Plate TectonicsPlate Tectonics

Plate BoundariesPlate Boundaries

Heat TransferHeat Transfer

Three types- Three types-

1.1.ConductionConduction

2.2.RadiationRadiation

3.3.ConvectionConvection

Heat transferHeat transfer

1.1. ConductionConduction – heat energy transfer between objects by – heat energy transfer between objects by

direct contact; touching direct contact; touching (solid)(solid)

2.2. RadiationRadiation – heat energy transfer through – heat energy transfer through space (‘air’)space (‘air’); ;

in the form of ‘short waves’in the form of ‘short waves’

3.3. ConvectionConvection – heat energy transfer by movement of air – heat energy transfer by movement of air

or a or a ‘fluid’ ‘fluid’ by circular movement of “convection circular movement of “convection

currents”currents”

Convection CurrentsConvection Currents

Convection Currents in the Mantle

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

Convection Currents in the Mantle

Forces Between Plates• Tension – two plates pulling apart

• Compression – two plates pressing into each other

• Shearing - two plates sliding/grinding past each other.

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

Plate BoundariesTENSION: Divergent boundaries

Within a continent – African Rift, Within a continent – African Rift, aka Red Seaaka Red Sea

Within an ocean – Mid-Ocean RidgeWithin an ocean – Mid-Ocean Ridge

Progression of a Progression of a Divergent BoundaryDivergent Boundary

Plate BoundariesPlate Boundaries

COMPRESSION: COMPRESSION:

Convergent BoundaryConvergent Boundary

Two plates moving toward each other; Two plates moving toward each other; the behavior/results depend on the the behavior/results depend on the typetype of crust… of crust…

Ocean – ContinentOcean – Continent convergent boundary – subduction convergent boundary – subduction zone (destruction of crust), zone (destruction of crust), volcanic mountain chainvolcanic mountain chain

Plate BoundariesPlate Boundaries (convergent boundary) (convergent boundary)

Continent – Continent convergent boundary - construction (yes construction) of crust, mountains

Plate Boundaries (convergent boundary)

Plate Boundaries (convergent boundary)

Ocean – Ocean convergent boundary – subduction zone, (destruction of crust), volcanic island arc

Plate BoundariesPlate Boundaries(Transform Boundary)(Transform Boundary)

Transform boundary - Shearing

• Two plates sliding / grinding past each other

Plate BoundariesPlate Boundaries(Transform Boundary)(Transform Boundary)

Plate BoundariesPlate Boundaries(Transform Boundary)(Transform Boundary)