Don

1
Dont Break Your Plate

• Notes on Plate Tectonics

2
Key Points

• Plate tectonics accounts for several features on
  the earths 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 Earths core heats up
  it becomes less dense and rises while the cooler
  rock near the surface sinksmantle convection
• Moves plates a few centimeters each year

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• http//www.classzone.com/books/earth_science/terc/
  content/visualizations/es0804/es0804page01.cfm?cha
  pter_novisualization

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Three types of plate boundaries

1. Divergent
2. Transform
3. Convergent

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Divergent Boundaries

• New crust is created as two plates pull away from
  each other
• If two oceanic plates, the ocean will grow
  widerseafloor 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
  Earths interior as one plate sinks below another
  platesubduction zones
• Mountains and volcanoes often form here

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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

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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 placeleads to earthquakes

12
Which of the following is not a plate boundary?

1. Divergent
2. Convergent
3. Transvergent
4. Transform

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Where are mountains and volcanoes often found?

1. Subduction Zones
2. Mid-ocean Ridge
3. Seafloor Spreading

14
Which of the following is NOT a type of
convergent boundary?

1. Ocean-ocean
2. Continental-ocean
3. Continental-continental
4. Continental-sea

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This type of boundary is two plates pulling away
from each other to create new crust.

1. Convergent
2. Divergent
3. Transform

16
This boundary type has two plates sliding past
each other

1. Convergent
2. Divergent
3. Transform

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This is where one plate sinks below another,
melting back into the mantle.

1. Transform boundary
2. Subduction zone
3. Mid-ocean ridge
4. Divergent boundary

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How do the tectonic plates move?

1. Convection currents in the mantle
2. Convection currents in the inner core
3. Conduction in the mantle