1. Differentiated earth

2. Earth Size Main Characteristics of the surface and interior

4. Statistics about the Earth Shape of Earth is nearly spherical (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

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

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

7. 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)

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

9. Trash in the ocean

10. How hot is the Earth? Up to 140° FDown to -100°F

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

12. Shape of Earth Oblate Spheroid

13. Column Demo

14. Lead questions 1)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 2)Looking at the column of material created in the graduated cylinder, what property make allows separation between materials?

15. Density determines the structure inside the Earth Formation of layers

16. Cross section diagram

17. 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

18. Includes atmosphere

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

20. 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)(this is a second definition)

21. 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)

22. Outer core 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 29.5% of the Earth’s total

23. Mantle Thickest section of the interior of the earth The entire mantle Comprises 80% of Earth volume The mantle is further divided into 3 important subsections --Lower Mantle (thickest section) –Asthenosphere –Lithosphere

24. 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

25. Crust The layer of the earth next to the surface Very thin –Oceanic 2-4 miles –Continental 40-65 miles The least dense of all layers –Ocean crust is denser than continental crust We have never drilled all the way through the crust

26. 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

27. 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

29. 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

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

32. 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)

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

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

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

36. 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

37. South African Gold Miner

38. 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

39. Geologists have used two main types of evidence to learn about Earth’s interior: direct evidence from rock samples and indirect evidence from seismic waves. Using data from seismic waves produced by earthquakes, geologists have learned that Earth’s interior is made up of several layers.

40. 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 The s-waves can not travel thru any liquid

41. Different form of Echolocation Using seismic waves Created by vibrations of the Earth Using time to indicate distance and type of material Causes of vibration Natural: Earthquakes Man-made: Gunshots

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. Shadow Zone

44. Using an air-gun to create seismic waves

46. A cross sectional map using info from seismic waves

47. 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

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

49. 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 The s-waves can not travel thru any liquid

50. How did the Earth get layered ?

51. Answer After enough material from the nebula dust cloud clumped together, the temperature inside the clump increased enough to melt it. When melted, the heavy material settled towards the core, lighter material rose to the surface. Another source of internal heat came from radioactive decay of materials. This still continues to today

52. Scientists think that movements in the liquid outer core create Earth’s magnetic field. Because Earth has a magnetic field, the planet acts like a giant bar magnet.