Coasts: All EGC & PMT FCs Flashcards
(155 cards)
1
Q
Abrasion
A
Sediment dragged over rocky surfaces smooths and erodes rock like sandpaper.
2
Q
Attrition
A
Rocks and pebbles collide, breaking into smaller, smoother particles.
3
Q
Backshore
A
The area of a beach that lies between the high-water mark (HWM) and the limit of wave activity. It is the upper beach closest to and including any cliffs or sand dunes.
4
Q
Beach Morphology
A
The surface shape of the beach
5
Q
Beach profile
A
The steepness and width of a beach. The profile of beaches changes over time.
6
Q
Coastal processes
A
The mechanisms that operate on the inputs and result in particular outputs, shaping coastlines.
7
Q
Coastal Recession
A
The retreat of a coastline due to erosion, sea-level rise or submergence.
8
Q
Concordant coastline
A
Coastlines with rock bands parallel to the shore, forming coves like Lulworth Cove.
9
Q
Constructive waves
A
Waves that add sediment to a beach as the swash pushes more material from offshore up the beach than the backwash removes.
10
Q
Corrasion
A
Material picked up by waves is hurled at cliffs, chipping away at rock.
11
Q
Currents
A
The permanent or seasonal movement of surface water in the seas and oceans.
12
Q
Dalmation Coast
A
A concordant coastline with several river valleys running perpendicular to the coast. They become flooded to produce parallel long islands and long intels.
13
Q
DEFRA’s 1:1 Cost-Benefit Analysis
A
The evaluation of a coastal town’s economic value compared to the cost of management required. Costs are tangible and intangible and can be economic or other costs like visual impacts.
14
Q
Deposition
A
When wave energy drops, sediment is deposited, forming sediment sinks.
15
Q
Destructive waves
A
Waves that remove beach material from the shoreline as the backwash is more forceful than the swash.
16
Q
Dip
A
The slope of rock layers, affecting cliff formations.
17
Q
Discordant coastline
A
Coastlines with rock bands at right angles to the shore, forming headlands and bays.
18
Q
Dynamic environment
A
One that is ever changing.
19
Q
Dynamic equilibrium
A
A state of balance where coastal inputs equal outputs in a system that is constantly changing. Where coastal erosion and deposition are balanced there will be a state of dynamic equilibrium.
20
Q
Emergent coast
A
A coastline that is advancing relative to the sea level at the time.
21
Q
Erosion
A
The wearing away of the Earth’s surface and removal of material by wind, waves, tides, and sea currents.
22
Q
Eustatic
A
Global changes to the sea levels.
23
Q
Fault line
A
Cracks in rock formed by tectonic movement, creating areas of weakness.
24
Q
Fetch
A
The length of water over which a wind has blown. The larger the fetch, the bigger the waves.
25
Fjord
A long narrow inlet deeper in the middle section that at the mouth. It is created when sea levels rise relative to the land, flooding coastal glacial valleys.
26
Foreshore
The area of a beach that lies between the high-water mark and the low-water mark (LWM). It is the lower part of the beach and is covered at high tide.
27
Freeze Thaw
A form of physical sub-aerial weathering where water freezes in the cracks of a rock, expands and enlarges the crack and therefore weakens it.
28
Geology
The rock composition of an area, including lithology (rock type) and structure (arrangement of rocks).
29
Glacial erosion
A necessary part of the formation of Fjords. It is the removal of loose material by glacier ice.
30
Grading
The layering of sediments based on their size.
31
High-energy coastlines
Coastlines experiencing strong, powerful waves with high erosion rates.
32
How can sea level rise affect wave-cut platforms?
Sea level rise can reinvigorate erosion by allowing waves to reach the cliffs directly again, bypassing the platform's protection.
33
How do destructive waves trigger negative feedback on beaches?
They scour the upper beach, deposit sediment lower down, and reduce wave energy offshore.
34
How do mudflats form?
By the gradual accumulation of flocculated sediment in sheltered areas.
35
How do sand dunes change as they mature?
Soil quality improves, biodiversity increases, and vegetation becomes more complex.
36
How do storm frequency and strength affect erosion?
Frequent and strong storms (e.g., in northern Scotland) accelerate coastal erosion.
37
How does a wave cut notch lead to cliff retreat?
The notch collapses, causing the cliff to retreat.
38
How does a wave cut platform protect the coast?
It dissipates wave energy, slowing further erosion.
39
How does lithology affect erosion rates?
- Hard rocks (granite, basalt) = slow erosion (mm/year).
- Soft rocks (glacial till, boulder clay) = rapid erosion (up to 10m/year).
40
How does marram grass stabilise dunes?
It traps sand and stabilises it with deep roots.
41
How does rock structure affect cliff stability?
- Rocks dipping inland = steep/vertical cliffs (more stable).
- Rocks dipping seaward = less stable cliffs (prone to sliding).
42
How does soft rock lithology (e.g., glacial till, boulder clay) affect coastal erosion rates?
Erodes rapidly, up to 10 metres per year.
43
How does tidal range affect erosion patterns?
- Small tidal range (e.g., Mediterranean) = focused erosion at cliff base → deeper notches.
- Large tidal range (e.g., UK Atlantic coast) = erosion spread over a wider vertical range.
44
How does vegetation succession occur on a salt marsh?
Different plants establish based on flooding frequency, leading to increasingly terrestrial conditions.
45
How does wave energy affect beach sediment movement?
Swash and backwash constantly move sediment; deposition depends on wave energy.
46
How does wave energy influence erosion?
High-energy environments (like the Atlantic coast) experience faster erosion.
47
How is a spit formed?
Sediment transported by longshore drift is deposited where energy levels drop, extending outwards from the coast.
48
Hydraulic action
Waves compress air in rock cracks, creating pressure that weakens cliffs.
49
Impermeable
A rock that does not allow rainwater to pass through.
50
Inputs
These include energy from waves, wind, tides, sea currents and gravity; sediment; sea level change and geology.
51
Integrated Coastal Zone Management (ICZM)
Large sections of coastline (often sediment cells) are managed with one integrated strategy and management occurs between different political boundaries.
52
Isostatic
A change in local coastline or land height relative to sea level
53
Littoral Cell
A section of the coast, within which involves much sediment movement. A littoral cell is not a closed system.
54
Longshore currents
These occur when waves approach the coastline at an angle, transporting sediment parallel to the coast.
55
Longshore drift
Zigzag movement of sediment along the coast due to swash and backwash.
56
Low-energy Environment
A coast where wave action is predominantly small constructive waves, causing deposition and leading to beach accretion.
57
Marine processes
Processes operating on coastlines, including erosion, transport, and deposition.
58
Mass movement
The movement of material downhill by gravity assisted by rainfall.
59
Neap tide
Occurs when the Sun and Moon are at right angles, causing a smaller tidal range.
60
Nearshore
Also called the inshore, this is the area of a beach between the low water mark and the point of the coast where waves no longer have any effect.
61
Negative feedback
When a change in the system causes other changes that have the opposite effect. This dampens the initial change and restores balance in a system.
62
Offshore
The area of a beach that is beyond the point where waves cease to impact upon the seabed.
63
Open system
Inputs (energy and matter) come from outside the system, and outputs leave the system, e.g. sediment is carried onto a coastline from further down the coast and eroded rock is washed offshore out into the ocean.
64
Outputs
- Dissipation of wave energy
- Accumulation of sediment above the tidal limit e.g. sand dunes
- Sediment removed from sediment cell e.g. carried out to sea.
65
Permeable
A rock that allows rainwater to pass through it.
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Plant Succession
Change to a plant community due to growing conditions adapting (eg. sand dunes and salt marshes).
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Positive feedback
When a change in the system causes other changes that have a similar effect so that the initial change is enhanced.
68
Prevailing wind
The direction from which the wind most usually blows from. In the UK it's from the southwest.
69
Ria
Narrow winding inlet which is deepest at the mouth, formed when sea levels rise causing coastal valleys to flood.
70
Rip currents
Strong localised underwater currents that move water away from the coastline just below the surface.
71
Saltation
Smaller sediment bounces along the sea bed, being pushed by currents.The sediment is too heavy to be picked up by the flow of the water.
72
Sediment budget
The balance between sediment being added to and removed from a sediment cell coastal system.
73
Sediment Cell
Sections of the coast bordered by prominent headlands. Within these sections, the movement of sediment is almost contained and the flows of sediment should act in dynamic equilibrium.
74
Sediment sink
Where sediment is permanently lost to the coastal system, e.g., offshore currents may transfer sediment out to sea.
75
Sediment sources
Sediment comes from rivers, streams, cliff erosion, longshore drift, wind, and offshore.
76
SMP - What does it identify and then action they recommend
Identifies all of the activities, both natural and human which occur within the coastline area of each sediment cell and then recommends a combination of four actions for each stretch of that coastline: Hold the Line, Advance the Line, Managed Realignment and No Active Intervention.
77
Solution (transport)
Dissolved materials transported in water, important in the carbon cycle.
78
Spring tide
Occurs when the Sun and Moon are aligned, causing higher high tides and lower low tides, resulting in a greater tidal range.
79
Stores
An accumulation of sediment - landforms e.g. beach.
80
Subaerial Processes
The combination of mass movement and weathering that affects the coastal land above sea.
81
Submergent Coast
A coast that is sinking relative to the sea level of the time.
82
Suspension
Fine sand and silt carried by moving water, creating a murky appearance.
83
Tidal range
The relative difference in height between high and low tides, affecting erosion and deposition.
84
Tides
Long-period waves caused by the gravitational pull of the moon and the Sun.
85
Till
Deposits of angular rock fragments in a finer medium.
86
Traction
Large stones rolled along the seabed by waves.
87
Transfer or flow
Sediment is moved from one place to another as a result of processes such as longshore drift and rip currents.
88
Transportation processes
The movement of sediment by waves and tides.
89
Upwelling
The movement of cold water from deep in the ocean towards the surface, replacing warmer surface water.
90
Wave pounding
The sheer force of water impacting rock surfaces, weakening and dislodging pieces.
91
Wave refraction
The bending of waves when they approach uneven coastlines, causing erosion on headlands and deposition in bays.
92
Weathering
The breakdown or decay of rock at or near the Earth's surface, in its original position (in situ).
93
What are beaches composed of?
Sand and/or shingle.
94
What beach conditions favour sand dune formation?
Wide, flat, dry beaches with high tidal ranges and available sand.
95
What causes the recurved end of a spit?
Storms from different directions and wave refraction bending waves around the spit.
96
What characterises a drift-aligned beach?
Sediment moves along the beach due to longshore drift.
97
What characterises a swash-aligned beach?
Sediment moves up and down the beach parallel to wave fronts.
98
What cliff type results from rocks dipping inland?
Steep or vertical cliffs.
99
What cliff type results from rocks dipping seaward?
Less stable cliffs, prone to sliding.
100
What energy source forms sand dunes?
Wind transporting dry sand inland.
101
What happens to beaches during storms?
Beaches become wider and more gently sloping due to stronger swash and backwash.
102
What happens to sediment as wave energy decreases?
Larger material deposits first; finer material travels further.
103
What impact does storm frequency and strength have on coastal erosion?
Frequent, strong storms accelerate erosion.
104
What initiates salt marsh formation?
Colonisation of mudflats by halophyte plants.
105
What is a tombolo?
A spit that connects the mainland to an island (e.g., Chesil Beach to Isle of Portland).
106
What is a wave cut notch?
An undercut at the base of a cliff formed by hydraulic action and abrasion.
107
What is a wave cut platform?
A gently sloping rock surface left behind after repeated cliff retreat.
108
What is a wave-cut notch?
- An undercut at the base of a cliff caused by hydraulic action and abrasion.
- Collapse of the notch leads to cliff retreat.
109
What is a wave-cut platform and how does it form?
- A gently sloping rock surface left behind after repeated cliff retreats.
- Grows wider over time and acts as protection by dissipating wave energy (negative feedback).
110
What is flocculation?
The process where fine sediments clump together in saline water and settle out.
111
What is saltation in sand dune formation?
The bouncing movement of sand grains inland by wind.
112
What is the trash line and its role in dune formation?
Debris accumulations that slow the wind, causing sand deposition.
113
What pioneer species is key to dune development in the UK?
Marram grass.
114
Outline the process of longshore drift?
Waves approach at an angle; swash moves sediment diagonally up, backwash pulls it straight down.
115
What role does vegetation play in sand dune formation?
Pioneer plants trap sand and stabilise dunes.
116
What threat does sea level rise pose to salt marshes?
It causes coastal squeeze if marshes can't migrate inland.
117
What type of sediment is deposited in low-energy coastal environments?
Fine sediments like silts and clays.
118
What type of sediment is found on high-energy coasts?
Pebbles and gravel.
119
Where are beaches located?
Between the high tide and low tide marks.
120
Where do low-energy coastal environments commonly occur?
Sheltered areas near estuaries or behind spits/tombolos.
121
Why are salt marshes important?
They provide coastal defence and habitats for a range of species.
122
Why are sand dunes important for coastal areas?
They provide natural coastal defence and habitats for specialist species.
123
Why can stopping erosion in one location impact deposition elsewhere?
Because erosion feeds sediment into the coastal system; stopping it can reduce sediment supply, affecting deposition rates down the coast.
124
Why don’t spits usually close off estuary mouths completely?
Tidal currents erode the end of the spit.
125
Why is marram grass vulnerable despite being hardy?
It can be easily damaged by trampling.
126
Why is understanding sediment movement important for coastal management?
To manage the coast effectively, we need to know how erosion and sediment transport interact across locations.
127
What is soil creep?
Slow movement of soil downhill due to gravity; creates terracettes.
128
Where does solifluction occur?
In cold climates where thawed soil flows over frozen ground.
129
What causes mudflows?
Heavy rain saturates soil, causing rapid downhill flow.
130
What is a landslide?
Rapid movement of rock or soil down a flat surface, often after rainfall.
131
What is slumping?
Downward movement along a curved surface; occurs with permeable over impermeable rock.
132
What causes rockfall?
Rocks break off steep cliffs due to physical weathering, falling freely.
133
Name 5 factor influencing mass movement.
Weathering, vegetation, rock structure, geology, or slope angle.
134
What is the speed of rockfall?
Fast.
135
What type of material is involved in rockfall?
Rock.
136
Is rockfall wet or dry?
Dry.
137
What is the slope condition for rockfall?
Steep.
138
What is the speed of a landslide?
Fast.
139
What material moves in a landslide?
Rock or soil.
140
Is a landslide wet or dry?
Wet.
141
What slope condition is typical for a landslide?
Steep.
142
What is the speed of mudflow?
Fast.
143
What material moves in mudflow?
Mud.
144
Is mudflow wet or dry?
Very wet.
145
What is the slope condition for mudflow?
Gentle or steep.
146
What is the speed of soil creep?
Slow.
147
What material moves in soil creep?
Soil.
148
Is soil creep wet or dry?
Wet.
149
What is the slope condition for soil creep?
Gentle.
150
What is the speed of slumping?
Moderate.
151
What material moves in slumping?
Clay or soil.
152
Is slumping wet or dry?
Wet.
153
What is the slope condition for slumping?
Steep.
154
Describe the process of slumping.
- Rain saturates permeable material
- Water can't pass impermeable layer
- Material becomes heavy and slips down a curved surface.
155
What is scree and how is it formed?
Scree is a pile of broken rock fragments at the base of a cliff, formed from rockfall.
