Earth and Environment - Prelim Study Flashcards

Question

List 3 igneous rocks?

Answer 1

- Andesite - Basalt - Granite - Obsidian - Pumice - Diorite - Tuff

Answer 2

- Sandstone - Siltstone - Coal - Limestone - Shale - Conglomerate - Dolomite

Answer 3

- Gneiss - Hornfels - Slate - Schist - Quartzite - Marble - Phyllite

Answer 4

1. Minerals - the process of weathering reduces the parent rock to the constituent minerals. It can occur locally or brought in by wind, water and gravity. 2. Organic matter – litter is undecomposed and is found on the surface of the soil; Humus is a flakey black matter consisting of decomposed animals and plants. It increases the water holding capacity of the soil. 3. Water – due to the shape of the grains, there are many spaces in the soil (called pores) which are fill up with water when it rains. 4. Air – soil air comes from the atmosphere and the gases that are formed from biological and chemical reactions within the soil. The air is found in the pore spaces between the grains.

Answer 5

A Horizon → Usually darkest, contains the most organic matter B Horizon → Brightest colour, more soluble minerals here by leaching C Horizon → Broken pieces of bedrock with clay D Horizon (bedrock) → Not considered soil

Answer 6

1. Porosity → the volume of pore spaces in the soil 2. Permeability → how freely water moves through the soil

Answer 7

Indigenous Australians depended on their stone implements to gather and process their food; ochre was a vital ingredient in art and religious practices; quarries and ‘processing’ sites were developed to cater for the demand for these products; and transport routes were established to allow for their trade.

Answer 8

Relative movement of the continents over the ocean bed Speed varies from 3 - 8 cm a year Alfred Wegner

Answer 9

Plate Tectonics Theory

Answer 10

The crust of the Earth is divided into numerous rigid slabs of crust called plates, each of which is moving relative to each other

Answer 11

Continents fit together Alfred Wegner

Answer 12

About 200 million years ago Laurasia Gondwana

Answer 13

About 140 million years ago Australia, South America, Antartica, India, Africa and parts of South East Asia

Answer 14

1. Matching fossils and rocks - deposits and fossils match up over wide areas, ie. when continents are placed together. Alfred Wegner 2. Convection current – heat from the mantle causes upwelling at mid-ocean ridge (MOR). Ridge push and slab pull aid in moving the plates. Arthur Holmes 3. Sea-floor spreading - at mid-ocean ridges new crust is created Harry Hess 4. Ocean floor - dating of the ocean floor supports Hess’ sea-floor spreading Glomar Challenger 5. Magnetic reversals - shows the matching magnetic orientation of the rock on either side of the mid-ocean ridge Frederick Vine and Drummond Matthews

Answer 15

Density of an object refers to how heavy it is given how much space it takes up This depends of how closely packed the molecules are

Answer 16

Density = Mass (g) \ Volume (cm3)

Answer 17

Is is the theory in which the lithosphere (earth's crust) is divided into a number of plates, each of which moves on the plastic asthenosphere to collide with, slide under, or move post adjacent plates. The oceanic and continental plates move, float and sometimes fracture, this interaction causes continental drift, earthquakes, volcanoes, mountains and oceanic trenches.

Answer 18

African Antarctic Eurasian Indo-Australian North America Pacific South America Nazca

Answer 19

1. Transform boundaries 2. Divergent boundaries 3. Convergent boundaries

Answer 20

1. Oceanic - is relatively thin (5 - 10 km thick, may be up to 70 km) Rock type - Mafic, e.g. basalt, often formed from mid-ocean ridges. Rich in magnesium and aluminium. Soft sediments 2. Continental - is relatively thick (25 - 50 km thick, may be up to 150 km) Rock type - Felsic, e.g. granite formed from slow cooling. Rich in silica and aluminium. Hard sediments.

Answer 21

When plates collide, compressional forces and cause rocks to bend or fold which produces anticlines and synclines If the forces are very large or occur over a short time or the rocks are brittle, they may snap to produce reverse faults

Answer 22

Magma is mostly formed at subduction zones, and mid-ocean ridges It is sometimes formed in hotspots or by intra-plate melting

Answer 23

Temperature, pressure, water content and mineral composition affects magmas formation

Answer 24

Raises the melting point

Answer 25

Lowers the melting point

Answer 26

Forms within the upper mantle

Answer 27

It is hotter and contains more high density materials such as iron and magnesium When released it creates a thermal plume and then an effusive eruption.

Answer 28

Formation occurs near the base of the lithosphere when a subducted plate is partially melted. Because if its relatively high viscosity, felsic magma is resistant to flow and plugs volcanic vents, causing a build-up of pressure releasing violently. This resistance to flow also produces steep sided, symmetric volcanoes. E.g. Andes mountains of South America

Answer 29

effusive (shield volcanoes) or explosive (composite volcanoes)

Answer 30

effusive eruption

Answer 31

An eruption where: -mmafic magma formed in upper mantle. - depth of formation leads to hotter magma, with more dense material. - magma rises into thermal plume below surface. - released as a flowing magma, with lower viscosity allowing gas to escape more easily.

Answer 32

Explosiv eruption

Answer 33

- Felsic magma form partially melted subjected oceanic plates - Buildup of pressure from plugged vents - Viscous magma, slow flowing forming steep sided composite volcanoes

Answer 34

- The hydrosphere is the liquid water component of the Earth. - It includes the oceans, seas, lakes, ponds, rivers and streams. - The hydrosphere covers about 70% of the surface of the Earth and is the home for many plants and animals.

Answer 35

- The water cycle is the natural movement of water in the environment. - The Sun evaporates water from lakes, rivers, the land and the sea. In the atmosphere the water condenses to form clouds. The water falls back to earth as rain, snow, sleet, dew or fog. - The energy to operate the water cycle comes from the Sun.

Answer 36

- Total distribution of water in all its forms and in all its natural reservoirs on Earth. - Can be classified as ocean (salt) or fresh water (includes ice and water vapour). - Earth has an uneven distribution of liquid water, even though it has more than anywhere else in the Solar System.

Answer 37

- Water has many properties that make it a unique substance and helps drive many systems of earth both living (biotic) and non-living (abiotic) - Water is necessary for all living matter - It is used for: A solvent to allow life processes to occur (reactions in cells) Used as a raw material in chemical reactions It transports materials to and from cells It helps with temperature regulation

Answer 38

Boiling point is affected by pressure and dissolved chemicals E.g adding salt will raise the boiling point At sea level it is 100℃, at the top of Kosciuszko it is 97.5℃

Answer 39

Temperature - Colder water is more dense because the particles are closer together. This causes it to sink - Particles in warmer water will have more, creating more space and are therefore less dense

Answer 40

The force acting on the surface of a liquid, keeping the area of the surface as small as possible. The force acts at right angles to the surface and causes liquids to form a ‘film’ on the surface or to form droplets The force is due to the attraction between the particles of liquid

Answer 41

It dissolves most substances

Answer 42

The substance that is to be dissolved

Answer 43

A natural part of the global climate system. They occur when the Pacific Ocean and the atmosphere above it change from their neutral (‘normal’) state for several seasons and occur every 3 - 7 year

Answer 44

Drier weather

Answer 45

- wind/air currents - Ocean currents and upwellings - Evaporation and cloud formation - The water cycle

Answer 46

The cryosphere → is the frozen water part of the Earth's system

Answer 47

The Arctic, Antarctica and Greenland Other components are snow, ice, glaciers and permafrost located around the globe

Answer 48

Snow and ice reflects heat from the sun, helping to regulate our planet’s temperature As the planet heats up the cryosphere shrinks, causing further heating As ice melts the albedo (reflection) reduces, causing more sunlight to be absorbed This causes more ice to melt further reducing the albedo, further heating up

Answer 49

1. Oxygen-demanding substances 2. Pathogens 3. Synthetic organic compounds 4. Nutrients 5. Inorganic chemicals 6. Sediments 7. Radioactive substances 8. Thermal discharge

Answer 50

where plates slide past each other E.g.San Andreas fault (pacific and North American plates sliding past each other)

Answer 51

spreading ridges - as plates move apart magma fills up the gap Example (continental): iceland is continental rifting (rift valley) Iceland has a divergent plate boundary running through its middle Example (Oceanic): Mid-Atlantic Ridge is a mid-ocean ridge (MOR) formed from plates diverging

Answer 52

There are three types of convergent boundaries: - Continent - continent convergence Folded mountain range with large Earthquakes and NO volcanoes E.g: Himalayas mountain range (Indian and Eurasian plates colliding) - Continent - oceanic convergence, where - Oceanic plates subducts underneath the continental plate - Oceanic plate heats and melts - The melt rises forming volcanic mountain range - Example: The Andes volcanic mountain range (Nazca and South American Plates) - Ocean - ocean convergence The subduction plate is bent downwards to form a very deep depression in the ocean floor called a trench Forms a volcanic Island arc E.g. Japan and the Mariana Trench (pacific and Mariana plates)

Answer 53

Usually organic material that is not entirely decomposed, for example, untreated or partially treated sewage. As the organic material enters a body of water, it continues to decompose and uses up oxygen from the water during the process. This reduces the level of dissolved oxygen available for aquatic plants and animals and also acts as a nutrient.

Answer 54

Organisms that cause disease if present in concentrated amounts in an ecosystem. For example, protozoan parasites Giardia and Cryptosporidium contaminated Sydney’s water supply in 1998. These can cause intestinal cramping and explosive diarrhoea. Other waterborne diseases common to Third World countries can be fatal, such as cholera and typhoid.

Answer 55

These are human manufactured chemicals predominantly made up of carbon and hydrogen. The most common types that pollute water are petrol and oil. Oil spills float on water, preventing light penetration for photosynthesis and covering shoreline food supplies. They typically blind, poison or drown fish, birds and mammal species.

Answer 56

These are natural or synthetic substances that promote plant growth. These typically contain nitrogen and/or phosphorus and include manure, humus, detergents, and fertilisers. The artificial promotion of plant growth in waterways favours weed species over natives. It can also promote algal blooms.

Answer 57

These are either pesticides and herbicides using in farming or substances released by industrial processes. These substances interfere with the normal functioning of individual organisms or entire ecosystems. Heavy metals released by some industries can accumulate in the food chain, causing skeletal malformation and a variety of diseases.

Answer 58

Undisturbed water environments are usually clear. Sediments can increase due to flooding and land clearing. Turbidity – how murky water is. Light cannot penetrate far down through water with a high turbidity, which can impact on bottom-dwelling aquatic plants. Stratification – formation of thermal layers in dams due to turbidity. This occurs when highly turbid waters in dams become heated by the sun and results in less gas exchange because of the warm temperature on the surface.

Answer 59

Radiation damages DNA in the cells of living things, resulting in diseases and mutations. In 2011 the Fukushima nuclear meltdown after an earthquake and tsunami contaminated large areas. Australia’s only nuclear reactor is at Lucas Heights, Sydney. Small reactor that produces radioactive isotopes for research, industry and hospitals. Concerns about the effect of buried low to medium level radioactive materials in the local environment. Tailings dam– sediments left over from mining. Main reason for failure of the NT uranium mine.

Answer 60

Hot water holds a lot less dissolved gas than cold water. Some industries that use water as a coolant, such as power stations, release their waste water into dams or streams. Although it may be free of chemical pollutants, this warm water can cause the suffocation or redistribution of plant and animal life in response to decreased oxygen and carbon dioxide levels.

Answer 61

1. Sewage - most of Australia’s sewage, from septic tanks to tertiary treated effluent, eventually ends up in oceans, rivers or ground water. To reduce this, some water authorities have set up programs to reuse treated effluent as a soil conditioner for agricultural use. Another method being trialled is large scale worm farming, which turns treated effluent into a disease free organic fertiliser. 2. Industrial waste - industry can be a major producer of water pollutants, especially of synthetic organic compounds and inorganic chemicals. 3. Garbage and refuse - stormwater run-off flushes huge amounts of litter and vegetation into streams and onto beaches. While collected rubbish is generally quickly buried at landfill sites, water movement through the soil at these sites can contaminate nearby waterways with a wide variety of chemical pollutants if barriers to prevent 4. Agriculture - the vast majority of Australian farmland is relatively infertile and farmed at near maximum capacity. This requires the addition of fertilisers to replenish soil nutrients and the use of herbicides and pesticides to eliminate competition to crops. Usually administered as water soluble liquids, they are inevitably washed into waterways and groundwater supplies.

Answer 62

Process where nutrients become concentrated in waterways, causing an explosion in the population of microscopic algae and cyanobacteria. The water becomes discoloured in an algal bloom. Algal blooms prevent light from penetrating the water which stops the bottom dwelling plants from carrying out photosynthesis. They also use up the oxygen which kills living organisms.

Answer 63

Human activity

Answer 64

Usually clears with rainfall which will replenish with clean water.

Answer 65

It is a blue-green algae which is common in Australia and is formed from fertilisers in low flow inland rivers. Produces toxins that can kill humans and cattle that drink it or produce rashes on those who bathe in it. It is a type of eutrophication.

Answer 66

The presence of soluble salts of sodium, magnesium and calcium in the soil and water.

Answer 67

There has been weathering of marine sediments from ancient inland seas and ancient sand dunes such as in northern SA, (e.g. Lake Eyre) southern NT and southern WA. Salts have been blown as sea spray from the oceans and deposited by rain as in parts of WA. Some saline areas are, quite naturally, completely unsuitable for agriculture or grazing. However, many areas are in use because the natural salinity was mostly deep in the sub-soil and did not interfere with plant growth. Unfortunately, some human land-use practices have caused salinity to come to the surface.

Answer 68

Clearing - where the deep-rooted native trees and shrubs have been largely replaced by shallow-rooted grasses grown as pasture. This has become a problem mainly in semi-arid land cleared for grazing - eg. particularly in south-west WA.

Answer 69

Due to over-irrigation of crops, combined with the clearing of native vegetation. Major problem in a number of areas, including the Murray-Darling catchment area which covers large areas of central and western NSW.

Answer 70

Land clearing Irrigation

Answer 71

In many parts of semi-arid Australia the deep sub-soil contains saline groundwater. Its “water table” is kept low because transpiration from the deep-rooted native vegetation constantly removes moisture from the soil. There is a balance between incoming water as rainfall, and outgoing evaporation and transpiration. When land is cleared for grazing or for irrigated farming, from 10 times to 100 times more water percolates downwards into the sub-soil. This raises the water table, bringing salt with it. Salt reaching the plant root zone kills plants, both native and crops.

Answer 72

1. Loss of productivity of agricultural and grazing land. 2. Increased soil erosion due to reduced vegetation cover. 3. Increased salinity of streams creates problems for human water supplies and irrigation schemes. 4. Salt damage to roadways, concrete structures, water pipes and buildings, due to corrosion and salt crystallisation. 5. Ecosystems are threatened. Soil salinity can kill native vegetation, and this deprives animals of food and habitat. Salinity in waterways affects the aquatic ecosystems by causing osmosis problems in all organisms.

Answer 73

Rehabilitation often involves maintaining the water table below the soil and includes: 1. Reducing the amount of rainwater reaching the water table by planting trees and shrubs to absorb and evaporate the rainwater. 2. Modern farming techniques allowing farmers to closely monitor soil moisture levels in irrigation areas to avoid overirrigation. Some crops can use drip irrigation rather than spray irrigating the entire paddock. 3. Government investing in salt interception schemes – borehole drilled into salty aquifers. Water that comes to the surface is fed into large basins where it is evaporated. Prevents salty water reaching streams. 4. Intermittently plant deep rooted trees on edges of crops or salt tolerant plants 5. Rotate crops with deeper roots

Answer 74

Removal of surface layers or topsoil from an area. The topsoil is nutrient rich and vital to plant growth. It can take decades to develop.

Answer 75

Blown away by wind or washed away by water. Wind - sandy and fine-grained soils are easily picked up and carried along by the wind. If there is no major vegetation, the wind can pick up speed and carry more soil. Water - moving water can remove larger particles than wind. Soil that has been laid bare by overstocking, or by rabbit plague, can be eroded away when a major rain event occurs. Gully erosion then occurs and reduces the area available for growing crops or livestock.

Answer 76

1. Direct competition with native species 2. Loss of species diversity – may cause native species to become endangered 3. Short-circuit interactions in natural communities & disrupt natural food web 4. Direct Predation 5. Affect entire ecosystem functions as water availability and nutrient cycle

Answer 77

1. Billions of dollars in damage to forests, property values, agricultural productivity, public utility operations, native fisheries, tourism, outdoor recreation 2. Billions of dollars in programs by federal and state agencies to control invasive species 3. $137 billion in damages per year

Answer 78

1. Feral animals such as rabbits, goats, pigs, and camels compete with native grazing animals. 2. Feral rabbits can take over the burrows of native bilbies and bandicoots. 3. Feral cats and foxes hunt and kill many native species and have wiped out numbats and mallee fowl from some regions. 4. Introduced fish such as mosquito fish and European carp feed on native fish, competing with native fish for food or habitat, uprooting aquatic vegetation, disturbing sediments and introducing diseases or parasites.

Answer 79

1. Prevention Preventing invasive species from being introduced somewhere in the first place, or preventing them from spreading if they do arrive, is the key to avoiding long-term harm to ecosystems 2. Eradicating potential invaders soon after invasion The complete and permanent removal of a pest. No pest animal has ever been eradicated from mainland Australia 3. Physical (manual and mechanical) Controlling plants: Mechanical – excavation, trimming, etc. Removal of plants by hand Installation of growth barriers Controlling animals: Culling Trapping and hunting Putting up barriers or fences 4. Cultural - ecosystem management 5. Biological - natural enemies Biological control is using living organisms to control the pest. Agents must be carefully assessed before release to ensure the control species will not become invasive itself e.g. cane toad. 6. Chemical - pesticides Chemical control involves applying poison to eliminate invasive species Insecticides & pesticides to control insect pests Herbicides (weed-killer) to control plants 7. Integrated pest management - uses a combination of the above methods - most effective

Answer 80

1. Biological – control species can become invasive 2. Chemical – may kill native species 3. Physical – may miss removing some of the invasive species 4. Prevention – apathy and lack of awareness

Answer 81

This is the things that you change in your experiment and are interested in how this change affects results. In a valid experiment there is only one independent variable. For example, in my experiment, the thing I am changing is how much light each plant is exposed to.

Answer 82

This is the thing that you are measuring For example, in my plant experiment, I am measuring how tall my plants grow in centimetres.

Answer 83

This is everything else that must be kept the same in order to maintain a fair test. This is important so that we can conclude that the effect we are observing is because of our independent variable and not some other factor. For example, in my plant experiment I should water all the plants the same, use the same soil to plant them in, use the same plant seed etc.That way I can say that any changes in plant growth can only be due to their different sunlight exposure as all else in the experiment was kept the same.

Answer 84

Observation Question Hypothesis Experiment Results Conclusion

Earth and Environment - Prelim Study Flashcards

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