1. Plate Tectonics 7 th Grade Science

2. Area of Focus: Plate Tectonics Copyright © 2010 Ryan P. Murphy

3. Plate tectonics: The earth’s crust and upper mantle are broken into sections called plates. – These plates float on the mantle like rafts (moving very slowly) Copyright © 2010 Ryan P. Murphy

4. Plate tectonics: The earth’s crust and upper mantle are broken into sections called plates. – These plates float on the mantle like rafts (moving very slowly) Copyright © 2010 Ryan P. Murphy

5. Continental Drift: The gradual movement of the continents across the earth. Copyright © 2010 Ryan P. Murphy

7. The speed at which the plates move is about the speed at which your fingernails grow. Copyright © 2010 Ryan P. Murphy

8. Video! How did the continents form?

9. In 1915, The German geologist Alfred Wegener (1880-1930) proposed continental drift. Copyright © 2010 Ryan P. Murphy

10. In 1915, The German geologist Alfred Wegener (1880-1930) proposed continental drift. Copyright © 2010 Ryan P. Murphy “I say.” “Africa and South America fit strangely like two puzzle pieces.”

11. In 1915, The German geologist Alfred Wegener (1880-1930) proposed continental drift. Not accepted until the 1950’s! Copyright © 2010 Ryan P. Murphy

12. Evidence for continental drift. – - Copyright © 2010 Ryan P. Murphy

13. The shapes match. Copyright © 2010 Ryan P. Murphy

14. Same fossils found on different continents – These are the pictures on the puzzle pieces. Copyright © 2010 Ryan P. Murphy

15. Same fossils found on different continents – These are the pictures on the puzzle pieces. Copyright © 2010 Ryan P. Murphy

19. The Same rock structures on different continents Copyright © 2010 Ryan P. Murphy

22. What is this a fossil of? – Where would you expect to find a specimen like this on the planet? Copyright © 2010 Ryan P. Murphy

23. Answer! This is a fossilized tropical plant found on Antarctica. Copyright © 2010 Ryan P. Murphy

24. Answer! This is a fossilized tropical plant found on Antarctica. – Remember, the continents have moved and Antarctica use to be in a warmer climate. Copyright © 2010 Ryan P. Murphy

25. Fossils of plants and animals in Antarctica Copyright © 2010 Ryan P. Murphy

26. Behold the Supercontinent! Pangea ? Copyright © 2010 Ryan P. Murphy

27. Behold the Supercontinent! Pangea Copyright © 2010 Ryan P. Murphy

28. Pangea: The “Super Continent” – All of the plates were once together. Copyright © 2010 Ryan P. Murphy

29. Pangea: The “Super Continent” – All of the plates were once together. Copyright © 2010 Ryan P. Murphy

30. – Gondwondaland and Laurasia were two mega continents after Pangea. Copyright © 2010 Ryan P. Murphy

31. Current Day + or – 4mm

33. What causes continental drift and plate tectonics? Copyright © 2010 Ryan P. Murphy

34. Answer! – Convection currents (Remember heat rises) move the plates Copyright © 2010 Ryan P. Murphy

35. Answer! – Convection currents (Remember heat rises) move the plates Copyright © 2010 Ryan P. Murphy

36. Answer! – Convection currents (Remember heat rises) move the plates Copyright © 2010 Ryan P. Murphy

37. Answer! – Convection currents (Remember heat rises) move the plates Copyright © 2010 Ryan P. Murphy

38. Video! Plate Tectonics

39. Layers of the earth Copyright © 2010 Ryan P. Murphy

40. Layers of the earth Copyright © 2010 Ryan P. Murphy

41. Layers of the earth Copyright © 2010 Ryan P. Murphy

42. Layers of the earth Copyright © 2010 Ryan P. Murphy

43. Layers of the earth Copyright © 2010 Ryan P. Murphy

44. Layers of the earth Copyright © 2010 Ryan P. Murphy

45. Earth’s layers formed early in it’s long history. Copyright © 2010 Ryan P. Murphy

46. Earth’s layers formed early in it’s long history. – (Archean Eon) Gravity pulled heavy elements toward the middle. Copyright © 2010 Ryan P. Murphy

47. Inner Core: Solid Iron and Nickel (Dense). Copyright © 2010 Ryan P. Murphy

48. Hot and Dense Less Hot and Dense Copyright © 2010 Ryan P. Murphy

49. The spinning inner cores of solid and liquid Iron creates a giant electromagnetic field. Copyright © 2010 Ryan P. Murphy

50. Outer Core: Liquid Iron and Nickel Copyright © 2010 Ryan P. Murphy

51. Mantle: Composed of Magnesium Silicates, Iron, Calcium Copyright © 2010 Ryan P. Murphy

52. Mantle: Composed of Magnesium Silicates, Iron, Calcium - Outer Mantle (Asthenosphere) Copyright © 2010 Ryan P. Murphy

53. Mantle: Composed of Magnesium Silicates, Iron, Calcium - Outer Mantle (Asthenosphere) - Lithosphere (Crust) Copyright © 2010 Ryan P. Murphy

54. Review! Heat from the earth rises and run along plates causing them to move. Copyright © 2010 Ryan P. Murphy

56. New Area of Focus: Earth’s Plate Boundaries. Copyright © 2010 Ryan P. Murphy

57. Two types of Crust – - Copyright © 2010 Ryan P. Murphy

58. Oceanic Crust: More dense so it sinks more (Basalts). Copyright © 2010 Ryan P. Murphy

59. Continental Crust: Less Dense so it floats higher (Granites) Copyright © 2010 Ryan P. Murphy

60. Which plates below are ocean plates?

61. Answer! Nazca Plate.

62. Answer! Pacific Plate

63. Answer!

65. Activity! Using Google Earth to look at divergent ocean plate boundaries on the sea floor. – http://www.google.com/earth/index.html http://www.google.com/earth/index.html

66. Divergent Boundaries: Crust is created as two or more plates pull away from each other. Copyright © 2010 Ryan P. Murphy

72. Newer

73. Older

74. Newer Older

75. Newer Older 4 miles thick

77. Convergent Boundaries: Crust is destroyed and recycled back into the interior of the earth. – One plate dives under another. Copyright © 2010 Ryan P. Murphy

78. Convergent Boundaries: Crust is destroyed and recycled back into the interior of the earth. – One plate dives under another. Copyright © 2010 Ryan P. Murphy

79. Ocean vs. Continent (Subduction zone) Copyright © 2010 Ryan P. Murphy

80. Ocean vs. Continent (Subduction zone) – The oceanic plate is forced below the continental plate. Copyright © 2010 Ryan P. Murphy

83. What is the “Ring of Fire”? Copyright © 2010 Ryan P. Murphy

84. What is the “Ring of Fire”? Copyright © 2010 Ryan P. Murphy

85. Ring of Fire: A zone of frequent earthquakes and volcanic eruptions that encircles the basin of the Pacific Ocean. Copyright © 2010 Ryan P. Murphy

86. Ring of Fire: A zone of frequent earthquakes and volcanic eruptions that encircles the basin of the Pacific Ocean. Copyright © 2010 Ryan P. Murphy

87. Ring of Fire: A zone of frequent earthquakes and volcanic eruptions that encircles the basin of the Pacific Ocean. Copyright © 2010 Ryan P. Murphy

88. Many tropical Islands like this are created by ocean plates and volcanism. Copyright © 2010 Ryan P. Murphy

92. Ocean Plate

93. Copyright © 2010 Ryan P. Murphy Ocean Plate

94. Copyright © 2010 Ryan P. Murphy Ocean Plate Volcanic Arch Island Chain / Archipelago

95. Video Link! New volcanic island forming – http://www.youtube.com/watch?v=kwETZSARMg E http://www.youtube.com/watch?v=kwETZSARMg E

96. Transform-Fault Boundaries: Where two plates are sliding horizontally past one another. Copyright © 2010 Ryan P. Murphy

102. Coastal California and the Baja Peninsula will become an Island.

105. Continental Convergence: (Mountain Building). Copyright © 2010 Ryan P. Murphy

106. The Swiss Alps is an example of mountains that form when continents collide. – The African Plate is colliding with the European Plate

107. The Swiss Alps is an example of mountains that form when continents collide. – The African Plate is colliding with the Eurasian plate/

108. Indian Continental Plate is crashing into Asian Plate causing the mountains to form. – They are still growing. Copyright © 2010 Ryan P. Murphy

109. Himalayas: Tallest Mountains on Earth.

110. Continent Divergence (Moving apart). Copyright © 2010 Ryan P. Murphy

115. Ocean vs. Ocean Convergence Copyright © 2010 Ryan P. Murphy

116. Antilles in Caribbean

117. Aleutian Islands Alaska

118. Indonesia – Every triangle is a volcano