1
Q
What are the 4 main layers of the earth
A
Crust
Mantle
Outer core
Inner core
2
Q
Crust
A
Outer layer
is solid
thinnest layer - 10-80km thick
there are 2 types
- Oceanic
- Continental
Contains rocks and minerals with lower densities than other layers
3
Q
Mantle
A
Thickest layer of the Earth- 2900km thick
Made of hot solid rock that can flow- called plastic rock
Drives the movements of the continents
4
Q
Sections of the mantle
A
Upper mantle- solid part (Lithosphere 1000 degrees
Asthenosphere plastic liquid like- reforming convection currents (1300 degrees)
Mesosphere Rigid and plastic rock flows slower
5
Q
Core
A
80% iron with nickel and other elements
Outer core is liquid
Inner core is solid
6
Q
Outer core
A
Liquid
2300 km thick
Made of metals- iron and nickel
magnetic field- makes compasses go
7
Q
Inner core
A
1220 across
5500 degrees
made of iron and nickel
Pressure/gravity squeezes into a solid sphere
8
Q
Atmosphere
Define
What causes weather?
What is in the stratosphere?
A
Relates to all earths gases
Changes in the atmosphere cause weather
Stratosphere contains ozone layer protecting us from harmful UV
9
Q
What are the four spheres?
A
- Lithosphere
- Hydrosphere
- Atmosphere
- Biosphere
10
Q
What are the 5 layers in the earth’s atmosphere?
Starting from closest to furthest out
A
- Troposphere (0-12km)
- Stratosphere (12-50km)
- Mesosphere (50-80 km)
- Thermosphere (80-700 km)
- Exosphere (700-190000 km)
11
Q
What is in the stratosphere?
A
The stratosphere contains the ozone layer (20-30km) which protects us from harmful UV radiation
12
Q
What causes ocean currents
A
the temperature difference between the tropics and the poles. These different warm and cold currents have a large effect on climate of coastal regions
13
Q
What is an example of an ocean current
A
The Gulf Stream, which carries warm water from the equator into the north atlantic ocean, warming specific continents
14
Q
What causes the convection currents that create wind
A
The temperature difference between the poles and the tropics as cold air near the poles sink and the hot air near the equator rises
15
Q
How do cyclones start
A
- Begin in the ocean feeding off warm water, 26.5 degrees and above.
- A cluster of thunderstorms are required to suck the warm air up 15 km, which causes the air pressure to drop.
- As surrounding air rushes in, new storms are created
- The low pressure systems begin to rotate as the storms intensify.
- When average wind speed is 63km/h=tropical cyclone
16
Q
What classifies a cyclone and what are the levels
What is the cat based off
A
When the speed hits 60kph
cat 1 lowest
cat 5 highest
Cat is based of wind speed
17
Q
which way do the cyclones spin in each hemisphere
A
clockwise in southern
anticlockwise in northern (hurricane)
18
Q
What size is the eye
A
around 40km
19
Q
what type of system is a cyclone
A
low pressure
20
Q
Effects of a cyclone
A
Rain causes river to flood
Storm surges- increase the tide level of the sea
Erosion of the land and waterways
Uproot trees destroying the habitats for living things
21
Q
How does the earthquakes impact the lithosphere?
A
Cause the lithosphere to move apart, together, rise or subside
22
Q
What features (natural or man-made) are impacted by earthquakes?
A
Earthquakes can change the course of rivers, create landslides, rockfalls and destroy dams causing flooding
23
Q
Volcano short term effects
A
Sends ash cloud into atmosphere which produce rain and lightning.
How is rain formed?
- ash causes water vapour to condense creating rain drops
Lava
- Lava will run a a pryclastic flow, destroying organism within its path, buring siol, killing animals adn plants and disrupting the function of the ecosystem
- Difference in charge creates voltage, when this is high enough leads to a flow of electricity = lightning
React with sulfric acid forming acid rain which harms soils, disintergrates nutrients in soil and can make water toxic for aquatic life
24
Q
Volcano long term effects
A
- Ash reduces the amount of sunlight reaching the earth causing a cooling effect which kills plants, crops and livestock
- toxic gas can suffocate plants and animals
-newformed lands from lava are too hot for living things- take years to cool
25
Describe the biosphere
What interactions are in the biosphere?
How are all the spheres linked?
1. Associated with all living organisms (plants, animals, bacteria, fungi and protists), it is the earth's life support system.
2. Interactions within the biosphere include cycles of essential elements (carbon, nitrogen, phosphorus)
3. As life exists everywhere the biosphere links to all the other spheres.
26
How does human activity impact the atmosphere?
| What has replaced CFCs?
Chlorofluorocarbons (CFCs) are used as coolant agents in fridges and air conditioners. However, when these compounds are released into the atmosphere, they will break down into chlorine atoms in the stratosphere and destroy ozone molecules.
A depletion of the ozone layer=increase UV radiation=damage to organisms
| Hydochlorofluorocarbons (HCFCs) which deplete ozone less
27
Describe Hydrosphere
| What is the cyrosphere?
This sphere is associated with water in solid (ice) and liquid states. E.g. Oceans, freshwater lakes, glaciers, rain and underground deposits.
| Frozen compartments on Earth
28
Human impact on hyrdosphere
Toxic wastes and untreated sewage in water systems can lead into bodies of water (eg. rivers).
Toxins can move along food chains and its impact is easily biologically magnified.
These wastes can be purposefully dumped or enter water systems through run off.
29
What is the lithosphere?
The lithosphere is made up of the Earth's crust and the uppermost mantle
Includes rocks, soil, landforms and mountains
30
What types of rocks are in the lithosphere?
Igenous, sedimentary and metamorphic.
31
How are biomes divided?
What impacts this factor?
| Give four examples of biomes
Through the types of vegetations present.
Eg. tropical rainforest, desert, tundra and temperate grasslands
Environemental factors such as:
- Rainfall
- Temperature
- latitude
will influence type of vegetation that can survive
32
Human impact on lithosphere
Soil exhaustion, pesticides, excessive clearing, deforestation and overgrazing can destroy the lithosphere and/or lead to desertification.
This has consequences on survival of organisms, their habitats and the resources.
33
What is the carbon cycle?
Process by which carbon from the environment is converted to carbon in living things.
34
What are the three groups of organisms contributing to the Carbon cycle?
1. Plants removes carbon dioxide from the atmosphere through photosynthesis
2. Animals obtain carbon dioxide by consuming plants and release it through respiration
3. Microorganisms return carbon dioxide to the envirnment through decomposition of dead organisms
35
what types of human activity impact the carbon cycle?
- burning of fossil fuels releasing CO2 and CH4
- Deforestation, releasing CO2 and reducing CO2 uptake by plants through photosynthesis
- Change of land use (agriculture or urban development) = release of CO2
- Production of cement and lime = release CO2
- Waste bruning
- Livestock cultivation
36
What is the nitrogen cycle?
| What is nitrogen important for?
Circulation of nitrogen in various forms through nature, where nitrogen is chemically and biologically transformed.
| Componenet of protein and nucleic acids, essential to life
37
# There are four steps
What is the process of the nitrogen cycle?
**1. Nitrogen Fixation:**
- N2 (nitrogen) -> NH4- (Ammonium)
- Bacteria in a symbiotic relationship with plants (legumes), free-living bacteria in soil, lightning, forest fires and fertiliser can all fix N2
**2. Nitrification**
- Amonium -> Nitrities (NO2-) -> Nitrates (NO3-)
- Plants can only absorb nitrates
**3. Assimilation**
- Plants absorb nitrates from soil into roots
- Nitrogen used as amino acids, nucleic acids and chlorophyll
**4. Ammonification**
- When plant/animal dies, decomposers turn nitrogen back into ammonium to re-enter cycle
38
What are the four bacteria in the nitrogen cycle?
**Nitrogen Fixing Bacteria:**convert atmospheric nitrogen to ammonia/ammonium
**Bacteria of Decay:** converts decaying nitrogen waste to ammonia e.g. fungi
**Nitrifying Bacteria:** converts ammonia to nitrates
**Dentrifying bacteria:** converts nitrates to nitrogen gas
39
# Water cycle
What is precipitation?
rain, snow, sleet or hail
40
# Water Cycle
What is evaporation?
The sun heats up water and returns to gas
41
# Water cycle
What is accumulation?
water stored in lakes and oceans
42
# Water cycle
What is condensation?
Water vapour cools and returns to liquid
43
# Water cycle
What is transpiration?
water evaporated from a plant
44
# Water cycle
What is sublimation?
The process where solid water (ice or snow) changes directly into vapor without becoming liquid, often occurring in cold, dry conditions.
45
# Water cycle
What is infiltration?
The process by which water on the ground surface enters the soil, replenishing groundwater supplies.
46
# Water cycle
What is evapotranspiration?
The combined process of evaporation from the land and transpiration from plants, representing the movement of water from the ground to the atmosphere.
47
Compare climate and weather
| Where does weather occur?
Weather refers to short term atmospheric conditions which can change within minutes or hours.
Climate is the weather of a specific region averaged over a long period of time in a specific place.
| Troposphere
48
How does sun influence climate on earth?
It is the source of energy behind the climate system.
Solar radiation warms the atmosphere and produces wind patterns, this is because solar radiation is unevenly distributed due to spherical shape and tilt.
49
How does the rotation of the earth impact the atmosphere and ocean? What does this then influence?
As the earth rotates, the atmosphere and the oceans are dragged around with it. This movement influences the circulation of the air and water on a global scale. However, the major factor influencing circulation of water in the oceans is temperature.
50
What is climate change?
Long-term alterations in the average weather patterns and conditions of a particular region or the entire planet.
These shifts can occur naturally over long periods of time, but recent climate change is primarily driven by human activities.
51
How does greenhouse effect occur?
1. Solar Radiation: The Sun emits energy in the form of sunlight(short-wave radiation), which passes through the Earth's atmosphere. During daytime, sunlight heats the surface.
2. Absorption and Reflection: Some of this energy is absorbed by the Earth's surface, warming it. The rest is reflected back toward space. When earth cools when the sun goes down, heat is released into air and trapped by greenhouse gases.
3. Heat Trapping by Greenhouse Gases: Greenhouse gases (such as carbon dioxide, methane, and water vapor) trap some of the reflected heat, re-radiating it in all directions, including back toward the Earth's surface.
4. Warming the Earth: This trapped heat keeps the Earth's surface and atmosphere warm enough to support life.
52
What are the evidence for climate change?
1. Glaciers can indicate climate change as they advance when climate cools and retreats when climate warms. When they move, they grind the rocks, hence as glaciers retreat the scoring becomes visible.
2. Ice cores can show date about the temperature and composition of air from hundreds of thousands of years ago. This can indicate how temperature is related to sea level and reveals amount of CO2.
3. Pollen analysis can indicate what species were growing when sediments that created the fossils were laid down as pollen decays extremely slowly. A change is pollen will indicate change in vegetation and climate.
4. Sea level changes is evident through distribution of sedimentary rocks and fossil types in the rock. eg. sedimentary rocks in central Australia have fossils of sea creatures.
53
What is glaciation?
The process or state of being covered by glaciers or ice sheets.
54
How much has the global sea level risen since 1880?
21-24 cm
55
How high is the global mean sea level likely to rise to by the end of the century?
At least 0.3 meters above the levels in the year 2000, even if greenhouse gas emissions follow a relatively low pathway in coming decades.
56
What is causing sea levels to rise?
How much ice has Antarctica loss?
Melting of land ice (mountain glaciers and ice sheets), when the ice melts, water flows into the ocean, adding new mass into the sea which increases total volume of water.
Antarctic ice loss nearly quadrupled from 51 billion tons per year between 1992 and 2001 to 199 billion tons per year from 2012-2016.
57
What is global warming?
Progressive increase in average temperature on Earth due to the accumulation of greenhouse gases in the atmosphere which trap the heat (infrared rays) from the sun and prevent its escape into space.
58
What is the ozone layer?
Barrier from harmful ultraviolet rays from the sun that is made of ozone molocules (3 oxygens). It is in the stratosphere.
It absrobs 98% of the UV rays from the sun
59
How does a decrease in ozone in the ozone layer impact living things?
Harmful for organisms that have adapted to being protected from uv radiation. For humans, the damage is in the form of sunburn and skin cancer.
60
How much of the excess heat produced by humans is absorbed by the ocean?
What happens to the heat?
93% making oceans heat stores.
Currents redistribute heat. The currents are driven by winds on the surface and by different water density caused by differences in temperatures and salinity.
61
What is the ocean in terms of carbon absorption?
It is a carbon sink absorbing 1/4 of CO2 produces by humans.
Marine plants and phytoplankton use CO2 for photosynthesis.
This regulates the climate and mitigate climate change.
62
What does the absorption of carbon by oceans impact the ocean?
Increase acidity, threatening marine life.
63
What factors impact how much carbon dioxide and heat oceans absorb?
1. Phytoplankton
2. Temperature
3. Waves
4. Salinity (high evaporation=high salinity, high rainfall=low salinity)
5. Ice cover
64
What is the thermohaline circulation?
Deep-ocean currents are driven by differences in the water’s density, which is controlled by temperature (thermo) and salinity (haline)
65
How does the thermohaline circulation work?
In areas of where sea ice forms there is high salinity, because salt is left behind when water freezes. This salty, cold dense water sinks into the oceans depths in a journey that lasts many centures.
66
What is the thermohaline circulation important for?
- regulation of global climate
- helps drive surface currents like the Gulf stream
67
How does global warming impact Thermohaline circulation?
Weakening it in the North Atlantic which can lead to cooler air in Europe and winter storms. The Atlantic coast of America can experience higher sea levels, warmer waters and powerful hurricanes
68
Evidence for global warming
- rise in global mean sea levels
- decline in Arctic sea ice and glaciers
- Birds migrating earlier
- increased heat content in ocean
- plants blooming earlier in spring
- frequency in extreme weather
69
What has caused glaciers to melt?
since the industrial revolution, carbon dioxide and other greenhouse gas emissions have raised temperatures, even higher in the poles
70
Relationship between glacier volume and meltwater?
As temperatures rise, glacier volume decrease and meltwater increases
71
What does a loss of ice impact?
Earth’s albedo (reflectivity)
72
What does Antarctica shrinking impact?
1. Changes ocean circulation impacting global systems
2. Change in food availability and breeding grounds
73
What is the enhanced greenhouse effect?
enhanced greenhouse effect refers to the intensification of Earth's natural greenhouse effect due to the increased concentration of greenhouse gases in the atmosphere from human activity.
This process traps more heat in the Earth's atmosphere, leading to a rise in global temperatures and contributing to climate change.
74
What is the function of greenhouse gases?
Greenhouse gases include water vapor, carbon dioxide (CO2), methane (CH4), and others.
Their primary function is to absorb and emit long-wave (infrared) radiation.
75
What is short-wave and long-wave radiation?
Short-wave radiation comes from the sun (visible light, UV) and reaches Earth’s surface.
Long-wave radiation is the heat emitted by the Earth and is primarily absorbed by greenhouse gases.
76
How does coral bleaching work?
An increase in ocean temperature or salinity stresses the symbiotic relationship between algae and coral reefs. If stressed the algae will leave the coral, leaving it bleached and vulnerable as the algae is the main source of food. 
77
How are humans impacted by climate change?
increases in vector-borne diseases
increases in extreme weather events such as cyclones and hurricanes
increases in water-related infections
increases in bushfires
impacts on mental health due to traumatic events such as flooding, cyclones and bushfires.
78
What is Biodiversity
total variety of living things on earth, their genes and the ecosystems in which they live
79
what is biodiversity vital for
Ecosystem Health
- helps ecosystems stay healthy and stable (more species = better balance, others can fill its role)
Resources for humans
- makes food medicine and materials
- Variety of life supports our needs and economy
Adaptation to change
- Increased biodiversity increases chnace that some species will survive enironmental changes (climate change)
- Helps ecosystems adn humans cope with challenges
80
Importance of nutrient recycling
Nutrient availability
- cycles ensure nutrients are recycled promting growth adn supporting diversity
Ecosystem resiliance
- recycling of matter enhancing ressiliance to environmental changes
Sustainability
- Sustainably support life without delepting resources
Climate regulation
- Nitrogen + Carbon regulate atmospheric condtions influencing climate nd weather patterms
81
What is Australia’s biodiversity influenced by?
Both biotic and abiotic factors.
82
El Nino
increased temperature
warmer water
weak trade winds
83
La nina
Coller temperature
cooler water
strong trade winds
84
Climate model predictions
- Temperature increase= rise by 1.5 to 4 degrees
- sea level rises from 0.3 to 1 meter due to melting ice
- Extreme weather - drpughts, natural disaters etc
85
how long do greenhouse gases stay in the atmosphere
tens to hundreds of years
86
How does abiotic factors impact animal’s survival?
animals have tolerance ranges for abiotic factors such as temperature and cannot survive outside of these ranges, which can lead to extinction
87
What places species at risk?
Those with a low genetic diversity, long life cycle, low fertility and require special resources
88
How has climate change impacted animals?
Change in:
- migration patterns
- shift in genetic composition of species with short life cycle
- change in lifestyle
- reproduction rates
89
How has climate change impacted plants and pollinators?
Flowers and pollinators have coevolved, but climate change has altered life cycles of pollinators and changed flowering times of plants. This causes plants to be out of synchronisation with pollinators leading to less flowers being pollinated, hence fewer bear fruit which contain seeds required for the production of more plants.
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