Plate Tectonics Study Guide Answers

1. Plate Tectonics Study Guide Answers

2. 1. List the Layers of the Earth in order from the interior out Inner core Outer core Mantle Crust

3. 4 Main Layers

4. 2. Temperature and Pressure both ___________ with depth Increases

6. 3. How do scientists study the interior of the Earth? Seismic Waves.

7. 4. What makes up the inner core and outer core? Iron and Nickel *Mostly IRON *Outer Core=liquid

9. 5. What 3 types of evidence did Alfred Wegener use to support his theory of Continental Drift • Geological: Mountains in S. America line up with those in Africa • Fossils: Glossopteris and dinosaur remains in certain areas • Climate: Glaciers in Africa and tropical plants in Antarctica

10. Geologic Evidence Fit of Continents Across the AtlanticMountain ranges in South America line up exactly with those in Africa!

11. Fossil Evidence http://evolution.berkeley.edu/evolibrary/images/history/fossils3.gif Notice how fossils lined up across continents!

12. Climate change Did you know... 1. that India was once in the Southern Hemisphere connected to Antarctica? 2. that North America was once surrounded by warm, tropical seas? 3. that Africa was once covered by glaciers, which were kilometers in thickness? 4. that the Sahara desert was once a tropical rain forest?

13. 6. What is Pangea? The supercontinent of all continents as one landmass

14. 7. What is a fossil Remains of living things. Has to have rapid burial and be preserved

15. 8. What is the mid-ocean Ridge The longest chain of mountains in the world. Found at the bottom of the Atlantic Ocean. Formed at a divergent boundary where molter material is coming up from the mantle

16. : www.ocean.udel.edu Did you know that the Earth’s longest mountain range is underwater and is called the mid-ocean ridge? The Mid-Ocean Ridge system, shown above snaking its way between the continents, is more than 56,000 kilometers (35,000 mi) long. It circles the earth like the stitching on a baseball!

17. 9. Explain the process of sea-floor spreading and where does it take place? Sea-floor happens at a divergent boundary at the mid-ocean ridge. New crust is being made and getting pushed further from the boundary. Old crust=further away from boundary

18. 10. The movment of the plates is caused by_____________ Convection Currents

19. 11. Explain the Theory of Plate Tectonics and Continental Drift • Plate Tectonics=plates are in constant motion due to convection currents. • Continental drift=all continents were once a single land mass named Pangea

20. 12. List and describe the 3 types of boundaries • Covergent: collide/coming together. Produces: Mountains, trenches, volancoes, volcanic islands • Divergent: apart. Produces: rift valleys and mid-ocean ridges • Transform: slide horizontally. Produces: earthquakes and faults

24. 13. A rift valley forms where two plates do what? Diverge on continental plates

25. Divergence can also occur in continental crust! Continental crust diverging from continental

27. 14. What is the lithosphere? Made up of the upper mantle and crust. It is the tectonic plates that are moving on top of the asthenosphere

29. 15. What is the asthenosphere? The plastic like layer that is found in the upper mantle. The plates float on this!

30. 16. Explain convection currents in the mantle. Convection=transfer of heat. It happens in the mantle because the molten material is getting heated from the inner core. Hot=less dense=rises Cold=more dense=sinks

32. 17. Where is new ocean crust created? Mid-ocean ridges *Sea floor spreading

33. This is a model of sea floor spreading at a divergentboundaryis called a mid ocean ridge.

34. 18. Explain the three different kinds of convergent boundaries • C + C=mountains • C + O= subduction of O. Volcanoes and trenches form. • O + O=subdction of one of the O’s. Volcanic islands and trenches form

36. 19. Earth’s Magnetic Field results from the spinning of the ___________ Inner core. *The liquid outer core makes the inner core spin

38. 20. Why is ocean crust younger than continental crust Ocean crust is being formed at divergent boundaries.

39. 21. What happens at trenches on the ocean floor? The ocean crust is being subducted back into the mantle causing a trench

41. 22. What is density? Density = mass/volume!

42. 23. What type of boundaries form at mid-ocean ridges? Divergent

43. 24. Which layer do the Earth’s plates float on? Asthenosphere

44. 25. Explain why oceanic crust is subducted at an oceanic-continental boundary. It’s MORE DENSE. Twice as much elements!!!