1. Theory of Plate Tectonics
By: Ms. R. Wallace, WFHS

2. Layers to Earth

3. Plates!
The Earth’s crust is made up of plates which move across the surface of the planet.
This moves the continents and oceans with them.

4. What causes plate tectonics?
Convection Currents:
Differences in density cause hot plastic like rock in the asthenosphere to be forced upward toward the surface
The lithosphere is carried with it
When it cools, it sinks into the mantle and takes the crust with it.
Activity INSIDE the earth causes changes to the OUTSIDE 

5. Convection Current Video

6. Movement

7. Convergent Boundaries
Oceanic-continental convergence

8. Subduction Zones
The area when one plate moves underneath another in a convergent boundary

9. Divergent Boundary

10. Transform Boundary

11. Summary! Boundary type Movement Feature Formed Examples on Earth
Divergent boundary
Move apart; divide
Rift Valley (on land),
New ocean floor, Mid ocean ridges
Mid-Atlantic Ridge,
East African Rift Valley
Red Sea
Convergent boundary
Continental-Continental collision
Folded Mountains
Earthquakes
Appalachian Mts, Himalayan Mts
Continental-Oceanic collision
Volcanic Mts,
Deep sea trenches, Deep Earthquakes
Cascade Mts (Mt Saint Helens)
Andes Mts
Oceanic-Oceanic collision
Volcanic island arcs, earthquakes,
Japan, Philippines,
Aleutian islands
Transform Fault boundary
Sliding/grinding past
Fault zones
Shallow Earthquakes
San Andreas Fault

12. Diver between plates!

13. Hot Spots!
Hot Spot: Hot magma rises through the mantle and pushes through a plate.
This creates volcanoes and can create islands.
The hotspot does not move, but the crust does, pulling islands away from the hotspot to form new islands.