Transcript Plate Boundaries

Plate Tectonics
Plate Boundaries
Heat Transfer
Three types…
Conduction
Radiation
Convection
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 within a ‘fluid’; circular
movement of “convection currents”
Convection 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.
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: Divergent boundary
Two plates moving away from each
other creating new crust
 within oceanic area – sea floor
spreading
 within continental area – rift valley
Plate Boundaries
TENSION: Divergent boundaries
Within a continent –
African Rift, aka Red Sea
Within an ocean –
Mid-Ocean Ridge
Progression
of a
Divergent
Boundary
Plate Boundaries
COMPRESSION:
Convergent Boundary
Two plates moving toward each
other; the behavior/results
depend on the type of crust…
Plate Boundaries
(convergent boundary)
Ocean – Continent convergent boundary
– subduction zone (destruction of crust),
volcanic mountain chain
Plate Boundaries
(convergent boundary)
 Continent – Continent convergent
boundary - construction (yes
construction) of crust, mountains
India into Asia
Plate Boundaries
(convergent boundary)
 Ocean – Ocean convergent boundary –
subduction zone, (destruction of crust),
volcanic island arc
Plate Boundaries
(Transform Boundary)
Shearing Transform
boundary
 Two plates
sliding /
grinding past
each other
Plate Boundaries
(Transform Boundary)
Most transform boundaries are associated with
‘fracture zones’ along the mid-ocean ridge
Convection Currents in the
Mantle
Plate Boundaries
(Transform Boundary)
Boundaries for lab
~ THE END ~
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