1. Plate Tectonics

2. Plate Boundaries Heat Transfer Three types- Conduction Radiation
Convection

3. Heat transfer
Conduction – heat energy transfer between objects by direct contact; touching (solid)
Radiation – heat energy transfer through space (‘air’); in the form of ‘short waves’
Convection – heat energy transfer by movement of air or a ‘fluid’ by circular movement of “convection currents”

4. Convection Currents

5. Convection Currents in the Mantle
Convection Currents – within the asthenosphere (and perhaps the upper mantle), convection currents are the driving force of plate movement.

6. Convection Currents in the Mantle

7. Forces Between Plates Tension – two plates pulling apart
Compression – two plates pressing into each other
Shearing - two plates sliding/grinding past each other.

8. Plate Boundaries (divergent boundary)
TENSION FORCE: Divergent boundary
Two plates moving away from each other creating new crust
within oceanic area – sea floor spreading
within continental area – rift valley

9. Within a continent – African Rift, aka Red Sea
Plate Boundaries
TENSION: Divergent boundaries
Within an ocean – Mid-Ocean Ridge
Within a continent – African Rift, aka Red Sea

10. Progression of a Divergent Boundary

11. Plate Boundaries COMPRESSION: Convergent Boundary
Two plates moving toward each other; the behavior/results depend on the type of crust…

12. Plate Boundaries (convergent boundary)
Ocean – Continent convergent boundary – subduction zone (destruction of crust), volcanic mountain chain

13. Plate Boundaries (convergent boundary)
Continent – Continent convergent boundary - construction (yes construction) of crust, mountains

14. Plate Boundaries (convergent boundary)
Ocean – Ocean convergent boundary – subduction zone, (destruction of crust), volcanic island arc

17. Plate Boundaries (Transform Boundary)
Transform boundary - Shearing
Two plates sliding / grinding past each other

18. Plate Boundaries (Transform Boundary)

19. Plate Boundaries (Transform Boundary)