Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Abi Geography 2016 > Forces that shape Earth's crust > Flashcards

Forces that shape Earth's crust Flashcards

You may prefer our related Brainscape-certified flashcards:
U.S. Geography flashcards World Geography flashcards
1
Q

What is weathering?

A

It is the wearing away of rocks and soil by the action

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What can weather the Earth?

A

Water
Hot and cold (expansion and contraction)
Wind

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is erosion?

A

Gradual wearing away of structures

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is exfoliation?

A

When expansion and contraction of rocks weakens the first layer of rock, causing it to crack and peel off.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is constantly happening to Earth’s surface?

A

It is being continually worn away

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What forces wear away the Earth’s surface?

A

Wind
Rain
Frost
Waves

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What carves out valleys?

A

Rivers

Thick layers of ice that move over the land

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What creates cliffs?

A

Waves

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What can create mountain peaks?

A

Water and ice that break up rocks in high areas

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What causes sand dunes?

A

Winds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is soil erosion caused by?

A

Human activity and natural processes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are the most important agents of weathering?

A

Temperature

Water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are the three types of weathering?

A

Physical
Chemical
Biological

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is physical weathering?

A

Physical forces such as frost and temperature changes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is chemical weathering?

A

Chemical changes that weaken rocks

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is biological weathering?

A

The action of plants and animals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

How long does weathering take?

A

It is a slow process

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What can weathering cause?

A

Many changes to a landscape

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What are two types of physical weathering?

A

Freeze thaw action

Exfoliation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

When does free thaw happen?

A

When water collects in cracks in rocks

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What happens to water when it freezes?

A

It expands

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What does freezing water do to the walls of a crack in a rock?

A

It puts pressure on them

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Where does freeze thaw action occur?

A

In cold, wet climates

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What are the four steps of freeze thaw action?

A

Water fills a crack in a rock
Water freezes from the top of the crack downwards
The ice cannot expand upward because the top is already frozen
The ice expands sideways, putting pressure on the rocks
After many cycles of this, the crack will widen and split the rock

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Where does exfoliation occur?

A

In climates with severe temperature changes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What parts of the rock are affected by exfoliation?

A

The outer layers of rock

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What are the steps of exfoliation?

A 
Sun heats up rocks
Outer layers expand
Night cools down rocks
The outer layers contract
After many cycles of this, the outer layers begin to peel off
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What are three types of chemical weathering?

A

Carbonation
Hydrolysis
Oxidation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What chemical has dissolved in droplets of rain water?

A

Carbon dioxide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What does this gas do to the rain?

A

It turns it into a weak carbonic acid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What does limestone contain?

A

Calcium carbonate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What happens when carbonic acid comes into contact with limestone?

A

A chemical reaction occurs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Is calcium carbonate soluble?

A

No

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Is calcium bicarbonate soluble?

A

Yes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What is the product of carbonisation?

A

Calcium bicarbonate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

What are the steps of carbonisation?

A

Carbon dioxide mixes with rain water
Forms carbonic acid
Rainwater falls on rocks
The calcium carbonate in rocks reacts with the carbonic acid
The reaction forms calcium bicarbonate
Calcium bicarbonate washes away in rain water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What kind of climate does carbonisation occur in the most?

A

Cold climates

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

What kind of water can hold more carbon dioxide?

A

Cold water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

Why does carbonisation happen faster in cold climates?

A

The carbonic acid is stronger in cold water (can hold more carbon dioxide)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

In what kind of rocks does oxidation occur?

A

Rocks that contain iron

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

What is oxidation?

A

When iron in rocks oxidises (rusts)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

Why does oxidation cause weathering?

A

Iron oxide is weaker than rock and is easier to break down

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

What substances does hydrolysis involve?

A

Silicates and water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

In what rocks are silicates present?

A

Sandstone

Granite

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

What do silicate minerals do?

A

They absorb water and turn into clay

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

What are the steps of hydrolysis?

A

Water mixes with silicates
Silicates turn into clay
Clay washes away

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

What can weaken soil and expose rocks to weathering agents?

A

Burrowing animals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

What are examples of burrowing animals?

A

Worms
Moles
Porcupines

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

What can plants cause rocks to do?

A

They can force the rocks to break apart

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

In what two ways can trees affect weathering?

A

Their roots can grow through rocks

When they blow over, they can pull up rocks

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

How do lichens weaken rocks?

A

The roots of lichens penetrate in between the grains in rocks, loosening them and making them fall away
Lichens contain chemicals that break down rocks

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

How many main ways are there that humans affect weathering?

A

9

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

What are the nine ways humans affect weathering?

A

New rocks exposed to weathering by roads
Vegetation removed and soil exposed by machines
Human activities add chemicals to the air, soil and water
Dams take up land which could have been used for farming
Cattle change the soil and rocks when they walk and spread their waste
Heat from fires changes the physical and chemical composition of soil
Underground tunnels weaken rocks and soil
Roads and railways bring pollution to the countryside
Human settlements pollute the air and water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

What linked forces constantly shape the Earth’s surface?

A

Erosion
Weathering
Deposition

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

What is the difference between weathering and erosion?

A

Erosion involves the movement of minerals and rocks etc. caused by the breaking down of these things. Whereas weathering is simply the breaking down of these substances

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

How do you identify erosion?

A

There will always be motion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

What is deposition?

A

It is the third step
After weathering has broken down rocks, and erosion has moved the broken down rocks, it will be DEPOSITED somewhere else. This is deposition.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

How do you identify weathering?

A

Movement will not be involved. I.e. A rock will crack, but will not move

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

How do you identify deposition?

A

A mineral/rock etc. That has been moved from one place to another

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

Why are rivers a muddy colour?

A

It carries different kinds of weathered material

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
61
Q

What is the river’s load?

A

The material carried by a river

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
62
Q

What is the river’s load made up of?

A

Sand
Stones
Silt

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
63
Q

Where do most rivers lead?

A

Into other rivers as tributaries

These river’s then flow into the sea

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
64
Q

Where do rivers flow faster?

A

On steep land

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
65
Q

What causes downward erosion?

A

In steep, strong rivers, boulders can be washed away

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
66
Q

What does downward erosion cause?

A

A river valley with steep sides

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
67
Q

What is a waterfall?

A

A waterfall is a sudden drop in the river’s gradient

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
68
Q

What are Rapids?

A

Places where the water flows faster, but there is no drop in height

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
69
Q

What are gorges and canyons?

A

Deep-sided valleys that have been formed by downward river erosion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
70
Q

What is the difference between gorges and canyons?

A

Gorges are often linked to waterfall formation

Gorges are usually straighter than a canyon

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
71
Q

How does a canyon form?

A

When water flows faster and downward erosion occurs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
72
Q

What can cause a river to flow faster?

A

When there is more water in the river
A drop in sea level
The land is uplifted

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
73
Q

What is backward erosion?

A

When river water grinds backwards

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
74
Q

What causes a gorge?

A

Backward erosion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
75
Q

Why does backward erosion occur?

A

When a river suddenly narrows, some water will fall back and grind the sand underneath

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
76
Q

How can you identify canyon?

A

A deep-sided pathway that has formed for the river
It will usually have softer stone
It is a more meandering type of erosion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
77
Q

How do you identify gorges?

A

They are a steep-sided “pool”

The type of erosion is fiercer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
78
Q

How is a meander formed?

A

By both erosion and deposition

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
79
Q

Why does a river meander?

A

It will choose the path of least resistance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
80
Q

When a river turns a bend, which side will be eroded?

A

The outside

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
81
Q

Why will the outside of a bend erode?

A

There is faster-flowing water there

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
82
Q

When a river turns a bend, which side will minerals be deposited on?

A

The inside of the bend

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
83
Q

Why will minerals be deposited on the inside of a bend?

A

The water will go slower, so some minerals will drop

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
84
Q

How are ox-bow lakes formed?

A

The erosion caused by a meander causes the neck of the meander to narrow
The meander neck will eventually become the new river path
The new river path makes its deposits at the join of the original meander
The original meander becomes an ox-bow lake

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
85
Q

What are levees?

A

They are natural mounds on river banks

86
Q

How are levees formed?

A

They are formed when a river floods and deposits minerals on the river bank

87
Q

What increases the height of levees?

A

Frequent floods

88
Q

What are deltas?

A

Mounds of deposits formed when two large bodies of water meet
The actual delta is the split water

89
Q

How are deltas formed?

A

When a river meets the sea, the force of the sea forces the river to slow down
As the river slows down, it deposits silt
This mound of silt grows, becoming an obstacle for the river to flow around
This splits the river into many “streams” which flow into the sea separately

90
Q

What is the difference between a meander and a delta?

A

A meander is when a river goes around an obstacle that is already there
A delta is when a river creates an obstacle with its deposits

91
Q

What do levees and deltas have in common?

A

They are both mounds caused by river deposits

92
Q

What is the difference between a levee and a delta?

A

A levee is formed because of floods

A delta is formed because a river meets the sea

93
Q

What are headlands?

A

They are pieces of the cliff that stick out into the sea

94
Q

How are headlands formed?

A

Soft rock is worn away by the waves bashing against it
The hard rock remains, appearing to jut out into the ocean
This is called a headland

95
Q

What are bays?

A

Curved areas between headlands

96
Q

What is the main cause of headlands and bays?

A

Rocks of different hardness and resistance

97
Q

What is a cliff?

A

It is a steep wall of rock that is formed by wave erosion

98
Q

Why do cliffs have a “bubble” at the bottom of cliffs?

A

The waves are always there, whereas they only reach higher up during floods

99
Q

What do caves, arches and stacks have in common?

A

They are different stages in wave erosion

100
Q

What are caves?

A

They are an early stage of arches and stacks

It is a hollow carved into a cliff face

101
Q

Why do caves form?

A

Waves pound against the cliff, and softer rock is swept away

102
Q

What are arches?

A

A hollow which goes straight through a cliff

103
Q

How do arches form?

A

When waves erode two sides of a cliff into caves, they may erode all the way through

104
Q

What are stacks?

A

A single pillar of rock that stands separately from the rest of the cliff

105
Q

How are stacks formed?

A

After the top of an arch collapses, the pillar of the arch remains

106
Q

What is the most common wave deposition feature?

A

A beach

107
Q

What is a beach?

A

A mass of loose sand along the cost

108
Q

How are beaches formed?

A

Waves can erode the original rock into the soft sand
Or rivers may have deposited this eroded material into the sea
The material was then deposited along the coast

109
Q

What are spits?

A

They are narrow ridges of sand that stick out into the sea or river mouth

110
Q

What is a longshore drift?

A

When waves push sand up the coast at an angle. The sand will roll down the beach at a different angle

111
Q

What is a salt marsh?

A

An area of water that has started to allow plants to grow

It is a marsh made of salt water

112
Q

What causes a salt marsh?

A

When salt water is trapped behind a spit

113
Q

What are glaciers?

A

Large masses of ice that move slowly over the land

114
Q

What kind of erosion does a glacier cause?

A

Abrasion

115
Q

How do glaciers cause deposition?

A

When they melt, all the materials within the glacier are deposited

116
Q

What are cirques?

A

Bowl-shaped hollows in glaciated mountain areas

117
Q

What is an arête?

A

A ridge caused by glacier erosion

118
Q

How are cirques caused?

A

When snow falls on a glacier, many layers are formed
The snow compacts into ice
This ice pushes down on a mountain
The pressure causes a depression in the mountain side
As the glacier slowly moves, it erodes a hollow from this depression

119
Q

What is a horn?

A

The pointy top of a mountain, which sometimes remains after an arête is formed

120
Q

What is a U-shaped valley?

A

A river valley where all of the spurs have been eroded away

121
Q

What causes U-shaped valleys?

A

When mountain glaciers meet up in river valleys, they are big enough to erode the river valleys from a V-shape to a U-shape

122
Q

What are truncated spurs?

A

Spurs that have been eroded by glaciers

123
Q

What are some features created by glacier deposition?

A

Moraines
Eskers
Drumlins

124
Q

What are the two types of moraines?

A

Terminal

Lateral

125
Q

What caused the deposition of glaciers?

A

When the world heated up and the glaciers began to melt

126
Q

What are moraines?

A

Moraine means water rock

Moraines are the rocks left at the side and the end of the valley that the glacier used to occupy

127
Q

What are terminal moraines?

A

The rocks left at the end of the valley

128
Q

What are lateral moraines?

A

The rocks left on the side of the valley

129
Q

What are eskers?

A

They are meandering ridges of sand and stones

130
Q

How are eskers formed?

A

Rivers that ran underneath the glaciers

131
Q

What are drumlins?

A

They are rounded hills of rock

132
Q

How big do drumlins get?

A

50-500 meters high

133
Q

What are some features created by deposition?

A

Sand dunes
Scree slopes
Beaches
River Deltas

134
Q

What are features created by rivers?

A 
Waterfalls
Rapids
Gorges
Canyons
Meander
Ox-bow lakes
Levees
Deltas
135
Q

When does river erosion occur?

A

When a river flows over the land

136
Q

What does the river’s load do?

A

It wears away the land

137
Q

What happens to the river’s load as it travels along?

A

The size of the stones reduce, as they get worn away

138
Q

What do faster-flowing rivers do?

A

They can transport heavier and larger loads

139
Q

How does downward erosion work?

A

Large boulders get swept away. Since the river bed is steep, (flows downhill) the boulder will grind away at the river bed with a downward motion

140
Q

How is a waterfall formed?

A

A river flows over varying degrees of rock
The soft rock wears away quicker
The hard rock will remain
This causes a drop in the river

141
Q

What is a plunge pool?

A

A deeper pool of water at the bottom of a waterfall

142
Q

How is a plunge pool formed?

A

This is where the softest rock exists

It will wear away even faster then the rock of the waterfall

143
Q

What kind of erosion is found in the middle and lower courses of a river?

A

Sideways erosion and sideways motion

144
Q

What happens to the size of a river in the middle and lower courses?

A

The river is wider

145
Q

What kind of deposition occurs in the middle and lower courses of a river?

A

More deposition

146
Q

What is a meander neck?

A

The gap between the two meanders

147
Q

What will eventually happen to an ox-bow lake?

A

If there is no water supply (rain) it will eventually dry up

148
Q

What happens when lots of deltas are formed?

A

The river will split into even more channels, forming a D-shaped area

149
Q

What are the features associated with wave action?

A 
Headlands
Bays
Cliffs
Caves
Arches
Stacks
Beaches
Spits
Bars
Lagoons
150
Q

What is wave action?

A

The result of waves pounding in the land

151
Q

Do waves carry a load?

A

Yes

152
Q

When is wave erosion much greater?

A

During storms and strong winds

153
Q

How is a cliff formed?

A

In a similar way to waterfalls. Waves erode the base of rocks on the coast, causing the rocks above to collapse

154
Q

What is a wave-cut platform?

A

As waves erode the cliff face, it will retreat. The hard rock remain at the bottom. This is called a wave-cut platform

155
Q

How does a wave carry deposition?

A

Material that is eroded from headlands is transported in waves and currents

156
Q

What is the most common deposition feature in the sea?

A

A beach

157
Q

How are spits formed?

A

When there is a bend in the coast, the deposition will continue in the direction of the longshoremen drift. This causes a spit of sand to build up

158
Q

What is a bar?

A

It is when two spits grow across a bay and join two headlands

159
Q

What is a lagoon?

A

An area of water behind a bar

160
Q

What are features caused by glaciers?

A 
Cirques
Arête
U-shaped valley
Moraines
Eskers
Drumlins
161
Q

How did glaciers form?

A

During the ice age, masses of snow froze together in many layers.

162
Q

How is an arête formed?

A

When two glaciers erode different sides of a mountain

163
Q

How does wind cause erosion?

A

It picks up sand and soil and transports it, suspended in the air or bouncing along the ground

164
Q

Where is wind erosion and deposition most obvious?

A

In places where there is little vegetation

165
Q

What kind of erosion is caused by wind?

A

Abrasion

166
Q

Where is the most intense abrasion?

A

Near the ground

167
Q

Why is there more abrasion near the ground?

A

This is where most of the material is transported

168
Q

What features are created by wind?

A

Mushroom rocks
Yardangs
Troughs
Sand dunes

169
Q

Which river features are created by erosion?

A 
Waterfalls
Rapids
Gorges
Canyons
Meander
Ox-bow lakes
170
Q

Which river features are created by deposition?

A

Levees

Deltas

171
Q

Which coastal features are created by erosion?

A 
Headlands
Bays
Cliffs
Caves
Arches
Stacks
172
Q

Which coastal features are created by deposition?

A

Beaches
Spits
Bars
Lagoons

173
Q

Which glacial features are created by erosion?

A

Cirques
Arête
U-shaped valley

174
Q

Which glacial features are created by deposition?

A

Moraines
Eskers
Drumlins

175
Q

Which wind features are caused by erosion?

A

Mushroom rock
Yardangs
Troughs

176
Q

Which wind features are caused by deposition?

A

Sand dunes

177
Q

What is a mushroom rock?

A

A rock where the base is larger than the top?

178
Q

How are mushroom rocks formed?

A

The rock at the base is softer than at the top
Wind erosion is stronger near the ground
Both of these factors cause the base of the rock erode faster than the top

179
Q

What are yardangs?

A

Horizontal columns of rock

180
Q

How are are yardangs created?

A

Wind blows along the ground
Blows away the softer rock quicker
The hard rock remains
The wind blows through these columns of hard rock, where the soft rock used to be.

181
Q

How does deposition occur with the wind?

A

Materials being carried by the wind are dropped when the speed of the wind decreases

182
Q

What is the most common feature of wind deposition in the desert?

A

A sand dune

183
Q

Do sand dunes have a constant shape?

A

No. The shape of a sand dune is constantly being changed by the wind

184
Q

What is a slip face?

A

The side of a sand dune that is not exposed to the wind

185
Q

Where does deposition occur on a sand dune?

A

On the slip face

186
Q

Where does the sand deposited on a sand dune come from?

A

The side of the sand dune that is exposed to the wind

187
Q

How does a sand dune move with the wind?

A

The side that the wind is blowing on will eventually erode completely. The previous slip face will now become the eroded side
The sand dune has therefore moved in the direction of the wind

188
Q

Are all San dunes the Sam shape?

A

No

189
Q

What are the three main sand dune shapes?

A

Barchans
Sief dunes
Transverse dunes

190
Q

What does a barchan look like?

A

The stereotypical sand dune

A mound with a meandering ridge

191
Q

What does a sief dune look like?

A

Like corrugated iron

192
Q

What does a transverse dune look like?

A

Like nails that have been laid alternately with first the tails being up, then the heads being up

193
Q

When is soil erosion an issue?

A

When more soil is eroded than is replaced

194
Q

How can humans cause unnatural soil erosion?

A

Human activities disturb the soil which is then carried away by natural processes of erosion

195
Q

What is the main contributor to soil erosion?

A

Agriculture

196
Q

What other human activities contribute to soil erosion?

A

Industry
Deforestation
Construction
Mining

197
Q

Why is soil erosion a bad thing?

A

Topsoil is removed
Formed over thousands of years
The land becomes infertile

198
Q

How does agriculture contribute to soil erosion?

A

It removes natural vegetation, which weakens the soil-as does ploughing the land- which makes it easier which means it blows/washes away easier

199
Q

How does overgrazing contribute to soil erosion?

A

Animals eat the vegetation

The animals stir up the soil with their feet. This exposes the soil to the elements

200
Q

How does construction contribute to soil erosion?

A

They require large areas of vegetation to be cleared
Soil is exposed
Soil may also be moved, or covered with concrete and other building materials

201
Q

How does mining contribute to soil erosion?

A

Surface mining exposes the rocks. The soil may be piled up. The chemicals could pollute the soil

202
Q

What are examples of surface mining?

A

Open-cast coal and iron ore mines

203
Q

What kinds of machinery contribute to soil erosion and concern agriculture?

A 
Ploughs
Seed planters
Crop sprayers
Harvesters 
Weeding machines
204
Q

Why are these machines damaging?

A

They are pulled by tractors which churn up the soil

205
Q

How does monoculture contribute to soil erosion?

A

Certain plants take particular nutrients from the soil. If that plant is planted in the same field year after year, that element of the soil will be completely used up and the soil will be weakened.

206
Q

What is the solution to monoculture?

A

Crop rotation

207
Q

What is crop rotation?

A

When new plants are planted in different fields every year / season

208
Q

What causes over- grazing?

A

Overstocking

209
Q

What is overstocking?

A

When farmers keep too many animals on their land

210
Q

Why does vegetation reduce erosion?

A

The roots hold the soil in place. In terms of wind erosion, the plants absorb some of the energy

Abi Geography 2016 (4 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions