1
Q
What is a high energy environment
A
Destructive waves breaking on shingle beaches
2
Q
What is a Low energy environments
A
Constructive waves breaking upon sandy beaches
3
Q
What is a Protected environment
A
Where wave action is limited in small shelter (eg a split)
4
Q
Characteristics of high energy coasts
Waves.
Processes.
Landforms.
General location.
A
Waves-more powerful (destructive) waves, calmer conditions
Processes-sediments from eroded land, mass movement and weathering, supplied by offshore currents.
Landforms-cliffs, wave cut platforms, arches, sea caves, stacks
General location- exposed to largest waves, highland and lowland coats, rocky landscape.
5
Q
Characteristics of low energy coasts
Waves.
Processes.
Landforms.
General location.
A
Waves- less powerful (constructive) waves, storm conditions
Processes- sediments from rivers, longshore drift and near shore currents
Landforms- beaches, spots, bars, sand dunes, mudflats and salt marshes
General location- sheltered from large waves, can cause vegetation to grow and sand dunes
6
Q
High energy coasts summarised
A
Where the rate of erosion exceeds the rate of deposition
7
Q
Low energy coasts summarised
A
Where the rate of deposition exceeds the rate of erosion
8
Q
Terrestrial factors affecting coasts
A
The type of rock (eg the soft rock will erode quicker, hard rock slower)
Tectonics in the area (earthquakes can move rock or trigger tsunamis)
9
Q
Human factors affecting coasts
A
Global warming is altering the shape of the coastlines due to the rising sea levels
Humans can settle on coastlines and will rise to the proximity of the sea
10
Q
atmospheric factors affecting coasts
A
Climate change
Temperature alter the shape of the coast
11
Q
Marine factors affecting the coasts
A
Waves, tides and salt spray play in altering the shape of coasts
Corals can alter the shape of the coasts
12
Q
Primary coasts facts
A
Develops from non marine processes
Only gets altered since the last raise in sea level
Partially drowned by the post glacial rise of sea level
13
Q
Secondary coasts facts
A
Shape primarily by Marine Action
May or may not be primary before
14
Q
what is macro-scale
A
concordant and discordant
15
Q
what is meso scale
A
folds,faults and dips
16
Q
what is a micro scale
A
bedding planes, joints, pores
17
Q
3 factors affecting rock resistance
A
-hardness
-structure~ affecting how water and wind interacts with the surface
-PH~ affects erosion resistance by influencing mineral stability + chemical reactions
18
Q
what is a permeable rock
A
it allows water to pass through them and cracks and joints enlarge
19
Q
what is a impermeable rock
A
it does not allow groundwater flow and allows greater amounts of surface runoff, this has its own erosive force on the face of a cliff
20
Q
examples of igneous rock (interlocking crystals make it v strong)
A
extrusive-basalt, andesite and obsidian
intrusive- granite diorite and gabbro
21
Q
examples of sedimentary rock (resistant to erosion less strong)
A
clastic rocks-bits of rock cemented together (sandstone, shale and mudstone)
organic rocks- chalk and coal
chemical rocks-limestone, gypsum and rock salt
22
Q
examples of metamorphic rock (clastic-loose parts erodes very quickly)
A
gneiss, schist, quartzite, slate and marble
23
Q
what is strata
A
its layers of rock
24
Q
what are bedding planes
A
natural breaks in the strata (horizontal cracks)
25
what are joints
these are by contraction as sediments dries out or by the earth movements during up lifts (vertical cracks)
26
what are folds
they are formed by pressure during tectonic activity which make rock buckle and crumble (looks like squares on cliff face)
27
what are faults
formed then the pressure to which a rock is subjected to exceeds its internal strength ( causing it to fracture)
28
what are dips
this refers to the angle at which rock strata lies (horizontally, vertically, dipping towards the sea or dipping inland)
29
how to tell the difference between concordant coasts and discordant coasts
CONcordant- constantly parallel to the coast
DIScordant-different when looking such as the angles or lines
30
what is an anticline
fold in the rock strata that is arched upwards to the ridge
31
what is a syncline
it folds in the rock strata that arches down
32
what is backshore
this is the area between the high water mark and the landward limit of marine activity (the sand between a cliff not in water)
33
what is foreshore
the area lying between the high water mark and the low water mark and is often seen as the most important area for marine activity (where you would swim)
34
what is nearshore
the area between the low water mark and the point where the waves start to have influence on land around them
35
what is offshore
the area beyond the point where waves cease to impact the seabed and in which activity is limited to the deposition of sediment
36
What is a submergence coastline
A stretch of coastline that has been inundated by the seal due to a relative rise in sea level
37
What is an emergence coastline
A stretch of coastline that have been exposed by the sea due to a relative fall in sea level
38
What are rias
-submerged river valleys caused by glaciers and ice sheets melting causing eustatic sea level rise so it fills up the valley
39
What is a fjord
A submerged glacial valley due to the effect of the glacial erosion which shapes the original V shaped valley submerged by rising sea levels
40
How is a fjord formed
• A glacier flows through a pre-existing river valley.
• The glacier’s weight and movement cause abrasion (erosion by embedded rock fragments) and plucking (removal of bedrock).
41
How is a ria formed (submergent coast line)
During glacial periods, rivers erode and shape V-shaped valleys through erosion.
The river cuts down into the landscape, creating a steep-sided valley.
glaciers and ice sheets melt, causing global sea levels to rise (eustatic change).
The rising sea level floods the lower parts of river valleys, submerging them
The highest land remains above sea level, forming headlands and islands.
42
What is a Dalmatian coastline
A Dalmatian coastline is a type of submergent coastline This results in long, narrow islands running parallel to the coastline
43
What is a concordant coast line
where rock layers (strata) run parallel to the coastline. This affects the rate of erosion and the shape of coastal landforms.
44
Rock lithology of a concordant coastline
The outermost layer, often harder rock (e.g., limestone), acts as a protective barrier against erosion.
If waves break through the harder rock (due to faults, joints, or erosion), they can rapidly erode the softer rock behind it.
This can create coves and inlets, which expand over time
45
What is a discordant coastline (discordant coastal landform)
where rock layers (strata) run perpendicular to the coastline. This results in alternating bands of hard and soft rock, which erode at different rates, creating headlands and bays.
46
Rick lithology of a discordant coastline (discordant coastal landform)
Soft rock (e.g., clay, sand, ) erodes faster, forming bays.
Hard rock (e.g., limestone, chalk, or granite) erodes more slowly, forming headlands.
Bays are created where soft rock is worn away more quickly by wave action.
Headlands are left protruding into the sea because they resist erosion
47
What is a raised beach
A beach above the high tide mark which Overtime becomes vegetated and develops into soil
48
How is a raised beach formed (Emergent coastal landform)
A raised beach is a former wave-cut platform and beach that has been lifted above the current sea level due to changes in sea level. It is an emergent coastal landform associated with isostatic uplift and eustatic sea level fall.
49
What is fossil cliff (emergent coastal landform)
The sea no ,longer eroded the cliffs above the raised beaches, meaning vegetation slowly establishes and covers them
50
How is a fossil cliff made (emergent coastal landform)
A fossil cliff is an abandoned steep coastal cliff that is no longer affected by wave action due to sea level fall. Fossil cliffs are typically found inland, above present sea levels, as part of a raised beach system raised beach to storm waves (storm beach)
51
What is a swash aligned coast
Where the wave crests approach parallel to the coast so there is limited LSD of sediment (approaches straight on -> parallel)
52
What is a drift aligned coast
Wave crests break at an angle to the coast so there is consistent LSD creating spits (wave hits the beach at an angle eg 45 degrees) moving sand along the beach
53
What is gravity settling for a beach
It occurs when the energy of transporting water becomes to low to move sediment, large sediment will be deposited first followed by smaller sediment (rocks, pebbles then sand on a beach for eg)
54
What is flocculation
Is a deposition at process that it’s important for very small particles such as clay which as so small they remain suspended in water. Clay particles clump together due to electrical or chemical attraction and become large enough to sink
55
Archie gimme 3 submergent coastal landforms
Rias, fjords and Dalmatian
Submergent->submerged
56
Gimme 3 emergent coastal landforms
Raised beaches, fossil cliffs
57
What is a psammosere and a halosere and what do they do
A psammosere is a sand dune and a halosere is a salt marsh
They both bind the loose sediment together and encourage further deposition
58
How is a fetch important for erosion processes
More energy and erosive power transferred from atmosphere to surface of the ocean
59
How is wave size/steepness important for erosion processes
They have more erosive power
60
How is the breaking point important for erosion processes
Because the point is which the wage breaks and energy is released.
If they break against cliff bases they erode more than a wave breaking on the wave cut platform
61
How is sea depth important for erosion processes
The wave breaks when the sea bed interrupts the circular movement of energy
A gradual sloping sea bed gradually takes energy out of the wave
62
How is the presence of longshore bars or reefs important for erosion processes
Longshoreman bars (sand/shingle banks) in the nearshore or nearshore reefs cause waves to break before hitting the beach so less erosion
63
How is geological structure important for erosion processes
Faults, folds and dips create area of weakness along the coast that the sea can exploit even with resistant rock
Discordant coastlines crease headlands and bays and headlands are more exposed to erosion
64
How is scouring important for erosion processes
The presence of unconsolidated material causes more abrasion therefore eroding the base of cliffs
65
How is the presence of beaches important for erosion processes
Beaches cause waves to break and absorbed wave energy, protecting the back shore cliffs/sand dunes
66
How is wave refraction important for erosion processes
The headlands attract wave energy therefore bays are more protected
67
3 Examples of mechanical weathering and what are they
Freeze thaw- Occurs in areas where temperatures fluctuate above and below 0 the water enters fractures in the rock face which freeze in the cracks and expands around 9% repeated cycle forces cracks to open
Salt crystallisation- is caused by salt water when waves break or splash on coastal rock the water evaporates leaving behind salt sodium and magnesium compounds in join and cracks the salt crystals grow and exert pressure and force
Wetting and drying- high tide minerals on the rock surface are soaked with sea water and expand in volume, low tide minerals dry and shrink eventually causing the rock to fragment and crumble
68
2 examples of Biological weathering and what are they
Plant roots-seeds fall into cracks then Germinate from rainwater as the plants roots grow into roots and expands thicken the roots exert force to widen the rock
Burrowing animals-a rock will have fractures in it and organisms may use there for habitats they then burrow in the rock breaking it apart undermining the rock structure
69
2 examples of chemical weathering and what is it
Carbonisation-Carbon dioxide from the atmosphere dissolves in rainwater to form carbonic acid , which reacts with calcium carbonate in rocks like limestone and chalk. Weakens the rock, making it more susceptible to further weathering and erosion.
Oxidation - Oxidation occurs when oxygen (often from air or water) reacts with minerals containing iron in rocks, leading to the formation of iron oxide (rust).
This weakens the rock as iron-rich minerals like pyrite or olivine are altered, causing the rock to break down.
70
What force is causing mass movement and what other factors influences mass movement
4
Gravity and water saturation, earthquakes and weathering
71
What is the definition of mechanical weathering
It breaks down due to the exertion of a physical barrier it does not Involve any chemical change
72
What is the definition of chemical weathering
Involves a chemical reaction and the generation of new chemical compounds
73
What is the definition of biological weathering
Often speeds up mechanical or chemical weathering through the action of plants, animals and bacteria
74
The link between weathering and climate
Weathering is influenced by the climate conditions and temp and precipitation have a very strong influence on the type of weathering experienced hot/wet is chemical and cold is mechanical also LITHOLOGY play a huge role in weathering
75
76
77
what does terrestrial mean
the rock type of the coast
78
what is the back shore
this is the area between the high water mark and the landward limit of marine activity (basically the beach)
79
what is foreshore
the are lying between the high water mark and the low water mark and is often seen as the most important area for marine activity (exposed at low tide)
80
what is nearshore
the are between the low water mark and pint where waves cease to have influence on land around them
81
what is offshore
the area beyond the point where waves cease to impact the seabed.
82
what are the 2 types of concordant coastlines
dalmation- long offshore islands and coastal inlets that are parallel to the coastline
haff-spits of sand or lagoons form parallel to the coast
83
what are anticlines
a fold in the rock strata that is arched upward to form a ridge
84
what are syncline
fold in the rock strata that arches down (sync/sink goes down)
85
discordant coastlines are
different to the coast when looking not parallel
86
why do waves approach headlands with high erosive power
the depth of water decreases therefore velocity reduces friction so waves compress and become higher steeper and closer together so their erosive power increases
87
why do waves enter bays with low energy
because of wave refraction towards the headland leabing the bay with dissipated wash energy
88
What is a sediment cell
Its lengths of coastlines which act as self contained ed units in the movement of sediment
89
How many sediment cells are around the English and Welsh coastline
11
90
What are 3 sources to a sediment cell and what is a source
Sources of erosion
-Erosion of cliffs
-land sediment eroded by rivers
-subaerial processes
91
What is a transfer and name 4
(Sediment cells)
It is how it moves
-wave transport through swash and backwash
-Longshore drift
-wind along shore or on and off shore
-on shore currents supplying sediment to the shore
92
What is a sink and name 4
(Sediment cells
It’s how the sediment is trapped
-back shore depositional landform (sand dunes)
-foreshore depositional landforms (beaches)
-Nearshore depositional landforms (bars)
-Offshore depositional landforms
93
what is a sediment budget
it’s the amount of sediment gained from sources and lost to sink
94
what is a positive sediment budget
where more sediment enters an area than leaves it
95
what is a dynamic equilibrium in a sediment cell
it’s when there’s a constant movement of sediment through the system and inputs from the source are balanced by the amount being deposited in sinks
96
what is a tombolo
A tombolo is a sandy strip that joins an island to the mainland, formed when waves drop sediment between them.
97
what is an offshore bar
An offshore bar is a ridge of sand found just offshore, formed when waves move beach sediment out to sea.
98
what is an cuspate foreland
A cuspate foreland is a triangular-shaped piece of land that sticks out into the sea, formed when waves from different directions push sediment together
99
how’s a cave stack then stump formed
9 stages
1) cracks at the base of the headland and they are widened through processes
2) cracks are further widened through weathering processes
3) over time cracks widen and develop to wave cut notches
4) as a result of wave refraction it becomes a cave
5) wave refraction effects all 3 sides of headland and if 2 caves are aligned they may form an arch
6) vertical joins are exposed and it becomes an arch
7) overtime the arch becomes unstable and collapses under its own weight
8) the stack of further eroded at its base creating new wave cut notches
9) then eventually turns into stump
100
what is the difference in wave attack for headlands and bays
headland-> concentrated wave energy
bay- dissipates wave energy
101
what is deposition
the process where agents of erosion (waves, wind, or rivers) lose energy and drop the sediment they are carrying
102
what is mass movement
the movement of a large volume of material due to the weakening of the cliff
103
what are the 3 types of weathering
mechanical-> freeze thaw, salt crystallisation
biological-> plant roots, animals
chemical-> carbonisation, oxidation
104
what type of material has little friction between between particles to hold it together
unconsolidated-> this is very loose and susceptible to mass movement
eg-> boulder clay
105
what is rotational slumping
the downslope movement of unconsolidated material in a rotational motion along a curved slip plane
106
what are types of mass movement
2
rotational slumping, rock fall
107
what is rock fall
when rock falls because the material has broken away from the source
108
why are pasammosere and halosere good for salt marshes and sand dunes
because they bind the loose sediment together and encourage further deposition
109
what is abrasion
where a wave picks up sediments and throws it against a rock
110
what is attrition
where transported material is eroded through collision with other materials
111
what is corrosion/solution
where water in waves dissolves rock minerals
112
what is beach morphology
it’s the form shape and composition of the beach
113
factors influencing beach profiles
3
-sediment supply
- changes to climate-> increased global warming-> increase storms-> winter beach profiles
-coastal management
114
how do waves affect beach morphology
-strong backwash creates steep profiles-> backwash moves sediment with gravity down slope
115
what is a beach profile
a transect from back shore to sea measuring gradient
116
how to work out wave length
crest to crest
117
what wave frequency
number of wave crests passing point A each second
118
what is a trough
the lowest point in the wave
119
what is a crest
highest point in a wave
120
what is a submerged coastline
stretches of coastline that have been inundated by the sea due to a relative SLR
121
what is an emergent coastline
stretches of the coastline that have been exposed by the sea due to a relative fall in sea levels
122
what does eustatic rise in sea level mean
it’s a global rise
123
what does isostatic rise in sea level mean
local rise
124
what does eustatic fall in sea level mean
global fall
125
what does isostatic fall in sea level mean
local fall
126
what are fjords
submerged glacial valleys due to the effect of glacial erosion
127
what are the characteristics of a fjord
2
long profile, straight ish
128
what is a dalmatian coastline
numerous islands lying parallel to the coast
129
what are synclines
fold in the rock strata that arches downward
130
what are synclines
fold in the rock strata that arches downward
131
what is a raised beach
when the fall in see level leaves beaches above the high tide mark
132
what is a fossil cliff
when the sea no longer erodes the cliffs above raised beaches
133
how is magnitude intensity affected by climate change
as climate change warms up the ocean the strength of winds will increase, which will produce stronger waves
134
global factors increasing flood risk-global sea level rise
2
-due to climate change-> warmer oceans and melting ice caps
135
local factors increasing flood risk height
2
-low elevation areas l, such as estuaries and deltas
- storms waves and a higher sea level
136
what is degree of subsidence
Degree of subsidence means how much the land has sunk or dropped down over time.
137
local factors increasing flood risk degree of subsidence
2
-some deltas are subsiding
-increased building of settlements in the land
138
what effect sediment starvation from dams have on flood risk for low lying coasts
less sediment flowing towards the delta will result in the land being lower lying
139
what effect sediment starvation from dredging have on flood risk for low lying coasts
dredging removes material from the sediment cell-> there will be less beach material available to build up the beach-> no sand to dissipate waves
140
what is the example for low lying delta
the maldives
141
why is the maldives the example for factors increasing flood risk for low lying coasts
3
-highest point of 2.4 m
- affected by seal level rise as sea level temps rising and eroding coral -> can’t absorb wave energy
142
what extreme weather events can cause flooding
storm surges
143
l
144
physical factors causing rapid coastal recession
5
wave type, tides, submerging coastline, geology, lithology
145
one factor influencing coastal recession
-fetch and wind direction-> bigger fetch and winds-> stronger waves
146
human action causing rapid coastal recession
2
-dredging-> starves beach of new sediment supply
-dam building-> decrease LSD-> less sediment input
147
what are the 6 key words for paper 1
resilience
vulnerability
governance
frequency
risk
magnitude
