Topic 4 Flashcards
(102 cards)
1
Q
How are igneous rocks formed?
A
After a volcano erupts, the magma cools down and hardens which forms rocks
2
Q
How are sedimentary rocks formed?
A
Formed by small particles of sediment that have been eroded, transported and deposited into layers which forms rocks
3
Q
How are metamorphic rocks formed?
A
Existing rocks that have been changed due to extreme pressure and heat. They have a lot of layers and are very hard
4
Q
Key features of the uplands
A
North west of UK
Usually metamorphic and igneous rocks
300m-600m years old
More resistant and steeper
5
Q
Key features of the lowlands
A
South east of UK
Usually sedimentary rock
2m-300m years old
Less resistant and flatter
6
Q
How did ice impact the UK landscape?
A
Ice is very powerful and therefore erodes the landscape which causes U shaped valleys. This is especially significant in the upland areas.
7
Q
What is weathering?
A
It is the breakdown of rock into smaller pieces which can be mechanical, chemical or biological
8
Q
What is erosion?
A
This is when rock is worn away. During the glacial period, ice eroded the landscape. Now, rivers and sea erode rock.
9
Q
What are post glacial processes?
A
At the end of glacial periods, the melting ice made much bigger rivers then normal which have more power to erode the landscape.
10
Q
What are slope processes?
A
Mass movements e.g. rockfall, slides, and slumps
11
Q
What are some physical processes which created the upland landscapes?
A
Freeze-thaw weathering leads to scree slopes
U-shaped valleys due to ice
Impermeable rocks resulted in a lot of streams
12
Q
What are some physical processes which created the lowland landscapes?
A
Very flat areas due to chalk
Impermeable clay causes meanders
13
Q
How is settlement different in the upland areas?
A
Farms are far away from each other and isolated
Developed transportation
Good roads which allow for easier access to surroundings
14
Q
How is settlement different in the lowland areas?
A
There are large villages around the farms
15
Q
How are building materials different in the upland areas?
A
Mainly use of local bricks and slate
Stone
Clay
16
Q
How are building materials different in the lowland areas?
A
The materials are much more varied
They are easily brought in by road or rivers
17
Q
How are field boundaries different in the upland areas?
A
Follow the shape of land
Stone walls
Well structured
Land will remain for a long time
18
Q
How are field boundaries different in the lowland areas?
A
Boundaries are structured
Trees have been cut down
Won’t last as long
19
Q
How is farming different in the upland areas?
A
Sheep and hay farming
Done on valley floors during winter
Done on higher ground in the summer
20
Q
How is the economic activity different in the upland areas?
A
Mainly the primary sector
21
Q
How is the economic activity different in the lowland areas?
A
Tertiary
22
Q
How are field boundaries different in the lowland areas?
A
Crops on smaller and more rigid fields
Lots of nutrients
23
Q
What is mechanical weathering?
A
The breakdown of rock without changing its chemical composition
24
Q
What is the process of salt weathering
A
Seawater gets into the rocks’ cracks
Water evaporates which causes salt crystals to form
Salt crystals expand
The process repeats which causes the rock to break off
25
What is chemical weathering?
The breakdown of rock by changing its chemical composition
26
What is the process of carbonation weathering
Seawater and rainwater have carbon dioxide dissolved in them
Carbonic acid reacts with rock
27
What is biological weathering?
The breakdown of rock by living things e.g. plant roots
28
What is the process of mass movement?
It is the shifting of rocks and loose material down a slope
This is usually due to gravity
Water can increase this process as it acts as a lubricant
29
What are slides (mass movement)
When material goes down in a straight line
30
What are slumps (mass movement)
When material goes down with a rotation
31
What are rockfalls (mass movement)
When material breaks off and falls
32
What is hydraulic action?
Waves crash against rock and compress air into the cracks. This increases the pressure on the rock. This repeats which causes the crack to widen and eventually fall off
33
What is abrasion?
Eroded particles in the water scrape and rub against rock which removes small pieces
34
What is attrition?
Eroded particles in the water smash into each other. They break into smaller fragments and the edges get rounded
35
What are concordant coastlines?
Coastlines which have hard rock and soft rock parallel to the coast :
HR
SR
HR
SR
36
What are discordant coastlines?
Coastlines which have hard rock and soft rock next to each other :
HR,SR,HR,SR
37
What are destructive waves?
High
Steep
High frequency
Backwash is more powerful then swash
Stronger erosion
38
What are constructive waves?
Low
Long
Low frequency
Swash is more powerful then backwash
Brings sand and gravel to beach
39
How do wave-cut platforms form?
Waves erode the coastline at the base of the cliff. Over many years, this results in a wave-cut notch at the base of the cliff. The overhanging rock weakens and eventually collapses. Waves continue to undercut the cliff which results in a gentle slope area. Repeated collapsing causes the cliff to retreat which makes the wave-cut platform visible.
40
How do headlands and bays form?
They usually form at discordant coastline
The sea attacks a section of the coast and the bands of soft rock will erode faster then those of hard rock. This leaves a section of land sticking out in the sea called the headland. The areas where the soft rock has been eroded are called bays, which have a gentle slope.
41
How do arch's, stacks and stumps form?
These form due to a headland. The waves are very strong because only the headlands are sticking out so far into the sea. Usually, they have cracks and as the sea constantly attacks those cracks, they eventually fall off and form a cave. Caves can form from opposite sides and when they meet, a natural arch is made. Erosion continues to wear away the rock supporting the arch, until it eventually collapses. This forms a stack which is just an isolated rock separate from the headland. Further erosion at the bottom will cause the top to collapse and a stump will be made.
42
What is longshore drift?
It is the process by which material is transported along the coastline
Waves follow the direction of the prevailing wind (SW)
They hit the coast from the same direction as the winds
Swash carries the material up the beach in the same direction as the winds
Backwash carries the material down the beach at a right angle
The next wave picks up this sediment
This process repeats over and over again
43
What is deposition?
When material is added by constructive waves which can form landscapes
44
How do spits form?
Spits form at sharp bends in the coastline
Longshore drift transports sand past this bend and deposits it into the sea
They are commonly found next to a headland
This is because behind it, there is a sheltered area which receives lower energy waves
Gradually, smaller sediment is dropped off and the spit grows
Strong winds and waves can cure the end
45
How do bars form?
It is formed when a spit joins two headlands together
It cuts off the bay from the sea
This means a lagoon can form
46
What is solution?
Dissolved chemicals in water, usually from limestone or chalk
47
What is suspension?
Particles carried with water
48
What is saltation?
Particles which are too heavy to be suspended often hop or bounce
49
What is traction?
Large pebbles rolled along the coastline
50
What are direct effects?
Effects on the coastline which have an immediate effect. For example, coastal defences will prevent erosion
51
What are indirect effects?
Effects that happen as a result of direct effects. For example, coastal defences will increase erosion further down the coast
52
How does agriculture have an effect on the coast?
It has low economic value which means it is often unprotected - land will erode faster
Changing farmland can affect stability of cliff
Vegetation binds soil together and makes the cliff more stable
Clearing vegetation can expose the soil and make it more vulnerable to erosion
53
How does development have an effect on the coast?
Coasts with a lot of settlement may have more coastal defences to protect homes and businesses
Coastal defences decrease the amount of sediment supply to that beach
54
How does industry have an effect on the coast?
Coastal quarries expose large areas of rock making them more vulnerable to erosion
Gravel is extracted and used in construction. This decreases cliff protection and increases erosion
55
How does coastal management have an effect on the coast?
Some protection makes erosion stronger down the coast
56
What is our coast case study?
Holderness
57
What is the coastal defence in Bridlington and why?
Groynes and sea wall
Large population (30,000), tourism and jobs
58
What is the coastal defence in Great Cowden and why?
No coastal defence
Only consists of farmland and parks
59
What is the coastal defence in Mappletown and why?
Groynes
Lots of properties, population of over 6000, intense erosion, good transport links
60
What is the coastal defence in Easington and why?
Rock armour and groynes
Gas terminal supplies 25% of the UK's gas
61
How are rising sea levels increasing the risk of coastal flooding?
They create a threat to low-lying and coastal areas
Increased sea levels can cause higher tides which mean more frequent floods
Higher tides also remove more material from beaches which will increase future erosion
62
How is rising storm frequency increasing the risk of coastal flooding?
Climate change has caused storms to be more frequent
Storms give the sea more power
Erosion will be more severe
Sea will have more energy to transport material and some areas may be starved leading to vulnerability
63
What are coastal threats to people?
Coastal areas could be permanently flooded which means it will be impossible to live there
Industries may be shut down due to the damage
Damage to roads and rail networks
Less likely for tourists to visit which provide a lot of money for the area
64
What are coastal threats to the environment?
Increased salt levels can damage or kill organisms
Reduced soil fertility
The force of the water can uproot trees and plants
65
What is hard engineering?
Man made structures to reduce flooding and erosion
66
What is soft engineering?
Schemes set up to reduce the effects of flooding and erosion
67
Benefits and drawback of sea wall
It acts as a barrier to prevent erosion and flooding
They are very expensive to build and mantain
68
Benefits and drawback of groynes
Create wider beaches which slow the waves. Fairly cheap and protects from flooding and erosion.
Beaches down the coast receive much less sand which leads to more erosion
69
Benefits and drawback of beach replenishment
Created wider beaches as sand slows down waves. Protects from flooding and erosion. Looks nicer.
Quite expensive as it has it is not permanent.
70
Benefits and drawback of slope stabilisation
Prevents mass movement
Very expensive and difficult to install
71
Features of a river upper course
Steep
V shaped
Steep sides
Narrow
Shallow
72
Features of a river middle course
Medium gradient
Gentle slope
Wider
Deeper
73
Features of a river lower course
Gentle gradient
Very wide
Flat
Very wide
Deep
74
What is vertical erosion
This deepens the river valley making it v shaped. Mainly happens in the upper course. This is caused by rough particles scraping the river bed.
75
What is lateral erosion
This widens the river valley. Mainly happens in the middle and lower course.
76
What is the river case study
River eden
77
What is the upper course of the river eden
Its source is 600m above sea level in an area of hard and resistant rock
Steep
Shallow
Discharge and velocity is low
78
What is the middle course of the river eden
Made from a less resistant rock which is easily eroded
Becomes wider and deeper
Sediment is made up of smaller and more rounded rocks
79
What is the lower course of the river eden
Very flat and wide
Few metres above sea level
High velocity due to little friction
Deep
80
What is freeze thaw weathering?
Water gets into a crack in a rock. When it freezes, it expands which adds a lot of pressure. After many times, the cracks widen and will eventually break off.
81
How do waterfalls form
It may occur when there is hard rock which lies over soft rock
Soft rock is eroded easier and over time a plunge pool is created
Eventually the hard rock collapses due to erosion and gravity
This process repeats many times
The waterfall will erode upstream which forms a steep-sided gorge
82
How do interlocking spurs form?
In the upper course the discharge is low and therefore only vertical erosion occurs which creates v shaped valleys
The rivers aren't powerful enough to erode laterally and therefore have to go in between any hills
These hills then interlock
83
How do meanders form
The flow of the water is faster on the outside of the bend because the river is deeper
More erosion takes place on the outside of the bend
The inside is much weaker and slower
Eventually, meanders will form
84
How do ox-bow lakes form
Erosion causes the outside bends to get closer
Eventually there will only be a small bit of land between them
During a flood, the river will break through this land
It will flow straight because it follows the shortest course
Deposition cuts off the meander
85
What is a flood plain
The land on either side of the river which occasionally gets flooded
86
How are levees natural embankments
They are natural raised bits along the edges of a river channel
During a flood, material is deposited
The heaviest material gets deposited the closest
Over time, the levees build up in size
87
How are rivers impacted by the climate?
Rivers in wetter climates have a higher discharge because there is more water entering
This increase the rate of erosion (more power and material)
More material carried due to the higher energy
88
How are rivers impacted by the geology?
Rivers flowing through areas of hard rock have slower erosion as it is more resistant
Softer rocks adds more sediment to the river
More resistant rock = steeper valley sides
Only certain areas form waterfalls and interlocking spurs
89
What are the stages in the river discharge
Peak discharge : the highest discharge in the period of time you're looking at
Lag time : they delay between peak rainfall and peak discharge
Rising limb : the increase in river discharge as rainwater flows in
Falling limb : the decrease in river discharge as the river returns to its normal level
90
Physical factors which affect River Eden's flooding
Mild and wet climate
Intense rainfall
Next to Lake District and the Pennines which are hard rock : impermeable
Snowfall adds even more water
91
Human factors which affect River Eden's flooding
Area has lots of development which means there is less soil and vegetation for the water to go into
Woodlands have been cleared which decreases the time for water to go into river
Not enough drainage
92
How do storms increase flooding
Climate change increases strength and frequency
Adds a lot of water to rivers
Ground is already wet and therefore will take in less water
93
How does land use change increase flooding
Expansion of urban areas leads to more impermeable surfaces
Water is harder to store
94
How do floods threaten people
Hurt or killed due to water
Roads and transport destroyed
Contaminated water can lead to a lack of clean drinking water
Damaged possessions
Homeless
95
How do floods threaten the environment
Contamination can damage habitats
Ruined farmland
Uprooted trees and plants
96
Hard engineering methods used to manage floods
Flood walls
Embankments
Flood barriers
97
Soft engineering methods used to manage floods
Flood plain retention
River restoration
98
What are flood walls
Barriers built along river banks
Designed to increase the height and hold more water
Very expensive and a bit ugly
99
What are embankments
High banks near river banks
Stop the river from flowing into built up areas
Can be made from natural materials
Quite expensive
Severe flooding if water goes over
100
What are flood barriers
Stop from storm surges
They can be shut to protect a large area
101
What is flood plain retention
Maintaining the river's flood plain
No money spent on building
Not effective in urban areas
102
What is river restoration
Removing any man made levees so the flooding can be more natural
Discharge is reduced and flooding will be weaker
Little maintenance required
