1. The Earth’s Crust in Motion…
Plate Tectonics
The Earth’s Crust in Motion…

2. Earth’s Structure Crust Mantle Inner Core Core Outer Core Lithosphere
(about miles thick)
Mantle
(about 1,790 miles thick)
Inner Core
(about 750 miles thick)
Core
Outer Core
(about 1,410 miles thick)
Using a laser pointer, briefly highlight and describe the layers of the earth’s interior. Also highlight the fact that the earth has oceanic and continental crust.
Lithosphere
(crust and upper mantle) broken into tectonic plates

3. The Theory of Plate Tectonics
In 1910 Alfred Wegener begins to wonder…
What’s the relationship
between the continents?
Perhaps all these pieces used to be connected.
He develops the theory of Continental Drift -
the belief that continents are slowing moving over
the Earth’s surface
300 million years ago…
Ask the students to look closely at the map. “What does it remind you of?” When ‘puzzle’ is suggested introduce first line. Click on the image of Wegener for the hyperlink to USGS while discussing who he was. Continue to discuss Wegener’s theory and introduce continental drift definition.

4. Pangea The Supercontinent
Discuss the theory of Pangea and show animation (click on link).
Tens of Millions of years!

5. How does it work? Plates – pieces of the lithosphere
Plates fit closely together along cracks called Plate Boundaries
Plate movement is caused by convection currents in the mantle
Plates move at a rate of a few centimeters a year
Explain that the lithosphere is broken into pieces called plates. The place where the pieces fit together are the boundaries. Using a laser pointer, explain the theory that plate movement is caused by convection currents in the mantle.

6. We live here
Ask the students to look closely at the map. “What does it remind you of?” When ‘puzzle’ is suggested introduce first line. Click on the image of Wegener for the hyperlink to USGS while discussing who he was. Continue to discuss Wegener’s theory and introduce continental drift definition.

7. How Plates Move Divergent Convergent Transform Move away from
each other
Convergent
Move toward
Transform
Slide past
Define each term. Have the students as a class mimic the movement of divergent, convergent, and transform boundaries using their hands. Use the hyperlinks as visuals while discussing each type of plate boundary.

8. Divergent

9. Convergent

10. Transform

11. A Divergent B Convergent C Transform
plates are moving apart
new crust is created
Magma is coming to the surface
plates are coming together
crust is returning to the mantle
plates are slipping past each other
crust is not created or destroyed

12. A Divergent B Convergent C Transform
Continental crust
 rift valley
Oceanic crust  mid-ocean ridge
2 continental plates  mountain range
Plates move against each other
Stress builds up
Stress is released
earthquake
2 oceanic plates or
oceanic + continental
subduction

13. The Big Picture
Remind students to look for their assigned boundaries and write down information to describe them.