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Differentiated earth

Differentiated earth. Earth. Size Main Characteristics of the surface and interior. Statistics about the Earth. Shape of Earth is nearly spherical (oblate spheroid) (only just 40 miles difference in circumferences) Because earth spins Circumference is about 24,000 miles around

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Differentiated earth

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  1. Differentiated earth

  2. Earth Size Main Characteristics of the surface and interior

  3. Statistics about the Earth Shape of Earth is nearly spherical (oblate spheroid) (only just 40 miles difference in circumferences) Because earth spins Circumference is about 24,000 miles around Radius is about 3800 miles Diameter 7600 miles

  4. Distance between New York and Los Angeles is 2400 miles Trip = 1/10 around the world = 2/3 to the center of the earth

  5. Earth facts Relatively smooth for the scale Highest mountains are 5.5 miles from sea level Deepest trenches about 7 miles below sea level

  6. Inside the earth? Deepest that man has traveled into the earth? A couple of miles down in the gold mines of South Africa 1 degree for every 33 m Without air conditioning it would be around 160-170°F With air conditioning it is 100 degrees with a 100% humidity

  7. South African Gold Miner

  8. Facts of Earth 71 % of Earth is covered by water 97% of that water is salty Air we breathe at this point in earth’s history is made up of 78% nitrogen 21 % oxygen 1% other gases (including CD)

  9. The Pacific ocean Largest ocean at present 64 million square Miles It would take 244 States of Texas To cover the same area

  10. Trash in the ocean

  11. How hot is the Earth? Up to 140° F Down to -100°F

  12. Black Smoker Vent at the bottom of the ocean (500°F)

  13. How do we know what is in the Earth if we have not been there? • Rocks that have been pushed up to the surface • Seismic waves (energy released from Earthquakes)

  14. Info from Seismic waves Can tell the texture of the rock through interpretation of the speed of seismic waves Seismic waves move faster in more dense material Certain seismic waves can not travel thru any liquid

  15. Shadow Zone

  16. How is the Earth (interior and exterior ) organized?

  17. Column Demo

  18. Lead questions If you could drill to the center of the Earth, would the rock you drill through be the same all the way down? Explain your answer Looking at the column of material created in the graduated cylinder, what property make allows separation between materials?

  19. Density determines the structure of the Earth Formation of layers

  20. ZONES of the EARTH 1) Inner core 2) Outer Core 3) Lower Mantle 4) Asthenosphere 5) Lithosphere 6) Crust (ocean and continent) 7) Hydrosphere 8) Atmosphere 9) Magnetosphere

  21. Cross section diagram

  22. Includes atmosphere

  23. Main difference between layers Density of material, which is determine by Composition of material Temperature of material Characteristics of the material

  24. Definitions of spheres Biosphere: Region where living organism exist, includes portions of the other spheres Atmosphere (Region of air) Hydrosphere (Region of water) Lithosphere (Region of solid earth)

  25. Layer details

  26. Inner Core Solid Metal, nickel and iron Under incredible temp and pressure Pressure on atoms in core from surrounding atoms keeps it solid Around 1000 miles thick in diameter (1700 km)

  27. Outer core Nearly same composition as the inner core Less heat and pressure Liquid (too much pressure to turn to gas) The movement of the Iron liquid, generates the Earth’s magnetic field Slightly thicker than inner core The volume occupied by both cores is about 25% of the Earth’s total

  28. Mantle Thickest section of the interior of the earth The entire mantle Comprises 75% of Earth’s volume The mantle is further divided into 3 important subsections --Lower Mantle (thickest section) Asthenosphere Lithosphere

  29. Mantle subsections Lithosphere topmost layer of mantle (nearest to surface of Earth) solid, brittle 100-200 miles thick Asthenosphere underlies the lithosphere texture like silly-putty, bends under pressure Similar thickness as lithosphere

  30. Crust The layer of the earth next to the surface Less than 1% of volume Some books consider crust as part of mantle Very thin Oceanic 2-4 miles Continental 40-65 miles The least dense of all layers We have never drilled all the way through the crust

  31. Differences between oceanic crust and continental crust Continental crust is generally thicker, less dense and older than ocean crust Continental crust has a higher % of silicon (a less dense material) in its composition

  32. Hydrosphere: Oceans • Atmosphere: Air • Some elements are so light that the pull of gravity does not keep them in the atmosphere

  33. Magnetosphere The region occupied by only the Earth’s magnetic field Extends beyond the atmosphere into space Northern lights May be caused by the movement of the Earth’s liquid core

  34. There may be another source of magnetic field Both Sun and Moon have magnetic fields Sun contains very little iron Moon does not have a liquid core

  35. Special characteristics of certain layers Thinnest: Thickest: Hottest, most pressure Composed of Liquid: Texture like silly-putty, because of pressure and temp: Least dense:

  36. The Moho Discontinuity The boundary between the crust and the lithosphere Named for a Croatian scientist with a last name of Mohorovicic The seismic waves travel much faster in the mantle than crust (denser material)

  37. QUESTIONS ABOUT HOW WE KNOW THAT THE EARTH IS DIFFERENTIATED

  38. How do you think we know anything about the inside the earth?

  39. Have we gone down and looked at each layer?

  40. Deeper into the earth About 20-40 km down = 350 ° F, the temperature you bake a cake About 1000-1200 miles down = 2300 ° F At the center of the Earth = up to 11,000 °F In other words, 110 times more hot than the hottest summer day you have ever experienced

  41. Geologists have used two main types of evidence to learn about Earth’s interior: direct evidence from rock samples indirect evidence from seismic waves.

  42. Seismic wave speed Faster in lithosphere than crust Slows down in Asthenosphere Increases through the rest of the mantle Drops off in Outer Core No S waves

  43. Using an air-gun to create seismic waves

  44. A cross sectional map using info from seismic waves

  45. Two types of Seismic waves used P-waves Primary-pressure wave (longitudinal) Fastest wave Some of the wave goes through all material, some reflects back Changes direction at each boundary

  46. S-waves Secondary, shear Slower than P-waves Can not go through liquid

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