Chapter 4: Plate Tectonics

Chapter 4: Plate Tectonics

Plate Tectonics Notes SheetName:

Directions: answer the following questions.

1. What is plate tectonics?

2. Identify the 4 plates that are moving apart (use page 480).

a.b.

3. Identify 4 plates moving together or colliding (use page 480).

a.b.

4. Identify 2 plates that are sliding past each other (use page 480).

a.b.

5. Name the layers of the Earth’s crust..

6. What is the lithosphere?

7. How are the composition and density of continental crust different than the rest of the lithosphere?

8. Where is the asthenosphere?

9. What is the major property of the asthenosphere?

10. How do the lithospheric plates move where convection currents are rising?

11. How do the lithospheric plates move where convection currents are sinking?

12. What is the theory of continental drift?

13. List 3 pieces of evidence that Alfred Wegener used to support the theory of continental drift.

a.

b.

c.

14. Why do earthquakes and volcanoes occur at plate boundaries?

15. Where is the largest belt of active earthquakes and volcanoes located?

16. Name 3 volcanoes that occur in this belt.

a.

b.

c.

17. Describe Earth’s magnetic polarity when the magnetic poles are reversed.

18. What is the pattern of polarity reversals at spreading plate boundaries.

19. Describe the age of rocks of the ocean floor relative to spreading plate boundaries.

20. What are spreading centers?

21. What occurs at spreading centers?

22. What is heat flow?

23. What is the relationship between heat flow and distance from spreading center?

24. How are the plates moving at a mid-ocean ridge?

25. What 2 features occur at mid-ocean ridges?

a.

b

26. Name and locate 2 mid-ocean ridges.

a.

b.

27. How are the plates moving at a transform boundary?

28. Give an example of a transform boundary.

29. What is a converging boundary?

30. What surface feature occurs at converging boundaries?

31. What is happening to the plates at a subduction zone?

32. What is a divergent boundary?

33. What features are characteristic of the collision of an oceanic plate and a continental plate?

34. Give an example of 2 oceanic plates colliding.

35. How are subduction boundaries related to mid-ocean ridges?

36. List 3 kinds of material that can become part of a continent.

a.

b.

c.

Answers:

1. study of the formation & movement of lithospheric plates

2. a. North American & Eurasian, b. South American & African

3. a. Indian & Eurasian, b. South American & Nazca

4. North American & Pacific

5. consists of crust & upper mantle

6. it is rigid & approx. 100 km thick

7. made of granite, rather than basalt, it is less dense

8. below the lithosphere

9. able to flow

10. they move apart

11. they move together

12. a large continent made from Africa & S. A. broke & moved apart

13. a. shape of coastline, b. fossils, c. distinctive rocks

14. plate movements cause stress

15. around the Pacific Ocean

16. a. Mt. St. Helens – Washington, b. Fujiyama – Japan, c. Pinatubo – Philippines

17. present north becomes South and South becomes North

18. they are in bands parallel to & on opposite sides of plate boundaries

19. they’re older further away from the boundary

20. area between spreading plate boundaries

21. new rocks form and pushes away older rocks

22. the measure of the amount of heat leaving rocks of the lithosphere

23. highest at center, decreases in temp. away from center

24. they are moving apart

25. a. rift valley, b. fracture zones

26. a. Mid-Atlantic Ridge - between N.A. & Eurasian plates; S.A. & African plates, b. East Pacific Rise - between Pacific & N.A. plates

27. they slide past each other

28. San Andreas Faults

29. 2 plates colliding

30. mountains

31. one plate is pulling down under another plate

32. where 2 plates are moving apart

33. trenches & mountain chains

34. fast-moving Pacific Plate against the slower moving Philippine Plate

35. the subduction plate is pulled further down than at other plate boundaries

36. lithosphere forms at ridges & disappears at trenches in subduction zones

37. a. deep-sea sediment, b. volcanic rock, c. continental sediments