1. Plate Tectonics Review

2. 1. List and describe the layers of the Earth in order from the interior out.
Inner core – hot, solid iron and nickel
Outer core – hot, molten iron and nickel
Mantle – hot rock
Crust – solid outer layer of the Earth

3. 2. Temperature and pressure both ______________ with depth.
Both Increase

4. 3. How do scientists study the interior of the Earth?
Seismic Waves from earthquakes

5. 4. What technology gave us the first look at the ocean floor?
Sonar

6. 5. What makes up the inner core and outer core?
Iron
Nickel

7. 6. What 3 types of evidence did Alfred Wegener use to support his theory of continental drift?
Evidence from Landforms
Evidence from Fossils
Evidence from Climate

8. 7. What is Pangaea?
Alfred Wegener’s supercontinent

9. 8. What is subduction? When and why does subduction take place
Subduction is the process by which old oceanic crust is pushed back down into the mantle melting rock and turning it back into molten material.
Subduction takes place at deep ocean trenches where convection currents are causing two lithospheric plates to move/push together.

10. 9. What is the mid-ocean ridge
Longest chain of mountains located on the ocean floor

11. 10. Explain the process of sea-floor spreading and where does it take place.
Process by which new material is continually added to the ocean floor and happens at the mid-ocean ridge

12. 11. The movement of the plates is caused by ________________.
Convection currents

13. 12. Explain the Theory of Plate Tectonics and Continental Drift.
Plate Tectonics – pieces of Earth’s lithosphere are in constant slow motion, driven by convection currents in the mantle.
Continental Drift – all continents were once joined together in a single landmass and has since drifted apart.

14. 13. List and describe the 3 types of plate boundaries
Transform boundary – 2 plates slip past each other causing earthquakes

15. 13. Plate boundaries continued…..
Divergent boundary – 2 plates move apart
Convergent boundary – 2 plates come together

16. 14. A rift valley forms where two plates do what?
A rift valley forms where two continental and continental plate move away from each other.

17. 15. What is the lithosphere?
Uppermost part of the mantle and the crust together form a rigid layer of rock

18. 16. What is the asthenosphere?
Layer beneath the lithosphere that is less rigid then the rock above it

19. 17. Explain how convection currents in the mantle cause the lithospheric plates to move
The warm less dense material rises and the cool more dense material sink causes movement of the plates

20. 18. Where is new ocean crust created?
At the mid-ocean ridge through sea-floor spreading

21. 19. Explain the 3 types of convergent boundaries and what each produces.
Convergent oceanic and oceanic plates – 1 plate is subducted (the more dense plate) through a trench and forms a chain of volcanic islands
Convergent oceanic and continental plates – oceanic is more dense and is subducted under the continental plate. Volcanoes on land are produced.
Convergent continental and continental plate – 2 continental plates collide, crust buckles and mountain ranges are formed.

22. 20. The Earth has a magnetic field because of the __________.
Core

23. 21. What is the difference between continental and oceanic crust
21. What is the difference between continental and oceanic crust? Why is ocean crust younger than continental crust?
Oceanic crust is more dense than continental crust. It also moves through the rock cycle faster than continental crust. New ocean crust is created at the mid-ocean ridge and old ocean crust is subducted at a trench.

24. 22. What happens at trenches on the ocean floor?
Oceanic crust is pushed back into the mantle and forms molten material (subducted).

25. 23. What is density? The amount of matter in a given amount of space.
Density = mass/volume

26. 24. What type of boundaries form at the mid-ocean ridge?
Divergent boundary

27. 25. Which layer do the Earth’s plates float on?
Asthenosphere

28. 26. Explain why oceanic crust is subducted at an oceanic and continental convergent boundary
Oceanic crust is more dense than continental