DYNAMIC EARTH
Click on the following site: https://www.learner.org/series/interactive-dynamic-earth/
Earth's Structure (review only)
Plate Tectonics.
Left
1. Does the right or left side look more like our current depiction of what the Earth looks like? ______________
Click that side. Are you right?
Yes
2. What does the other side show a picture of?
Earth before the continents divided
Click How Do We Know This?
3. What is the name of the scientist who noticed that the coastlines of South America and Africa looked like they
fit together like a puzzle piece.
Alfred Wegener
4. What did this scientist call this supercontinent?
Pangaea
5. True or False: Although scientists have constantly tried to disprove the theory of the supercontinent, it is still
the basis for the development of the theory of plate tectonics.
True
Click on Continents Over Time. Follow Directions.
6. What is the name of the theoretical future Pangaea?
Pangaea Ultima
Click on Plate Boundaries
7. How many major tectonic plates currently exist?
15
8. What is the name of the crust that is underneath land?
Continental
9. What is the name of the crust that is underneath water?
Oceanic
10. How thick is continental crust? _______ How thick is oceanic crust? _______
30 to 70 km, 7 to 10 km
11. What is the border between two tectonic plates called?
Boundary
12. Explain, and give an example of the difference between the 3 types of plate boundaries.
Convergent – When two plates push toward each other.
Divergent – Plates that move apart from each other.
Transform – When two plates slide past each other.
13. Which type of boundary is closest to us in NC?
Caribbean
Complete the Plates and Boundaries Challenge to get to the next section.
Click next. Slip, Slide, and Collide
14. What is happening to the Himalayan mountains?
They grow taller every year
15. True or False: The different types of occurrences at plate boundaries cause specific types of natural
phenomena to occur.
False
Click See What Happens at Plate Boundaries.
16. If oceanic and continental plates collide, which one will go under the other one? WHY?
Oceanic because it is denser
17. What is this known as?
Subduction
18. As the ocean crust sinks, what is formed at the edge of the continent?
A valley
19. Use the diagram to define the following terms:
Volcanic Arc – An arc-shaped chain of volcanoes
Trench – A steep-sided depression on the ocean floor
Subduction Zone – Where one plate is being pulled to the other
20. What happens when 2 oceanic plates collide?
It forms Island Arcs
21. What else exists as these plates collide? (Hint: what causes tsunamis?)
A shift in the ocean floor causes tsunamis
22. What happens when two continental plates converge?
It creates mountain ranges
23. How much taller are the Himalayan Mountains each year?
50 to 20 mm per year
Click next. Divergent Boundaries.
24. What causes seafloor spreading?
Divergent boundaries in the middle of the ocean
Transform Boundaries.
25. Explain what causes stress to build up at fault lines.
Friction
26. What happens when this stress is released?
It causes a dip in the landslide
27. What is another name for a transform boundary?
A strike-slip fault
28. Where is the most frequently studied fault of this nature?
San andreas in california