in the relative sea level because of a movement of land relative to the sea
65
During interglacial times there is a eustatic sea level ____ (because ____) and during glacial times there is a eustatic sea level ____ (because ___)
During interglacial times there is a eustatic sea level rise (because of thermal expansion and melting ice) and during glacial times there is a eustatic sea level fall (due to water freezing)
66
What is the term for land rising that was previously weighed down by glacial sheets in the ice age
Isostatic Rebound
67
How does isostatic rebound affect the UK
As Scotland and North England were previously under an ice sheet during the ice age, it is now rising from the isostatic rebound
68
What is a ria
An upland river valley that has been flooded after a rise in sea levels
69
What is a fjord
An upland ex-glacial valley than has been flooded after a rise in sea levels
70
What is a raised beach
A former beach that is now comfortably above sea level due to eustatic or isostatic changes
71
What is a raised cliff
Cliffs often found behind raised beaches that were once in contact with the sea but no longer are due to eustatic or isostatic changes. They often have wave cut notches
72
What are 3 economic benefits of rias
- Trade
- Ship Harbour/Repair
- Tourism for Watersports/Sightseeing
73
Name 5 examples of hard engineering in Shoreline Management
- Recurved Sea Walls
- Revetments
- Groynes
- Rip Rap
- Offshore Breakwater
74
What is a recurved sea wall
A sea wall usually made out concrete that is curved in order to reflect the majority of wave energy away
75
What are 2 advantages and 2 disadvantages of recurved sea walls
Advantages:
- Effective at limiting erosion
- Can act as a promenade for people to walk on
Disadvantages:
- Very expensive to build and maintain (£6000 per metre to build)
- Can look ugly reducing tourism
76
What are revetments
Sloping structures on a beach or cliff foot made out of wood, rock or concrete which absorb the impact of wave erosion
77
What is an advantage and 2 disadvantages of revetments
Advantage:
- They are relatively cheap to build (£4000-4500 per metre)
Disadvantages:
- Expensive to maintain
- Can look ugly reducing tourism
78
What are groynes
Wooden or rock structures placed perpendicular along the beach to prevent longshore drift
79
What are 2 advantages and 2 disadvantages of groynes
Advantages:
- Can build up parts of the beach increasing tourism potential
- Not too expensive
Disadvantages:
- Oftentimes starves certain parts of the beach from sediment movement which can increase erosion in those areas
- Can be ugly
80
What is rip rap
Large rocks or boulders placed at the foot of a cliff
81
What are 2 advantages and 2 disadvantages of rip rap
Advantages:
- Cheap
- Useful as a spot to sunbathe or fish
Disadvantages:
- Can look ugly
- Can be dangerous to climb
82
What is offshore breakwater
Placing a partially submerged rock barrier in the ocean to break up the waves before the reach the coast
83
What is 2 advantages and two disadvantages of offshore breakwater
Advantages:
- Cheap
- Effective at reducing erosion
Disadvantages:
- Ugly
- Navigation hazard
84
Name 5 soft engineering strategies in Shoreline Management
- Beach Nourishment
- Cliff Regrading
- Cliff Drainage
- Dune Stabilisation
- Marsh Creation
85
What is beach nourishment
The addition of sand/pebbles to a beach to increase its height or width
86
What are 3 advantages and a disadvantage of beach nourishment
Advantages:
- Cheap
- Looks natural and blends in
- Larger beach creates more tourism possibly
Disadvantages:
- Maintenance is not expensive but has to be done extremely often as sediment is lost in erosion or longshore drift
87
What is cliff regrading
- Altering the angle of the cliff in order to stabilise it and make it less vulnerable to collapsing
88
What is an advantage and disadvantage of cliff regrading
Advantage:
- Useful for clay or loose rock coasts where other soft methods don't work
Disadvantage:
- Altering the cliff angle involves removing part of it, making it essentially a form of cliff retreat
89
What is cliff drainage
Removing water in cliffs to reduce the chance of landslides and slumping
90
What is an advantage and disadvantage of cliff draining
Advantage:
- It is cost effective
Disadvantage:
- Drying the cliff too much increases the chance of rock fall
91
What is dune stabilisation in SMPs
Fencing off areas and planting marram grass in them to bind sediment and stabilise a dune area to make it more erosion resistant
92
What are 3 advantages and 2 disadvantages of dune stabilisation in SMPs
Advantages:
- Maintains a natural coastal environment
- Provides important wildlife habitats
- Cheap and sustainable
Disadvantages:
- Time-consuming to plant marram grass and wait for it to grow
- People may not be happy about having the area fenced off
93
What is marsh creation in SMPs
Allowing low lying areas by the sea (oftentimes farms) to become flood and eventually become a salt marsh
94
What are 3 advantages and 2 disadvantages of marsh creation in SMPs
Advantages:
- Cheap
- Creates a natural defence against further inland areas
- It creates an important wildlife habitat
Disadvantages:
- Agricultural land can be lost
- Local farmers may need to be compensated
95
What is the difference between adaptation and mitigation in regards to climate change
Adaptation is finding ways to lessen the impacts of change
Mitigation is finding ways to reduce the change itself
96
Name 6 stakeholders that would care about coastal management plans
- Residents
- Environmental Groups
- Local Government
- National Government
- Local Businesses
- Tourists
97
What is an ICZM
Integrated Coastal Zone Management - The idea of coastal management being done in complete sections covering entire sediment cells rather than individual towns or councils doing it for themselves
98
Why is ICZM more logical than having each place manage their coasts indivually
One SMP in one place can have an adverse effect in another place so ICZMs ensure no places are negatively impacted by other areas.
99
What does SMP stand for
Shoreline Management Plan
100
What are the 4 categories of SMPS
- Advance the Line
- Hold the Line
- Managed Retreat
- Do Nothing
101
bangladesh cyclone sidr
maldives
holderness
swanage
happisburgh
102
3 reasons why Bangladesh's location makes it vulnerable to flooding
- Relatively low development
- 80 million people live within 10m of sea level
- Bangladesh lines on the floodplains of many large rivers including the Ganges
103
What month was Cyclone Sidr
November 2011
104
What was a social, economic and environmental impact of Cylcone Sidr
S: 3447 - 15,000 deaths
Ec: $2.31 billion of damage
En: 25% of Sundarbans Mangrove Forest damaged
105
What has Bangladeshi citizens being doing in recent years which increases its flood risk
Destroying large areas of mangrove forest (The Sundarbans) ,which is naturally good at reducing flood impacts, to make space for things such a shrimp farms
106
Why is the Maldives at threat from sea level rise
It is extremely low lying - it averages only 1m above sea level and its maximum elevation is 2.4m
107
Why are Maldivian jobs at risk
They are often reliant on tourism and fishing which are threatened by rising sea levels
108
What is the Maldives doing within the country to protect itself from rising sea levels
- Building higher up 'fortress' islands
- Relocating population away from the lowest islands to higher up ones
- Building sea walls for the most populated islands
109
What long term solution outside the country is the Maldives doing to try and protect its citizens
Inquiring into purchasing land in India, Sri Lanka or Australia and permanently resettle the population
110
What are 3 reasosns why the Holderness Coast experiences more erosion than many places
- Geology (lots of soft rock like boulder clay and chalk)
- Fetch
- Longshore Drift out of the area
111
Holderness Coast has receded _km since Roman Times and lost __ villages to cliff retreat
Holderness Coast has receded 4km since Roman Times and lost 29 villages to cliff retreat
112
What do subaerial processes include
weathering and mass movement
113
which 2 subaerial processes are particularly common at the Holderness Coast
freeze thaw weathering and slumping
114
6 stakeholders in Holderness Coast
- Residents and business owners who want homes protected
- Farmers who want land protected
- Tourism industry like campsite owners want greater coastal protection
- Environmentalists who want to protect Spurn Head
- Local Gov
- National Gov
115
What management scheme was applied in the Holderness Coast
ICZM
116
