ASTR Spring 2008 Joel E. Tohline, Alumni Professor 247 Nicholson Hall [Slides from Lecture28]

Chapter 9: The Living Earth (Seismic) Studies of earthquakes reveal layered interior structure (§ 9-2) Continental drift, seafloor spreading, and plate tectonics (§ 9-3) Temperature and chemical composition of Earth’s atmosphere (and surface temperature) –Note differences among terrestrial planets –Balance between absorption & radiation of heat (§ 9-1) –Greenhouse effect (§ 9-1) –Atmosphere’s changed substantially over time (§ 9-5) –Impact of living organisms (§§ 9-5 and 9-7)

Chapter 9: The Living Earth (Seismic) Studies of earthquakes reveal layered interior structure (§ 9-2) Continental drift, seafloor spreading, and plate tectonics (§ 9-3) Temperature and chemical composition of Earth’s atmosphere (and surface temperature) –Note differences among terrestrial planets –Balance between absorption & radiation of heat (§ 9-1) –Greenhouse effect (§ 9-1) –Atmosphere’s changed substantially over time (§ 9-5) –Impact of living organisms (§§ 9-5 and 9-7)

Chapter 9: The Living Earth (Seismic) Studies of earthquakes reveal layered interior structure (§ 9-2) Continental drift, seafloor spreading, and plate tectonics (§ 9-3) Temperature and chemical composition of Earth’s atmosphere (and surface temperature) –Note differences among terrestrial planets –Balance between absorption & radiation of heat (§ 9-1) –Greenhouse effect (§ 9-1) –Atmosphere’s changed substantially over time (§ 9-5) –Impact of living organisms (§§ 9-5 and 9-7)

Mid-Atlantic Ridge Seafloor is spreading (hence, continents are separating) at rate of 3 cm per year!

Chapter 9: The Living Earth (Seismic) Studies of earthquakes reveal layered interior structure (§ 9-2) Continental drift, seafloor spreading, and plate tectonics (§ 9-3) Temperature and chemical composition of Earth’s atmosphere (and surface temperature) –Note differences among terrestrial planets –Balance between absorption & radiation of heat (§ 9-1) –Greenhouse effect (§ 9-1) –Atmosphere’s changed substantially over time (§ 9-5) –Impact of living organisms (§§ 9-5 and 9-7)

Chapter 9: The Living Earth (Seismic) Studies of earthquakes reveal layered interior structure (§ 9-2) Continental drift, seafloor spreading, and plate tectonics (§ 9-3) Temperature and chemical composition of Earth’s atmosphere (and surface temperature) –Note differences among terrestrial planets –Balance between absorption & radiation of heat (§ 9-1) –Greenhouse effect (§ 9-1) –Atmosphere’s changed substantially over time (§ 9-5) –Impact of living organisms (§§ 9-5 and 9-7)

Chapter 9: The Living Earth (Seismic) Studies of earthquakes reveal layered interior structure (§ 9-2) Continental drift, seafloor spreading, and plate tectonics (§ 9-3) Temperature and chemical composition of Earth’s atmosphere (and surface temperature) –Note differences among terrestrial planets –Balance between absorption & radiation of heat (§ 9-1) –Greenhouse effect (§ 9-1) –Atmosphere’s changed substantially over time (§ 9-5) –Impact of living organisms (§§ 9-5 and 9-7)

Absorption & Radiation of Heat  T 4 = L sun /(4  d 2 ) d

Surface temperatures of Planets

Absorption & Radiation of Heat  T 4 = L sun /(4  d 2 ) d Result needs to be corrected for amount of radiation reflected and amount trapped.

Chapter 9: The Living Earth (Seismic) Studies of earthquakes reveal layered interior structure (§ 9-2) Continental drift, seafloor spreading, and plate tectonics (§ 9-3) Temperature and chemical composition of Earth’s atmosphere (and surface temperature) –Note differences among terrestrial planets –Balance between absorption & radiation of heat (§ 9-1) –Greenhouse effect (§ 9-1) –Atmosphere’s changed substantially over time (§ 9-5) –Impact of living organisms (§§ 9-5 and 9-7)

Chapter 9: The Living Earth (Seismic) Studies of earthquakes reveal layered interior structure (§ 9-2) Continental drift, seafloor spreading, and plate tectonics (§ 9-3) Temperature and chemical composition of Earth’s atmosphere (and surface temperature) –Note differences among terrestrial planets –Balance between absorption & radiation of heat (§ 9-1) –Greenhouse effect (§ 9-1) –Atmosphere’s changed substantially over time (§ 9-5) –Impact of living organisms (§§ 9-5 and 9-7)

Chapter 9: The Living Earth (Seismic) Studies of earthquakes reveal layered interior structure (§ 9-2) Continental drift, seafloor spreading, and plate tectonics (§ 9-3) Temperature and chemical composition of Earth’s atmosphere (and surface temperature) –Note differences among terrestrial planets –Balance between absorption & radiation of heat (§ 9-1) –Greenhouse effect (§ 9-1) –Atmosphere’s changed substantially over time (§ 9-5) –Impact of living organisms (§§ 9-5 and 9-7)

First Astronauts on the Moon