Unit 2 Flashcards
(169 cards)
1
Q
what are minerals?
A
minerals are solid inorganic substances made by natural geological processes.
2
Q
what are the 2 ways minerals can form?
A
- by the cooling of molten materials
2. formed by solutions -> as water evaporates from solutions, minerals are left behind.
3
Q
what boundaries can minerals be found at?
A
destructive and constructive.
4
Q
how do minerals form at a destructive boundary?
A
when the oceanic plate slips below the continental plate, it drags down sea water and oceanic sediment which is know as subduction. The sea water and oceanic sediment lowers the melting point and causes explosive volcanic eruptions. The magma carries metallic minerals which are deposited near the volcano after the eruption.
5
Q
what are the examples of metals found at a destructive boundary?
A
copper, nickel and zinc
6
Q
how do minerals form at a constructive boundary?
A
cracks in the sea bed can be found where oceanic plates move apart. cold sea water flows down the cracks and is heated through contact with magma. The heated water returns to the surface through hydrothermal vents. The water cools and dissolved minerals found in the water are deposited on the sea floor.
7
Q
what are examples of minerals found at a constructive boundary?
A
copper, zinc, tin and iron ore
8
Q
what is an ore?
A
an ore is a rock or other material (E.g. gravel) from which a metal can be economically extracted. It is usually composed of valuable ore minerals and usually worthless gangue minerals
9
Q
What is aluminium extracted from?
A
Bauxite ore
10
Q
what are the properties of aluminium?
A
- relatively soft
- light weight
- non-magnetic
- very good conductors of heat and electricity
- ductile- can be drawn into a wire
- highly reflective-mirrors
- resistant to corrosion
- easily recycled
11
Q
what is aluminium used in?
A
transport, construction, packaging and electrical sectors
12
Q
where is bauxite typically found?
A
found in countries with high rainfall and high temperatures.
13
Q
why is bauxite found in these ares?
A
when vegetation decomposes, it produces organic acids. The high rainfall mixes with the acids and the underlying rock is chemically weathered to reveal the ore.
14
Q
explain the formation of bauxite
A
as water percolates down the soil, nutrients are leached downwards through the soil. The acidic rainfall percolates through the soil and strips the top soil of its nutrients. Soil left behind is known as laterite soils (the soils contain bauxite)
15
Q
what are the issues with extracting bauxite?
A
- when mining produces a lot of dust which could cause health problems for locals.
- noise pollution
- visual pollution
- gets into water systems and cause health problems
- land less sturdy - could cause mudslides
- effect on biodiversity
16
Q
what are the issues converting bauxite into aluminium?
A
- a lot of energy required to extract
- extraction plants are typically in developed countries so bauxite needs to be transported thousands of miles causing pollution.
17
Q
what is the hydrological system?
A
the hydrological system describes the distribution and movement of water between the earth and its atmosphere. This is an example of a closed system as the total amount of volume remains the same.
18
Q
what is evaporation
A
evaporation is the conversion of water from a liquid to a gas by using solar energy.
19
Q
what is condensation
A
condensation is the conversion of vapour/ gas to liqiuid.
20
Q
what is precipitation and give examples
A
precipitation is the term for moisture that falls from the air to the ground. Examples include rain, sleet, snow, hail, fog, mist, drizzle.
21
Q
what is evapotranspiration
A
evapotranspiration is the water lost to the atmosphere by evaporation from land surfaces
22
Q
what is sublimation
A
sublimation is the process by which ice or snow goes from a solid to a gas without becoming a liquid.
23
Q
what is inflitration
A
infiltration is the physical movement of water through soil.
24
Q
what is groundwater flow
A
groundwater flow is water that occupies pore spaces in soil, sediment, and rock.
25
what is collection of groundwater known as?
an aquifer (underwater reservoir)
26
what is transpiration
transpiration is the water loss from plants
27
what is advection
movement of clouds.
28
what is percolation
the movement of water through soil by gravity and capillary action
29
what are the types of water storages?
surface storage and subterranean
30
give examples of surface storage
- water courses - rivers, lakes, streams
- soil moisture
- vapour - clouds
- ice and snow
31
give examples of subterranean storage
- groundwater
| - aquifer
32
what is soil parent material derived from?
- weathered bedrock
| - sediment/materials carried by flooded rivers or glaciers
33
what transforms parent material into soil?
weather such as wind, rain, sand, ice, sand and living things
34
what are provisional ecosystem services than soils provide?
- grow food in soils
- grow cotton for clothes
- produce lumbar bricks for houses
35
what are regulation ecosystem benefits?
- filters water
| - stores carbon
36
what does soil consist of?
- mineral matter 45%
- organic matter 5%
- water 25%
- air 25%
37
what does the mineral matter consist of?
consists of minerals derived from parent material by physical and chemical weathering.
38
what does the organic matter consist of?
consists of decaying roots, leaves, needles and remains of dead organisms.
39
what does air and water do?
air and water co-exist in everchanging volumes and occupy spaces in the soil.
40
what is stage 1 in soil formation?
- physical and chemical weathering attack the rock and weaken it
- chemicals are released from the weathered rock surface which provides nutrients for plant life.
- pioneer species such as mosses and lichens are present.
41
what is stage 2 in soil formation?
- roots in plants cause cracks in the rocks and help weather it
- the plants add nutrients to the soil when they die (humus)
- this makes it easier for the next generation of plants to survive - grasses and shrubs.
42
what is stage 3 in soil formation?`
- as more plants start to die, nutrients (humus) in soil increases
- continued weathering breaks the rock down into smaller fragments
- the soil develops into 4 horizons
43
what are the 6 main factors affecting soil formation?
- parent material
- organisms
- climate
- relief
- time
- human activity
44
what does the Ao horizon consist of?
- L (litter) which consists of leaves and pineneedles/cones
- F (fermentation) where organic materials start to decompose
- H (humus) the decomposed remains of vegetation, animals and bacteria which provide the soil with nutrients.
45
what is humus?
humus is a jelly like substance made of decomposed organic matter which provides the soil with nutrients.
46
what does the A horizon consist of?
- main top layer
- topped with organic debris e.g. twigs, cones
- it is here that organic material is introduced from the Ao horizon
- dark in colour
- it is usually nutrient rich and fine in texture
47
what does the B horizon consist of?
- This is a subsoil which contains less organic material and is coarser in texture
- minerals and nutrients may be leached out of horizon A and into horizon B.
- lack of organisms due to lack of air
48
what is leaching?
leaching is the removal of soluble materials and humus by water
49
what does the C horizon consist of?
- zone of regolith whose larger particle sit upon the underlying bedrock
- physical and chemical weathering of parent material is a further source of nutrients
50
Where is podsol soil found?
- northern boreal coniferous forests
| - cold and wet climates where precipitation is greater than evaporation
51
why does podsol have distinct layers
there is a lack of organisms due to low temperatures so there is less mixing of the soils
52
what does the Ao horizon of podsol consist of?
- leaf litter consists of pine needles, cones and twigs from coniferous forests
- due to cold climate, organic matter decays very slowly and forms a acidic mor humus
- cold climate and acidity means there is less organisms and soil bacteria present.
- pH < 4.5 meaning there are few nutrients
- because of this there is a thin layer of dark humus
53
what does the A horizon of podsol consist of?
- ash - grey in colour due to the leaching of minerals.
- minerals are washed down the soils (eluviated) due to high levels of rainfall
- the rainfall mixes with the acidic humus this causes the acidic rainfall to strip minerals and nutrients away
- this results in minerals (iron, aluminium, clay) and nutrients leaving the A horizon and deposited in the B horizon which leaves behind silica and sand particles causing the grey colour.
54
what does eluviation mean?
eluviation is the movement of suspended or dissolved compounds by percolating water from an upper into a lower horizon.
55
what does illuviation mean?
illuviation is the process of deposition of soil materials moved from upper horizon to lower horizon.
56
what does the B horizon of podsol consist of?
- aluminium, iron, clay and minerals are washed in (illuviated)and deposited here causing the reddish, brownish colour.
- contains iron pan. Iron pan prevents drainage of soil and causes waterlogging.
57
what does the C horizon of podsol consist of?
- forms weathered parent rock
| - the rock is less broken up.
58
give examples of the uses of podsol.
podsol soils are not fertile soils and crop yields rapidly decrease. Lime is added to counteract the acidity and add manure to boots the quality of humus.
59
where is brown earth soil located?
brown earth soil is located beneath temperate deciduous forests of Europe and North America. Found in mild and wet climates.
60
why do brown earth soils have less distinct layers?
organisms like earthworm and woodlice are present and mix up the soil.
61
what does the Ao horizon of brown earth soil consist of?
- rich of nutrients
| - litter decomposes rapidly due to mild wet climate producing only slightly acidic mull humus
62
what does the A horizon of brown earth soil consist of?
- dark brown in colour because humus replaces minerals as they are leached out
- leaching is less because precipitation is slightly greater than evaporation so there is slow movement of moisture through soil
63
What does the B horizon of Brown Earth soil consist of
- less distinct but is usually lighter in colour as humus becomes less abundant.
64
What does the C horizon of Brown Earth soil consist of?
- less acidic parent material
- Chemical and Biological weathering is rapid which helps to form a deep soils.
- plant roots extract minerals and replace those lost by leaching
65
What are some land uses of brown earth soil?
Agriculture
66
What are Biofuels?
Biofuels are fuels that are produced from renewable resources. They are derived from biological processes. The fuels are made from biomass - plant, vegetable oil and treated waste. They are an alternative to fuels.
67
What are first generation biofuels?
First generation biofuels are derived from sources which include starch, sugar, animal fats and vegetable oil.
68
What are examples of first generation biofuels?
Bioethanol and biodiesel.
69
Give a profile of Bioethanol?
How it is produced:
Fermentation of sugar
Advantages:
- low in toxicity
- biodegradeable
- little pollution produced
- can be mixed
Disadvantages:
- increased food prices
- highly corrosive
- vehicles on Bioethanol struggle in low temperatures
70
Give a profile of Biodiesel
How it is produced:
Transesterification
Advantages:
- produced less CO2
- useful by product glycerine which makes soap
Disadvantages:
- generates less energy than regular diesel
- more corrosive to engine parts than regular diesel meaning specific engines needed to be fitted for biodiesel
- fuel lines can stop functioning in cooler weather => car heating need to be continuous
71
What are second generation of biofuels?
Second generation biofuels are typically greener because they are made from more sustainable feedstock and non-food biomass including plant stems, leaves, husks, grasses and wood chips from industrial waste.
72
What are examples of second generation biofuels?
Biomethanol and bio crude-oil
73
Give a profile of biomethanol
How it is produced:
Destructive distillation of wood and also by gasification
Advantages:
- less expensive to produce
- less expensive to reduce carbon footprint
Disadvantages:
- obtained from wood therefore less agricultural land available
- corrosive
- fumes harmful to humans
- produces less energy than crude oil.
74
Give a profile of bio crude-oil
How it is produced:
Involves using a thermal chemical reaction
Advantages:
- puts less pressure on fresh water and land resources
- up to 10 times more energy output
- distilled into biodiesels and bioethanol
Disadvantages:
- currently small scale
- quite expensive to produce large quantities
75
What are the advantages of using Biofuels?
- same cost of gasoline but cost benefit is much higher
- cleaner fuels meaning they produce fewer emissions on burning
- easy to source as it is made from manure, waste from crops and plants specifically grown
- renewable because from sources like manure, corn, switchgrass, soyabeans meaning they are unlikely to run out anytime soon as crops can be replanted again and again.
- reduce greenhouse gases biofuels reduce greenhouse gases up to 65%
- economic security if people start shifting towards biofuels then more jobs will be created which will keep our economy secure.
- reduce the dependence on fossil fuels and fossil fuels are costing a lot of money
- lower levels of pollution. Release CO2 but can be used to grow plants
76
What are the disadvantages of biofuels?
- high cost of production. Investment into biofuels is very low but can be increased if there is more demand. This prevents them from becoming more popular.
- monoculture. Same crops are being grown each year meaning the soil will be deprived of nutrients that are put back into the soil after crop rotation.
- use of fertilisers - the crops for biofuels need to grow well and is why fertilisers are used- they have a harmful affect on the environment such as eutrophication and bioaccumulation and biomagnification.
- food shortages - first generation biofuels are derived from starch and sugar crops which are also used as food. Biofuels will take up agricultural space and could cause food shortages or rise in food prices.
- industrial pollution production of biofuels rely on lots of water and oil. Producing biofuels emit large amounts of emissions and water pollution
- production of biofuels requires water and may cause water shortages.
77
Why do we use sampling techniques?
- found out what animals and plants live there
| - found out how abundant they are.
78
What are examples of all sampling techniques?
- simple
- stratified
- systematic
79
When is simple sampling used?
Simple is used when studying an area fairly uniform. E.g. a field
80
When is systematic sampling used?
Systematic is used when you want to investigate a gradual change in species present e.g organisms measured across a coastline.
81
When is stratified sampling used?
Stratified is used to sample different areas within a habitat e.g. a grass land with shrubs and branches.
82
What are qualitative techniques?
Qualitative techniques assess the presence/absence of a species and/or provides a species list
83
What are quantitative techniques?
Quantitative techniques provide data about numbers and densities.
84
Give examples of quantitative techniques
- pitfall traps
- tullgren funnel
- quadrants
- tree beating
- kick sweep method
85
Explain the tullgren funnel
The tullgren funnel is used samples creatures living in the soil
A soil sample is taken and placed in the funnel which contains a bright light. The creatures move away from the light through the sieve and into the beaker.
86
Give an example of qualitative techniques
Classification keys
87
What are the four spheres of the Earth’s system?
Geosphere, hydrosphere, atmosphere and biosphere
88
How does the atmosphere and geosphere interact
The atmosphere (weather) erodes away the rocks from the geosphere
89
What are natural resources?
Natural resources are materials or substances occurring in nature which have intrinsic (always have) economic value to humans
90
What are renewable resources?
Renewable resources are resources that can be used over and over again and are replace or regenerated by natural process.
91
What is the Earth’s system?
The Earth’s can be viewed as a complex system of four spheres which can interact with each other.
92
What are the four earth systems?
- atmosphere
- biosphere
- hydrosphere
- geosphere
93
What mostly powers these spheres?
Solar energy
94
How does the atmosphere/hydrosphere interact with the geosphere?
The atmosphere (weather) erodes the rocks in the geosphere.
95
How does the atmosphere interact with the hydrosphere?
To provide the water and the water cycle
96
How does the atmosphere/hydrosphere interact with the biosphere?
The atmosphere/hydrosphere provides the water for the organisms and allows the biosphere to grow.
97
How does the geosphere interact with the biosphere?
After many year, broken down rock forms soil.
98
What are natural resources?
Natural resources are defined as materials or substances occurring in nature which have intrinsic economic value to humans.
99
What are renewable resources?
Renewable resources as resources that can be used over and over again and are replaced or regenerated by natural process. The material has to be able to be produced within a lifetime.
100
What are non-renewable resources?
Non-renewable resources are resources that typically can only be used once and are formed by biological processes. These resources take longer than a life time to form such as fossil fuels.
101
What are the 4 layers of the earth?
- Crust
- Mantle
- Inner core
- Outer core
102
What are the features of the crust?
The crust is made of rock. It’s depth is around 8-55km and it is the thinnest layer of the earth and is solid.
103
What are the features of the mantle?
The mantle is made of heavier molten rock. It’s depth is around 2900km and It is the thickest layer of the earth. It is made of liquid.
104
What are the features of the other core.
It is made of iron and nickel. It is around 2220 km deep and is a liquid.
105
What are the features of the inner core?
Is made of iron and nickel. It’s depth is around 1260km and is a solid.
106
What are convection currents?
Convection currents are what drive the tectonic plates apart.
1. Heat rises from the core and tables toward the core. This causes hot, less dense material to rise.
2. As it reaches the crust, the molten material starts to harden, cool, becomes more dense and started to sink back towards the core ready to be heated again.
3. This creates a system of convection currents and drives the plates apart.
107
What is a plate boundary?
The point where 2 plates meet.
108
What is the name of the boundary when plates move in opposite directions?
A constructive boundary
109
What are the names of boundaries when plates move towards each other know as?
A destructive or collision boundary.
110
What is the name of a boundary when plates slide by each other?
A conservative boundary
111
What is another name of a constructive boundary?
Divergent boundary
112
What is another name for a destructive boundary?
Convergent boundary
113
What is another name of a conservative boundary?
Transform boundary
114
What happens at a constructive boundary?
When the two plates move apart, it causes cracks and splits in the crust. This means that magma from the mantle is released causing volcanic eruptions. The magma then cools and solidifies forming part of a new crust which consists of new ocean floors, land and volcanoes.
115
What happens at a destructive boundary?
The oceanic plate is heavier than the continental plate. Because if this, the oceanic plate slips under the continental plate and is pushed into the mantle. The mantle then melts the oceanic plate and magma and gas is produced. This forces the magma up through the cracks in the earth and causes volcanic eruptions and earthquakes. The earthquakes are caused due to the friction of the oceanic plate sliding under the continental plate.
116
What happens at a collision boundary?
The two continental plates have the same density and are unable to sink. These plates are pushing towards each other forces the surrounding land upwards to form mountains.
117
What happens at a conservative boundary?
The two plates slide next to each other. The sliding movement is not a smooth movement as is a continuous process. Most of the time the two plates are locked together but when pressure builds up the plates suddenly jerk past each other and causes earthquakes.
118
What is geothermal energy?
Geothermal energy is a renewable and sustainable form of energy which uses heat within the earth to produce hot water and electricity. Geothermal energy is only restricted to areas near to a plate boundary, where the crust is thinner or at areas where plumes create geothermal hot spots.
119
What is the source of the earths internal heat?
- The radioactive decay of material
- friction caused the the rocks in the mantle
- the initial collision forming earth.
120
How does geothermal energy work?
- Hot water in the form of steam is taken from the hot rocks within the earth
- This steam is then used to turn a turbine
- The generator converts kinetic energy into electrical potential energy
- The water is then cooler in a cooling tower
- The cold water is then injected back deep within the earth
121
How is geothermal energy generated?
By convection currents
122
What are the benefits of using geothermal energy?
- Using geothermal energy practically produces no emissions when compared to fossil fuels. CO2 emits 2000 times
- It is a reliable and renewable resource of energy. It will never run out unlike fossil fuels in 40 years. It is available all year round
- the heat pumps that pumps energy into homes use less energy than typical heating and cooling systems. 25% to 50% less energy than typical systems
- not many repairs are needed to geothermal energy systems that last around 20 years.
- geothermal systems run silently unlike wind farms
123
What are the disadvantages of using geothermal energy?
- they release other greenhouse gases such as hydrogen suffice, carbon dioxide, methane and ammonia but release low amounts
- some locations may cool overtime meaning energy is unable to be harvest. A solution is source geothermal energy straight from magma but technology hasn’t been developed yet
- They cost a lot of money to install although it will last many years
- Requires a piece of land next to it to install meaning that apartments in the city would be unable to have uncles a vertical ground source pump is installed
- can cause minor earthquakes due to the injection of high pressure water into the ground
124
What is the atmosphere made up of?
Nitrogen - 78%
Oxygen - 21%
Argon - 1%
- small variable amounts of CO2 and water vapour these are the greenhouse gases
125
What is the atmosphere?
A blanket of gases which contains solid particles such as volcanic dust and blown soil and is attached to the earth by the force of gravity
126
What are the five layers of the atmosphere?
- Troposphere
- Stratosphere
- Mesosphere
- Thermosphere
- Exosphere
127
What is the troposphere?
The troposphere that is closest to earth. It contains the most atmospheric gas and where weather occurs. Between 10-12km depth with a temperature between 15 to -50
128
What is the stratosphere?
The stratosphere contains the ozone layer. This is where commercial airlines fly. 12- 50km deep and around -60 degrees.
129
What is the mesosphere?
The mesosphere protects the earth from meteorites by burning them up. Is around 50-80km and -100 degrees.
130
What is the thermosphere?
The thermosphere is where satellites orbit. Above 80km and around 2000 degrees.
131
What is the exosphere?
The exosphere Is the edge of space. Is is around 320 km and -60 degrees
132
Why do commercial airlines fly at the stratosphere?
There are no birds that could affect the aircraft. There is less consumption of fuel due to the jet stream and less noise pollution.
133
Why is only 51% of energy absorbed by earth?
- 20% is reflected by the clouds
- 3% is absorbed by clouds
- 16% absorbed by dust and water vapour
- 6% are scattered by gases
- 4% is reflected by earth
- 30% is reflected due to albedo
134
What is the Albedo effect?
The albedo effect is the reflectiveness of the earths surface. Albedo effect is made up of the % of solar energy reflected and the % of solar energy scattered.
135
Why are there variations in global heat energy?
1. Curvature of the earth:
The solar rays cover a larger surface of the earth at the poles compared to the equator. This means that at the equator, the solar rays are more concentrated compared to rays on the poles.
2. Depth of the atmosphere:
There is less distance for the solar rays to travel at the equator compared to the poles.
3. Albedo effect:
The snow and ice on the poles reflect the solar rays due to it being light in colour where as at the equator, there are forest which will absorb the solar rays and therefore heat up the surroundings
4. Seasons:
At different times of orbit, due to the tilt of the earth, the northern hemisphere faces the earth more causing the seasons of spring and summer in the north and in the southern hemisphere, autumn and winter.
136
What type of pressure is at the equator?
Low pressure
137
What type of pressure is at the poles?
High pressure
138
What direction are winds deflected in the northern hemisphere?
From high to low pressure to the right
139
What direction are winds in the Southern Hemisphere deflected?
From high to low pressure and to the left.
140
What are factors affecting the distribution of biomes?
- Temperature and precipitation
- Latitude
- Altitude
- Wind
- Ocean currents
141
What happens when air is heated?
It rises away from the earths surface. Rising air reduces the weight pushing down on the earth’s surface. This means the pressure is low.
142
What happens when the air is cooled?
When the air is cold, it falls towards the earths surface. Falling air increases the weight of air pressing down on the earth’s surface and therefore the pressure is high.
143
What happens at the Hadley cell?
At the equator warm air rises. The warm then diverges 30N and 30S. The air then cools and sinks. The air then returns to the equator to be heated again. This causes deserts at 30N and 30S.
144
What happens in the polar cell?
At the poles cold air sinks causing high pressure. The air then diverges to 60N and 60S where the air is then heated and rises and returns to the poles and then cooled. This causes the tundra biome at 60N and 60S.
145
What happens at the Ferrell cell?
Due to friction, at 60N and 60S the air rises. At 30N and 30S It causes the air to sink due to friction.
146
What are ocean currents?
Ocean currents is how energy is distributed in oceans. This is a permanent or continuous fixture. This is when warm water is transferred to areas that are cold and cold water is transferred to areas that are hot.
147
What is an ocean gyre?
An ocean gyre is a spiral of ocean currents that circulate above and below the equator.
148
What are the factors affecting ocean currents?
- Thermohaline circulation
- surface winds
- Coriolois force
149
What is thermohaline circulation?
Water at the equator is warmer and less salty and therefore it is less dense. This means that the warm water travels along the surface towards the poles. Water at the poles is colder, saltier due to all of the freshwater being frozen as ice. This makes it more dense so therefore travels along the ocean bed towards the equator.
150
How does surface winds affect ocean currents?
Winds blowing across the surface drag the surface layers of the ocean with it in the direction the wind is blowing. The surface also drag deeper water along with it can causes currents to form.
151
What is the Coriolis force?
The Coriolis force is the Earth’s rotation causing the surface winds and ocean currents to be deflected.
152
What direction are ocean currents deflected in the northern hemisphere?
Clockwise
153
What direction are ocean currents deflected in the Southern Hemisphere?
Anti-clockwise
154
What is Climate change?
Climate change is the long term shift in the planets weathers patterns or average temperature.
155
What are the physical causes of climate change?
- Changing output of solar radiation
- Volcanic eruptions
- Milankovitch theory
- ocean currents
- continental drift
156
What is the greenhouse effect?
The greenhouse effect is a process that occurs when Earths atmosphere traps the suns heat.
157
What are the greenhouse gases?
- Carbon dioxide
- Nitrous Oxide
- Ozone
- Methane
- Water vapour
158
What is the changing output of solar radiation?
The sun doesn’t always emit the same amount of solar radiation. This means that there is sometimes a rise in solar radiation meaning there is a rise in global temperatures.
159
What are sunspots?
Sunspots are dark spots on the sun. If there are many of them, it means that there will be more solar output.
160
How can volcanic eruptions contribute to climate change?
Volcanic eruptions release lots of dust, ash and gas that gets trapped in the atmosphere. Examples include sulfur dioxide. The sulfur dioxide mixes with water in the atmosphere to form sulfuric acid droplets called aerosols. These droplets absorb radiation from the sun and therefore prevents incoming radiation from entering the earth. Because the earth isn’t receiving enough solar radiation, it causes global temperatures to decrease.
161
How does ocean currents contribute to climate change?
Retreating/ice capes melting:
- Cause a decrease in water temperature when melting
- Melting ice caps reduces albedo effect and therefore raises temperatures
- This could have an impact on the North Atlantic Drift.
Changes in thermohaline circulation:
- Thermohaline currents occur in cycles of every 70 years. This means that when the currents are less strong, the warmer the climate is.
162
How does continental drift contribute to climate change?
- When there are many continents at the equator, the earth heats up (Pangea)
- When continents break up, it can trigger volcanic eruptions.
- When there are many continents near the poles, the world cools down.
- Continents that sit on top of tectonic plates are constantly moving and will continue to. Climate can change as the plates move.
163
What are the three Milankovitch cycles?
- Stretch
- Wobble
- Tilt/roll
164
Explain the stretch?
The Earths orbit is usually uniform but sometimes it can become more elliptical and elongated. This means that the earth will sometimes be closer to the sun. This occurs every 96,000 years.
165
Explain the tilt/roll?
The Earth rotates on its axis at 23.5 and sometimes this changes. It can either go to 22.5 or 24.5 and this means that if there is a greater tilt towards the sun then the global temperatures of earth will rise. This occurs every 40,000 years.
166
Explain the wobble?
The Earth wobble like a spinning top in space. This means that sometimes the Earth will be closer the the sun causing a global temperature increase.
167
What is a Environmental Impact Assessment (EIA)?
This was introduced by the EU. The EIA aims to protect the environment. This ensure that the environmental impact is known before it goes ahead. This evaluates the likely impact of a proposed development. This is usually for individual projects such as the building of a power plant.
168
What is a Strategic Environmental Assessment (SEA)?
A SEA aims to provide a high level of protection of the environment from development. This is mandatory for large scale development plans or policies which changes the land use.
169
What is policy?
A policy is a plan of action that focuses on a specific target.
