Transcript 11.1
Chapter 11 Resources and Energy A resource is any useful information, material or services. Resources can be described as being: • natural resources -goods and services provided by our environment, and • human resources - those provided by humans (experience, skill, wisdom and human enterprise). Nonrenewable resources (exhaustible resources) • Resources that exist in limited supply and which cannot be replaced once they are used. (May take thousands or even millions of years to form within the Earth). Examples include • fossil fuels and natural gas, • precious metals (gold, silver etc..) Most natural resources on Earth are finite. That is there is only so much of a resource available on this planet. This applies to both renewable and nonrenewable resources. • • • • 4 trillion barrels of oil, 10-50 million species of living organisms 38,874 cubic kilometers of fresh water, 6 billion humans. Because many of the resources that we rely on are finite their availability can be greatly impacted by 3 human factors: • population • affluence, and • technology Population (P) - The number of humans living on Earth using resources. Affluence (A) - The amount of a resource consumed by an individual (per capita use). The United States has • 5% of the world’s population; • uses 25% of the world’s energy; and • accounts for 25% of the world’s Gross National Product. India has • 16% of the world’s population; • uses 3% of the world’s energy; and • accounts for 1% of the world’s Gross National Product. Technology (T) - Affects the rate at which a resource is extracted/used. The Impact on a resource can therefore be calculated by using the formula I=(P)(A)(T). I= Impact P=Population A=Affluence T=Technology Renewable Resources These resources are self renewing, and can usually be replaced on a human time-scale. Examples? • solar energy • air, • water (excluding aquifer water supplies), & • non-endangered biological organisms. Formation of Ores • Most metallic and non metallic elements are found chemically combined forms as minerals in the crust. • Deposits of minerals from which metals and nonmetals can be removed profitably are called ores. • Many ores form in or near a mass of molten magma, so igneous and nearby rocks are often fruitful hunting grounds. Metals • Shiny luster, ability to conduct heat and electricity, bend easily when in thin sheets. Can occur in pure form as native elements (copper a good example). Non-metals • Dull surface, poor conductors of heat and electricity. In Cooling Magma • Dense, metalbearing minerals form layers on the bottom of the magma chamber. Contact Metamorphism • Heat and hot fluids flowing from the magma change the surrounding rock. Dissolved minerals form a band of ore around the igneous rock. Veins • Hot, mineral-bearing solutions break through many small cracks that deposit narrow, finger-like bands. Lodes • A deposit formed by a large number of mineral veins. Ores and Moving Water • Streams carry ore fragments until, due to their high density, they are deposited where the currents are weak. Placer Deposits • These deposits are concentrated at the bottom of stream beds. Uses of mineral resources • Some metallic ores such as gold, platinum and silver are prized for their beauty and rarity. • Some nonmetallic minerals are gemstones; rare mineral crystals that display extraordinary brilliance and color when specially cut for jewelry. • Other minerals are used for many other industrial purposes. Uses of Mineral Resources Manganese nodules on ocean floor • See table on p. 197 for the most common ores and their uses. • Untapped mineral resources include deposits that could be mined from the ocean floor, but we currently don’t have the technology to do it. Mineral Conservation • Increased PAT (population, affluence, and technology) means increased use of mineral resources. Ways to Preserve Mineral Resources • Through conservation, use of alternative materials, or by recycling. Assignment 11.1 Key Terms 11.1 Review p. 197, #1-4 11.1 Worksheet Due tomorrow, beginning of period.