1. Plate Interactions
Tectonic Plate Theory

2. Definition of Plate Tectonics
Plate Tectonics is the theory that Earth’s lithosphere is broken into about 20 plates that move on top of the asthenosphere.

3. Map of the Plates

4. Questions 1-3 Use the map to answer the following questions
Questions 1-3 Use the map to answer the following questions. Put your answers on the back of the map.
What is the name of the plate that we live on?
About where on the plate is New York City (on the edge, near the edge, in the middle)?
What cities in the United States are on the edge of a plate?

5. The Plates Are Moving! Evidence to Support Plate Tectonics
Puzzle-like fit of continents

6. Shape of Continents

7. The Plates Are Moving! Evidence to Support Plate Tectonics
Puzzle-like fit of continents
Fossils of same species of plants and animals on various continents, across oceans

8. Fossil Evidence

9. The Plates Are Moving! Evidence to Support Plate Tectonics
Puzzle-like fit of continents
Fossils of same species of plants and animals on various continents
Glacial grooves that match across continents

10. Glacial Grooves

11. The Plates Are Moving! Evidence to Support Plate Tectonics
Puzzle-like fit of continents
Fossils of same species of plants and animals on various continents
Glacial grooves that match across continents
Coal in cold climates

12. Coal in Antarctica

13. The Plates Are Moving! Evidence to Support Plate Tectonics
Puzzle-like fit of continents
Fossils of same species of plants and animals on various continents
Glacial grooves that match across continents
Coal in cold climates
Earthquake boundaries that match the tectonic plate boundaries

14. Earthquakes
Looking at the boundaries of earthquakes around the world… There is a lot in common to those plate boundaries!!!

16. Questions 4-7 Use the map to answer the following questions
Questions 4-7 Use the map to answer the following questions. Put your answers on the back of the map.
Between the west coast of the North American plate and the northeastern part of the Pacific plate, the plates are moving in what way?
What do we have a lot of in this part of the world?
Between the African Plate and the South American plate, the arrows show the plates moving in what way?
What do you think might be occurring there?

17. More Evidence: Seafloor Spreading

19. Visualization of SeaFloor Spreading
erc/content/visualizations/es0803/es0803page01 .cfm?chapter_no=visualization

20. Questions 8 -10 Use the map to answer the following questions
Questions Use the map to answer the following questions. Put your answers on the back of the map.
8. Between what two plates would seafloor spreading be happening?
What does this do to the size of the ocean floor?
What force makes the magma rise up through cracks in the seafloor?

21. Types of Plate Boundaries
Convergent (Coming Together)
Divergent (Dividing Apart)
Transform (Slipping Past)

22. Converge!

23. Diverge!

24. Transform!

25. Convergent Boundaries
Definition: Two plates move into one another
Two Types of Convergent Boundaries
Continent to Continent
Subduction Zone

26. Subduction Zone

27. Subduction Zone Formation of Andes Mountains
Nazca plate is moving under South American plate - this is called subduction
Nazca plate is ocean crust and therefore more dense, it sinks below the continental crust
Question 11: What is a subduction zone?

28. Continent-to-Continent Collisions

29. Continent-to-Continent Collision….
Formation of Himalayas
Indo-Australian plate moved into Eurasian plate
Eurasian plate began to crumble up
Over millions of years, Himalayas were built and continue to grow today
Question 12: Why have geologists found fish fossils at the top of the Himalayas?

30. Divergent Boundaries Definition - when two plates move apart
Example: Mid-Atlantic Ridge
Ocean floor is growing as the plates move apart

31. Transform Boundary

32. Ring of Fire

33. Hot Spots - Volcanoes in the middle of plates