1. Follow the key below to positively participate in class today: All information in () is the instructor “speaking” to you – this does not need to be written down. All information in LIME GREEN – main ideas – should be written to the LEFT of your divided page notes All information in YELLOW – details – should be written to the RIGHT of your divided page notes

2. Setting up your notes 1 (Get a lined piece of paper) 2 (Fold the left side 1/3 of the way in to create a column to the left.) 3 (Put the heading at the very top – NAME -DATE -BLOCK) 4 (Title your notes “Plate Tectonics”) 5 – REMEMBER: LIME GREEN – LEFT YELLOW - RIGHT

4. Looking at the world map, what do you notice about the shape of the continents? Jot down your ideas on your paper…

6.  The lithosphere is divided into a number of large and small plates and the plates are floating on the asthenosphere Layers Review

7. crust mantle Lithosphere = the Earth’s crust plus the upper portion of the mantle layer

10. Alfred Wegener Early 1900’s - German scientist – expertise in weather/climate Theorized that continents shift and slowly move over long periods of time Coined the term, Pangaea Theory NOT accepted during his lifetime – could not prove how they moved (missing link)

11. Small error in Wegener’s theory NOT the continents that are drifting, it’s the PLATES PLATES are composed of both oceanic and continental crust FAULTS – the cracks between each plate

12. (Notice the plates contain oceanic and continental crust)

14. Plate motion based on The Global Positioning System (GPS)

16. Evidence of Continental Drift Theory (Write these four topics with THREE SPACES in between) 1. Fossils 2. Landforms 3.Climate 4. Puzzle fit (Now, with your buddy, DESCRIBE these four topics on the right side.)

17. oMinerals, fossils, and mountains on now different continents match if the continents were together Evidence The Mystery of Brachiosaurus (~3 min)

19. oGlaciation patterns indicate a common ice cap at the South Pole Evidence

21. oPangaea began to split apart 200 million years ago oDiagram North America LaurasiaGreenland Eurasia Pangaea Africa West G.S.America Gondwanaland Antarctica East G.Australia India

22. 5. Seafloor spreading Mid-ocean ridge – underwater mountain chains that run through all of Earth’s ocean basins Oldest crust near the borders, newest crust in the center

23. New ocean floor crust is being created at the mid- ocean ridges

24. 2-3  Atlantic Ocean – 2-3 cm/year 7-9  South Pacific Ocean – 7-9 cm/year Speed of Spreading

26. oMidocean ridges are warmer than surrounding ocean floors oActive volcanoes on ridges, earthquakes on ridges oMidocean ridge rocks are younger than surrounding ocean floor rocks oMidocean ridge volcanoes are younger than volcanoes further away What evidence do we have to support this idea of seafloor spreading?

27. 6. Magnetic Reversals most important evidence for seafloor spreading is recorded magnetic reversals in the ocean floor magnetic minerals in molten rock provide clues to the magnetic reversal of the poles final, concrete proof that the seafloor is spreading AND plates are drifting

29. Polar Reversal Magnetism Magnetic PolesMagnetic Field Reversals—2:54

30. HOW do the plates move?

31. Convection Currents Hot magma in the Earth moves toward the surface, cools, then sinks again. Creates convection currents beneath the plates that cause the plates to move.

33. Heat Transfer Three Main Types: Conduction Radiation Convection

34. Conduction Transfer of heat by direct contact Conductors – the better the conductor the faster the heat transfer Ex) egg frying in the pan Hand on the fire

35. Radiation Heat transfer through empty space Ex) sun – common source of heat

36. Convection Heat transfer through the movement of “fluids” – can be liquid or gas ex)boiling water, earth’s asthenosphere

43. Plate Boundaries Divergent boundary:

44. Divergent Boundaries Boundary between two plates that are moving apart or rifting   RIFTING causes SEAFLOOR SPREADING

45. Plate Boundaries Divergent boundary: oPlates are moving away from each other oMidocean ridges are created and new ocean floor plates are created

46. Features of Divergent Boundaries Mid-ocean ridges rift valleys – Great Rift Valley, East Africa fissure volcanoes

47. Leif the Lucky Bridge Bridge between continents in Reykjanes peninsula, southwest Iceland across the Alfagja rift valley, the boundary of the Eurasian and North American continental tectonic plates.

51. Transform Fault Boundary  Plates are neither moving toward nor away from each other, they are moving past one another.

52. Transform Fault Boundary  The plates may move in opposite directions or in the same directions but at different rates and frequent earthquakes are created (example: San Andreas Fault)

53. Transform Fault Boundaries Boundary between two plates that are sliding past each other EARTHQUAKES along faults

54. San Andreas Fault

56. San Andreas Fault, CA

57.  Convergent Boundary  Convergent Boundary: plates are moving toward each other and are colliding (3 types)

58. Convergent Boundaries Boundaries between two plates that are colliding   There are 3 types…

60. Type 1 Ocean plate colliding with a less dense continental plate Subduction Zone: where the less dense plate slides over the more dense plate VOLCANOES occur at subduction zones

61. Andes Mountains, South America

62. Create subduction zones, trenches Create near coast volcanoes Benioff shear zones (a pattern of earthquakes as an ocean plate grinds down the underneath side of a continent) When Ocean Plates collide with Contintental Plates

63. Benioff Shear Zones

65. Type 2 Ocean plate colliding with another ocean plate The less dense plate slides over the more dense plate creating a subduction zone called a TRENCH

67. Aleutian Islands, Alaska

68. When ocean plates collide with other ocean plates Island arcs are created (a pattern of volcanic islands created from a subduction zone that is located off the coast)

71. Type 3 A continental plate colliding with another continental plate Have Collision Zones: –a place where folded and thrust faulted mountains form.

72. MountainrangesMountain ranges are created (example: Himalayan Mountains) When a continental plate collides with another continental plate

73. Himalayan Mountains Mountains 2:46

77. So is the Earth getting bigger?

78. oNo oPlates are destroyed as fast as they are created (2 ways) oPlates may be subducted and melted or may be pushed upward to form mountains So is the Earth getting bigger?

79. Convection currents within the mantle  The up-welling leg of the current creates a divergent boundary which produces midocean ridges What causes this?

80.  The down-welling leg of the current creates one type of convergent boundary that results in trenches and a subduction zone