1. Plate Tectonics
What evidence do scientists have to support the fact that the Earth’s crust is continuously moving?

2. Plate Tectonics
The theory that describes how tectonic plates move and shape Earth’s surface
Tectonic plates are huge pieces of crust that fit together at their edges to cover Earth’s surface.

3. About 12 plates exist on Earth

4. Earth’s Interior Crust – Rigid outer shell of Earth Mantle
Oceanic and Continental Crust
Mantle
Upper mantle is partially molten
Lower mantle is rigid (solid)

5. Earth’s Interior
Core
Outer core is molten iron, source of Earth’s magnetic field
Inner core is solid, Iron and Nickel

6. Plate Boundaries Divergent Boundary Convergent Boundary
Transform Boundary

7. Divergent Boundary Two tectonic plates move apart from each other
Rift valleys – long narrow depressions
Rift valley in East Africa

8. Convergent Boundary
Two tectonic plates move towards each other (come together)
Oceanic Plates are more dense
Continental Plates are less dense

9. Subduction
Process when one tectonic plate slips beneath another plate

10. Oceanic – Oceanic
Subduction Occurs
Deep Sea Trenches (Marianas Trench)

11. Oceanic – Continental
Subduction Occurs
Trench and Volcanic Arch (Peru – Chile Trench)

12. Continental – Continental
Mountain Building
Himalayas
Aleutian Islands

13. Transform Boundary Region where two plates slide past each other
Earthquakes occur at transform boundaries
San Andreas Fault in San Francisco

14. San
Andreas
Fault