The Structure of the Earth and Plate Tectonics

1. The Structure of the Earth and Plate Tectonics By: Ms. Nikki

2. Journey to the Center of the Earth What would I find if I journeyed to the center of the Earth?

4. How did the layers form?

5. How did the layers form? • The Earth’s layers were formed because of density.

6. How did the layers form? • The Earth’s layers were formed because of density. • The heavier, more dense, materials were pulled in more by gravity.

7. How did the layers form? • The Earth’s layers were formed because of density. • The heavier, more dense, materials were pulled in more by gravity. • Lighter, less dense, materials were not pulled in as much by gravity.

8. What are the layers made of?

9. What are the layers made of? • Inner Core: solid iron (Fe) and Nickel (Ni).

10. What are the layers made of? • Inner Core: solid iron (Fe) and Nickel (Ni). • Pressure is 48 to 52 million psi.

11. What are the layers made of? • Inner Core: solid iron (Fe) and Nickel (Ni). • Pressure is 48 to 52 million psi. • Temperatures range from about 9,000 to 12,000 degrees Fahrenheit.

12. What are the layers made of? • Outer core: liquid iron (Fe) and Nickel (Ni).

13. What are the layers made of? • Outer core: liquid iron (Fe) and Nickel (Ni). • Temperatures range from about 4,400 to 6,100 degrees Fahrenheit.

14. What are the layers made of? • Outer core: liquid iron (Fe) and Nickel (Ni). • Temperatures range from about 4,400 to 6,100 degrees Fahrenheit. • It is believed that the Earth’s magnetism is produced here.

15. What are the layers made of? • Mantle:

16. What are the layers made of? • Mantle: • Made of various minerals (Iron (Fe), Magnesium (Mg), Aluminum (Al), Silicon (Si), and Oxygen silicates ) that are in constant motion.

17. What are the layers made of? • Mantle: • Made of various minerals (Iron (Fe), Magnesium (Mg), Aluminum (Al), Silicon (Si), and Oxygen silicates ) that are in constant motion. • Temperatures of up to 6,700 degrees Fahrenheit.

18. What are the layers made of? • Crust:

19. What are the layers made of? • Crust: The top layer of the Earth

20. What are the layers made of? • Crust: The top layer of the Earth • The two types are continental and oceanic.

21. What are the layers made of? • Crust: The top layer of the Earth • The two types are continental and oceanic. • Made of mostly Silicon (Si), Aluminum (Al), Calcium (Ca), Sodium (Na), and Potassium (K)

22. What are the layers made of? • Crust: The top layer of the Earth • The two types are continental and oceanic. • Made of mostly Silicon (Si), Aluminum (Al), Calcium (Ca), Sodium (Na), and Potassium (K) • Fractures during earthquakes.

23. Where is the lithosphere?

24. Where is the lithosphere? • The lithosphere contains:

25. Where is the lithosphere? • The lithosphere contains: • The crust.

26. Where is the lithosphere? • The lithosphere contains: • The crust. • A small layer of the upper mantle.

27. Where is the lithosphere? • The lithosphere contains: • The crust. • A small layer of the upper mantle. • Large chunks or plates that move gradually because they ride on hotter parts of the mantle.

28. Where is the lithosphere? • The lithosphere contains: • The crust. • A small layer of the upper mantle. • Large chunks or plates that move gradually because they ride on hotter parts of the mantle. • These “chunks” or plates make up the surface of the Earth.

29. Structure of the Earth • The Earth is made up of 3 main layers: • Core • Mantle • Crust Mantle Outer core Inner core Crust

30. What IS the Lithosphere? • The lithosphere is made up of the crust and small layer of the upper mantle that together form large chunks or plates that move gradually because they ride on hotter mantle. These plates make up the surface of the Earth.

31. Warm Up • 1. Take out a piece of paper and put your name on it. • 2. BE QUIET!

32. The Crust • This is where we live! • The Earth’s crust is made of: • Continental Crust • thick (10-70km)- buoyant (less dense than oceanic crust) - mostly old Oceanic Crust - thin (~7 km)- dense (sinks under continental crust)- young

33. How do we know what the Earth is made of? • Geophysical surveys: seismic, gravity, magnetic, electrical, geodesy • Acquisition: land, air, sea and satellite • Geological surveys: fieldwork, boreholes, mines

34. http://video.google.com/videoplay?docid=4835712194315869074#

35. What are Plate Tectonics?

36. If you look at a map of the world, you may notice that some of the continents could fit together like pieces of a puzzle.

37. Plate Tectonics • The Earth’s crust is divided into 12 major plates which are moved in various directions. • This plate motion causes them to collide, pull apart, or scrape against each other. • Each type of interaction causes a characteristic set of Earth structures or “tectonic” features. • The word, tectonic, refers to the deformation of the crust as a consequence of plate interaction.

38. World Plates

39. What are tectonic plates made of? • Plates are made of rigid lithosphere. The lithosphere is made up of the crust and the upper part of the mantle.

40. What lies beneath the tectonic plates? • Below the lithosphere (which makes up the tectonic plates) is the asthenosphere.

41. Continents of the Past • “Pangaea” : exists ~ 225 million years ago • Supercontinent: the only continent on Earth • Division of Pangaea ~ 135 million years ago • Into “Laurasia” (N. Hem) • Included modern North America & Eurasia • And “Gondwana” (S. Hem) • Included modern South America, Africa, Antarctica, Australia, Madagascar, India and New Zealand

42. 250 Million Years Ago

43. 200 Million Years Ago

44. 135 Million Years AgoJurassic Period

45. 65 Million Years Ago

46. Present Day

47. In 50 Million Years

48. In 150 Million Years

49. In 250 Million Years

50. What is a convection current? • A convection current is a circular flow due to molecules heating, moving faster, and becoming less dense-so they weigh less and rise. • When they cool, they move slower and closer together-so they weigh more per space and sink.