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Origins PowerPoint Presentation

Origins

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Origins

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Presentation Transcript

  1. Origins Stars and Seas

  2. Earth is a Water Planet • 3rd rock from the Sun • Ocean covers 71% of Earth’s surface • Life on Earth almost certainly evolved in the ocean • Earth’s position allows H2O to exist in its 3 states • Too far – H2O frozen • Too close – H2O evaporates

  3. The Science of the Ocean • Over 97% of the water on Earth is found in ocean • Less than 3% is found in glaciers, lakes, rivers, and ground water

  4. The Origin of Earth • Releases clouds and dust • Solar System formed about 5 bya • Big Bang = 15 billion years ago (bya) • Vast cloud collapses under its own gravity • Central mass hot enough for thermonuclear fusion (HHe) • Formation of our Sun • Earth formed about 4.6 bya

  5. Origin of the Earth • Gravity caused clouds to attract more particles • Meteors and Asteroids bombarded the Earth • Impacted material accumulated at Earth’s surface – trapping heat • Gravitational compression • Increased weight of material compressed interior – further heating Earth’s interior • Density Stratified planet • Heavier, dense iron and nickel sank to core; while lighter silicates formed outer crust

  6. Origin of the Ocean • Oceans are byproducts of heating and differentiation • Earth warmed and partially melted • Hydrogen and Oxygen released by volcanic venting • Vapor condensed with other gases to form clouds • Hot Earth boiled rains into vapor • As Earth cooled, H2O condensed to form rain • Rain formed our oceans

  7. Origin of the Atmosphere4 steps • Later lost from Sun’s radiation 1. Primordial gases 2. Volcanic venting, bombardment of icy comets • Exhalation from Earth’s surface 3. Volcanic activity • Addition of CO2, H2O and other gases 4. Plant/bacterial life addition of oxygen • Addition of Oxygen

  8. Today’s Ocean • Traditionally divided into 4 large basins • Pacific, Atlantic, Indian, and Arctic Ocean • Marginal seas connect the 4 large basins • Mediterranean, Gulf of Mexico, Red Sea • Oceans are interconnected