Paper 1: Physical landscapes in the UK Flashcards
1
Q
What is a wave?
A
A wave is a disturbance on the surface of the sea or ocean, in the form of a moving ridge or swell.
2
Q
What causes waves?
A
Waves are caused by the transfer of energy from the wind to the sea due to the friction of wind on the water€™s surface.
3
Q
What 3 factors affect the size of waves?
A
Fetch, wind speed and wind duration
4
Q
What is the fetch of a wave?
A
The distance a wave has travelled
5
Q
What word describes the movement of a wave up a beach?
A
Swash
6
Q
What word describes the movement of a wave down a beach?
A
Backwash
7
Q
Identify the two types of wave.
A
Destructive and constructive
8
Q
Which type of wave builds beaches?
A
Constructive
9
Q
Which type of wave has a strong swash and a weak backwash?
A
Constructive
10
Q
Describe the swash and backwash of a destructive wave.
A
Weak swash, strong backwash
11
Q
What is weathering?
A
Weathering is the breakdown of rock in situ by the action of rainwater, extremes of temperature, and biological activity.
12
Q
What is mechanical weathering?
A
Mechanical weathering is the breakdown of rock without changing its chemical structure (composition).
13
Q
Describe the processes of freeze-thaw weathering.
A
Freeze-thaw weathering occurs when rocks are porous (contain holes) or permeable (allow water to pass through). Water enters the rock and freezes. The ice expands by around 9%. This causes pressure on the rock until it cracks. Repeated freeze-thaw can cause the rock to break up.
14
Q
Describe the characteristics of rock that has recently gone through freeze-thaw.
A
Recently weathered rock can be seen at the foot of chalk and limestone cliffs and is easily identified because it is angular.
15
Q
What is chemical weathering?
A
Chemical weathering is the breakdown of rock through changing its chemical composition.
16
Q
What is mass movement?
A
Mass Movement is the downhill movement of cliff material under the influence of gravity.
17
Q
Identify 4 types of mass movement.
A
Rock fall, landslide, mudslide and slumping
18
Q
Describe the process of slumping
A
The soft boulder clay holds rainwater and run-off. Waves erode the base of the cliff creating a wave-cut notch. The clay becomes saturated and forms a slip plane. The weight of the saturated cliff causes it to slump.
19
Q
Large blocks of rock sliding downhill is which type of mass movement?
A
Landslide
20
Q
Which type of mass movement involves fragments of rock breaking away from the cliff face, often due to freeze-thaw weathering?
A
Rockfall
21
Q
Which type of mass movement involves saturated soil and weak rock flows down a slope, typically where cliffs are made up of boulder clay?
A
Mudslide / mudflow
22
Q
What is coastal erosion?
A
Coastal erosion is the wearing away of the land by the sea.
23
Q
Identify the main processes of coastal erosion.
A
Corrasion, abrasion, hydraulic action, attrition and corrosion/solution.
24
Q
Give an outline of what corrasion involves.
A
Corrasion is when destructive waves pick up beach material (e.g. pebbles) and hurl them at the base of a cliff. Over time this can loosen cliff material forming a wave-cut notch.
25
Give an outline of what abrasion involves.
Abrasion occurs as breaking waves, concentrated between the high and low watermarks, which contain sand and larger fragments wear away the base of a cliff or headland. It is commonly known as the sandpaper effect. This process is particularly common in high-energy storm conditions.
26
Give an outline of the steps involved in hydraulic action.
Waves hitting the base of a cliff causes leads to air compression in cracks, joints and folds in bedding planes causing repeated changes in air pressure. As air rushes out of the crack when the wave retreats it leads to an explosive effect as pressure is released. This process is supported further by the weakening effect of weathering. Material breaks off cliffs, sometimes in huge chunks. This process is known as hydraulic action.
27
What is attrition?
Attrition is when waves cause rocks and pebbles to bump into each other and break up.
28
What is corrosion/solution?
Corrosion/solution is when certain types of cliff erode as a result of weak acids in the sea.
29
What is coastal transportation?
The movement of sediment and beach material through wave action.
30
Identify the 4 main processes of coastal transportation.
Solution, suspension, saltation and traction
31
What is traction?
Traction – large pebbles and boulders are rolled along the seafloor.
32
What is saltation?
Saltation – beach material is bounced along the seafloor.
33
What is suspension?
Suspension – beach material is suspended and carried by the waves.
34
What is solution?
Solution – material is dissolved and carried by the water.
35
What is the zig-zag movement of material along the shore by wave action called?
Longshore Drift
36
Describe how longshore drift transports material.
Waves approach the beach at an angle. The swash carries material up the beach in the direction of the prevailing wind. The backwash carries material back into the sea at right angles. This process slowly moves material along the beach.
37
What is coastal deposition?
Coastal transportation involves material being transported by the sea being deposited or dropped.
38
Why does coastal deposition occur?
Wave energy reduces leading to material being deposited.
39
Give three conditions that lead to coastal deposition happening.
Any three from: Waves enter an area of shallow water / waves enter a sheltered area, e.g. a cove or bay / there is little wind / a river or estuary flows into the sea reducing wave energy / there is a good supply of material and the amount of material being transported is greater than the wave energy can transport.
40
What is a headland?
A headland is a cliff that sticks out into the sea and is surrounded by water on three sides.
41
What is a bay?
A bay is an inlet of the sea where the land curves inwards
42
Do headlands form along concordant or discordant coastlines?
Headlands form along discordant coastlines
43
What is a discordant coastline?
A discordant coastline is where the geology alternates between strata (bands) of soft and hard rock.
44
What is a concordant coastline?
A concordant coastline is where the same rock runs along the length of the coast. Concordant coastlines tend to have fewer bays and headlands.
45
Explain the formation of bays and headlands.
The bands of soft rock, such as sand and clay, erode more quickly than those of more resistant rock, such as chalk. This leaves a section of land jutting out into the sea called a headland. The areas where the soft rock has eroded away, next to the headland, are called bays.
46
Why are sandy beaches likely to form in bays?
Sandy beaches are often found the sheltered bays where waves lose energy, and their capacity to transport material decreases resulting in material being deposited.
47
What is a wave-cut platform?
A wave-cut platform is a wide, gently sloping surface found at the base of the cliff and extends into the sea.
48
Explain the formation of a wave-cut platform.
A wave-cut platform is formed when the sea erodes a weakness in the base of the cliff by hydraulic action and abrasion. As the notch becomes larger the cliff becomes unstable and collapses as the result of gravity The cliff retreats inland. The material from the collapsed cliff face is eroded and transported away. This leaves a wave-cut platform. The process repeats over time.
49
What are the steps in the formation of a stump?
Crack - cave - arch - stack - stump
50
Identify your case study location for landforms of coastal erosion.
Jurassic coast - Dorset (Old Harry Rocks)
51
Describe the landforms that have formed here.
Landforms will include wave cut platforms, headlands, bays, stacks, arches and stumps.
52
Identify 3 landforms of coastal deposition
Beaches, sand dunes, spits and bars.
53
What is a beach?
The beach is the area between the lowest spring tide level and the point reached by the storm waves in the highest tides.
54
Where do sandy beaches typically form?
A sandy beach is usually formed in a sheltered bays, where low energy, constructive waves transport material onto the shore.
55
What is a spit?
A spit is an extended stretch of beach material that sticks out to sea and is joined to the mainland at one end.
56
What is a bar?
A bar is a ridge of sand or single that joins two headlands either side of a bay.
57
Explain the formation of a bar.
Material is carried along the coast by longshore drift. The deposited material eventually joins up with the other side of the bay and a strip of deposited material blocks off the water in the bay. The area behind the newly formed bar is known as a lagoon.
58
What is a sand dune?
A sand dune is a small ridge or hill of sand found at the top of a beach, above the reach of the waves.
59
How are sand dunes formed?
Sand is deposited by the wind around an object such as a rock, forming embryo dunes. Vegetation such as marram grass stabilise the sand dunes forming fore dunes. As the vegetation around the fore dunes decomposes nutrients are released and soil begins to form. A wider range of plants are then able to colonise the dunes.
60
What is hard engineering?
Hard engineering involves building artificial structures which try to control natural processes.
61
Give three examples of hard engineering techniques used to protect the coast.
Groynes, rock armour, sea walls, revetments, gabions or breakwater.
62
How does a groyne help reduce coastal erosion?
Groynes trap material being transported by longshore drift. This builds up a wide beach which helps absorb energy from waves, reducing the rate of cliff erosion.
63
What is the impact of groynes down drift?
Beaches beyond the defences are starved of beach material due to their impact on longshore drift.
64
Give an advantage of using rock armour to protect the coast.
Cheap and efficient at reducing energy in waves approaching the coast.
65
What are gabions?
Gabions are coastal defences that consist of rocks and boulders encased in a wired mesh. They absorb the energy from waves.
66
What is soft engineering?
Soft engineering does not involve building artificial structures but takes a more sustainable and natural approach to managing the coast.
67
Give three examples of soft engineering.
Beach nourishment, managed retreat, dune regeneration, brief reprofiling.
68
Identify the soft engineering technique being described: This is when areas of the coast are allowed to erode. This is usually in areas where the land is of low value.
Managed retreat
69
Identify the soft engineering technique being described: Beaches are made higher and wider by importing sand and shingle to an area affected by longshore drift.
Beach nourishment
70
Identify the soft engineering technique being described: This involves taking action to build up dunes and increase vegetation
Dune regeneration
71
Identify the soft engineering technique being described: This technique involves redistributing sediment from the lower part of the beach to the upper part of the beach.
Beach reprofiling
72
Identify your coastal management case study location.
Holderness coast
73
Why are coastal management strategies needed at your case study location?
The coastline is rapidly eroding at an average of 1.8 metres a year. There are several reasons why the coast at Holderness is eroding so quickly including rock type and powerful waves
74
Identify the coastal management strategies used at your case study location.
Bridlington is protected by a 4.7 km long sea wall. Hornsea is protected by a sea wall, groynes and rock armour. Coastal management at Withersea has tried to make the beach wider by using groynes, and also uses a seawall to protect the coast.
75
What conflicts have been caused by the coastal management strategy at your case study location?
Some people disagree with where the sea defences are located, especially if it means the land in their community is not protected. Some sea defences negatively impact tourism and reduce the amount of money coming in to the area.
76
What is the long profile of the river?
A Long profile shows the gradient of the river from its source to mouth.
77
Where is the steepest gradient in the long profile of a river?
The steepest gradient in the long profile of a river is found in the upper course near to the source.
78
Why in the upper course is the cross profile of a river valley narrow and steep sided?
It becomes narrow and steep sided in the upper course due to vertical erosion.
79
Why does the river channel become wider and deeper with distance downstream?
The river channel becomes deeper due to the increase in discharge and wider due to lateral erosion.
80
In the middle course of the river valley floor becomes wider why is this?
The increase in lateral erosion.
81
Why do discharge and velocity increase downstream?
Discharge increases downstream because of additional water from tributaries. Velocity increases due to the additional water from tributaries and less water is in contact with the bed and banks so there is less friction.
82
What is vertical erosion?
Vertical erosion involves the deepening of the river bed. This is mostly by hydraulic action. It is most common in the upper course of the river.
83
What is lateral erosion?
Lateral erosion erodes the banks of the river. This is more common in the middle and lower courses of a river.
84
Identify the four Processes of erosion that occur within a river.
Abrasion or corrasion, attrition, hydraulic action and solution or corrosion
85
What is hydraulic action?
Hydraulic action is when the force of fast-flowing water hits the bed and banks and forces water and air into cracks in the bedrock. The repeated changes in air pressure cause the river bed to weaken.
86
What is abrasion?
Abrasion, also known as corrasion, is when boulders and stones wear away the river banks and bed. Angular rocks that have entered the channel recently are useful tools of abrasion because they are more angular. Abrasion is responsible for both lateral and vertical erosion of the river channel
87
What is attrition?
Attrition is when sediment particles knock against the bed or each other and break, becoming more rounded and smaller as you move down the river.
88
What is the solution?
Solution (or corrosion) is when acidic water dissolves rocks such as chalk or limestone.
89
What happens to the shape and size of bed load as you move down the river?
It becomes more rounded and smaller.
90
What is the main process of erosion in the upper course of a river?
Hydraulic action.
91
Identify the four main processes of transportation in a river?
Solution, suspension, saltation and traction.
92
What is traction?
Large boulders and rocks are rolled along the river bed.
93
What is saltation?
Small pebbles and stones are bounced along the river bed.
94
What is suspension?
Fine, light material is carried along in the water.
95
What is solution?
Minerals are dissolved in the water and carried along in solution.
96
What is deposition?
Deposition is the processes by which a river drops its load.
97
Why do rivers deposit sediment?
Deposition occurs whenever a river loses energy and velocity falls.
98
Give three examples of where a river may deposit sediment.
Deposition occurs: a river enters a shallow area (this could be when it floods and comes into contact with the flood plain)at the base of a waterfall on the inside bend of a meander towards its mouth where it meets another body of water.
99
What is a cross profile?
River cross profiles show you a cross-section, taken sideways, of a river channel and/or valley at certain points in the river course.
100
What is a channel cross profile?
A channel cross-profile is a cross section of only the river channel.
101
What is a valley cross profile?
A valley cross-profile includes the channel, the valley floor and the sides of the valley.
102
How does a channel cross-section change downstream?
In the upper course the channel is very narrow and very shallow. By the middle course the channel becomes wider and deeper usually over 1 m. By the lower course the channel becomes wider still and the channel is much deeper.
103
Why does the channel cross-section change downstream?
In the upper course, the river erodes its bed by hydraulic action and abrasion. As the river flows downstream it is joined by tributaries, increasing the volume of water, velocity and therefore its erosive power. This enables it to cut a deeper channel as it flows downstream.
104
What are interlocking spurs?
Interlocking spurs are fingers of land that jut out into the river valley that streams and rivers are forced to flow around in the upper course.
105
Give three characteristics of interlocking spurs.
Steep gradient, convex slopes, project from alternate sides of the family, separated by a narrow valley floor which is mainly taken up by the river channel, sometimes covered in Woodland and may have scree slopes.
106
What are rapids?
Rapids are fast flowing, turbulent sections of the river where the bed has a relatively steep gradient. They are found in the upper course of the river.
107
Where are waterfalls and gorges typically found along the long profile of a river?
Waterfalls and gorges are typically found in the upper course of the river.
108
What is a waterfall?
A waterfall is a step in the long profile of the valley. It is where water falls down the vertical drop in the channel usually from a considerable height.
109
What is a gorge?
A gorge is a narrow, steep sided valley, with bare, rocky walls
110
Give three characteristics of a gorge.
Characteristics of gorge include: very narrow valley, very steep, high valley sides. Is located immediately downstream of a waterfall. River channel takes up most, if not all, of the valley floor. Boulders litter the river bed. Turbulent, fast flowing whitewater
111
How does a waterfall create a gorge?
As a waterfall retreats it leaves behind the steep sided valley which is called gorge. Every time the overhanging Rock breaks off the gorge retreats and grows longer.
112
How is a meander formed?
Fast flowing water on the outside bank causes lateral erosion through hydraulic action and abrasion which under cuts the bank, creating a river cliff. Eroded material is then deposited on the inside of the next meander where friction slows the flow, creating a slip-off slope.
113
What is an oxbow lake?
An oxbow lake is a small, horseshoe shaped lake that is located several meters from a straight stretch of river.
114
Explain the formation of an oxbow lake.
Due to erosion on the outside of a bend and deposition on the inside, the shape of a meander will change over a period of time. Erosion narrows the neck of the land within the meander and as the process continues, the meanders move closer together. When there is a very high discharge (usually during a flood), the river cuts across the neck, taking a new, straighter and shorter route. Deposition will occur to cut off the original meander, leaving a horseshoe-shaped oxbow lake.
115
What is a levee?
Levees are naturally raised riverbanks found along the sides of the river channel that has experienced flooding.
116
What are the characteristics of levees?
The main characteristics of levees are: raised river banks consist of gravel, stones and small sediment. Steep on the channel side, gentle sloping on the land side. Relatively flat top covered in grass
117
How are levees formed?
When a river floods friction with the floodplain leads to a rapid decrease in the velocity of the river and therefore its capacity to transport material. Larger material is deposited closest to the river bank. This often leads to large, raised mounds being formed. Smaller material is deposited further away and leads to the formation of gently sloping sides of the levees.
118
What is a flood plain?
A flood plain is a large area of flat land either side of the river that experiences or has experienced flooding.
119
What are the characteristics of a flood plain?
Characteristics of a flood plain include: A large area of flat land either side of a river. Layers of alluvium (silt/sand//sediment) cover the flood plain
120
How is a flood plain formed?
Floodplains form due to erosion and deposition. Erosion removes any interlocking spurs, creating a wide, flat area on either side of the river. During a flood, material being carried by the river is deposited (as the river loses its speed and energy to transport material). Over time, the height of the floodplain increases as material is deposited on either side of the river. The floodplain is often a wide, flat area caused by meanders shifting along the valley.
121
What is an estuary?
Where a river meets the sea
122
How do estuaries form?
The river loses energy when it flows into the sea. This causes it to deposit (drop) all the sediment it was carrying. The deposited sediment builds up, forming mudflats.
123
Give an example of a river valley in the UK that you have studied
The River Tees
124
Give a feature of the uppercourse of the River Tees
High Force waterfall - the waterfall with the highest volume of water in England
125
Give a feature of the middlecourse of the River Tees
The meanders near Barnard Castle and surrounding Yarm
126
Give a feature of the lowercourse of the River Tees
The Tees estuary
