earth’s resources chapter 4. energy and mineral resources section 1

Earth’s ResourcesChapter 4

Energy and Mineral Resources

Section 1

Renewable and Non-Renewable

Resources•A resource is any material that can be utilized

•There are two types of resources: renewable and nonrenewable

•A renewable resource is one which can be replenished over a relatively short period of time, such as months, years, or decades

•A nonrenewable resource is one that takes millions of years to form and accumulate

Examples of Renewable Resources•Plants

•Animals

•Natural Fibers

•Water

•Wind

•Sun

•Air

Examples of Nonrenewable

resources

•Fossil fuels

•Rocks and minerals

•Radioactive fuel

Fossil Fuels

•Nearly 90% of all energy in the United States comes from fossil fuels

•A fossil fuel is any hydrocarbon (what elements make up hydrocarbons?) that may be used as a source of energy

•Fossil fuels include coal, oil, and natural gas

Coal• Coal is either a sedimentary (or

sometimes metamorphic) rock that forms from plant material over millions of years

• In olden times, coal was used to heat individual houses

• Nowadays, coal is mainly used in power plants to generate electricity

• 70% of all coal mined today is used in power plants

• Coal is a plentiful resource, however its use and recovery present certain problems

• Coal is nonrenewable and if being used faster than it is being replaced

• The surface mining for coal leaves the landscape scarred

• Underground mining doesn’t scar the land, but is more dangerous for the miners

• The burning of coal releases sulfur, which causes pollution issues

US coal deposits

Formation of coal

Surface, or strip, mining

Underground mine collapse

Sulfur causes air pollution

Cleopatra’s Needle shows the effects of acid rain

Petroleum and Natural Gas

•Petroleum is another name for oil

•Oil forms when the remains of plant and animal matter was buried in ancient seas

•Over millions of years, chemical reactions occur and some of the organic material is turned into liquid and gaseous hydrocarbons which we call petroleum and natural gas

Formation of oil and natural gas

Sometimes, oil and gas get trapped underground

Untapped oil resources in the US

Tar Sands and Oil Shale

•Some people think that tar sands and oil shale could be a suitable substitute for petroleum resources

Tar Sands•A tar sand is a mixture of clay, sand, water,

and a black thick tar (called bitumen)

•Bitumen is similar to crude oil, however it is thicker, so it cannot be pumped like petroleum

•Tar sands must be strip mined, then refined, so that only the bitumen remains

•The refining of tar sand takes almost half as much energy as is yielded by the product

Tar sand

Tar sand deposits in the Canadian province of

Alberta

Oil Shale

•Oil shale is a rock that is rich in a substance called kerogen

•Oil shale is mined, and the kerogen is removed by vaporization

•The kerogen vapor is then refined to remove impurities before use

Oil shale

Oil shale deposits

Formation of Mineral Deposits

•Nearly all manufactured items come from minerals

•A mineral reserve is a mineral deposit in which the mineral can be extracted profitably

•Mineral deposits typically occur as an ore

•An ore is a type of rock that contains important minerals or elements, including metals

•Some minerals occur in very small concentrations, or in very few locations throughout the world

•For example, copper only makes up about 0.0135% of Earths crust. However, a material must have at least 6.5% copper to be considered copper ore

•The reason for this uneven distribution of minerals can be credited to the rock cycle

•Some minerals only occur in certain areas because of the way the minerals are formed

•When magma cools, it deposits certain minerals

•Typically, the conditions must be just right for a certain mineral to form while magma cools. Therefore, the conditions only happen to be right in a few places

Mineral Resources and Igneous Processes

Hydrothermal Solutions

•In some places, minerals form because the exact chemical reaction needed to form them happens due to hydrothermal solutions

•These chemical reactions occur in very small areas

Placer Deposits•If an ore is eroded, sometimes the

mineral is left behind in a river, etc.

•The minerals are carried until they are deposited. The minerals then settle together

•Placer deposits typically occur with heavier, chemically resistant minerals

Placer deposits

Nonmetallic Mineral Resources• Nonmetallic mineral resources are extracted

and processed either for the nonmetallic elements they contain or for their physical properties

• Fluorite, limestone are used for fertilizers and steelmaking

• Nonmetallic mineral resources tend to be used for industrial purposes

• One drawback is that industrial minerals are less plentiful than building resources

Alternate Energy Sources

Section 2

Solar Energy

•Solar energy is the collection and use of the sun’s rays to supply heat or electricity

•Solar energy has two big advantages: the source of the energy is free and it is nonpolluting

•Passive solar energy systems do not move

•They include south facing windows, where sunshine is most abundant, that the rays pass through and the energy is absorbed by objects inside, which in turn radiate the heat back out

Passive solar design

•Other solar energy systems include an active solar energy collector. These collect heat energy from the sun and transfer it to circulated air or through piping

Active solar heating

•Another system is one in which photovoltaic cells (solar panels) convert the suns energy directly into electricity

Solar cells being used to generate electricity

•What are some drawbacks of using solar energy?

• Nuclear energy accounts for about 7% of the energy in the United States

• Nuclear energy relies on radioactive materials for their fuel

• When a radioactive element undergoes nuclear fission, energy is released

• Nuclear fission is where the nucleus of heavy atoms are split into smaller nuclei. This process emits neutrons and heat energy

Nuclear Energy

Nuclear Fission

A fission chain reaction

•In nuclear power plants, fission chain reactions are being controlled to prevent an explosion

Nuclear reactor

•The energy released from a nuclear fission reaction is used to produce steam, which powers a turbine

•A turbine is an electrical generator that when turned, creates electricity

Nuclear power

• BENEFITS

• Only steam is released into the atmosphere

• Relatively cheap

• Efficient

• DISADVANTAGES

• Radioactive waste

• Security

• Safety concerns

Chernobyl disaster

Wind Energy•Wind power is a system in which turbines

are used to turn the winds power into electricity

•There is a lot of promise in wind energy, but improvements need to be made before widespread wind power is a reality

•More efficient turbines, reduced noise pollution, land area needs for the turbines

Wind farms

Hydroelectric Power

•Water carries a tremendous amount of energy - especially falling water

•In order to harness hydroelectric power on a large scale, a dam must be built

•The water stored behind the dam can be released or slowed to increase or decrease the amount of power

Water wheel

Fontana dam

•Dams are only viable for 50-300 years because sediments build up behind the dam, eventually rendering it useless

•Geothermal energy is harnessed by using natural underground pockets of steam and/or hot water

•The steam/hot water is used to directly heat and to turn turbines to generate electricity

•Geothermal energy is common in areas with current or recent volcanic activity

Geothermal Energy

•Geothermal energy is a clean energy source

•However, it can be used up if the “hot spot” is completely drained. They cannot be recharged

A geyser is a natural example of how much energy is contained in

geothermal hot spots

Geothermal energy

Tidal Power

•Tidal power is harnessed by building a dam across an enclosed body of water influenced by tides. The force of the water during tidal changes powers turbines to produce electricity

Tidal Power

Water, Air, and Land Resources

Section 3

The Water Planet•Water covers about 71% of Earth’s surface

•Most of this water is salt water, the currents of which help regulate Earth’s climate

•Ocean water also plays a pivotal part in the water cycle and provides a habitat for marine life

•However, people rely on fresh water for survival

•We use fresh water for drinking, cooking, bathing, and plant growth

Freshwater Pollution

•Pollution contaminates our fresh water supply and can make it unsafe for use

•There are two types of sources for freshwater pollution: point source pollution and nonpoint source pollution

• Point source pollution comes from a known and specific location, like a factory that dumps its waste from a pipe

• Nonpoint source pollution does not have a specific point of origin. The most common nonpoint source of pollution is runoff

• Runoff is water that flows over land, picks up pollution, and carries it into the water supply

• It is difficult to pinpoint exactly where the water picked up the pollutants. They could come from a road, or a farm, or a mine, etc.

Point source pollution

Nonpoint source pollution

Earth’s Blankey of Air

•Earth’s atmosphere is mainly composed of nitrogen, oxygen, water vapor, and small amounts of other gases

•The composition of the atmosphere helps maintain life on Earth in several different ways

•The atmosphere provides the oxygen in which we breath

•It provides nutrients for several other organisms

•Harmful solar radiation is filtered out by the atmosphere

•It helps to provide a livable temperature at Earth’s surface

• Pollution can change the chemical makeup of the atmosphere, which alters the natural cycles that occur

• Fossil-fuels generate a majority of the air pollution when they are burned to create energy

• Carbon monoxide, nitrogen oxide, soot, and other pollutants are released

• Sometimes, these pollutants can form smog, a mixture of smoke and fog

• Sometimes, these pollutants can form acid precipitation

Pollution in the Air

•The burning of fossil fuels also releases carbon dioxide, normally an important greenhouse gas

•However, too much carbon dioxide alters the carbon cycle

•The increased carbon dioxide in the atmosphere has trapped more heat, a process known as global warming

•Global warming could lead to melting glaciers and ice caps, rising sea level, and coastal flooding

Melting glaciers in Greenland

Land Resources•Land provides soil and forests, as

well as mineral and energy resources

•Soil is needed for agricultural growing

•Forests provide trees for lumber and paper

•Minerals are used for coins

Damage to Land Resources

•Mines are essential because they produce many resources that are necessities

•However, it can destroy vegetation, pollute soil and water, and destroy ecosystems

•Agriculture, tree removal, and garbage dumps all impact and can harm the land

Coal mining sludge

Deforestation in the Amazon rainforest

Protecting Resources

Section 4

Conservation• Each year, we produce billions of pounds of

trash that is simply thrown out

• In the United States lives only 6% of the world’s population. However, Americans use about 1/3 of the worlds resources and produce about 1/3 of the worlds garbage

• Some people think conservation and prevention is the answer

• Conservation is the careful use of resources (think the 3 R’s)

Keeping Water Clean and Safe

• In the 1970’s the government passed two legislative acts in order to reduce pollution and keep water clean

•1972 - the Clean Water Act required industries to reduce or eliminate point source pollution

•1974 - the Safe Drinking Water Act set a maximum level of pollutants that water could contain and still be safely consumed

The Cuyahoga River in Cleveland was so polluted, that it has caught fire several

times. This image is from 1952

Protecting the Air

•In 1970, the Clean Air Act was passed by Congress

•The Clean Air Act established a criteria for what constituted pollution

•Today, power plants and automobiles use pollution control devices to reduce certain products of fossil fuel combustion

LA with pollution

LA without pollution

Caring for Land Resources

• Farmers can use soil conservation techniques, such as crop rotation and strip cropping

• Forestry can be conserved through selective cutting as opposed to clear cutting

• Natural fertilizers and pesticides can be used over inorganic fertilizers and pesticides (compost is an example of a natural fertilizer)

• Recycling can help reduce the waste that accumulates in landfills