1. Earth Science
Plate Tectonics
Chapter 12

2. The Structure of the Earth

3. The Structure of the Earth

4. The Structure of the Earth
Crust:
solid rock plates which float on the liquid mantle.
Mantle:
thickest layer, fluid, flows like “thick toothpaste”
Outer Core:
liquid, very hot, under fairly high pressure, mostly Fe & Ni.
Inner Core:
solid, under high pressure, mostly Fe.

5. The Structure of the Earth
the rock plates are called “tectonic plates” and they are always in motion.
The reason for this is the mantle’s
CONVECTION CURRENTS
Crust
molten rock near the core heats up and rises. As it reaches the crust it cools and moves back down to the core, creating a circular current.
Liquid
Mantle

6. Tectonic plates

7. The Structure of the Earth

8. The Structure of the Earth

9. The Theory of Plate Tectonics
Describes the idea that the Earth’s outer rigid shell is made up of moving plates
the movement is responsible for volcanoes and earthquakes, mountain building, and ocean ridges.
the plate boundaries have “fault zones” around them where many volcanoes & earthquakes occur.

10. The Theory of Plate Tectonics
there are 3 kinds of faults (plate boundaries)
colliding (moving together) (convergent)
rifting (tearing apart) (divergent)
sliding sideways (transform)

11. Examples: Convergent Boundary Oceanic - Continental

12. Examples: Convergent Boundary Oceanic - Oceanic

13. Examples: Convergent Boundary Continental - Continental

14. Examples: Divergent Boundary

15. Examples: Transform Boundary

16. Assignment
Homework:
Workbook Pages 210, 212, 218, 219