Coatal Systems And Landscapes - PMT Essential Notes Flashcards
(198 cards)
1
Q
What is the coastal system defined as?
A
An open system that receives inputs from outside and transfers outputs away from the coast
Inputs and outputs can include terrestrial, atmospheric, or oceanic systems.
2
Q
What are sediment cells?
A
Sections of coasts bordered by prominent headlands where sediment movement is contained
They act in dynamic equilibrium which can be disrupted by human interventions or natural variations.
3
Q
What are the three main areas of coastal inputs?
A
- Marine: Waves, Tides, Salt Spray
- Atmosphere: Sun, Air Pressure, Wind Speed and Direction
- Humans: Pollution, Recreation, Settlement, Defences
4
Q
What are the outputs of the coastal system?
A
- Ocean currents
- Rip tides
- Sediment transfer
- Evaporation
5
Q
What are stores/sinks in the coastal system?
A
- Beaches
- Sand Dunes
- Spits
- Bars and Tombolos
- Headlands and Bays
- Nearshore Sediment
- Cliffs
- Wave-cut Notches
- Wave-cut Platforms
- Caves
- Arches
- Stacks
- Stumps
- Salt Marshes
- Tidal Flats
- Offshore Bands and Bars
6
Q
What processes link inputs, outputs, and stores in the coastal system?
A
- Wind-blown sand
- Mass-movement processes
- Longshore drift
- Weathering
- Erosion
- Transportation
- Deposition
7
Q
What are tye types of erosion in the coastal system?
A
- Hydraulic Action
- Corrosion
- Attrition
- Abrasion
8
Q
What are the forms of transportation in the coastal system?
A
- Bedload
- In suspension
- Traction
- In solution
9
Q
What are the types of deposition in the coastal system?
A
- Gravity Settling
- Flocculation
10
Q
What drives the transfers and flows in the coastal system?
A
- Wind
- Gravitational
- Flowing Water
11
Q
True or False: Sediment cells can contain smaller subcells.
A
True
12
Q
What accounts for the majority of sediment in the coastal zone?
A
Rivers account for the majority of sediment in the coastal zone.
Sediment may be deposited in estuaries which are brackish and important wildlife habitats.
13
Q
What is the significance of cliff erosion?
A
Cliff erosion is particularly important in areas with unconsolidated cliffs because these cliffs are easily eroded, leading to rapid coastal recession and significant sediment input into the marine environment
Cliff erosion is very important in areas with unconsolidated cliffs that are eroded easily. Most erosion occurs during the winter months due to more frequent storms.
14
Q
How does wind contribute to sediment transport?
A
Wind is a coastal energy source that can cause sand to be blown along or up a beach.
Sediment transport by winds may occur where there are sand dunes, or in glacial and desert environments which provide sediment inputs.
15
Q
What role do glaciers play in sediment deposition?
A
Glaciers can flow directly into the ocean, depositing sediment that was stored in the ice when they calve.
16
Q
How is sediment transferred to the coastal zone?
A
Sediment is transferred to the coastal zone when waves, tides, and currents erode offshore sediment sinks such as offshore bars.
The sediment is transported onto the beach, helping to build up the beach.
17
Q
What is longshore drift?
A
Longshore drift is the movement of sediment along the beach due to prevailing winds that alter the direction of the waves.
This allows sediment to be transported from one section of coastline (as an output) to another stretch of coastline (as an input).
18
Q
What is a sediment budget?
A
Sediment budgets use data of inputs, outputs, stores, and transfers to assess the gains and losses of sediment within a sediment cell.
19
Q
What is the principle of dynamic equilibrium in sediment budgets?
A
In principle, a system will operate in a state of dynamic equilibrium where input and outputs of sediment are equal.
However, human actions and natural variation in the system can disrupt the state of equilibrium.
20
Q
What is the littoral zone?
A
The littoral zone is the area of land between the cliffs or dunes on the coast and the offshore area that is beyond the influence of the waves.
21
Q
What factors cause changes in the littoral zone?
A
The littoral zone is constantly changing because of short-term factors like tides and storm surges,
and long-term factors like changes in sea level and human intervention.
22
Q
What is the primary source of energy for all natural systems?
A
The sun is the primary source of energy for all natural systems.
23
Q
What is the main energy source at the coast?
A
The main energy source at the coast is from waves which are formed offshore.
24
Q
How do waves form?
A
Waves form when wind moves across the surface of the water, causing frictional drag which creates small ripples and waves.
25
What happens to water particles as waves approach the coastline?
As the seabed becomes shallower towards the coastline, the orbit of the water particles becomes more elliptical, leading to horizontal movement of the waves.
26
What changes occur to wave height, wavelength, and wave velocity as waves approach the shore?
The wave height increases, but the wavelength and wave velocity both decrease.
27
What causes a wave to break?
Water backs up from behind the wave until the wave breaks (collapses) and surges up the beach.
28
What factor affects wave energy related to wind strength?
The larger the pressure gradient between two areas, the stronger the winds, resulting in stronger waves.
29
How does the duration of wind affect wave energy?
If the wind is active for longer periods of time, the energy of the waves will build up and increase.
30
What is the fetch in relation to wave energy?
The fetch is the distance over which the wind blows; the larger it is, the more powerful the waves will be.
31
What are constructive waves?
Constructive waves act to build up and create a beach and increase its size.
32
What are destructive waves?
Destructive waves act to remove the beach and decrease its size.
33
How are constructive waves formed?
Constructive waves are formed by weather systems that operate in the open ocean.
34
How are destructive waves formed?
Destructive waves are formed by localized storm events with stronger winds operating closer to the coast.
35
What is the wavelength of constructive waves?
Constructive waves have a long wavelength.
36
What is the wavelength of destructive waves?
Destructive waves have a short wavelength.
37
What is the frequency of constructive waves?
Constructive waves have a frequency of 6-9 per minute.
38
What is the frequency of destructive waves?
Destructive waves have a frequency of 11-16 per minute.
39
What are the wave characteristics of constructive waves?
Constructive waves are low waves, which surge up the beach.
40
What are the wave characteristics of destructive waves?
Destructive waves are high waves, which plunge onto the beach.
41
What are the swash characteristics of constructive waves?
Constructive waves have strong swash and weak backwash.
42
What are the swash characteristics of destructive waves?
Destructive waves have weak swash and strong backwash.
43
Where do constructive waves occur?
Constructive waves occur on gently sloped beaches.
44
Where do destructive waves occur?
Destructive waves occur on steeply sloped beaches.
45
What type of waves dominate in summer and winter in a coastal environment?
Constructive waves dominate in summer, while destructive waves dominate in winter.
46
Can constructive waves become destructive waves?
Yes, constructive waves may become destructive waves if a storm begins.
47
How might climate change affect storms in the UK?
Climate change may increase the storm frequency within the UK.
48
What impact can coastal management have on wave types?
Coastal management may affect the type of waves that occur.
49
What is the relationship between constructive waves and beach profile?
The presence of constructive waves causes deposition on the beach, leading to a steeper beach profile.
50
How do steeper beaches influence wave types?
Steeper beaches favour the formation of destructive waves, which are then more likely to occur.
51
What happens to the beach profile during summer and winter?
The beach profile is more gentle in summer and steeper during winter when destructive waves are more common.
52
What is tidal range?
The difference in height between the tides is known as the tidal range.
53
What creates a spring tide?
The highest high tide and the lowest low tide occur when the sun and the moon are in alignment.
54
What creates a neap tide?
The lowest high tide and the highest low tide occur when the sun and the moon are perpendicular to each other.
55
What are rip currents?
Rip currents are powerful underwater currents occurring close to the shoreline when plunging waves cause a buildup of water.
56
What is the effect of rip currents in coastal environments?
Rip currents are an energy source and can lead to outputs of sediment from the beach area.
57
What characterizes high-energy coastlines?
High-energy coastlines are associated with powerful waves, large fetch, rocky headlands, and frequent destructive waves.
58
What is the erosion-deposition relationship in high-energy coastlines?
High-energy coastlines are often eroding as the rate of erosion exceeds the rate of deposition.
59
What characterizes low-energy coastlines?
Low-energy coastlines have less powerful waves, occur in sheltered areas, and are often sandy.
60
What is the erosion-deposition relationship in low-energy coastlines?
In low-energy coastlines, the rates of deposition exceed the rates of erosion.
61
What is wave refraction?
Wave refraction is the process by which waves turn and lose energy around a headland on uneven coastlines.
62
What happens to wave energy during wave refraction?
The wave energy is focussed on the headlands, creating erosive features in these areas.
63
What occurs in bays during wave refraction?
The energy is dissipated in bays, leading to the formation of features associated with lower energy environments such as beaches.
64
How does erosion relate to rock strength?
Erosion leads to the formation of headlands where resistant rock exists and bays where unconsolidated rocks and clays are dominant.
65
What is the effect of wave refraction on headlands and bays?
Wave refraction dissipates wave energy, increasing erosion on headlands and reducing it in bays.
66
What is the outcome of headlands being worn away?
Eventually, the headlands are worn away, which then again increases erosion within the bays.
67
What is corrasion?
Corrasion is when sand and pebbles are picked up by the sea from an offshore sediment sink and hurled against the cliffs at high tide.
68
What is cavitation?
Cavitation is an erosive process where air bubbles implode under high pressure, creating tiny jets of water that erode the rock.
69
What is abrasion?
Abrasion is the process where sediment is moved along the shoreline, causing it to be worn down over time.
70
What is corrosion (solution)?
Corrosion occurs when mildly acidic seawater erodes alkaline rock such as limestone.
71
What is hydraulic action?
Hydraulic action occurs when a wave crashes onto a rock or cliff face, forcing air into cracks and causing them to force apart.
72
What is wave quarrying?
Wave quarrying is when breaking waves hit the cliff face to directly pull away rocks or remove smaller weathered fragments.
73
What are the factors affecting coastal erosion?
Several factors affect coastal erosion, which can be marine or land based.
## Footnote
These factors include Waves, Beach Size and Presence, Activity of Subaerial Processes, Rock Faults, and Rock Lithology.
74
What is one factor that affects coastal erosion?
Waves
## Footnote
Waves can contribute to the erosion of coastal areas.
75
How does beach size affect coastal erosion?
Beach Size and Presence
## Footnote
The size and presence of a beach can influence the rate of coastal erosion.
76
What role do subaerial processes play in erosion?
Activity of Subaerial Processes
## Footnote
Subaerial processes refer to weathering and erosion that occur on land.
77
What are rock faults?
Rock Faults
## Footnote
Faults in rock can create weaknesses that are susceptible to erosion.
78
What is rock lithology?
Rock Lithology
## Footnote
The physical and chemical characteristics of rocks can affect their erosion rates.
79
What is coastal transportation responsible for?
Transferring sediment within a sediment cell and between other sediment cells.
80
What are the four main processes of transportation?
1. Traction 2. Saltation 3. Suspension 4. Solution
81
What is traction in coastal transportation?
Large, heavy sediment rolls along the sea bed, pushed by currents.
82
What is saltation in coastal transportation?
Smaller sediment bounces along the sea bed.
83
What is suspension in coastal transportation?
Small sediment is carried within the flow of the water.
84
What is solution in coastal transportation?
Dissolved material is carried within the water.
85
What is longshore drift?
The process where waves hit the beach at an angle and move sediment along the beach over time.
86
How do waves contribute to longshore drift?
Waves push sediment up the beach in the swash and carry it back down in the backwash.
87
What occurs during deposition?
Sediment becomes too heavy for the water to carry or the wave loses energy.
88
What happens in high-energy coastlines regarding deposition?
Smaller sediment is transported, while larger rocks and shingle are deposited.
89
What happens in low-energy coastlines regarding deposition?
Much smaller sediment is deposited where there is lower water velocity.
90
What are the two processes included in deposition?
Gravity settling and flocculation.
91
What is weathering?
The breakdown of rocks over time.
92
What is positive feedback in the context of weathering?
If the rate of removal of the weathered rock from the base of the cliff is higher than the rate of weathering, then this will promote further weathering as this will increase the area of exposed rock.
## Footnote
This will increase the amount of erosion that occurs because this will increase the supply of rocks which can become part of the erosive processes of saltation and abrasion.
93
What is negative feedback in the context of weathering?
If the removal of weathered rock from the base of the cliff is slower than the rate of weathering, then this will lead to a build-up of debris at the base of the cliff, reducing the exposed cliff area and therefore reducing the rates of weathering.
## Footnote
It will also reduce erosion as the cliff foot will be protected from the other forces of erosion.
94
What is freeze-thaw weathering?
Water enters cracks in rocks and then the water freezes and expands in volume causing cracks to develop.
95
What is salt crystallisation in weathering?
As seawater evaporates, salt is left behind. Salt crystals will grow over time, forcing the cracks to widen.
## Footnote
Salt can also corrode ferrous rock.
96
What is wetting and drying in weathering?
Rocks such as clay expand when wet and then contract again when they are drying, and these cycles cause the rocks to break up.
97
What is carbonation in chemical weathering?
Rainwater absorbs CO2 from the air to create a weak carbonic acid. Acid rain reacts with limestone to form calcium bicarbonate, which is then easily dissolved allowing erosion.
98
What is oxidation in chemical weathering?
When minerals become exposed to the air, they become oxidised, increasing their volume and causing the rock to crack. This is most common with iron minerals.
99
What is solution in chemical weathering?
When rock minerals such as rock salt are dissolved.
100
How do plant roots contribute to biological weathering?
Roots of plants grow into the cracks of rocks, exerting pressure and eventually splitting the rocks.
101
How do birds contribute to biological weathering?
Some birds, such as Puffins, dig burrows into cliffs, weakening them.
102
What is rock boring in biological weathering?
Many species of clams secrete chemicals that dissolve rocks.
103
How do seaweed acids contribute to biological weathering?
Kelp contains sulphuric acid, which dissolves rock minerals.
104
How does decaying vegetation contribute to biological weathering?
Water flows through decaying plants and becomes acidic.
105
What is mass movement?
Mass movement is the movement of material down a slope under the influence of gravity.
106
What are the four main categories of mass movement?
The four main categories of mass movement are creeps, flows, slides, and falls.
107
What is soil creep?
Soil creep is the movement of soil particles downhill due to wetting and freezing, forming shallow terracettes.
108
What is solifluction?
Solifluction occurs mainly in periglacial environments when the top layers thaw during summer and flow over frozen layers.
109
What are mudflows?
Mudflows occur when an increase in water content reduces friction, causing earth and mud to flow over underlying bedrock or slippery materials like clay.
## Footnote
Mudflows can be very fast flowing and represent a serious threat to life.
110
What is rockfall?
Rockfall occurs on sloped cliffs (over 40°) due to mechanical weathering, leading to scree building up at the base of the slope.
111
What causes a landslide?
A landslide is caused by heavy rainfall reducing friction in cliffs, leading to a block of intact rock moving down the cliff face quickly along a flat slope.
112
What is a landslip or slump?
A landslip or slump occurs when the slope is curved and collapses under its own weight due to increased pore water pressure, creating a terraced appearance.
113
What is runoff?
Runoff may erode the cliff face or pick up sediment that enters the littoral zone, and it may also increase pollution in coastal areas.
114
How does temperature influence weathering?
Temperature and climate can influence the prominence of weathering.
115
What type of weathering is more common in colder climates?
Mechanical weathering is more common in colder climates.
116
What type of weathering is more common in warmer climates?
Chemical weathering is more common in warmer climates.
117
What occurs at headlands due to wave energy?
Wave energy is concentrated at headlands, leading to erosion.
118
What forms first during the erosion process at headlands?
Joints are eroded first to form a blowhole/cave.
119
What is formed after caves are eroded through the headland?
An arch is formed.
120
What happens to the rock above the arch over time?
The unsupported rock above the arch collapses to form a stack.
121
What does the stack become over time due to weathering and erosion?
The stack becomes a stump.
122
What are steep cliffs?
Steep cliffs are most common where the rock is strong and fairly resistant to erosion. An absence of a beach, long-fetch, and high energy waves promote steep cliff development.
## Footnote
Most commonly found in high-energy environments.
123
What are gentle cliffs?
Gentle cliffs are commonly found in areas with weaker rocks that are less resistant to erosion and prone to slumping. A large beach reduces wave energy and prevents steep cliffs from forming.
## Footnote
Commonly found in low-energy environments.
124
What factors influence the rate of cliff retreat?
The rate of retreat depends on the relative importance of marine and terrestrial factors. Cliffs made of unconsolidated rock and sands are most likely to retreat.
125
What is a negative feedback mechanism in coastal erosion?
Negative feedback mechanisms can help protect and restore a coast. During a storm, part of a cliff may collapse, and the material can protect the base from further erosion, reducing cliff recession.
## Footnote
Sediment produced may be deposited in offshore bars, which protect the coastline by dissipating wave energy.
126
What occurs at steep cliffs due to erosion?
Erosion is concentrated around the high-tide line creating a wave-cut notch.
127
What happens to the cliff face as the wave-cut notch becomes deeper?
The cliff face becomes unstable and collapses.
128
What is left behind after the cliff collapses?
A platform of the unaffected cliff base.
129
What is formed over time as a result of the wave-cut notch and platform?
A wave-cut platform.
130
What limits the length of a wave-cut platform?
Eventually, the waves can no longer reach the cliff, reducing the erosion.
131
How does the act of erosion creating the wave-cut platform affect future erosion?
It has acted to directly decrease the rate of erosion in future.
132
What is a beach?
A beach is a depositional landform that stretches from roughly the low tide to the high tide line.
133
What occurs during beach accretion?
Beach accretion occurs due to constructive waves during the summer.
134
What occurs during beach excavation?
Beach excavation occurs due to destructive waves in winter.
135
What are swash-aligned beaches?
Swash-aligned beaches have wave crests that approach perpendicular to the coast, resulting in limited longshore drift.
136
What are drift-aligned beaches?
Drift-aligned beaches have waves that approach at an angle, allowing sediment to travel along the beach, which may form a spit.
137
Where is larger sediment found on a beach?
Larger sediment is found toward the top of the beach where it has been left from winter storms.
138
What does scree near cliffs indicate?
Scree near the cliffs means that angularity of sediment increases towards the cliff, where hydraulic action acts less frequently to round the sediment.
139
What are spits?
Spits occur when the coast suddenly changes direction and longshore drift continues to deposit material in line with the coast but at sea.
140
What leads to a recurved spit?
Changes in wind direction or wave refraction lead to a curved end, forming a recurved spit.
141
What is a compound spit?
Multiple curved ends form a compound spit.
142
What develops in the area behind a spit?
The area behind the spit is sheltered and often develops into mudflats and saltmarshes.
143
Can spits extend across estuaries?
Spits cannot extend across estuaries but can extend across bays to form a barrier beach.
144
What is a Barrier Beach?
A Barrier Beach occurs when a beach or spit extends across a bay to join to headlands. It traps water, forming a brackish lagoon which is separated from the sea.
145
How can Barrier Beaches form?
Barrier Beaches can form from contemporary processes or due to rising sea levels after the last glacial period, when glaciers deposited sediment in the coastal zone.
146
What happens if a Barrier Beach is separated from the mainland?
If a Barrier Beach is separated from the mainland, it becomes a barrier island.
147
Where are Barrier Beaches commonly found?
Barrier Beaches are common in areas with low tidal ranges.
148
What is a Tombolo?
A Tombolo is a bar or beach that connects the mainland to an offshore island.
149
How is a Tombolo formed?
A Tombolo is formed due to wave refraction off the coastal island, which reduces wave velocity.
150
What are Offshore Bars?
Offshore Bars are regions where sand is deposited offshore, as the waves don’t have enough energy to carry the sediment to shore.
151
What role do Offshore Bars play in sediment dynamics?
Offshore Bars absorb wave energy and may provide important sediment input into the coastal zone when waves pick up sediment from them.
152
How can Offshore Bars be formed?
Offshore Bars can also be formed when backwash removes sediment from a beach.
153
Why is vegetation essential in coastal areas?
Vegetation stabilises coastal landforms such as dunes by binding soil together, reducing erosion.
154
How do plants protect the ground when submerged?
Plants provide a protective layer for the ground when completely submerged.
155
What effect do plants have on wind speed at the surface?
Plants reduce the wind speed at the surface, leading to less wind erosion.
156
What causes sand dunes to develop?
Sand dunes develop as wind blows sand landwards from the beach or offshore bar.
157
How does the tidal range affect sand movement?
A large tidal range allows sand to dry, making it light enough to be carried by the wind.
158
What is the role of pioneer species in dune formation?
Pioneer species like sea rocket are resistant to salty sand and help bind the dunes together.
159
How does decaying organic matter contribute to dune vegetation?
Decaying organic matter adds nutrients and humus to the soil, allowing marram grass to grow.
160
What occurs during the climatic climax of dune succession?
The climatic climax occurs when trees are able to colonise the area.
161
What is Marram grass an example of?
Marram grass is a good example of a pioneer plant.
162
How does Marram grass adapt to sandy conditions?
It is tough and flexible, allowing it to cope with sandy conditions.
163
What adaptation does Marram grass have to reduce water loss?
It has adapted to reduce water loss through transpiration.
164
How deep can the roots of Marram grass grow?
Their roots can grow up to 3 metres deep.
165
What temperature can Marram grass tolerate?
Marram grass can tolerate temperatures of up to 60 °C.
166
What occurs in river estuaries due to low water velocity?
Deposition occurs as the water can no longer carry its sediment in suspension.
167
Where may mudflats and marshes occur?
Mudflats/marshes may occur in sheltered areas such as behind a spit.
168
What leads to the formation of mud above the high tide level?
Deposition occurs as a result of flocculation.
169
What happens when pioneer plants colonise the transition zone?
More sediment becomes trapped, leading to the formation of a meadow.
170
What climatic climax occurs in vegetation succession?
The climatic climax occurs when trees begin to colonise the area.
171
What is isostatic change?
Isostatic change occurs when the land rises or falls relative to the sea.
172
What is a localised change in sea level called?
Isostatic sea level change.
173
What can cause isostatic sea level change?
Isostatic subsidence and tectonic activity may cause isostatic sea level change.
174
What happened to the city of Banda Aceh in 2004?
It sank permanently by 0.5m due to the Indian Ocean earthquake.
175
What is eustatic change?
Eustatic change affects sea level across the whole planet.
176
What may cause eustatic change?
Thermal expansion/contraction or changes in glacial processes.
177
What is thermal expansion?
The process of water expanding when it gets warmer, increasing the volume of water.
178
How much lower were sea levels during the last ice age?
Sea levels were over 100m lower than they are currently.
179
What are emergent coastal landforms?
Emergent coastal landforms occur where the land has been raised in relation to the coastline. Raised beaches are common before cliffs, which are also raised (relic cliffs), with wave-cut notches and similar features proof of historical marine erosion.
180
What are submergent coastal landforms?
Submergent coastal landforms occur when the sea level rises or the coastline sinks in relation to the sea.
181
What are rias?
Rias are formed when rising sea levels flood narrow winding inlets and river valleys. They are deeper at the mouth of the inlet, with the water depth decreasing further inland.
182
What are fjords?
Fjords are formed when rising sea levels flood deep glacial valleys to create natural inlets and harbours. They are deeper in the middle than at the mouth, with the shallower section showing where the glacier left the valley.
183
What are Dalmatian coasts?
Dalmatian coasts occur when valleys running parallel to the coast become flooded as a result of sea level change, leaving a series of narrow, long, and rugged islands.
184
What are the two main types of strategies used in coastal management?
The two main types are hard engineering and soft engineering.
185
What is hard engineering?
Hard engineering involves man-made structures that aim to prevent erosion.
186
What is a potential drawback of hard engineering?
While effective at preventing erosion in one area, it may exacerbate erosion elsewhere.
187
What are offshore breakwaters?
Offshore breakwaters are rock barriers that force waves to break.
188
What are the benefits of offshore breakwaters?
They are effective at reducing wave energy.
189
What are some drawbacks of offshore breakwaters?
They are visually unappealing, can be a navigation hazard, and interfere with longshore drift.
190
What is Integrated Coastal Zone Management (ICZM)?
ICZM is a strategy for managing large sections of coastline with an integrated approach across different political boundaries.
191
What does ICZM prioritize in coastal management?
ICZM prioritizes environmental protection over economic development.
192
Who must be involved in ICZM?
All stakeholders must be involved in the ICZM process.
193
What is a key consideration in ICZM regarding coastal communities?
ICZM recognizes that protecting one coastal community may expose another to increased erosion.
194
What initiative did the EU adopt in 2013 related to ICZM?
In 2013, the EU adopted a new initiative that promotes the use of ICZM.
195
What is the impact of installing a sea wall on sediment cells?
Installing a sea wall reflects wave energy downdrift, increasing wave energy and erosion elsewhere on the coastline.
## Footnote
Less erosion occurs in areas with the sea wall, resulting in less sediment in areas with increased wave energy.
196
How does a sea wall affect beach size?
Less sediment reduces the beach size, exposing the cliff to erosion from higher energy waves.
197
What is the effect of building groynes on sediment transport?
Building groynes prevents longshore drift from transporting sediment away from one stretch of coastline, affecting downdrift areas.
198
What are unconsolidated cliffs
a steep or vertical landform f**ormed from loose, uncompacted material**s like sand, gravel, or clay, rather than solid rock
