Coasts-The Coastal System And Processes Flashcards
What is a high energy coastline and give an example
High energy coastlines are those in which wave power is strong for a greater part of the year for example the Western coast of the British Isles
What is a low energy coastline and give an example
Low energy coastlines are those in which wave power is weak for a greater part of the year for example in, sheltered bays
What is the fetch of a wave
The horizontal distance over which wave generating winds blow
What is swash
Swash is when water runs up the beach
What is backwash
Backwash is where water is taken back to sea
Define a tide
The alternate rising and falling of the sea, usually twice in each lunar day at a particular place, due to the attraction of the moon and sun
What is hydraulic action
Hydraulic action is where a wave breaking against rocks forces air into cracks in the rock under pressure, which is released suddenly as the wave retreats.
What is corrasion/abrasion
Corrasion/abrasion is where the material carried by waves (load) is used as ammunition to wear away rocks on a cliff or a wave cut platform as they are thrown or rubbed against them repeatedly by each wave.
What is attrition
Attrition is the process by which loose rocks are broken down into smaller and rounded pebbles, which are used then in abrasion
What is solution/corrosion
Acids contained in sea water will dissolve some types of rock such as chalk or limestone
What is weathering
The disintegration and decomposition of rocks by the combined actions of the weather, plants and animals
What is regolith
The collective name for all of the material produced by weathering, extending down from the ground surface to the unaltered bed rock
What is frost shattering (or freeze thaw)
First shattering (or freeze thaw) is a form of physical weathering in rocks that contain cervices and joints, where temperatures fracture around 0’C
What is mass movement
The downhill movement of rock and soil in response to gravity. This is due to a combination of marine and weathering process
What does evaluate/assess mean?
If a questions says evaluate/assess then a well balanced argument is developed on an issue and the student is required to give their own judgement.
How would answer a justify question
Justify is the hardest command word. A decision has to be made on the most appropriate form of action on an issue, but also ensuring the potential negative consequences for this course of action are mentioned and/or dealt with. Links are made between the points you make.
How would you answer a discuss question
When answering a discuss question build up a well balanced argument on an issue which is evidenced
How do you answer an analyse question
When answering an analyse question breakdown the topic into parts and give an in depth account
How do you answer an annotate question
When answering and annotate question add to a diagram, image or graphic a number of words that describe and/or explain features, rather than just identify them (which is labelling)
How do you answer a compare question
When answering a compare question describe the similarities and differences of at least two phenomena
How do you answer a comment on question
When answering a comment on question make a statement that arises from a factual point made - add a view, or an opinion, or an interpretation. In data/stimulus response questions, examine the stimulus material provided and then make statements about the material and it’s content that are relevant, appropriate and geographical
How do you answer a contrast question
When answering a congrats question point out the differences between at least two phenomena
How do you answer a critically question and when does it occur
Critically often occurs before ‘Assess’ or ‘Evaluate’ inviting an examination of an issue from the point of view of a critic with a particular focus on the strengths and weaknesses of the points of view being expressed
How do you answer a define… what is meant by… question
When answering a define… what is meant by… question state the precise meaning of an idea or concept
How do you answer a describe question
When answering a describe question give an account in words of a phenomenon which may be entity, an event, a feature, a pattern, a distribution or a process. For example, if describing a landform say what it looks like, give some indication of size or scale, what it is made of, and where it is in relation to something else (field relationship)
How do you answer a distinguish between question
When answering a distinguish between question give the meaning of (two or more) phenomena and make it clear how they are different from each other
How do you answer an examine question
When answering an examine question consider carefully and provide a detailed account of the indicated topic
How do you answer a explain… why…, suggest reasons for… question
When answering a explain… why…, suggest reasons for… question set out the causes of a phenomenon and/or the factors which influence its form/nature. This usually requires an understanding of processes
How do you answer an interpret question
When answering an interpret question give meaning to geographical information and issues
How do you answer an outline…, summarise… question
When answering an outline…, summarise… question provide a brief account of relevant information
How do you answer a to what extent… question
When answering a to what extent… question form and express a view as to the merit or validity of a view or statement after examining the evidence available and/or different sides of an argument
Name 4 inputs within a coastal system
4 inputs within a coastal system are:
- Wave energy
- Geological structure
- Weathering
- Human activity including climate change
Name 4 processes/flows within a coastal system
4 processes/flows within a coastal system are:
- Process of wave erosion
- Mass movement
- Transport
- Hard/soft engineering
Name 4 stores with a coastal system
4 stores within a coastal system are:
- Landforms of erosion
- Landforms of deposition
- Coastal defence-holing the line or retreat
Name an output within a coastal system
the transfer of sediment into the sea is an output within a coastal system
What are free effects of the North Sea storm surge of 1953
3 effects of the North Sea storm surge of 1953 were:
- 1,836 deaths
- 47,300 buildings destroyed
- 30,000 animals drowned
What 2 major schemes were built in response to the North Sea storm surge of 1953
The 2 major schemes built in response to the North Sea storm surge of 1953 were:
- Delta works
- Thames flood barrier
What are the 4 sources of coastal sediment
The 4 sources of coastal sediment are:
- Rivers
- Seabed
- Erosion of coastline
- Shell material
Where do sediment movements occur and why
Sediment movements occur in distinct areas, within which inputs & outputs are in balance.
How many sediment cells are in England & Wales
In England & Wales, there are 11 of these cells.
How are sediment cells separated
Sediment cells are separated from each other by well-defined boundaries such as headlands and stretches of deep water.
Can sediment cells vary in size
Sediment cells can vary in size
What are larger sediment cells divided into and give an example
The larger sediment cells are divided into smaller sections called subcells. An example of this is the one that operated between Flamborough Head and the Humber Estuary
What causes a wave to form
A wave is formed because of wind blowing over the surface of the sea
Wave energy is controlled by what 3 factors
Wave energy is controlled but these 3 factors:
- Force of the wind and its direction
- The duration of wind
- The fetch of the wave
Why do waves grow taller as they approach the shore
Waves grow taller as they approach the shore because the water is very shallow, so the wave spills forward as a breaker
What type of waves have the longest wavelength and why
Constructive waves have longer wavelengths than destructive as they are less frequent
Which wave type has a lower height and why
Constructive waves have a lower height than destructive waves as they have a smaller fetch.
Which wave types the most frequent and why
Constructive waves are less frequent than destructive waves as they have a longer wavelength.
How frequent a constructive waves
There are 6-8 constructive waves per minute
How many destructive waves are there per minute
There are 10-14 destructive waves per minute
How often do tides happen in the UK
In the UK, the interval between each high tide is 12 hours and 25 minutes
Explain how a tide happens
Tides are caused by the gravitational pull of the moon and to a lesser extent the sun, usually resulting in two high tides and two low tides each day
When do spring tides occur and why and what do they cause
Spring tides occur when the sun, moon and earth are in a straight line, which happens twice a lunar month when the gravitational pull is strongest. It causes the high tide to be at its highest point and the low tide to be at its lowest
How often do neap tides occur and why and what do they do
Neap tides happen during the alternate week in the lunar month when the earth, moon and sun form a right angle, lessening the overall gravitational pull and giving a lower tidal range
Give 2 reasons why tides are an important influence at a coast
- If there is a small tidal range the power of the waves (and hence erosion) is concentrated on a relatively narrow element of coastline, such as a cliff base.
- If there is a large tidal range, large parts of beach can become exposed at low tide. When this sand dries onshore winds can blow the sand to create sand dunes inland.
What is cavitation and when does it occur and how and what does it do
Cavitation occurs when air bubbles trapped in the fast moving water collapse, causing shock waves to break against the rocks under the water. Repeated shocks of this nature are thought to weaken the rock
If you looked down on a coastline from above and saw the geology of the area the what would you see and what does that tell you
If you looked down on a coastline from above and saw the geology of the area, you’d be able to see that the rock type changes as you approach the coastline and that the different rock are arranged in bands. The angle these bands make with the coastline makes it either a concordant or discordant coastline
What is a concordant coast and give an example
Concordant coasts have alternating layers of hard and soft rock that run parallel to the coast. The hard rock acts as a protective barrier to the softer behind it preventing erosion. If the hard rock is breached though the soft rock is exposed and a cove can form (e.g. Lulworth Cove)
What is a discordant coastline and give an example
On a discordant coastline, alternating layers of hard and soft rock are perpendicular to the coast. Because the soft rock is exposed, it’s eroded faster than the hard rock. This differential creates headlands and bays (e.g. Flamborough Head) along discordant coast lines
Explain the role of coastal shape on the rate of erosion, use an example
Headlands of a coastline are exposed to the full force of destructive waves. Bays are more sheltered from the wave energy because of wave refraction, so erosion is slower, an example of a place where this happens is Flamborough Head
Explain salt weathering
Salt weathering:
- Rock become saturated with water containing salt (usually in coastal environment)
- Some of the salt crystallises and begins to exert pressure on the rock because the salt crystals are larger than the spaces in which they are formed
- Like frost shattering the process repeats over time, causing the disintegration of the rock
What is mass movement and how does it occur
Mass movement is the downhill movement of rock and soil in response to gravity. This is due to a combination of marine and weathering processes
What are the 5 types of mass movement
The 4 types of mass movement are: Landslide Mudflow Rockfall Slumping/rotational slip Soil creep
What are the 5 ways the sea transports derided material
The 5 ways the sea transports eroded material are:
Longshore Drift
Traction
Solution
Suspension
Solution
Where does the sea deposit material give 3 examples
The sea deposits material when it meets at breakwaters like a river, headland or groyne
How does the sea deposit material at a headland or groyne
The sea deposits material when it meets a headland or groyne, as the sea cannot carry it any further
How does the sea deposit material at a river
The sea deposits material when it meets a river, as the rivers current stops the sea from carrying the material further. As well when the sea meets a river, saltwater meets freshwater which results in a chemical reaction resulting in the sediment to be deposited
