1. Universe Eighth Edition Universe Roger A. Freedman William J. Kaufmann III CHAPTER 9 The Living Earth CHAPTER 9 The Living Earth

3. HW – Read Chapter 10, 11 Online Quizzes for Chapters 9,10, and 11 due Monday 10/18 Exam 2 – Scheduled for Monday 10/25 (will cover Chapters 7-15)

10. The Earth shows very little evidence of meteor impacts because A.plate tectonics is continuously recycling the Earth’s crust. B.wind and rain have continually eroded the Earth’s surface. C.very few meteors struck the Earth in the past. D.vegetation has covered the craters. E.Both A and B are correct. Q9.11

11. The Earth shows very little evidence of meteor impacts because A.plate tectonics is continuously recycling the Earth’s crust. B.wind and rain have continually eroded the Earth’s surface. C.very few meteors struck the Earth in the past. D.vegetation has covered the craters. E.Both A and B are correct. A9.11

16. In the greenhouse effect, A. some infrared radiation emitted by the Earth’s surface is absorbed by the atmosphere. B. some ultraviolet radiation emitted by the Earth’s surface is absorbed by the atmosphere. C. vegetation traps thermal energy near the surface. D. infrared radiation from the Sun is captured as it enters the Earth’s atmosphere. E. infrared radiation from the Sun is reflected by the Earth’s atmosphere into space. Q9.4

17. In the greenhouse effect, A. some infrared radiation emitted by the Earth’s surface is absorbed by the atmosphere. B. some ultraviolet radiation emitted by the Earth’s surface is absorbed by the atmosphere. C. vegetation traps thermal energy near the surface. D. infrared radiation from the Sun is captured as it enters the Earth’s atmosphere. E. infrared radiation from the Sun is reflected by the Earth’s atmosphere into space. A9.4

27. Which of the following is a correct statement about seismic waves used to map the Earth’s interior structure? A.P waves are longitudinal and are able to travel through solids and liquids; S waves are transverse and can only travel through liquids. B.P waves are transverse and are able to travel through solids and liquids; S waves are longitudinal and can only travel through liquids. C.P waves are transverse and are able to travel through solids and liquids; S waves are longitudinal and can only travel through solids. D.P waves are longitudinal and are able to travel through solids and liquids; S waves are transverse and can only travel through solids. Q9.7

28. Which of the following is a correct statement about seismic waves used to map the Earth’s interior structure? A.P waves are longitudinal and are able to travel through solids and liquids; S waves are transverse and can only travel through liquids. B.P waves are transverse and are able to travel through solids and liquids; S waves are longitudinal and can only travel through liquids. C.P waves are transverse and are able to travel through solids and liquids; S waves are longitudinal and can only travel through solids. D.P waves are longitudinal and are able to travel through solids and liquids; S waves are transverse and can only travel through solids. A9.7

35. The Earth’s magnetic field is generated by A.electric currents in the liquid outer core; the field has never changed direction. B.electric currents in the liquid inner core; the field has never changed direction. C.electric currents in the liquid outer core; the field has reversed many times in the past. D.electric currents in the liquid inner core; the field has reversed many times in the past. E.electric currents caused by interactions with the solar wind. Q9.8

36. The Earth’s magnetic field is generated by A.electric currents in the liquid outer core; the field has never changed direction. B.electric currents in the liquid inner core; the field has never changed direction. C.electric currents in the liquid outer core; the field has reversed many times in the past. D.electric currents in the liquid inner core; the field has reversed many times in the past. E.electric currents caused by interactions with the solar wind. A9.8

40. The oxygen in our atmosphere is chemically reactive, combining with other elements to form compounds, and is also being used by respiratory life. Despite this, the amount of oxygen in our atmosphere is not decreasing because it is being replenished by A.outgassing from seawater. B.volcanic eruptions. C.biological activity, such as photosynthesis. D.meteors and comets, which bring oxygen to the Earth. E.solar radiation breaking down CO 2. Q9.14

41. The oxygen in our atmosphere is chemically reactive, combining with other elements to form compounds, and is also being used by respiratory life. Despite this, the amount of oxygen in our atmosphere is not decreasing because it is being replenished by A.outgassing from seawater. B.volcanic eruptions. C.biological activity, such as photosynthesis. D.meteors and comets, which bring oxygen to the Earth. E.solar radiation breaking down CO 2. A9.14

48. Key Ideas The Earth’s Energy Sources: All activity in the Earth’s atmosphere, oceans, and surface is powered by three sources of energy. The Earth’s Energy Sources: All activity in the Earth’s atmosphere, oceans, and surface is powered by three sources of energy. Solar energy is the energy source for the atmosphere. In the greenhouse effect, some of this energy is trapped by infrared absorbing gases in the atmosphere, raising the Earth’s surface temperature. Solar energy is the energy source for the atmosphere. In the greenhouse effect, some of this energy is trapped by infrared absorbing gases in the atmosphere, raising the Earth’s surface temperature. Tidal forces from the Moon and Sun help to power the motion of the oceans. Tidal forces from the Moon and Sun help to power the motion of the oceans. The internal heat of the Earth is the energy source for geologic activity. The internal heat of the Earth is the energy source for geologic activity.

49. Key Ideas The Earth’s Interior: Studies of seismic waves (vibrations produced by earthquakes) show that the Earth has a small, solid inner core surrounded by a liquid outer core. The outer core is surrounded by the dense mantle, which in turn is surrounded by the thin low- density crust. The Earth’s Interior: Studies of seismic waves (vibrations produced by earthquakes) show that the Earth has a small, solid inner core surrounded by a liquid outer core. The outer core is surrounded by the dense mantle, which in turn is surrounded by the thin low- density crust. Seismologists deduce the Earth’s interior structure by studying how longitudinal P waves and transverse S waves travel through the Earth’s interior. Seismologists deduce the Earth’s interior structure by studying how longitudinal P waves and transverse S waves travel through the Earth’s interior. The Earth’s inner and outer cores are composed of almost pure iron with some nickel mixed in. The mantle is composed of iron rich minerals. The Earth’s inner and outer cores are composed of almost pure iron with some nickel mixed in. The mantle is composed of iron rich minerals. Both temperature and pressure steadily increase with depth inside the Earth. Both temperature and pressure steadily increase with depth inside the Earth.

50. Key Ideas Plate Tectonics: The Earth’s crust and a small part of its upper mantle form a rigid layer called the lithosphere. The lithosphere is divided into huge plates that move about over the plastic layer called the asthenosphere in the upper mantle. Plate Tectonics: The Earth’s crust and a small part of its upper mantle form a rigid layer called the lithosphere. The lithosphere is divided into huge plates that move about over the plastic layer called the asthenosphere in the upper mantle. Plate tectonics, or movement of the plates, is driven by convection within the asthenosphere. Molten material wells up at oceanic rifts, producing seafloor spreading, and is returned to the asthenosphere in subduction zones. As one end of a plate is subducted back into the asthenosphere, it helps to pull the rest of the plate along. Plate tectonics, or movement of the plates, is driven by convection within the asthenosphere. Molten material wells up at oceanic rifts, producing seafloor spreading, and is returned to the asthenosphere in subduction zones. As one end of a plate is subducted back into the asthenosphere, it helps to pull the rest of the plate along.

51. Key Ideas Plate tectonics is responsible for most of the major features of the Earth’s surface, including mountain ranges, volcanoes, and the shapes of the continents and oceans. Plate tectonics is responsible for most of the major features of the Earth’s surface, including mountain ranges, volcanoes, and the shapes of the continents and oceans. Plate tectonics is involved in the formation of the three major categories of rocks: igneous rocks (cooled from molten material), sedimentary rocks (formed by the action of wind, water, and ice), and metamorphic rocks (altered in the solid state by extreme heat and pressure). Plate tectonics is involved in the formation of the three major categories of rocks: igneous rocks (cooled from molten material), sedimentary rocks (formed by the action of wind, water, and ice), and metamorphic rocks (altered in the solid state by extreme heat and pressure).

52. Key Ideas The Earth’s Magnetic Field and Magnetosphere: Electric currents in the liquid outer core generate a magnetic field. This magnetic field produces a magnetosphere that surrounds the Earth and blocks the solar wind from hitting the atmosphere. The Earth’s Magnetic Field and Magnetosphere: Electric currents in the liquid outer core generate a magnetic field. This magnetic field produces a magnetosphere that surrounds the Earth and blocks the solar wind from hitting the atmosphere. A bow-shaped shock wave, where the supersonic solar wind is abruptly slowed to subsonic speeds, marks the outer boundary of the magnetosphere. A bow-shaped shock wave, where the supersonic solar wind is abruptly slowed to subsonic speeds, marks the outer boundary of the magnetosphere. Most of the particles of the solar wind are deflected around the Earth by the magnetosphere. Most of the particles of the solar wind are deflected around the Earth by the magnetosphere. Some charged particles from the solar wind are trapped in two huge, doughnut-shaped rings called the Van Allen belts. An excess of these particles can initiate an auroral display. Some charged particles from the solar wind are trapped in two huge, doughnut-shaped rings called the Van Allen belts. An excess of these particles can initiate an auroral display.

53. Key Ideas The Earth’s Atmosphere: The Earth’s atmosphere differs from those of the other terrestrial planets in its chemical composition, circulation pattern, and temperature profile. The Earth’s Atmosphere: The Earth’s atmosphere differs from those of the other terrestrial planets in its chemical composition, circulation pattern, and temperature profile. The Earth’s atmosphere evolved from being mostly water vapor to being rich in carbon dioxide. A strong greenhouse effect kept the Earth warm enough for water to remain liquid and to permit the evolution of life. The Earth’s atmosphere evolved from being mostly water vapor to being rich in carbon dioxide. A strong greenhouse effect kept the Earth warm enough for water to remain liquid and to permit the evolution of life.

54. Key Ideas The appearance of photosynthetic living organisms led to our present atmospheric composition, about four-fifths nitrogen and one-fifth oxygen. The appearance of photosynthetic living organisms led to our present atmospheric composition, about four-fifths nitrogen and one-fifth oxygen. The Earth’s atmosphere is divided into layers called the troposphere, stratosphere, mesosphere, and thermosphere. Ozone molecules in the stratosphere absorb ultraviolet light. The Earth’s atmosphere is divided into layers called the troposphere, stratosphere, mesosphere, and thermosphere. Ozone molecules in the stratosphere absorb ultraviolet light. Because of the Earth’s rapid rotation, the circulation in its atmosphere is complex, with three circulation cells in each hemisphere. Because of the Earth’s rapid rotation, the circulation in its atmosphere is complex, with three circulation cells in each hemisphere.

55. Key Ideas The Biosphere: Human activity is changing the Earth’s biosphere, on which all living organisms depend. The Biosphere: Human activity is changing the Earth’s biosphere, on which all living organisms depend. Industrial chemicals released into the atmosphere have damaged the ozone layer in the stratosphere. Industrial chemicals released into the atmosphere have damaged the ozone layer in the stratosphere. Deforestation and the burning of fossil fuels are increasing the greenhouse effect in our atmosphere and warming the planet. This can lead to destructive changes in the climate. Deforestation and the burning of fossil fuels are increasing the greenhouse effect in our atmosphere and warming the planet. This can lead to destructive changes in the climate.