Earth as a System Table of Contents Section 1 Earth: A Unique Planet Section 2 Energy in the Earth System Section 3 Ecology
Section 1 Earth: A Unique Planet Objectives Describe the size and shape of Earth. Describe the compositional and structural layers of Earth s interior. Identify the possible source of Earth s magnetic field. Summarize Newton s law of gravitation.
Bellringer Similar Earth vs. Moon Different
Section 1 Earth: A Unique Planet I. Earth Basics Earth is the third planet from the sun in our solar system. Earth formed about 4.6 billion years ago and is made mostly of rock. Approximately 70% of Earth s surface is covered by a thin layer of water.
Section 1 Earth: A Unique Planet II. Earth s Interior Scientists have made important discoveries about Earth s interior through studies of seismic waves. Seismic waves are vibrations that travel through Earth and that are caused by earthquakes and by explosions near Earth s surface. By studying seismic waves as they travel through Earth, scientists have determined that Earth is made up of three major compositional zones and five major structural zones.
Section 1 Earth: A Unique Planet A. Structural Zones of Earth s Interior The three compositional zones of Earth s interior are divided into five structural zones. lithosphere the solid, outer layer of Earth that consists of the crust and the rigid upper part of the mantle asthenosphere the solid, plastic layer of the mantle beneath the lithosphere; made of mantle rock that flows very slowly, which allows tectonic plates to move on top of it
Section 1 Earth: A Unique Planet mesosphere literally, the middle sphere ; the strong, lower part of the mantle between the asthenosphere and the outer core Below the mesosphere is the liquid outer core. The outer core surrounds the solid inner core
Section 1 Earth: A Unique Planet Earth s Interior, continued The diagram below shows the layers of Earth s interior.
Section 1 Earth: A Unique Planet III. Earth as a Magnet Earth s magnetic field extends beyond the atmosphere and affects a region of space called the magnetosphere. Scientists think that motions within the liquid iron of Earth s outer core produce electric currents that in turn create Earth s magnetic field.
Section 1 Earth: A Unique Planet Earth s Gravity Gravity is the force of attraction that exists between all matter in the universe. According to Newton s law of gravitation, the force of attraction between any two objects depends on the masses of the objects and the distance between the objects. The larger the masses of two objects are and the closer together the objects are, the greater the force of gravity between the objects will be.
Section 1 Earth: A Unique Planet A. Weight and Mass Weight is a measure of the strength of the pull of gravity on an object. An object s weight depends on its mass and its distance from Earth s center. B. Weight and Location Because the distance between Earth s surface and its center is greater at the equator than at the poles, the weight of an object at the equator is about 0.3% less than its weight at the North Pole.
Section 2 Energy in the Earth System Objectives Compare an open system with a closed system. List the characteristics of Earth s four major spheres. Identify the two main sources of energy in the Earth system. Identify four processes in which matter and energy cycle on Earth.
Section 2 Energy in the Earth System I. Earth-System Science Some Earth scientists combine knowledge of several fields of Earth science in order to study Earth as a system. system a set of particles or interacting components considered to be a distinct physical entity for the purpose of study All systems have boundaries, and many systems have matter and energy that flow though them. Even though each system can be described separately, all systems are linked.
Section 2 Energy in the Earth System The operation of the Earth system is a result of interaction between the two most basic components of the universe: matter and energy. Matter is anything that has mass and takes up space. Energy is defined as the ability to do work. Energy can be transferred in a variety of forms, including heat, light, vibrations, or electromagnetic waves. A system can be described by the way that matter and energy are transferred within the system or to and from other systems.
Section 2 Energy in the Earth System Closed Systems A closed system is a system in which energy, but not matter is exchanged with the surroundings. Open Systems An open system is a system in which both energy and matter are exchanged with the surroundings.
Section 2 Energy in the Earth System The figure below compares open and closed systems.
Section 2 Energy in the Earth System II. The Earth System Technically, all systems that make up the Earth system are open. However, the Earth system is almost a closed system because matter exchange is limited. Energy enters the system in the form of sunlight and is released into space as heat. Only a small amount of dust and rock from space enters the system, and only a fraction of the hydrogen atoms in the atmosphere escape into space.
Section 2 Energy in the Earth System Earth-System Science, continued Reading Check What types of matter and energy are exchanged between Earth and space?
Section 2 Energy in the Earth System Earth-System Science, continued Reading Check What types of matter and energy are exchanged between Earth and space? Dust and rock come to Earth from space, while hydrogen atoms from the atmosphere enter space from Earth. Solar energy enters Earth s atmosphere and reradiated energy leaves Earth.
Section 2 Energy in the Earth System III. Earth s Four Spheres Matter on Earth is in solid, liquid, and gaseous states. The Earth system is composed of four spheres that are storehouses of all of the planet s matter. The Atmosphere atmosphere a mixture of gases that surrounds a planet or moon The atmosphere provides the air you breathe and shields Earth from the sun s harmful radiation.
Section 2 Energy in the Earth System The Hydrosphere hydrosphere the portion of Earth that is water Water covers 71% of Earth s surface. Water in the hydrosphere occur in the form of oceans, lakes, rivers, streams, glaciers and ice sheets, and groundwater.
Section 2 Energy in the Earth System The Geosphere geosphere the mostly solid, rocky part of Earth; extends from the center of the core to the surface of the crust The geosphere includes all of the rock and soil on the surface of the continents and on the ocean floor. The geosphere also includes the solid and molten interior of Earth.
Section 2 Energy in the Earth System The Biosphere biosphere the part of Earth where life exists; includes all of the living organisms on Earth The biosphere is composed of all of the forms of life in the geosphere, in the hydrosphere, and in the atmosphere, as well as any organic matter that has not decomposed. The biosphere extends from the deepest parts of the ocean to the atmosphere a few kilometers above Earth s surface.
Section 2 Energy in the Earth System IV. Cycles in the Earth System A cycle is a group of processes in which matter and energy repeatedly move through a series of reservoirs. A reservoir is a place where matter or energy is stored. Many elements on Earth cycle between reservoirs. These cycles rely on energy sources to drive them. The length of time that energy or matter spends in a reservoir can vary from a few hours to several million years.
Section 2 Energy in the Earth System A. The Nitrogen Cycle In the nitrogen cycle, nitrogen moves from the air to soil, from soil to plants and animals, and back to air again. Nitrogen is removed from air mainly by the action of nitrogenfixing bacteria in the soil. The nitrogen enters plants, which are eaten by animals. The nitrogen is returned to the soil by decay and by animal wastes. Chemical processes that occur in the soil then release the nitrogen back into the air.
Section 2 Energy in the Earth System Cycles in the Earth System, continued The figure below illustrates the nitrogen cycle.
Section 2 Energy in the Earth System Cycles in the Earth System, continued Reading Check Identify two nitrogen reservoirs on Earth.
Section 2 Energy in the Earth System Cycles in the Earth System, continued Reading Check Identify two nitrogen reservoirs on Earth. Answers should include two of the following: the atmosphere, animals, soil, and plants.
Section 2 Energy in the Earth System B. The Carbon Cycle Carbon moves through all four spheres through the carbon cycle. In the short-term carbon cycle, plants convert carbon dioxide, CO2, from the atmosphere into carbohydrates. When organisms bodies break down the carbohydrates and release some of the carbon back into the air as CO2 or through their organic wastes as CO2 or methane, CH4. In the long-term carbon cycle, carbon is stored in the geosphere in a type of rock called a carbonate.
Section 2 Energy in the Earth System Cycles in the Earth System, continued The figure below illustrates the carbon cycle.
Section 2 Energy in the Earth System C. The Phosphorus Cycle During the phosphorus cycle, phosphorus moves through every sphere except the atmosphere. Phosphorus enters soil and water when rock breaks down, when phosphorus in rock dissolves in water, or when organisms excrete phosphorus in their waste. Plants absorb phosphorus through their roots and incorporate the phosphorus into their tissues. Animals absorb the phosphorus when they eat the plants. When the animals die, the phosphorus returns to the environment through decomposition.
Section 2 Energy in the Earth System D. The Water Cycle The movement of water from the atmosphere to Earth s surface and back to the atmosphere is called the water cycle. In the water cycle, water changes from liquid water to water vapor through the energy transfers involved in evaporation and transpiration. During these processes, water absorbs heat and changes into a gaseous state. When the water loses energy, it condenses to form water droplets, such as those that form clouds and fall to Earth s surface as precipitation.
Section 2 Energy in the Earth System V. Humans and the Earth System All natural cycles can be altered by human activities. The carbon cycle is affected when humans use fossil fuels. The nitrogen and phosphorus cycles are affected by agriculture. Humans must be careful to moderate their influences on natural systems.
Section 3 Ecology Objectives Define ecosystem. Identify three factors that control the balance of an ecosystem. Summarize how energy is transferred through an ecosystem. Describe one way that ecosystems respond to environmental change.
Section 3 Ecology I. Ecosystems Ecology is the study of the complex relationships between living things and their nonliving, or abiotic environment. ecosystem a community of organisms and their abiotic environment An ecosystem may be as large as an ocean or as small as a rotting log. The largest ecosystem is the entire biosphere.
Section 3 Ecology Organisms that make their own food are called producers. Most producers use energy from the sun to produce their own food. Consumers are organisms that get their energy by eating other organisms. Consumers may get energy by eating producers or by eating other consumers. Some consumers get energy by breaking down dead organisms. These consumers are called decomposers.
Section 3 Ecology II. Balancing Forces in Ecosystems Because amounts of matter and energy in an ecosystem are limited, the population growth within the ecosystem is limited, too. carrying capacity the largest population than an environment can support at any given time Carrying capacity depends on available resources and on how easily matter and energy cycle between life-forms and the environment in the ecosystem.
Section 3 Ecology A. Ecological Responses to Change In general, ecosystems react to changes in ways that maintain or restore balance to the ecosystem. Environmental change in the form of a sudden disturbance can damage and disrupt ecosystems. However, over time, organisms will migrate back into damaged areas in predictable patterns. Ecosystems are resilient and tend to restore a community of organisms to its original state unless the physical environment is permanently altered.
Section 3 Ecology Balancing Forces in Ecosystems, continued Reading Check Explain the relationship between carrying capacity and the amount of matter and energy in an ecosystem.
Section 3 Ecology Balancing Forces in Ecosystems, continued Reading Check Explain the relationship between carrying capacity and the amount of matter and energy in an ecosystem. The amount of matter and energy in an ecosystem can supply a population of a given size. This maximum population is the carrying capacity of the ecosystem.
Section 3 Ecology B. Energy Transfer The ultimate source of energy for almost every ecosystem is the sun. Producers, such as plants, capture solar energy by a chemical process called photosynthesis. This captured energy then flows through the ecosystem from the producers, to the consumers, and finally to the decomposers. As matter and energy cycle through an ecosystem, chemical elements are combined and recombined. Each chemical change results in either the temporary storage of energy or the loss of energy.
Section 3 Ecology An energy pyramid is one way to see how energy is lost as it moves through the ecosystem. Producers form the base of the pyramid. Consumers that eat the producers are the next level of the pyramid. Animals that eat those consumers form the upper levels of the pyramid. As you move up the pyramid, more energy is lost at each level. Therefore, the least amount of energy is available to organisms at the top of the pyramid.
Section 3 Ecology Food Chains and Food Webs The sequence in which organisms consume other organisms can be represented by a food chain or by a food web. food web a diagram that shows the feeding relationships among organisms in an ecosystem
Section 3 Ecology Balancing Forces in Ecosystems, continued The figure below illustrates a food web.
Section 3 Ecology Food Chains and Food Webs
Standardized Test Prep Multiple Choice 1. The crust and the rigid upper part of the mantle are found in what part of the Earth? A. the asthenosphere B. the lithosphere C. the mesosphere D. the stratosphere
Standardized Test Prep Multiple Choice, continued 1. The crust and the rigid upper part of the mantle are found in what part of the Earth? A. the asthenosphere B. the lithosphere C. the mesosphere D. the stratosphere
Standardized Test Prep Multiple Choice, continued 2. Because phosphorus rarely occurs as a gas, the phosphorus cycle mainly occurs between the? F. biosphere, geosphere,and hydrosphere G. biosphere, geosphere, and atmosphere H. geosphere, hydrosphere, and atmosphere I. biosphere, hydrosphere, and atmosphere
Standardized Test Prep Multiple Choice, continued 2. Because phosphorus rarely occurs as a gas, the phosphorus cycle mainly occurs between the? F. biosphere, geosphere,and hydrosphere G. biosphere, geosphere, and atmosphere H. geosphere, hydrosphere, and atmosphere I. biosphere, hydrosphere, and atmosphere
Standardized Test Prep Multiple Choice, continued 3. How are scientists able to study the composition and size of the interior layers of Earth? A. by direct observation B. by analyzing surface rock samples C. by using seismic waves D. by deep-drilling into the interior layers
Standardized Test Prep Multiple Choice, continued 3. How are scientists able to study the composition and size of the interior layers of Earth? A. by direct observation B. by analyzing surface rock samples C. by using seismic waves D. by deep-drilling into the interior layers
Standardized Test Prep Multiple Choice, continued 4. Which of the following methods of internal energy transfer drives volcanic activity on Earth s surface? F. radioactive decay G. convection H. kinetic transfer I. conduction
Standardized Test Prep Multiple Choice, continued 4. Which of the following methods of internal energy transfer drives volcanic activity on Earth s surface? F. radioactive decay G. convection H. kinetic transfer I. conduction
Standardized Test Prep Multiple Choice, continued 5. Earth s primary external energy source is A. cosmic radiation. B. the moon. C. distant stars. D. the sun.
Standardized Test Prep Multiple Choice, continued 5. Earth s primary external energy source is A. cosmic radiation. B. the moon. C. distant stars. D. the sun.
Chapter 1 Standardized Test Prep Short Response 6. What do decomposers break down to obtain energy?
Chapter 1 Standardized Test Prep Short Response, continued 6. What do decomposers break down to obtain energy? dead organisms
Standardized Test Prep Short Response, continued 7. What scientific principle states that energy can be transferred but that it cannot be created or destroyed?
Standardized Test Prep Short Response, continued 7. What scientific principle states that energy can be transferred but that it cannot be created or destroyed? First Law of Thermodynamics
Chapter 1 Standardized Test Prep Reading Skills Read the passage below. Then, answer questions 8 9. Acid Rain Acid rain is rain, snow, fog, dew, or sleet that has a ph that is lower than the ph of normal precipitation. Acid rain occurs primarily as a result of the combustion of fossil fuels a process that produces, as byproducts, oxides of nitrogen and sulfur dioxide. When combined with water in the atmosphere, these compounds form nitric acid and sulfuric acid. When it falls to Earth, acid rain has profound effects. It harms forests by damaging tree leaves and bark, which leaves them vulnerable to weather, disease, and parasites. Similarly, it damages crops. And it damages aquatic ecosystems by causing the death of all but the hardiest species. Because of the extensive damage that acid rain causes, the U.S. Environmental Protection Agency limits the amount of sulfur dioxide and nitrogen oxides that can be emitted by factories, power plants, and motor vehicles.
Standardized Test Prep Reading Skills, continued 8. According to the passage, which of the following contributes to the problem of acid rain? A. the use of fossil fuels in power plants and motor vehicles B. parasites and diseases that harm tree leaves and bark C. the release of nitrogen into the atmosphere by aquatic ecosystems D. damaged crops that release too many gases into the atmosphere
Standardized Test Prep Reading Skills, continued 8. According to the passage, which of the following contributes to the problem of acid rain? A. the use of fossil fuels in power plants and motor vehicles B. parasites and diseases that harm tree leaves and bark C. the release of nitrogen into the atmosphere by aquatic ecosystems D. damaged crops that release too many gases into the atmosphere
Standardized Test Prep Reading Skills, continued 9. Which of the following statements can be inferred from the information in the passage? F. Acid rain is a natural problem that will correct itself if given enough time. G. Ecosystems damaged by acid rain adapt so that they will not be damaged in the future. H. Human activities are largely to blame for the problem of acid rain. I. Acid rain is a local phenomenon and damages plants and animals only near power plants or roadways.
Standardized Test Prep Reading Skills, continued 9. Which of the following statements can be inferred from the information in the passage? F. Acid rain is a natural problem that will correct itself if given enough time. G. Ecosystems damaged by acid rain adapt so that they will not be damaged in the future. H. Human activities are largely to blame for the problem of acid rain. I. Acid rain is a local phenomenon and damages plants and animals only near power plants or roadways.
Standardized Test Prep Interpreting Graphics Use the figure below to answer question 10. The figure shows the interior layers of Earth. The layers in the diagram are representative of arrangement and are not drawn to scale.
Standardized Test Prep Interpreting Graphics, continued 10. Which layer of Earth s interior does not transmit S waves? F. layer B G. layer C H. layer D I. layer E
Standardized Test Prep Interpreting Graphics, continued 10. Which layer of Earth s interior does not transmit S waves? F. layer B G. layer C H. layer D I. layer E
Standardized Test Prep Interpreting Graphics, continued Use the figure below to answer questions 11 12. The figure shows predicted world-wide energy consumption by fuel type between the years 2001 and 2025.
Standardized Test Prep Interpreting Graphics, continued 11. Which of the following sources of energy is predicted to see the greatest increase in usage between 2001 and 2025? A. oil B. natural gas C. coal D. renewables
Standardized Test Prep Interpreting Graphics, continued 11. Which of the following sources of energy is predicted to see the greatest increase in usage between 2001 and 2025? A. oil B. natural gas C. coal D. renewables
Standardized Test Prep Interpreting Graphics, continued 12. What trends in energy consumption by fuel type will change over the 25 years shown on the graph above? What trends will stay the same?
Standardized Test Prep Interpreting Graphics, continued 12. What trends in energy consumption by fuel type will change over the 25 years shown on the graph above? What trends will stay the same? Answers should include the following: overall, general energy trends are predicted to remain the same over the next 25 years; oil is predicted to continue to be the leading fuel source in the future; natural gas is expected to overtake coal by 2010 as an energy source, and the difference between the use of the two sources is expected to continue to increase steadily through 2025; nuclear power is predicted to remain the least-used energy source and is expected to slightly decrease in usage; fossil fuels are predicted to continue to outpace nuclear and renewable energy resources by a ratio of more than 4 to 1.
Earth s Interior
Open and Closed Systems
Earth s Energy Budget
The Nitrogen Cycle
The Carbon Cycle
A Food Web
Concentration of Plant Life on Earth