Cost Ai Flashcards
How do waves form?
Waves are formed by the wind blowing over the sea, causing ripples that develop into waves.
What factors determine the size of waves?
- The strength of the wind
- How long the wind blows for
- The length of water the wind flows over (the fetch)
Why does Cornwall have the biggest waves in England?
Cornwall has the biggest waves due to the fetch, as it allows the wind to blow over a longer distance.
What is wave amplitude?
Wave amplitude is the vertical height from trough to crest.
Define wavelength.
Wavelength is the horizontal distance from trough to trough (or crest to crest).
What is the movement of a wave onto the beach called?
Swash
What is the movement of a wave back into the sea called?
Backwash
What is the top of the wave referred to as?
Crest
What is the base of the wave called?
Trough
What is the vertical distance from trough to crest of a wave?
Wave amplitude
What is the horizontal distance between two crests called?
Wavelength
What is wave frequency?
The number of waves breaking per minute.
What is the first step in the sequence of events when waves break?
Waves are created by wind blowing over the surface of the sea, creating friction.
What happens to water particles as waves are formed?
The energy of the wind causes water particles to rotate, moving the wave forward.
What does the size and energy of a wave depend on?
- How long the wind blows
- The strength of the wind
What happens when a wave breaks?
Water is washed up the beach, which is called swash, and then the water runs back down the beach, which is called backwash.
What type of waves are created in storm conditions?
Destructive waves
Destructive waves are characterized by their stronger backwash and tendency to erode the coastline.
What kind of wave has a strong swash that transports sand up the beach?
Constructive waves
Constructive waves are typically formed in calm weather and help build up beaches.
What is the characteristic of the wave front in constructive waves?
Gently sloping wave front
Constructive waves have a swash stronger than backwash and are less powerful than destructive waves.
What type of wave has a steep wave front and is often associated with winter conditions?
Destructive waves
These waves have a shorter wavelength and are high and steep.
Fill in the blank: Constructive waves have a _______ wavelength.
long
Long wavelengths contribute to the gentle nature of constructive waves.
What is a key feature of destructive waves?
Strong backwash erodes beach sand
Destructive waves tend to erode the coastline due to their stronger backwash.
What type of wave is characterized by a plunging wave?
Destructive waves
Plunging waves are typically found in stormy conditions and contribute to coastal erosion.
What happens to sand during constructive wave activity?
Sand is deposited
Constructive waves help build up beaches by depositing sand.
True or False: Constructive waves are more frequent than destructive waves.
True
Constructive waves are less vigorous and occur more frequently in calm weather.
What is the characteristic of the beach associated with constructive waves?
Gently sloping beach
The gentle slope is a result of the deposition of sand from constructive waves.
What type of wave is associated with a strong backwash and erodes the coastline?
Destructive waves
Destructive waves have a backwash that is stronger than the swash.
Fill in the blank: The beach feature created by constructive waves is a _______.
Beach berm
Beach berms are formed by the accumulation of materials deposited by constructive waves.
What is a common feature of the wave crest in destructive waves?
Steep and high
Destructive waves are characterized by their steep crests.
What type of wave is typically less powerful and created in calm weather?
Constructive waves
These waves are associated with building up the beach rather than eroding it.
What is weathering?
The breakdown of rock at or near the surface caused by weather conditions such as changes in temperature.
Weathering is a key process in coastal and geological formations.
What are the three types of weathering?
- Mechanical weathering
- Chemical weathering
- Biological weathering
Each type of weathering has distinct processes and effects on rocks.
Define mechanical weathering.
The physical breakdown of rocks without changing their chemical composition.
An example of mechanical weathering is freeze-thaw action.
What is freeze-thaw action?
A process where water fills cracks in rocks, freezes, expands, and widens the cracks until a block of rock breaks off.
This repeated action contributes significantly to mechanical weathering.
What happens to the size of the crack during freeze-thaw action?
The size of the crack increases until a block of rock breaks off.
Loose blocks of rock that result from this process are known as scree.
Define chemical weathering.
A process that occurs when water reacts with calcium carbonate in rocks like limestone and chalk, causing it to dissolve and weaken the rock.
Chemical weathering can significantly alter landscapes over time.
What is biological weathering?
Weathering caused by the actions of flora and fauna, such as plant roots growing in cracks and animals burrowing into weak rocks.
This type of weathering can lead to further breakdown of rocks and soil formation.
What is mass movement?
When rocks are loosened by weathering and erosion and move down the slope under the influence of gravity
Mass movement includes processes such as sliding, slumping, and rock falls.
What causes sliding?
Large pieces of land slide down the slope quickly without any warning
Sliding occurs when the stability of the slope is compromised.
What is slumping?
Common when cliffs are made of clay, where the saturated clay slides down towards the sea during heavy rainfall
The process is characterized by a curved slip plane.
What happens during a rock fall?
Pieces of rock are continuously weathered and eroded until they separate from the cliff and fall off
Rock falls often occur from steep cliff faces.
What is the role of weathering in mass movement?
Weathering loosens rocks, making them susceptible to erosion and gravity
It is a crucial factor in the processes of sliding, slumping, and rock falls.
Fill in the blank: _______ is when large pieces of land slide down the slope quickly.
[Sliding]
Fill in the blank: _______ occurs when saturated clay slides down towards the sea.
[Slumping]
True or False: Rock falls can occur without prior weathering.
False
Weathering is essential for rock falls to occur as it weakens the rock structure.
What are the components involved in slumping?
- Head
- Scarp
- Foot
- Curved slip plane
- Toe
Each component plays a role in the mechanics of slumping.
What is the primary factor that influences mass movement?
Gravity
Gravity pulls the loosened materials down the slope.
What is the effect of heavy rainfall on slumping?
It saturates the clay, increasing the likelihood of land sliding down
Saturation reduces the cohesion of the clay material.
What is hydraulic action?
Water is forced into cracks in the rock, compressing air which blasts out when the wave retreats, forcing the rock apart.
What is abrasion in the context of erosion?
Loose rocks, called sediment, are thrown against the cliff by waves, wearing it away and chipping bits of rock off.
What is attrition?
Loose sediment knocked off the cliff by hydraulic action and abrasion is swirled around by waves, colliding and gradually getting worn down into smaller sediment.
What is solution in erosion?
Seawater dissolves material from the rock, particularly along limestone and chalk coasts where calcium carbonate is dissolved.
What are the four main types of transportation in coastal processes?
- Suspension
- Solution
- Traction
- Saltation
What happens during suspension?
Fine sediment is carried as a suspension in the water, making it look muddy or murky.
How does solution function in the transportation of materials?
Dissolved material is carried along in solution, making it invisible.
What is traction?
Larger pebbles and cobbles are rolled along the sea bed.
What is saltation?
Small pebbles are moved when one pebble hits another, causing it to bounce, which can create a chain reaction.
Fill in the blank: The process of erosion where seawater dissolves material from the rock is called _______.
[solution]
True or False: Attrition involves the rounding of sediment due to collision with other sediments.
True
What is the effect of attrition on sediment?
It makes sediment more rounded.
What is the process called that carries eroded material along the coast?
Longshore drift
What type of waves deposit more material than they remove from the coastline?
Constructive waves
Where does coastal deposition primarily occur?
In areas where the flow of water slows down
What happens to waves in sheltered bays?
They lose energy and deposit sediment
What is the term for the reduction of wave energy in bays, leading to sediment deposition?
Wave refraction
Name two types of coastal processes involved in shaping the coast.
Weathering processes and erosion
List the types of weathering processes.
- Mechanical
- Chemical
What are the types of mass movement?
- Sliding
- Slumping
- Rock falls
Name the processes of erosion.
- Hydraulic power
- Abrasion
- Attrition
- Solution
What are the methods of transportation in coastal processes?
- Traction
- Saltation
- Suspension
- Solution
- Longshore drift
Fill in the blank: Sediment is deposited in coastal areas because _______.
[waves lose energy]
True or False: Destructive waves remove more material from the coastline than they deposit.
True
What materials are typically carried by wave action to be deposited?
- Sand
- Shingle
- Pebbles
What is the result of wave energy converging on headlands?
Increased erosion
What occurs when wave energy diverges?
Sediment deposition
What influences coastal landforms?
Geology and rock type
Geological structure influences the types of landforms found at the coast.
What are faults in rock?
Cracks in rock that are lines of weakness easily carved out by the sea
Faults contribute to coastal erosion.
What is a discordant coastline?
A coastline made up of different types of rock at right angles to the sea
Some rocks in a discordant coastline are more resistant to erosion.
What is a concordant coastline?
A coastline with the same type of rock along the whole coastline
This results in a more uniform coastal landscape.
What forms headlands and bays?
Alternating bands of hard and soft rock eroded by the sea
Headlands are formed from resistant rock while bays are formed from less resistant rock.
What is the process of hydraulic action?
Air forced into the cracks in the rock, weakening them
This contributes to the erosion of soft rock.
What is abrasion in coastal erosion?
Small pieces of rock in the water grinding against the cliff
This process further erodes the cliff face.
What is left sticking out into the sea after erosion?
A headland
Headlands are formed from more resistant rock.
What is formed in a sheltered bay?
A beach
Sand is deposited in these areas due to wave action.
How are cliffs shaped?
Through a combination of erosion and weathering
Weathering is the breakdown of rocks caused by weather conditions.
What type of rock erodes easily to create gently sloping cliffs?
Soft rock, e.g., sand and clay
These types of cliffs are less steep.
What type of rock is more resistant and erodes slowly?
Hard rock, e.g., chalk
This type of rock leads to the formation of steep cliffs.
What is a wave-cut platform?
A flat area created at the base of a cliff due to erosion by waves
Wave-cut platforms form as a result of continuous erosion and weathering processes.
What role does weathering play in cliff formation?
Weathering weakens the top of the cliff
This weakening contributes to further erosion and instability.
What happens to the notch as erosion continues?
The notch increases in size
This leads to rocks breaking off and being carried away by the sea.
What is the result of the cliff above the notch becoming unsupported?
It becomes unstable
This instability can lead to the collapse of the overhanging cliff.
What process erodes the wave-cut notch?
Hydraulic action and abrasion
These processes occur primarily between the high and low tide water marks.
What happens to eroded material at the base of the cliff?
It falls to the base of the cliff and some is dragged into the sea
The backwash contributes to further erosion and smoothing.
Fill in the blank: The eroded material is smoothed into a _______.
wave-cut platform
What occurs when the wave-cut notch is eroded sufficiently?
The overhanging cliff will collapse
This is a critical point in the erosion process.
What is cliff retreat?
The process where the cliff continues to move backwards due to erosion
This process is a continuous cycle of erosion and instability.
What action opens up a large crack in coastal landforms?
Hydraulic action
Hydraulic action is the force of moving water that can erode rock.
What happens to the crack as it continues to erode?
The crack grows into a cave by hydraulic action and abrasion
Abrasion occurs when particles carried by water wear away the rock.
What is formed when the cave breaks through the headland?
A natural arch
Natural arches are created through the erosion of rock.
What occurs after the arch erodes and collapses?
A tall rock stack is left
A rock stack is a column of rock isolated by erosion.
What is the final stage of erosion in this coastal process?
The stack is eroded, forming a stump
A stump is the remnant of a stack after further erosion.
What type of landform is a beach classified as?
Depositional landform
Beaches are formed from the deposition of materials transported by waves.
What is the general characteristic of a beach?
A gently sloping area of land between the high and low water marks
The beach is usually covered by the sea during high tides.
What are the two main types of beaches?
- Sandy beach
- Pebble beach
What is the gradient of a sandy beach?
Generally shallow, almost flat
Sandy beaches have a gentle slope.
What type of waves typically form sandy beaches?
Constructive waves
Constructive waves build up beaches by depositing material.
What is the gradient of a pebble beach?
Generally steep
Pebble beaches have a more pronounced slope due to larger particles.
What type of waves typically form pebble beaches?
Destructive waves
Destructive waves erode beaches and can carry away smaller materials.
What is a berm on a beach?
A terrace/ridge that has formed above the water level at high tide
Berms are created by the deposition of materials during high-energy events.
How are berms formed?
When constructive waves transport material onto the beach by storms and spring tides
This process occurs during periods of high wave activity.
What are beaches?
Deposits of sand and shingle that lie between high and low tide levels
Beaches are formed by the action of waves and currents, which deposit sediment along the shoreline.
How are beaches formed?
By constructive waves that deposit sediment
Constructive waves have a strong swash and weak backwash, leading to the accumulation of sand and shingle.
What type of waves form steep beaches?
Powerful destructive waves
Destructive waves have a strong backwash that removes sediment, resulting in a steep beach profile.
What are sand dunes?
Large heaps/mounds of sand held together by long-rooted grasses
Sand dunes provide important habitats and protect coastal areas from erosion.
What conditions are necessary for sand dunes to form? (List at least three)
- A large flat beach
- A large supply of sand
- A strong onshore wind to move sand
- An obstacle such as driftwood for the dune to form against
These conditions facilitate the accumulation and stabilization of sand into dunes.
What is the profile of a sand dune?
Includes components such as embryo dune, fore dune, yellow dune, grey dune, dune scarp, dune slack, and beach
Each component plays a role in the overall structure and ecology of the dune system.
Fill in the blank: A _______ is a zone where sand is deposited by the swash of waves.
[swash zone]
The swash zone is critical for the movement and deposition of sand on beaches.
True or False: Sand dunes can only form on narrow beaches.
False
Sand dunes require a large flat beach for formation.
What is a storm berm?
A ridge formed by storm waves that deposit sand higher on the beach
Storm berms are part of the beach profile and can help protect against erosion.
What is the role of driftwood in the formation of sand dunes?
Acts as an obstacle for sand accumulation
Driftwood helps trap sand, allowing dunes to develop and stabilize.
What is a spit?
A long, narrow finger of sand or shingle jutting out into the sea from the land.
Spits form on coasts where there is significant longshore drift.
How do spits form?
Spits form on coastlines where there is longshore drift, and the coastline changes direction and bends sharply.
Sediment is deposited out to sea as the coastline changes.
What is the first step in the formation of a spit?
Longshore drift transports sand along the coast.
This process is crucial for the initial buildup of sediment.
What happens after sediment is deposited to form a spit?
As the deposited sediment builds up, it starts to form an extension from the land.
This extension continues to grow with ongoing sediment deposition.
What influences the shape of a spit?
Changes in wind and wave direction can cause the end of the spit to become curved.
This curvature is important for the dynamics of coastal features.
What forms in the sheltered water behind a spit?
Salt marsh forms in the sheltered water behind the spit.
Vegetation grows in these areas due to the calmer waters.
Fill in the blank: A spit is a long, narrow finger of sand or shingle _______ into the sea from the land.
[jutting out]
True or False: Salt marshes are typically found in open water areas.
False
Salt marshes form in sheltered water behind spits.
List the steps in the formation of a spit.
- Longshore drift transports sand along the coast
- Sediment is deposited out to sea
- Deposited sediment builds up to form an extension
- Changes in wind and wave direction affect the spit shape
- Salt marsh forms in the sheltered water behind the spit
What is a bar in geographical terms?
A bar is a ridge of sand or shingle across the entrance to a bay or river mouth.
What happens when a bar grows all the way across an entrance?
A stretch of water is cut off and dammed.
What is a lagoon in relation to a bar?
An area of water dammed by the bar that gradually gets infilled by deposition.
How is a bar formed?
A bar is formed as a spit grows across a bay, joining up two headlands.
Fill in the blank: A bar is formed as a spit grows across a bay, _______.
[joining up two headlands]
True or False: A bar can completely block the flow of water in a river mouth.
True
What is the county in the south west of England that features a coastline with major landforms of erosion and deposition?
Dorset
What type of beach is located at Barton-on-Sea?
Cliff with rotational slumping
Name a bay found along the Dorset coastline.
Swanage Bay
What type of landform is Sandbanks?
Beach, spit, and offshore bars
What are the major landforms located in Studland?
Bay and sand dunes
What major landform is located at Old Harry?
Stacks
What is the name of the cove found at Lulworth?
Lulworth Cove
What type of platform is found at Kimmeridge?
Wave cut platforms
What is the name of the headland/cliff located at Durlston Head?
Durlston Head
What major landform is associated with Hurst Castle?
Spit
Fill in the blank: Poole is known for its _______.
Sandy beach
True or False: The Solent is located near the Isle of Wight.
True
What major landform is associated with the cliffs at Seacombe?
Cliffs
What is the geographical feature of Lulworth that contributes to its uniqueness?
Cove
What is the name of the large bay mentioned in the text?
Swanage Bay
List three major landforms found at the Dorset coastline.
- Cliffs
- Bays
- Beaches
What is the notable feature of the Isle of Purbeck?
Old Harry (stacks)
What type of geological formation is Washing Ledge?
Wave cut platform
What is a wave-cut platform?
Flat piece of land at the bottom of the cliff.
It is formed by the erosion of the cliff by wave action.
What is Swanage Bay?
A bay along the Dorset coast.
It is characterized by its sandy beach and surrounding cliffs.
What is Old Harry?
A coastal feature known as a stack.
It is located near Swanage and is formed from erosion.
What are the characteristics of cliffs?
Steep rock faces formed by erosion.
They may have wave-cut platforms at their base.
What is a spit?
A coastal landform formed by deposition of sand.
It extends from the shore into the sea.
What is Hurst Castle Spit?
A spit located in the Dorset area.
It is a notable feature formed by coastal deposition.
What is Studland Bay?
A bay characterized by a sandy beach.
It is formed by deposition and is located on the Dorset coast.
What influences coastal landforms?
Geological structure and rock type.
Different rock types erode at different rates, affecting landform shapes.
What are the characteristics of headlands?
Protruding landforms created by erosion.
They are typically made of harder rock that resists erosion.
How are caves formed?
By erosion along the coastline.
They can develop into arches and stacks over time.
What are the characteristics of beaches?
Sandy or pebbly landforms created by deposition.
They are typically found along coastlines.
What are sand dunes?
Mounds of sand formed by deposition and wind action.
They are often found behind beaches.
What are bars?
Coastal landforms formed by deposition that connect the mainland to an island or another landform.
They can create lagoons behind them.
What coastal landforms are found on the Dorset coast?
Features such as bays, cliffs, spits, and beaches.
These are shaped by both erosion and deposition.
What is coastal management?
Controlling the development and change in the coastal zone
What are the three main options for coastal management?
- Hard engineering
- Soft engineering
- Managed retreat
What is hard engineering in coastal management?
Total protection of the present coastline
Name two methods used in hard engineering.
- Maintaining and extending existing sea defences
- Building hard structures such as sea walls
What is the purpose of rock armour?
To stop waves from reaching the coastline
What do groynes do?
Trap sand and keep the beach as wide as possible
What are gabions used for in coastal management?
To deflect wave energy
What is soft engineering?
Working with nature to help maintain the present coastline
What is beach nourishment?
Bringing sand and shingle from elsewhere to maintain beach size
What does sand dune regeneration involve?
Planting grasses, bushes, and trees to stabilise dunes
What does managed retreat mean?
Allowing the present coastline to change without intervention
What happens during managed retreat?
- No repairs to old sea defences
- Abandon the coast to the forces of nature
- Allow the tide to invade low-lying land
What is beach re-profiling?
Artificially reshaping the beach
How do sea walls work?
Reflect waves back out to sea and/or absorb their energy
What is a promenade in relation to sea walls?
A walkway built on top of the sea wall
What are the benefits of sea walls?
- Effective in reflecting wave energy
- Reduces overtopping
- Can increase tourism
What are the costs associated with sea walls?
- Expensive (£5,000 to £10,000 per meter)
- Limits beach access
- Can look unattractive
What do groynes prevent?
Longshore drift
What is a negative impact of groynes?
They can cause problems further along the coast where beaches are starved of sand
What is a positive effect of wider beaches?
Increased protection from erosion and potential attraction for tourists
True or False: Hard engineering is always the cheapest strategy.
False
What is rock armour?
Big boulders placed at the base of the cliff that absorb the energy of waves, reducing erosion.
What are gabions?
Wire cages filled with rocks used to build a wall, usually at the foot of a cliff.
How do gabions help in coastal defense?
They absorb the energy of the wave, providing greater protection from erosion and flooding.
What are the cost benefits of using gabions?
Fairly cheap in comparison with other strategies.
What is a disadvantage of gabions in strong waves?
Boulders can be moved around, requiring replacement.
True or False: Gabions blend in with natural geology.
False
What is the lifespan of gabions before they need replacing?
5-10 years.
What is beach nourishment?
Adding sand and shingle from elsewhere to the beach, usually from another local beach or the seabed.
What is the benefit of beach nourishment?
Creates wider beaches which slow the waves and provide greater protection from erosion and flooding.
What is a drawback of beach nourishment?
Needs constant maintenance as sediment can easily be washed away by the waves.
What is dune regeneration?
Restoring existing, or creating new sand dunes.
What role do sand dunes play in coastal defense?
They act as a natural physical barrier between the sea and the land.
What is a benefit of dune regeneration?
It is cheap, protects wildlife, and is popular with locals.
What is a limitation of dune regeneration?
Limited to a small area that is suitable for sand dunes.
