1. Plate Tectonics

2. Tectonic Plates
Tectonic Plates are massive, irregularly shaped slabs of solid rock, composed of the lithosphere.
Plate Tectonics is the theory that describes the large-scale motions of Earth's lithosphere

5. Layers of the Earth

6. What is the Earth like on the inside? Core – (mantle)  Crust
What is the status of the core?
Hot
Warm things float because
of the density difference also
known as the convection current
Mantle flows
upward from the core

7. What do we need to know before we move on?
Oceanic Crust – very dense. Like cooled mantle, thin
Continental Crust – Much less dense; very thick
Convection current – the motion of magma inside the earth
Upwelling – blob of hot magma is coming up
Downwelling – blob of cool magma is going down

8. How do these massive slabs of solid rock float despite their tremendous weight?

9. Convection in the Earth’s Core

11. Sea Floor Spreading

13. Sea Floor Spreading

14. Sea Floor Spreading

19. Types of Boundaries
Convergent
Divergent
Transform

23. Divergent Boundaries

24. Mountain building

25. Divergent Boundary
caused by Upwelling (blob of hot magma is coming up)
Under a continent  eventually makes a new ocean
Under the ocean  creates mid-ocean ridge

29. Convergent Boundaries

30. Mountain Building & Volcanoes

31. Convergent Boundary  caused by Downwelling
(blob of cool magma is going down)
Under the ocean  trench (makes volcanoes on the overriding plate)
Under a continent  Mountains
(also volcanoes until
continental collision)

32. Subduction –
when one plate slides under another
(only oceanic crust can sink)

33. Three Types of Convergent Boundaries

34. Oceanic to Oceanic Crust collision
When two oceanic plates collide one subducts under the other. The one being subducted melts and pops up through the other generating volcanoes.

35. Oceanic Crust to Continental Crust collision
When a continental plate collides with an oceanic plate, the oceanic plate subducts under the continental plate

36. Continental to Continental Crust Collision
When two continental plates collide neither one subducts under the other so you get very high mountains but no volcanoes.

37. Transform Boundaries

38. Earthquakes