1. Notes on Plate Tectonics
Don’t Break Your Plate
Notes on Plate Tectonics

2. Key Points
Plate tectonics accounts for several features on the earth’s surface
Seafloor spreading
Subduction zones
Earthquakes
Volcanoes
Mountain ranges
Plates move due to mantle convection

3. How do plates move?
The plates of the Earth float on top of the aesthenosphere
When mantle rock near the Earth’s core heats up it becomes less dense and rises while the cooler rock near the surface sinks—mantle convection
Moves plates a few centimeters each year

5. Three types of plate boundaries:
Divergent
Transform
Convergent

6. Divergent Boundaries
New crust is created as two plates pull away from each other
If two oceanic plates, the ocean will grow wider—seafloor spreading
If two continental plates, creates a rift that will form two different land masses
Fills with water in the rift

7. Transform Boundaries
Two plates are sliding horizontally past one another
Sometimes known as faults
Earthquakes take place along these boundaries

8. Convergent There are 3 types of convergent boundaries:
Oceanic-oceanic convergence
Continental-continental convergence
Oceanic-continental convergence
Crust is destroyed and recycled back into the Earth’s interior as one plate sinks below another plate—subduction zones
Mountains and volcanoes often form here

9. Oceanic-Oceanic Convergence
When one oceanic plate subducts under another:
A deep ocean trench is formed
Creates undersea volcanoes that over time, can build up to form volcanic islands

10. Continental-Continental Convergence
When two continental plates meet head-on, neither one subducts.
Plates tend to buckle and rise up/sideways to form mountain ranges
i.e. Himalayan Mountains

11. Oceanic-Continental Convergence
When an oceanic plate subducts below a continental plate:
The continental plate rises to form mountains
When oceanic plate sinks deep, some pieces break off and get locked in place—leads to earthquakes

12. Which of the following is not a plate boundary?
Divergent
Convergent
Transvergent
Transform 20

13. Where are mountains and volcanoes often found?
Subduction Zones
Mid-ocean Ridge
Seafloor Spreading
20 Seconds
Remaining

14. Which of the following is NOT a type of convergent boundary?
Ocean-ocean
Continental-ocean
Continental-continental
Continental-sea 20

15. This type of boundary is two plates pulling away from each other to create new crust.
Convergent
Divergent
Transform 20

16. This boundary type has two plates sliding past each other
Convergent
Divergent
Transform 20

17. This is where one plate sinks below another, melting back into the mantle.
Transform boundary
Subduction zone
Mid-ocean ridge
Divergent boundary 20

18. How do the tectonic plates move?
Convection currents in the mantle
Convection currents in the inner core
Conduction in the mantle 20