The Physical Geography of the UK Flashcards
1
Q
What is the relief ?
A
The shape of the land .
2
Q
What causes waves
A
-Waves are caused by wind blowing over the sea (friction) .
3
Q
What is the crest ?
A
The top of a wave
4
Q
What is a trough ?
A
The base of a wave
5
Q
What is the wave height ?
A
Vertical distance from trough to crest .
6
Q
What is the wave length ?
A
The vertical distance between two successive crests .
7
Q
What is the wave frequency ?
A
The number of waves breaking per minute .
8
Q
What is the fetch ?
A
The distance over which the wind ahs blown .
-How far the wave has stretched .
9
Q
What is the swash ?
A
Movement of water up the beach .
10
Q
What is backwash ?
A
Movement of water down the beach .
11
Q
What does the strength of a wave depend on ?
A
-The speed of the wind ; strong wind s result in stronger waves because more energy is transferred intoo waves .
12
Q
What does the strength of a wave depend on (2) ?
A
-How long the wind has been blowing , the longer the wind has been blowing , rhw more energy is transgerred and the stronger the waves .
13
Q
What does the strength of a wave depend on (3) ?
A
-The fetch , the longer the fetch , the greater is the possibiliry of large waves if the storms are widespread.
14
Q
Formation of a shallow wave in water .
A
- In deep water , each water molecule moves within a circular motion .
- As a wave moves into shallower water , they begin to stack up .
- Waves slow down due to friction with sea bed , and increase in height .
- Water moelecules now move in elliptical shape (oval)
- Frictional drag increases clsoer to beach so bottom of wave slows down so top part of wave is travelling faster , casuing wave to tilt , break and move towards shore in surf zone .
- As wave breaks and flows onto the beach , swash and gravity takes i down beach as backwash .
15
Q
What are some characteristics of constructive waves ?
A
- Constructive waves are found in sheltered bays and spits , where they build up sandy beaches .
- Are low energy
- Long wave elngth so low frequency 8-10 per min
- only gains little height when breaking a water spreads long way up gently sloping beach .
- Strong swash and very weak backwash .
16
Q
How is it possible to build beach with contructive waves .
A
Strong swash means a lot of sediment can be deposited and weak backwash so cannot be broguht back into sea .
17
Q
How is it possible to build a beach with destructive ways ?
A
-Found in pebble beaches ,
-common winter than summer .
Short wave length so hgih frequency 10-14/m
-Wave height 1 m gains much height .
-Plunges on to a steep beach but dosent travel far up .
-Restricted swash but very strong backwash .
18
Q
How do destructive ways drag material out to sea ?
A
-Stronger backwash than swash drags beach material out to sea eroding the beach .
19
Q
Similarity betwene constructive and destructive waves .
A
-Both waves are fromed by wind blwoign over the surface of th sea and have a swash and backwash .
20
Q
What is weathering ?
A
The breakup of material like rock on site .
21
Q
What is erosion ?
A
Erosion is the break up of material like rock along some sort of transport process (landslide)
22
Q
What is mechanical weathering ?
A
Mechanicl weathering is a physical processes take place to break apart large rocks into smaller ones .
Example freeze thaw .
23
Q
Explain freeze thaw mechanical weathering :
A
-Water settles between cracks in a cliff and then turns into ice which naturally has a larger volume than water .
As a result , the rock is slightly displaced outwars , hwoever , when the ice melts , the water travels further down the crack and then expands agin ,t his cyle of weathering continues until rock fully splits .
24
Q
What is salt weatherig , mechanical weathering ?
A
whenn salt spray from sea gets into a rock , evaporates and crystalises , putting pressure on the surroudnign rock ,weakening its strucutre .
25
What is Biological weathering ?
Biological weathering is to do with how organisms physically alter the environemnt .
- E.g rabbits dig hoels which break apart soil and begetation like treesbreak up under soil undenreath .
- Seen in old roads , tarmac lifted by tree roots .
26
What is chemical weathering ?
-In chemical weathering, the chemical composition of rock changes.
CARBONATION
-When the climate is warm and wet, carbon dioxide can dissolve in rain to create a 'carbonic acid'.
-The carbonic acid in rainfall hits rocks and dissolves the parts of the rock made of calcium carbonate.
-Warm wet conditions btw This also breaks down rock.
27
What is mass movement ?
Mass movement describes the large movement of soil and rock down the slope of a hill or cliff.
28
Causes of mass movement ?
- Mass movements are caused by weathering, erosion, and gravity.
- Small changes over time can mean that the centre of gravity of a cliff can hang over the sea, instead of over land making the cliff unstable and prone to mass movement.
29
Types of mass movement
- rockfall
- slides
- slumps
30
What are rock falls ?
Rockfalls are when the cliff (materials) break and crumble down the cliff down a slope .
31
What are landlsides ?
Slides are when material moves down a slope in a straight line.
32
What are slumps ?
- Slumps are when material moves down a slope at a curve .
| - Slump is a slip plane under the land is formed . The cliff slumps down in layers .
33
What are the different type of erosions ?
- Hydraulic Power .
- Atrrition
- Solution
- Abrasion
34
What is hydraulic power ?
Hydraulic power is where the force of waves hits against a cliff face and causes rock to break off.
35
What is attrition ?
- Attrition is where different bits of material carried by waves in seawater hit against each other.
- This causes them to break apart but also become smaller and more rounded.
36
What is solution ?
Solution is where weak acids in seawater dissolve soluble rocks like chalk and limestone .
37
What is abrasion ?
-Abrasion is where pieces of material are picked up by waves and hit or scrape against the sea bed or the side of a cliff.
This wears away the sea bed or cliff because the material acts like sandpaper.
38
What is a wave-cut platform ?
a wave-clut platform is when cliffs are eroded by destructive waves, resulting in the formation of wave-cut platforms.
39
Stage 1 of a wave-cut platoform ?.
Destructive waves are responsible for most of the erosion at the base of cliffs.
- Hydraulic action and abrasion wear away the base of the cliff around the high tide mark.
- Eventually, this erosion causes a wave-cut notch to form.
40
Stage 2 of a wave-cut platform ?
Continued erosion of the wave-cut notch causes the rock above it to become less and less stable until it collapses.
Stage 3
Stage 4
41
Stage three of a wave-cut platform ?
- Waves wash away the debris from the cliff collapse.
| - The destructive waves begin to erode the cliff, causing a new wave-cut notch to form.
42
Stage four of a wave-cut platform ?
- As stages 1-3 happen again and again, more debris falls into the ocean and the cliff retreats.
- What is left behind is called a wave-cut platform.
- A wave-cut platform is a flat, gently sloping ledge of rock that extends out into the sea from the base of the cliff.
43
Where will erosion be higher ?
- Soft rocks
- A headland jutting out into sea
- Area has no beach ot cts as buffer between sea and cliffs .
44
`How is load transported onto a beach ?
- By waves .
- larger and heavieer the load paricles ,t he greter elcoity needed to transport it .
- Lighter loads carried by suspension and heavier by traction .
45
What is the porcess at whcih load is transported by?
Transported by longshore dirft .
46
What is the previaling wind ?
the direction the wind comes from most often .
47
Explain long shore drift .
- Wind approaches the coast at an angle due to a prevailing wind direction.
- Waves are controlled by the wind, so this angle will be the direction the swash moves up the beach.
- Gravity is the only force that acts on the backwash, so it falls back to the sea at right angles to the coastline.
- This causes sediment to repeatedly move in the shape of a right-angled triangle
- . Over time, sediment is carried along a beach.
48
What is load ?
Transported Material .
49
What is depostion ?
When waves drop and leave behind the load they were trnansporting . Deposited load is called sediment .
50
Where do headlands and bays form ?
Headlands and bays are formed in areas that have alternate areas of hard and soft rock facing the sea.
51
How do headlands and bays form ?
- Rock with lots of cracks and joints is called soft rock.
- When the sea hits both the soft and hard rock, more of the soft rock is eroded.
- soft rock erodes inwards, creating a bay.
- The hard rock that erodes more slowly is called a headland.
52
What is classified as a soft rock ?
A rock with lots of cracks and joints is called a soft rock .
Headlands amde of mroe restsant rock , less weaknesses .
53
What landforms can be made when Headlands are eroded ?
-Caves
-Arches
-Stacks
(In order of erosion)
54
How are caves formed .
- There are cracks, joints, and weaknesses in rocks.
- When cracks get wider (because of hydraulic action, abrasion or attrition), they can become large enough to create a cave.
55
How are arches formed ?
Caves can be eroded from one side of the rock through the other.
This creates an arch.
You can see right through an arch to the other side of the rock.
Durdle Door (Dorset), Bow Fiddle Rock (Scotland),
56
How are stacks formed ?
When the top of an arch collapses because of gravity, a column called a stack is left behind.
57
What does rock structure include ?
- How rocks are aligned in relation to the coast .
| - How rocks dip down t sea as a result of folding .
58
What are the foru processes of transport that water can transport sediment ?
-Solution
Suspension
-Saltation
-Traction
59
What is solution ?
A solution is where rocks that are soluble are dissolved by water (limestone and chalk in particular). They are then transported within the water.
60
What is suspension ?
A suspension is where silt (sand, clay or other material) and sand particles are held in water (but not dissolved). The silt and sand particles are then transported along with the water.
61
What is saltation ?
Saltation is where small sand and gravel particles bounce along the river bed or sea bed.
They will travel in the direction of the flow of water.
62
What is Traction ?
Traction is where large rocks or large particles are dragged along the river bed or sea bed by the current.
63
Why does depostion happen ?
- Deposition happens when constructive waves break on the shore. The sediment being carried by the sea is put (deposited) on the coastline.
- This usually creates beaches made of sand or shingle in the area between the 'high' water mark and the 'low' water mark.
- The high water mark is the point the highest up the beach that the sea level rises to.
- The low water mark is the point the lowest down the beach that the sea level falls to.
64
What increases the amount of deposition ?
- If erosion on the nearby coast is high, then lots of rock and sand will fall into the ocean. This will increase deposition on nearby beaches.
- The more sediment in the ocean, the more deposition there will be.
Why are some beaches sandy & some shingle?
65
Why are some beaches sandy and some shingle ?
- Sandy beaches are created by sand being deposited on the shoreline.
- Sandy beaches are usually very long, side, and flat because particles of sand are very small and easy to wash back into the ocean with the backwash.
- Shingle beaches are made when pebbles and shingle are deposited on the coast. --Shingle and pebbles are big and hard to wash back into the ocean, so they build up (making short and steep beaches).
66
In addition to beaches , the deposition of sediment can also create ...
-bars, spits, and sand dunes.
67
What are spits .
Spits are piles of sand that create sheltered zones on the coast.
68
How do spits form ?
- When the coast changes direction at an estuary (where a river meets the sea), longshore drift continues to move sediment across the inlet.
- The river doesn't let the longshore drift completely join to the coast on the other side because the river has the energy to move the sediment.
- Spits are the long fingers of sand sticking out from one side on a coastline.
- They often have marshland forming in the sheltered zone.
69
Whtat are sand dunes ?
Sand dunes are hills of sand created at the back of a beach.
70
How do sand dunes form ?
The wind blows deposited sand up the beach.
- Objects like wood, driftwood or human rubbish can block the wind, leading to hills of sand.
- The hills of sand can allow plants and vegetation to grow.
- This leads to more sand building up.
- Older sand dunes (hills) are called mature dunes.
- Newer sand dunes are called embryo dunes
71
How are bars created ?
- A bar is created when a spit grows across a bay.
| - Lagoons (saltwater pool separated from the ocean) are often created behind a bar.
72
What is on Dorset Cost ?
The Dorset Coast is also known as the 'Jurassic Coast'. At Lyme Regis, there are lots of soft rock (like clay and shale). In other parts of the Dorset Coast, there is hard rock (like limestone and sandstone).
73
Major landmarks in Dorest coast with soft rock ?
Studland Bay and Swanage Bay are 2 areas of soft rock that have beaches very close to each other.
74
Headland in Dorest Coast ?
Between Studland Bay and Swanage Bay is a headland (called the Foreland). The Foreland has a stack at the end of it called Old Harry.
75
A bay or cove in Dorset ?
- Lulworth Cove is a bay or cove next to the town of West Lulworth.
- The sea had eroded the soft rock (clay) surrounded by the hard rock (limestone) that makes up the headland at Lulworth Cove.
76
Arch in Dorest
- Durdle Door
- Durdle Door is a famous arch.
- Arches are created when caves in a headland are fully eroded.
- The headland in Dorset is usually made of limestone and sandstone.
77
A bar in Dorset ?
- Chesil Beach is a bar that joins an island and the mainland.
- There is also a lagoon behind the bar at Chesil Beach.
78
Examples of coastal landforms in dorset coast ?
- Chesil Beach
- Lulworth Cove
- Durdle Door
- Swanage and Studland bays .
79
What is Hard Engineering ?
- Hard engineering strategies to protect coastlines use man-made constructions to protect the coastline from the sea's erosion and destructive waves.
- Hard engineering can also be used to stop the sea or rivers from flooding areas.
80
Examples of Hard Engineering
- Rock armour
- Groynes
- Gabions
- Sea Walls
81
What is Rock armour ?
- Rock armour is simply a pile of rocks or boulders.
- The rocks absorb some of the pressure and energy transferred by waves.
- Enormous waves can remove the boulders, but they are a very cheap form of coastal protection.
82
What are Groynes ?
- Groynes are fences that stick out at 90o to the coast.
- Groynes stop the process of longshore drift by trapping material against the fence.
- Groynes create wide beaches, which are better for protecting the coastline from erosion and floods.
- Building fences is also cheap.
83
What are sea walls ?
- Sea walls are made out of materials that block waves.
- Making them out of hard rock or materials like concrete means that they are more resilient and last longer.
- Their shape can be designed to reflect a wave's power back out to sea, instead of being absorbed by the sea wall head-on.
- Sea walls can protect -promenades from flooding and can reduce coastal erosion.
- Sea walls cost a lot of money and have to be built all along a town's coastline to protect the town.
84
What are Gabions ?
- Gabions are wire cages full of boulders and rocks.
- The gabions absorb some of the pressure and energy transferred by waves.
- This leads to less erosion, but the wire in the cages is corroded over time.
85
What is Soft Engineering ?
-Soft engineering strategies artificially use the sea, physical and natural processes to protect coastal areas from flooding and erosion
86
Examples of Soft enginerring ?
- Beach Nourishment
- Beach reprofiling
- Dune regeneration
87
Whta ia beach nourishment ?
- Beach nourishment involves adding more sand to a beach.
- The sand can be purchased or moved from another part of the beach.
- Sand and shingle will naturally be pushed up against groynes and this sediment can be put back on other parts of the beaches.
88
What is beach reprofiling ?
- Beach reprofiling involves The sediment is redistributed from the lower part of the beach to the upper part of the beach.
- Creating wider beaches can slow waves and reduce the energy that waves have when they hit the shore.
- Reprofiling and moving sand & shingle can damage the wildlife living amongst it
89
What is dune regeneration ?
- Dune regeneration focuses on improving and maintaining sand dunes.
- Nourishing or planting plants can help to support the dunes and help them resist wind and absorb destructive waves' energy.
- Again, planting lots of vegetation all the way up and down sand dunes can be expensive.
90
What is managed retreat ?
- Managed retreat involves accepting defeat. Instead of trying to stop the sea advancing, coastal defences are removed, and land is flooded.
- This land will likely become mangrove swamps or marshland.
- However, this will protect the land behind it.
91
Advanatages of managed retreat ?
- Managed retreat protects the land behind the mangroves or swamps.
- Managed retreat costs no money & no maintenance is needed.
- Swamps and mangroves are often biodiverse.
- Managed retreat moves the coastline.
- Because of this, it can be called coastal realignment.
92
What are the disadvanatages of managed reterat ?
-Land is lost to the sea.
Some people may lose their land or livelihoods if farmland is allowed to be flooded.
-Someone's house could be lost if they lived in the area that would become marshland.
93
Example odf a coastilne in the UK ?
Swanage Dorset .
| -Swaage is located on the south coast of England . Swanage is on a stretch of coastline known as the jurassic coast .
94
What is the coastline of Swanage like ?
- The coastline at Swanage is discordant.
- A discordant coastline is made up of lots of different types of rock.
- The discordant coastline has led to the formation of bays and headlands.
95
What is the coastline of swanage made up of ?
-Bands of hard rock (e.g. chalk).
Limestone.
-Soft clays.
-Sands.
96
Characteristics of swanage bay ?
- Swanage Bay is a sandy beach.
| - Swanage Bay has formed in a sheltered bay.
97
Example of a headlanad near Swanage ?
Ballard point :
- Ballard Point is an example of a headland near Swanage.
- Ballard Point was created by a band of chalk in the coastline.
- The well-known Old Harry stack, cliffs and arches are found at the end of Ballard Point.
98
Full answer explain how hydraulic action causes erosion to coasts ?
- Hydraulic action is a form of coastal erosion. It happens when the waves break against the cliffs and over long periods of time it makes pieces of the cliff break off.
- Hydraulic action happens when the waves break against the cliff. Air is trapped between the sea water and the cliff. The wave keeps going and forces the compressed air into cracks in the cliff.
-Waves continue hitting the cliff and forcing air into cracks in the cliff. Eventually, this begins to enlarge the crack and erode the rock.
