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Explore renewable and nonrenewable resources such as fossil fuels, tar sands, oil shale, mineral deposits, and solar energy. Learn about energy extraction, formation processes, environmental impacts, and alternate sources like nuclear energy.
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PrenticeHallEARTH SCIENCE TarbuckLutgens
Chapter4 Earth’s Resources
Renewable and Nonrenewable Resources 4.1Energy and Mineral Resources • Renewable resources can be replenished over fairly short spans of time, such as months, years, or decades. • Examples: Plants, animals, trees, water, wind, sun. • Nonrenewable resources take millions of years to form and accumulate. • Examples: coal, oil, natural gas, iron, copper, gold.
Fossil Fuels 4.1Energy and Mineral Resources • Fossil fuels are hydrocarbons that may be used as fuel, including coal, oil, and natural gas. • Nearly 90% of the energy used in the US comes from fossil fuels.
Forms when heat and pressure transform plant material over millions of years. Power plants primarily use coal to generate electricity. Mining for coal can cause many problems – the land is messed up if mining above ground, and roofs can collapse or gas can explode in underground mining. Burning coal creates air pollution problems. Coal
Form from the remains of plants and animals that were buried in ancient seas. Sometimes an oil trap which allows large amounts of fluids to accumulate will stop the upward movement of oil and gas. One structure that acts as an oil trap is an anticline – a series of sedimentary rock layers. Petroleum and Natural Gas
Tar Sands and Oil Shale 4.1Energy and Mineral Resources Fuels derived from tar sand and oils shales could become good substitutes for dwindling petroleum supplies.
Tar sands are usually mixtures of clay and sand combined with water and varying amounts of a black, thick tar called bitumen. The oil in tar sands is much thicker and cannot be pumped out easily. This takes a lot of energy and water to refine the oil to make it usable. Tar Sands
Oil shale is a rock that contains a waxy mixture of hydrocarbons called kerogen. The heat energy in oil shale is only about 1/8 of crude oil because oil shale contains large amounts of minerals. Current technology makes mining oil shale an unprofitable solution. Oil Shale
Formation of Mineral Deposits 4.1Energy and Mineral Resources Some of the most important mineral deposits form through igneous processes and from hydrothermal solutions. • Ore is a useful metallic mineral that can be mined at a profit.
Igneous processes produce important deposits of metallic minerals Examples: gold, silver, copper, mercury, lead, platinum, and nickel. Mineral Resources and Igneous Processes
Hydrothermal (hot water) solutions generate some of the best known and most important ore deposits. Most hydrothermal deposits form from hot, metal-rich fluids that are left during the late stages of the movement and cooling of magma. Hydrothermal Solutions
Placer deposits are formed when eroded heavy minerals settle quickly from water while less dense particles remain suspended and continue to move. Common sites of accumulation: bends in streams, cracks, depressions, and other streambed irregularities. Gold is the best known placer deposit – think California Gold Rush! Placer Deposits
Nonmetallic Mineral Resources 4.1Energy and Mineral Resources • Nonmetallic mineral resources are extracted and processed either for the nonmetallic elements they contain or for their physical and chemical properties. • Nonmetallic mineral resources are divided into two broad groups – building materials and industrial minerals.
CAUSE: Harvesting Peat Wood Mining Coal Uranium/Plutonium Drilling Oil Natural Gas EFFECT: Harvesting Leads to deforestation Leads to erosion Mining Deforms the lithosphere Water pollution Drilling Deforms the lithosphere Water pollution How do we harvest these energy resources and what are their effects?
Peat Oil Uranium/Plutonium Natural Gas WoodCoal
What is the difference between a renewable and a nonrenewable resource? What are the three major fossil fuels? What are tar sands and oil shale? How do hydrothermal deposits form? What are the two broad categories of nonmetallic mineral resources? Compare and contrast the formation of coal with that of petroleum and natural gas. Questions:
Solar Energy 4.2 Alternate Energy Sources Solar energy has two advantages: 1. Solar energy’s “fuel” is free. 2. Solar energy is non-polluting.
Simplest and most widely used are passive solar collectors – south facing windows – sunlight passes through glass, objects in the room absorb heat, heat warms air. Active solar collector – mounted on the roof – absorb heat and heat is transferred to areas where it is needed by circulating air or liquids through piping. How to Collect Solar Energy
Solar collecting equipment is expensive. You have to have a backup plan on cloudy days, at night, or during the winter. Drawbacks to Solar Energy
Nuclear Energy 4.2 Alternate Energy Sources In nuclear fission, the nuclei of heavy atoms such as uranium-235 are bombarded with neutrons. The uranium nuclei split into smaller nuclei and emit neutrons and heat energy.
Expensive to build safe nuclear facilities. Health hazards associated with disposing nuclear waste High chance of accidents that could allow radioactive material to escape. Downside to Nuclear Energy
Wind Energy 4.2 Alternate Energy Sources In the next 50 to 60 years, wind power could meet between 5 to 10 percent of the country’s demand for electricity.
According to one estimate, if just the winds of North and South Dakota could be harnessed, they would provide 80% of the electrical energy used in the US. Wind Energy
Need new technological advances Noise pollution – wind turbines are very loud! Cost of land is high and areas are often very populated with people. Problems with Wind Power
Hydroelectric Power 4.2 Alternate Energy Sources Hydroelectric poweris the power generated by falling 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. The strong water flow that results drives turbines and electric generators.
Hydroelectric dams have to be replaced because rivers deposit sediment behind the dam. Eventually, the sediment fills the reservoir and the dam can produce no power. Available space is limited – has to be tall enough, water must move rather quickly, and most places that have this already have a dam in use. Downside to Hydroelectric Power
Geothermal Energy 4.2 Alternate Energy Sources Geothermal energy is harnessed by tapping natural underground reservoirs of steam and hot water. Hot water is used directly for heating and to turn turbines that generate electric power.
Once the hot fluids are pumped from volcanically heated reservoirs, the reservoir cannot be recharged – they last no more than 10-15 years. Problems with Geothermal Energy
The Geysers Is the World’s Largest Electrical Geothermal Facility
Tidal Power 4.2 Alternate Energy Sources Tidal power is harnessed by constructing a dam across the mouth of a bay or an estuary in coastal areas. The strong in-and-out flow of tidal water drives turbines and electric generators.
Tidal power isn’t economical if the tidal range is less than 8 meters or if a narrow, enclosed bay isn’t available. Tidal Power Disadvantages
What are the advantages and drawbacks of using solar energy? How do nuclear power plants produce energy? What percent of our energy might be met by wind power over the next 60 years? What are the advantages and drawbacks of hydroelectric power, geothermal energy, and tidal power? Why will the interest in alternate energy sources probably grow in the future? Identify solar, nuclear, and wind power as renewable or nonrenewable energy sources. Explain your answer. Review Questions
The Water Planet 4.3Water, Air, and Land Resources • Each day, people use fresh water for drinking, cooking, bathing, and growing food. • Water covers 71% of Earth’s surface. • Less than 1% of the water on the planet is usable freshwater.
The Water Planet 4.3Water, Air, and Land Resources Freshwater Pollution • Point source pollution comes from a known and specific location, such as factory pipes, sewage treatment plants, or leaking landfills. • Nonpoint source pollution is pollution that does not have a specific point of origin. • Runoff is the water that flows over the land rather than seeping into the ground, often carrying nonpoint source pollution, like oil from streets.
Earth’s Blanket of Air 4.3Water, Air, and Land Resources The chemical composition of the atmosphere helps maintain life on Earth. Pollution in the Air • The increase of greenhouse gases such as carbon dioxide in the atmosphere has altered the carbon cycle and contributed to global warming—the unnatural warming of the lower atmosphere. • Through a series of chemical reactions, these pollutants in the air are converted into acids that are a major cause of acid precipitation.
Land Resources 4.3Water, Air, and Land Resources Earth’s land provides soil and forests, as well as mineral and energy resources Damage to Land Resources • Mines produce many mineral resources, but mines are destroying, soil, vegetation, and Earth’s contours. • Mines also cause soil erosion and pollution that contaminates soil and water and destroys ecosystems. • We also cut down trees, irrigate dry land to produce crops on it, and fill it with our trash (landfills)
Urbanization – making an area that was once farm land or open land into developments – buildings, roads, etc. Deforestation – cutting down all of the trees – less oxygen produced, more pollution. Agriculture – depleting the ground of its minerals and nutrients – also allows erosion to occur easily. We are Destroying Earth’s Surface (the lithosphere)!
