1. EARTH'S DYNAMICS

2. The Earth’s Crust Four layers of the Earth:
Core: the solid inner core of the Earth
Outer core: liquid core rich in iron
Mantle: partly solid partly molten magma
Crust: thin, rigid crust of land

3. The Earth’s Crust

4. Plate Tectonics
The Earth’s crust is divided into rigid, slow moving plates
The plates are floating on the Earth’s mantle
Plates move with the current of magma
The movement of these plates build mountains and valleys

5. The Theory of Plate Tectonics
The “theory of plate tectonics” was developed by a German Scientist named Alfred Wegener
He was a polar researcher, geophysicist
and meteorologist.
His hypothesis was controversial
and not widely accepted until the 1950s

6. World Plates

8. Forces Beneath the Crust
The Current of the magma moves the Earth’s Crust
Volcano: opening in the crust of the Earth where lava flows
Movement of magma can break or bend the crust
Fold: layers of rock are folded
Fault: layers of rock break (cause of earthquakes)

10. PLATE BOUNDRY ZONES

11. Plate Boundaries / Zones
Three types of plate boundaries:
Divergent: plates moving away from each other
Convergent: plates moving towards each other
Conservative (transform): plates sliding past each other

12. Divergent
Mid Atlantic Ridge is an example of divergent forces or sea-floor spreading
                                            

13. Convergent
Subduction Zone: a tectonic plate collides with another plate forcing the lighter plate into the mantle

14. Conservative (Transform)
Faults slip past each other causing earthquakes
                                           

17. CONTINENTAL DRIFT

18. Continental Drift
200 million years ago, the continents were locked together in a single land mass called Pangea
Pangea broke into two supercontinents named Laurasia and Gondwanaland

19. EROSION

20. Erosion Erosion is the wearing away of land
Rock weathering: the process that breaks up rock (sediment is small particles of rock)
Water: most powerful force of erosion (V- canyons and U-canyons)

21. Erosion Continued.. Wind: transports light sediment Glaciers:
sheet glaciers: ice sheets that cover large areas pressing outwards
Mountain glaciers: small ice sheets covering mountains flowing downhill