1. Plate Boundary Notes

2. The 3 types of Boundaries:
They can crash together or collide =
= Convergent Boundary
They can move away from each other or divide = Divergent Boundary
They can slide past each other
= Transform Boundary

3. Plate Boundaries

4. 1. Convergent Boundaries
Two types A. SUBDUCTION or B. COLLISION:
Subduction: when one plate is more dense than another, the more dense plate goes underneath the less dense plate. The plate on top is called the overriding plate.
Subduction

5. Convergent Boundaries: Subduction
Subducting plate: plate that goes under the other.
Features that occur at subduction zones: Earthquakes, Volcanoes, Ocean Trench
Remember:
“The Ocean floor is going DOWN!!!!”

6. Example:
Mt. St. Helens- Juan de Fuca plate goes under the North American Plate.
What are some indicators that a volcano might erupt soon?

7. Convergent boundary SUBDCUTION Zone Sketch:

8. Convergent Boundaries, Collision
Collision: when the 2 plates are the same material. When they hit, they both buckle up (this makes mountains).
The two plates have the same density, they buckle up or move up to a higher elevation.
Features that occur at collision zones: Earthquakes & Folded Mountains

9. Example Mt. Everest, Himalayas
They are continuing to collide and gain elevation.
What are some forces of nature that keep Everest from getting much higher?

10. Convergent Boundary COLLISION Zone Sketch:

11. 2. Divergent Boundaries:
When two plates move apart.
Features include the following:
In continents:
Rift Valley, Volcanoes, Earthquakes
Example:
Great Rift Valley, Africa

12. Example: Great Rift Valley, Africa

13. 2. Divergent Boundaries:
In oceans:
Mid-Ocean Ridge, Volcanoes, Earthquakes
Examples: Mid-Atlantic Ridge, Atlantic Ocean

14. Example: Mid-Atlantic Ridge

15. Divergent Boundary Sketch:

17. 3. Sliding/Transform Boundary
When two plates slide past each other.
Features: Earthquakes

18. Example:
California- Pacific Plate slides past the North American Plate at the San Andreas Fault.

20. Example: San Andreas Fault Where is it?