1. Earth Shakes, Rattles, and Rolls
Plate Tectonics
Earthquakes

2. What is the relationship between the earth’s plates, volcanoes, and earthquakes?

3. Plates

4. Earthquakes

5. Volcanoes

6. Let’s look at those maps again.

7. Plates
Volcanoes
Earthquakes

8. Earthquakes and Volcanoes are found
where plates meet.

9. Evidence Wegener used to support theory of continental drift:
Continents fit like a puzzle
Fossil evidence
Rocks were similar in Africa and South America
Evidence Antarctica once had a tropical climate
SUPERCONTINENT PANGAEA

10. How did geologists explain how the earth’s plates moved?
Continental Drift

11. To see how geologists believe the plates moved go to the sites below.
Notice the Atlantic Ocean seafloor spreading (Handout).
More!
Seafloor spreading

12. Layers of the Earth Label the following: Trench Ridge Crust Mantle
Outer core
Inner core
Use p. 92 (Fig. 10.5) to help!

13. Convection currents in the magma move the earth’s crust.

14. Convection currents in the Earth's mantle are what drive plate motions
Convection currents in the Earth's mantle are what drive plate motions. Convection currents are driven by the simple fact that hot things (such as gases and liquids) rise while cool things fall.

15. VIDEO

16. Convection currents in action
Convection currents in action! At left, two animal cookies represent two of the Earth's tectonic plates. At right, the two plates have moved apart, much like what happens at a divergent margin. The chocolate pudding represents the Earth's mantle. The heat source beneath the pot created convection cells in the chocolate pudding. Think of the cookie on the left as South America, and the cookie on the right as Africa. Over time they have moved apart. You'll see this again.

17. How do we measure the intensity of an earthquake?
Earthquakes
How do we measure the intensity of an earthquake?

18. epicenter
The point on the surface of Earth that is right above the focus of an earthquake                                                 

19. or the strength of an earthquake
Seismograph measures
Magnitude
or the strength of an earthquake

20. Seismograph records energy waves of the earth

21. Richter Scale Earthquake Magnitudes Effects
Less than Generally not felt 
Rarely causes damage.
Under Slight damage to well-designed buildings.  
Destructive to about 100 kilometers across
Major earthquake. Serious damage over larger areas. 
8 or greater Great earthquake.

22. Each number is 10X stronger than the previous number.
How much stronger is the 3 than the 1?
100 Times
How much stronger is the 8 than the 1?
10,000,000
Write the number in scientific notation.
106

23. Richter Magnitude
Number of Earthquakes per year
1.0 to 3.9
900,000 +
6200
800
226 18
Less than 2

24. Can you think of a recent earthquake?
Haiti

27. Earthquakes in the ocean cause
Tsunamis

28. Tsunamis
30’ Wall of Water
Destruction