Plate Tectonics Review

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

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

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

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

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

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

7. What is Pangaea? Alfred Wegener’s supercontinent

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.

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

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

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

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.

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

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

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.

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

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

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

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

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.

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

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.

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

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

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

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

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