1. Lecture 1 The big picture: Origin of the Earth §What is Geology about? §The origin of the Universe §The solar system §Planet Earth and its dynamic systems

2. What is Geology about? §Greek: geology = geo ( Earth ) + logos (study of) §A view of Earth from the moon.

3. The origin of the Universe The expanse of the universe Human has yet to detect the edges of the universe. Powerful radio telescopes allow us to reach 15 billion light years away. Red shifts and expanding universe In 1929, Hubble and Humason observed that light from distant stars shifted towards the red direction, suggesting the universe is expanding. The big bang hypothesis The universe was created by a cataclysmic explosion from a dense mass at about 10 billion years ago.

4. Doppler Shift

5. Red Shift  This animation demonstrates the Doppler effect as applied to light by simulating the effect of a star ’ s velocity upon the starlight as viewed from Earth. Use the horizontal scrollbar to change the star ’ s velocity. Notice the red shift as the star recedes from you, and the blue shift as it moves toward you. The greater the star ’ s speed, the greater the spectral shift. [by Declan DePaor] § Play Animation Windows version >> Play Animation Windows version >> § Play Animation Macintosh version >> Play Animation Macintosh version >>

6. (a) (b) How can all galaxies be moving away from us, regardless of which direction we look? Hubble proposed the expanding universe theory. An analogy: All raisins move away from each other regardless of direction, after the bread expands during baking. (S. Marshak)

8. Thermonuclear fusion §The big bang produced hydrogen and helium from subatomic particles. The other elements formed later during the life cycles of stars through thermonuclear fusion. §Nuclear fusion: a process that occurs when two positively charged nuclei are brought together that the short-range nuclear forces of attraction overcomes the electrical forces of repulsion. §The abundance of the elements generally decreases with increasing atomic numbers, the most abundant being H and He.

9. Production of Elements §H formed during the big bang; §He formed partly during the big bang and in stars by fusion; §Larger atoms up to iron formed in stars; §Very heavy elements only formed during supernova of massive stars. So, H, He most abundant, intermediate atoms are less, heavy elements are rare.

10. ( Left) Two rovers, Spirit and Opportunity, landed on Mars early 2004 after traveling for more than six months. (Above) One of the first sweeping images captured by Rover Opportunity, showing unusual rock outcropping in Endurance Crater. The layered rocks are believed to be either volcanic ash deposits, or sediments laid down by wind or water. Mars! Mars!! Mars!!! Mars!!!! Mars!!!!!

11. The Solar System §The solar system was formed about 4.6 billion years ago. §Nebular hypothesis: §The solar system is formed from a gaseous disk, which was formed from gravitational collapse of a rotating, interstellar cloud of dust and gas (mostly H2 and He). The idea can be traced back to 18th century by Kant and Laplace.

12. Nebular hypothesis: gravitational collapse of solar nebular -> spread to form to a rotating disk -> more than 90% of materials gravitate towards the center to form protosun; local clusters contract to from protoplantes

14. §The solar system has nine planets.

15. §Relative sizes of the Sun and the nine planets.

16. §The planets can be divided into two groups §The inner terrestrial (Earth-like) planets (Mercury, Venus, Earth, Mars): small, dense §The outer Jovian (Jupiter-like) planets (Jupiter, Saturn, Uranus, and Neptune): gaseous, giant, low density §Pluto is an exception; it is an "icy planet". §A planet's size and composition were determined largely by its distance from the Sun. The strong solar wind blew gaseous H and He away from the inner region. In addition, near the Sun with high temperature, only scarce metal and silicates could crystallize. Away from the Sun with cooler temperature, water, methane, and nitrogen could also solidify.

17. §Internal structure of Jovian and terrestrial planets.

18. Planet Earth §A view of Earth from Apollo 17.

19. §The Earth is a dynamic system, consisting of five interacting subsystems (spheres). § atmosphere: gaseous layer surrounding the Earth. § hydrosphere: all of the liquid water on surface and in the ground (groundwater). Water covers 70% of the surface (98% of it in the ocean). § snow and ice -- polar ice, permafrost, and sea ice. § biosphere: living part of the Earth -- plants and animals. § Solid earth: rocky part of the Earth (crust, mantle, core). lithosphere: solid outermost layer of the solid Earth. The lithosphere consists of a dozen rigid "plates". asthenosphere: a mobile weak zone of the upper mantle beneath lithosphere.

20. §Earth’s layered structure. (Tarbuck and Lutgents)

22. §The Earth is a dynamic system with its subsystems constantly interact with each other.