1 / 54

Earth: Key Ideas and Formation Process

Learn about the key ideas about Earth, including its formation process, constant changes, and the distribution of mass in the solar system. Explore the evidence of plate tectonics and the role of volcanoes and earthquakes in shaping our planet. Discover the importance of Earth's geochemical cycles.

rodriguezmatthew
Download Presentation

Earth: Key Ideas and Formation Process

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Great Ideas in Science:Lecture 9 – Earth as a Planet Professor Robert Hazen UNIV 301 Great Idea: Earth, one of the planets that orbits the Sun, formed 4.5 billion years ago from a great cloud of dust and gas.

  2. Today: Key Ideas About Earth • Earth, one of the planets that orbits the Sun, formed 4.5 billion years ago from a great cloud of dust and gas. 2. The surface of our planet changes constantly; no feature is permanent. 3. The entire Earth is still changing, due to the slow convection of soft, hot rocks deep within the planet. 4. Earth materials move in cycles; a change in one cycle affects others.

  3. Clues to the Origin of the Solar System Solar System = Objects gravitationally bound to the Sun

  4. Clue #1: Planetary Orbits Features of solar system • All planets orbit in the same direction • All planets orbit in the same plane • Most planets rotate in the direction of orbit

  5. Clue #2: Distribution of Mass • Almost all mass is in the Sun (99.9%) • Two types of planets • Terrestrial planets • Jovian planets • Other objects • Moons, asteroids, comets

  6. The Nebular Hypothesis

  7. Terrestrial (Inner) Planets • Mercury, Venus, Earth, Mars • Rocky and relatively small • Mercury and Venus too hot for life • Mars may have had life long ago

  8. Terrestrial (Inner) Planets • Mars Exploration • Multiple missions • Found evidence of water

  9. Jovian (Outer) Planets Jupiter, Saturn, Uranus, Neptune

  10. Jovian (Outer) Planets Jupiter, Saturn, Uranus, Neptune • Layered structure • No solid surface

  11. Pluto and the Plutoids • Only 0.3% of Earth’s mass • Three moons • Captured comet or asteroid? • Is it a planet?

  12. Asteroids, Comets, and Meteors Asteroids Small rocky bodies Orbit sun Asteroid belt Comets Dirty snowballs Highly elongated orbits Stardust and Deep Impact missions Meteors and Meteorites Meteor showers Original solar system material

  13. The Formation of Earth The Great Bombardment

  14. Differentiation Heat produced from collisions Dense material sank to center Lighter material rose to surface Layered structure • Core • Mantle • Crust

  15. The Formation of the Moon “Big Splash” Large object impacted Earth Parts of mantle blown into orbit Moon formed from this material

  16. The Formation of the Moon “Big Splash”

  17. The Evolution of Earth’s Atmosphere • Volcanoes released N2, CO2, H2, & H2O • Large impacts blew off most atmosphere • Hydrogen lost by gravitational escape • Living organisms introduced oxygen

  18. Volcanoes and Earthquakes:Evidence of Earth’s Inner Forces • Volcanoes: Magma breaks through surface

  19. Volcanoes and Earthquakes:Evidence of Earth’s Inner Forces Earthquakes • Rocks breaks along fault • Energy transmitted as wave • Tsunamis

  20. The Case of the Disappearing Mountains Old Young

  21. Deep Time James Hutton at Jedburgh Scotland ca.1790

  22. Deep Time • Sediments • Burial • Uplift • Sediments

  23. Great Idea: Earth is constantly changing, due to the slow convection of soft, hot rocks deep within the planet. Plate Tectonics

  24. Plate tectonics – 6 lines of evidence • Physiology: Similar shapes of continents

  25. Plate tectonics – 6 lines of evidence • Physiology: Shape of continents • Seismology: Earth’s inner structure

  26. Plate tectonics – 6 lines of evidence • Physiology: Shape of continents • Seismology: Earth’s inner structure • Geology: Distribution of rocks and fossils

  27. Plate tectonics – 6 lines of evidence • Physiology: Shape of continents • Seismology: Earth’s inner structure • Geology: Distribution of rocks and fossils • Oceanography: Sea floor topography Bruce Heezen and Marie Tharp

  28. Plate tectonics – 6 lines of evidence • Physiology: Shape of continents • Seismology: Earth’s inner structure • Geology: Distribution of rocks and fossils • Oceanography: Sea floor topography • Volcanology: Ages of Atlantic volcanoes <5 95 75 55 125

  29. Plate tectonics – 6 lines of evidence • Physiology: Shape of continents • Seismology: Earth’s inner structure • Geology: Distribution of rocks and fossils • Oceanography: Sea floor topography • Volcanology: Ages of Atlantic volcanoes • Paleomagnetismof sea floor rocks

  30. New Support for Plate Tectonics • Measurements of the distance between continents • North America and Europe are separating at ~5 cm per year

  31. Earth’s Tectonic Plates

  32. Plate Boundaries Three Main Boundary Types • Divergent • Convergent • Transform

  33. Divergent Boundaries

  34. Convergent Plate Boundaries Three Types: 1. Ocean-ocean

  35. Convergent Plate Boundaries Three Types: 1. Ocean-ocean 2. Continent-continent

  36. Convergent Plate Boundaries Three Types: 1. Ocean-ocean 2. Continent-continent 3. Ocean-continent

  37. Transform Plate Boundary

  38. Another Look at Volcanoes and Earthquakes Volcanoes Occur: 1. At Divergent Plate Boundaries 2. Close to Convergent Plate Boundaries 3. Above Hotspots

  39. Another Look at Volcanoes and Earthquakes Earthquakes Occur at: • Transform Plate Boundaries • Convergent boundaries

  40. Earth’s Geochemical Cycles Earth materials move in cycles; a change in one cycle affects the others. 1. Atoms recycle; they’re used over and over. Reservoirs (Aluminum can) Hydrologic cycle Atmospheric cycle Rock cycle 2. Energy flows through the system.

  41. Geochemical Cycles • Account for all the repositories of that substance. • Document processes by which the substance moves from repository to another. • Gold

  42. ROCK CYCLE: Igneous Rocks • Igneous Rocks • Solidify from hot liquid • Types • Extrusive rocks solidify at the surface • Intrusive rocks solidify below surface

  43. ROCK CYCLE: Sedimentary Rocks Rocks deposited layer by layer from weathered particles (sand, silt, etc.) or chemicals (i.e., coral).

  44. ROCK CYCLE: Metamorphic Rocks • Rocks formed by pressure and heat • Examples • Slate • Schist • Gneiss • Quartzite • Marble

  45. Atmospheric Cycle Air mass: Uniform temperature and moisture Weather: State of the atmosphere Climate: Long-term average of weather

  46. The General Circulation of the Atmosphere • Circulation powered by Sun • Air heated and rises • Cools and sinks • Prevailing winds • Caused by earth’s rotation

  47. Weather Five variables define state of atmosphere • Temperature • Air pressure • Humidity • Cloudiness • Prevailing winds

  48. Climate • Gradual change over long periods • Influences on climate • Large bodies of water • Ocean currents • Mountain ranges • Position of tectonic plates • Solar output • Greenhouse gases

  49. The Water (Hydrologic) Cycle • The total amount of Earth’s water is constant; the same atoms cycle from one reservoir to another • Total volume ~ 1.4 billion km3 Oceans 97.3% Lakes and Rivers 0.01% Groundwater 0.6% Ice Caps & Glaciers 2.1% Atmosphere 0.001% All life 0.00004%

  50. How does water move among reservoirs?

More Related