Earth s Resources 3 RD QUARTER

Transcription

1 Earth s Resources 3 RD QUARTER

2 Renewable and nonrenewable Resources 1. A renewable resource can be replenished over fairly short time spans such as months, years, or decades.

3 Renewable and nonrenewable Resources 1. A renewable resource can be replenished over fairly short time spans such as months, years, or decades. a)examples: i. Plants and animals ii. Natural fibers for clothing (cotton) iii. Trees for lumber and paper iv.energy from flowing water, wind and sun

4 Renewable and nonrenewable Resources 2. A nonrenewable resource takes millions of years to form and accumulate.

5 Renewable and nonrenewable Resources 2. A nonrenewable resource takes millions of years to form and accumulate. a)examples i. Coal, oil, natural gas ii. Iron, copper, uranium, and gold

6 Renewable and nonrenewable Resources 2. Earth's population is growing fast which increases the demand for resources. The rate of mineral and energy resources use has climbed faster than population growth. a)what does this mean?

7 Fossil Fuels (coal) 1. A fossil fuel is an hydrocarbon that may be used as a source of energy. a)coal, forms when heat and pressure transform plant material over millions of years.

8 Fossil Fuels (coal) Stages of development (Coal) Stage 1, peat, partially decayed plant material that sometimes looks like soil. Stage 2, lignite, a sedimentary rock that is called brown coal Stage 3, bituminous coal or soft coal, a sedimentary rock Stage 4, anthracite or hard coal, a metamorphic rock

9 Fossil Fuels (coal)

10 Fossil Fuels (coal) Surface mining Underground mining Burning coal Disadvantages of using coal Scars the land Disturbs the ecosystem Costly to restore the land surface after mining ends Costly in terms of human life and health (collapsing tunnels and explosions) Creates air pollution Increases sulfur in the air which can cause acid precipitiation. Which affects forests, aquatic ecosystems, metals and stone structures.

11 Fossil Fuels (petroleum & Gas) b)petroleum (oil) and natural gas i. Remains of plants and animals that were buried under seas

12 Fossil Fuels (petroleum & Gas) Formation of oil and natural gas 1. Plant and animal remains be come buried in the ocean-floor sediments. Sediments protect the organic remains from oxygen and decaying. 2. Over millions of years, sediments builds up while chemical reactions slowly change the liquid and gaseous hydrocarbons into oil and natural gas. 3. Oil and natural gas are squeezed from the compacting, mud rich sediment layers. Oil and gas move into nearby permeable beds such as sandstone

13 Fossil Fuels (petroleum & Gas) Oil Trap (anticline)

14 Fossil Fuels (petroleum & Gas) Oil Trap 1. An oil trap stops the upward movement of oil and gas. a. Has permeable reservoir rock that allows oil and gas to collect in large amounts b. A cap rock, an impenetrable layer of rock, keeps the oil and gas from escaping to the surface. 2. An anticline is an up arched series of sedimentary rock layers (see diagram in slide 13) a. A drill punctures the cap rock, releasing pressure, causing the oil and gas toward the drill hole.

15 Tar Sands and Oil Shale

16 Tar Sands and Oil Shale 1. Tar sands, a mixture of clay and sand combined with water and varying amounts of black, thick tar called bitumen. a)occur in sands, sandstone, shales and limestones b)does not flow easier so it cannot be pumped out easily c)strip mining or surface mining i. Excavated material is heated with pressurized steam to cause the bitumen to soften and rise. ii. Bitumen is processed to remove impurities, add hydrogen and refine into oil.

17 Tar Sands and Oil Shale d)disadvantages:

18 Tar Sands and Oil Shale d)disadvantages: d)refining tar sand requires a lot of energy e)cause land disturbances f) Processing needs a lot of water g)accumulation of toxic water and sediments

19 Tar Sands and Oil Shale

20 Tar Sands and Oil Shale 2. Oil shale a)a rock that contains a waxy mixture of hydrocarbons called kerogen. i. Mining kerogen, oil shale is heated to vaporize the kerogen. ii. Kerogen vapor is then processed to remove impurities and then refined into oil b)disadvantages: i. Produces less heat energy than oil ii. Costly to remove the minerals iii. Needs large amounts of water in areas where water is scarce iv. Fracking! Can make mining profitable but it s fracking!

21 Formation of Mineral Deposits 1. Mineral resources are deposits of useful minerals that can be extracted. Mineral reserves are deposits from which minerals can be extracted for a profit. a)ore is a useful metallic mineral that can be mined at a profit. b)mineral deposits exist that are not profitable enough to extract. These are still considered mineral reserves. c)some of the most important mineral deposits form through igneous processes and from hydrothermal solutions.

22 Formation of Mineral Deposits 2. Mineral resources and Igneous processes a)produces deposits of metallic minerals: gold, silver, copper, mercury, lead, platinum and nickel b)as magma cools, heavy minerals crystallize early and settle to the bottom. Chromite (chromium ore), magnetite and platinum can form this way.

23 Formation of Mineral Deposits 3. Hydrothermal Solutions a)gold, lead, zinc, silver, copper b)as magma cools and becomes a solid, liquids and metal ions collect near the top which moves into fractures or cracks in the rock or between rock layers. c) Produce vein deposits d)gold, silver, and mercury deposits occur as hydrothermal vein deposits

24 Formation of Mineral Deposits 4. Placer deposits

25 Formation of Mineral Deposits 4. Placer deposits a)erosion of heavy minerals that settle from moving water, while less dense particles remain suspended and continue to move. b)like-size grains are deposited together due to the density of the particles. c)minerals are heavy, durable and chemically resistant

26 Formation of Mineral Deposits 4. Placer deposits d)point bars inside of bends in streams, cracks, depressions and other streambed irregularities. e)gold! f) Can follow the placer deposits up stream to find the original mineral deposits.

27 Nonmetallic Mineral Resources 1. Nonmetallic mineral resources are extracted and processed either for nonmetallic elements they contain or for their physical and chemical properties. 2. Nonmetallic minerals are divided into two broad groups a) Building materials i. Natural aggregate (crushed stones, sand and gravel) ii. Limestone, crushed rock and building stone, ingredient in cement b) Industrial minerals i. Limestone, used to make steel; used by farmers to neutralize acidic soils ii. Not as abundant as building materials iii. Need more processing than building materials

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30 Answers 1. Renewable resources have unlimited supplies an can be replaced; nonrenewable resources have limited supplies and cannot be replaced 2. Coal, petroleum, natural gas 3. Geological structures that contain low grade hydrocarbons mixed with clay, sand, or shale 4. Hydrothermal deposits formed from hot, metal-rick fluids that are left when magma cools. The metal ions collect as mineral deposits in small openings such as rock fractures. 5. Building materials and industrial minerals 6. Coal was formed from plant material that collected in swamps. Petroleum and natural gas were formed from plant and animal material that collected and were buried in ancient seas. 7. Most of the world s tar-sands deposits are in Canada. The fe deposits in the US are in California. In Addition, mining tar sands has serious environmental drawbacks and is expensive 8. Placer deposits are minerals that are carried by moving water from a source upstream. By following the deposits upstream, it is possible to find the original deposit.

31 4.2 Alternative Energy Sources

32 Solar Energy Videos: Energy 101: Solar Power Electric Generation

33 Solar Energy 1. Solar energy can amount to more than 100,000 times the amount of energy used by all human society in a day. 2. Solar energy is more than the Earth s internal energy or geothermal energy. 3. Advantages of solar energy: a) fuel is free b)nonpolluting

34 Solar Energy 4. Passive solar collectors a)south-facing windows; b)objects in the room absorb the heat c) Objects radiate the heat (warming the air)

35 Solar Energy 5. Active solar collectors a)roof mounted devices (panels) b)heat is transferred to circulating air or water through pipes c) Domestic uses or commercial uses

36 Solar Energy 6. Disadvantages to solar energy a)equipment is costly b)on cloudy days, a different heating unit is necessary 7. As fossil fuels become more expensive, solar energy equipment costs will lower.

37 Nuclear Energy Videos: Fusion Energy Explained 3 Reasons why nuclear energy is.. Parts 1, 2, 3 1. Nuclear power comes from radioactive materials that release energy through nuclear fission.

38 Nuclear Energy 2. Nuclei of heavy atoms such as uranium-235 are bombarded with neutrons. The uranium nuclei then split into smaller nuclei and emit neutrons and heat energy.

39 Nuclear Energy 3. Neutrons that are emitted, bombard (hit) other nuclei causing a chain reaction. 4. Fission releases an enormous amount of energy as an atomic explosion.

40 Nuclear Energy 5. Nuclear power plants control fission reactions by using neutron absorbing rods. a)a large amount of heat is produces that turns water into steam that drives turbines that turn electrical generators.

41 Nuclear Energy 6. Factors that have slowed the use of nuclear energy: a)cost has increased b)hazards associated with the disposal of nuclear wastes c) Possibility of accidents that would cause radioactive material to escape 7. Nuclear Power Plant Accidents: a)1979 Three Mile Island in Pennsylvania; the reactor was damaged due to the lack of water for several hours. No danger to the public.

42 Nuclear Energy b)1986, Chernobyl in the Ukraine i. Reactor went out of control ii. Two explosions, pieces of uranium spread over the surrounding area iii. After the explosions, a fire broke out for 10 days Video: 1. Atmosphere carried high levels of radioactive materials as far away as Norway 2. Thousands of people face increased risk of death from cancers associated with the fallout.

43 Wind Energy Video: Wind Power 1. Wind power has been used in the past: a)sailing ships b)windmills for grinding grains 2. In the next years, wind power could meet up to 5% - 10% of USA s demand for electricity.

44 Wind Energy Video: Wind Power 3. It would benefit people on islands or other isolated areas. 4. Disadvantages of wind energy: The need for technical advances Creating noise pollution The cost of large tracts of land in populated areas.

45 Hydroelectric Power 1. The mechanical energy that waterwheels produce has powered mills and other machinery. 2. The power that generated from falling water can drive turbines that produce electricity. 3. In USA, the hydroelectric power plants produced through large dams, it is producing 5% of the country s electricity. 4. The dams allow for a controlled flow of water. The water held in a reservoir behind a dam is a form of stored energy that can be released through the dam to produce electric power.

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50 Disadvantages; 1. Dams have finite lifetimes as rivers deposit sediments behind the dam and the sediments fills the reserevior. Then the dam can no longer produces the power. This takes about years depending on the amount of material the river carries. Aswan s dam on the Nile in Egypt was completed in 1960s, It is estimated the half the reservoir will be filled by

51 2. The availability of suitable sites is a limiting factor in development of hydroelectric power. A good site must provide a significant height for the water to fall. It must have a high rate of water flow.

52 Geothermal Energy 1. It is harnessed by tapping natural underground reserviors of steam and hot water. Hot water is used directly for heating and turning turbines to generate electric power. The reservoirs of steam and hot water occur where subsurface temperatures are high due to relatively recent volcanic activity.

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55 1. The first commercial geothermal power plant in USA in 1960 at The Geysers. 2. It is an important power source of electrical power for nearby San Francisco and Oakland. It continues to provide electrical power with little environmental impact. 3. Advantages; It is clean energy resource.

56 Disadvantages; 1. It is not inexhaustible. When hot fluids are pumped from volcanically heated reservoirs, the reservoir can not be recharged. The steam and hot water from individual wells usually lasts for years. That s why engineers must drill more wells to maintain power production. 2. It is not expected to provide a high percentage of the world s growing energy needs.