1. Plate Tectonics

2. Main Ideas The Earth’s crust is made up of plates
These plates move slowly
Plates move because of circulating molten rock in the Earth’s mantle

4. Types of Plate Boundaries
Divergent: plates move away from each other
Convergent: plates move toward each other
Transform: plates slide past one another

5. Divergent Boundaries
Mid-ocean ridges are examples of where plates move away from each other.
Lava flows up from the mantle and creates new sea floor.
“Seafloor spreading” is another term used to describe divergent boundaries.

6. Divergent Plates

7. The Mid-Atlantic Ridge is an example of a divergent plate boundary.

8. The Red Sea: A New Ocean is Born

9. A divergent boundary runs right through the middle of the Red Sea and is splitting it apart. This allows sea water to flow in from the Indian Ocean.

10. Convergent Boundaries
Where two plates collide, the more dense plate (oceanic) will be pushed under the less dense plate (continental).
This process is called subduction.
The plate that is subducted gets destroyed (melted).
Deep-sea trenches occur at subduction zones

11. Convergent Plates

12. Deepest spot in the oceans – 11,033 m deep

13. Transform Boundaries
When two plates slide past each other, the friction often triggers earthquakes.
An example is the San Andreas Fault in California.