Objective 5 Highlight 3

1. Objective 5 Highlight 3 Students are expected to understand the basic movements of Earth’s plates and features of tectonics, such as right valleys, trenches, seafloor spreading, and mountain building.

2. 8.14B • The students is expected to predict land features resulting form gradual changes such as mountain building, beach erosion, land subsidence, and continental drift.

3. PLATE TECTONICS Why the Earth is Like It Is

4. Names of Plates

5. Plates are “pushed” and “pulled” over the surface of the Earth due to unbalanced forces. Why Do Plates Move? When convection currents reach the surface, plates are pushed apart As the plates move away from each other, part of them are pulled into the Earth’s mantle

6. Plates Move Toward Each OtherThis is called Convergence – these are destructive boundaries since they deform the plates Continent/Continent Ocean/Continent Ocean/Ocean

7. Plates Move Away From Each OtherThis is called Divergence – these are constructive boundaries since they produce new land Africa and Arabia Mid-Atlantic Ridge

8. Results of Movements

9. Convergence – Moving Together Mountains Trenches Structural Mountains Volcanic Mountains

10. Divergence – Moving Apart Rift Valley – if the land is above water Sea Floor Spreading – when the land is below water

11. Where Do We See Evidence?

12. Hot Spots

13. Volcanoes and Earthquakes Ring of Fire – very active region of subduction

14. Ring of Fire – Circles Pacific Ocean

15. Earthquakes and Plate Movements East Africa Rift Valley is one Coastal Ranges Hawaii is typical Aleutian Islands (Alaska) Mid-Ocean Ridge in Atlantic Ocean Drawing of plate movements and resulting land forms

16. Active Movements - Faults One day – Los Angeles and San Francisco will be next to each other

17. What Did The Earth Look Like In The Past?

18. TAKS Type Items and Answer Analysis

19. As two continental plates move toward each other, what landforms would you expect to see? • Volcanoes • Cliffs • Mesas • Structural Mountains

20. As two continental plates move toward each other, what landforms would you expect to see? • Volcanoes Incorrect These form at edges of plates or over hot spots

21. As two continental plates move toward each other, what landforms would you expect to see? • Cliffs Incorrect These are erosional landforms or minor uplift areas

22. As two continental plates move toward each other, what landforms would you expect to see? • Mesas Incorrect These are erosional landforms in a desert

23. As two continental plates move toward each other, what landforms would you expect to see? • Structural Mountains – correct - because 2 continental masses will push into each other and “crumple” the edges to form mountains

24. Where would you find the newest land on Earth? • In areas of continental convergence • In areas where two ocean plates come together • In areas where plates are moving apart • In areas where two plates are sliding past each other

25. Where would you find the newest land on Earth? • In areas of continental convergence Incorrect Structural mountains would form here from existing land.

26. Where would you find the newest land on Earth? • In areas where two ocean plates come together Incorrect You would find trenches and subduction in this area.

27. Where would you find the newest land on Earth? • In areas where two plates are sliding past each other Incorrect You would find land movement but not new land being formed

28. Where would you find the newest land on Earth? • In areas where plates are moving apart Correct When plates move apart it is due to magma reaching the surface. When magma cools new land is formed.