Plate Boundary Notes

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

Plate Boundaries

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

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!!!!”

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

Convergent boundary SUBDCUTION Zone Sketch:

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

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?

Convergent Boundary COLLISION Zone Sketch:

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

Example: Great Rift Valley, Africa

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

Example: Mid-Atlantic Ridge

Divergent Boundary Sketch:

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

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

Example: San Andreas Fault Where is it?