Plate

8th Grade Science

With the marvelous Mr. Christine

Tectonics

What is Plate Tectonics?

• Remember what a theory was?– A scientific Theory is a well tested concept

that explains many observations.• So, the Theory of Plate Tectonics is …

– Pieces of the Earth’s Lithosphere are in slow, constant motion, driven by convection currents in the mantle.

Remember the Interior of the Earth or else …

What a full plate

What is a plate?

• A plate is a section of the lithosphere that slowly moves over the asthenosphere, carrying pieces of oceanic and continental crust.

Remember Convection

• The transfer of heat by movement of a fluid. • This causes plate movement

Plate Boundaries

• The Earth is broken up into many plates

• So, the plates meet at areas called boundaries

• Plate Boundaries: Where edges of world’s plates meet.

• 3 types– Divergent, Convergent, and Transform

Divergent Boundary

• Divergent Boundary: Place where two plates move apart or diverge.

• Ocean = Mid Ocean Ridge• Land = Rift Valley

Divergent Boundary

Convergent Boundary

• Convergent Boundary: Place where two plates come together or converge and collide.

• Remember Subduction?

Convergent Boundary

Transform Boundary

• Transform Boundary: Place where two plates slip past each other moving in opposite directions.

• Earthquakes occur but no crust is destroyed

San Andreas Fault (Transform)

All Boundaries

Pangea to Future