1. Unit 2E B
Plates of Earth

2. 4. Earthquakes

3. A shaking of the surface of Earth when the plates of Earth move
About one million earthquakes happen every year
Vocabulary
earthquake
A shaking of the surface of Earth when the plates of Earth move

4. Most earthquakes happen under the ocean or are too small to notice

5. In a strong earthquake the ground can shake violently and even split open

6. Remember: a fault is the place where two plates meet
Most earthquakes are caused by the sudden movement of plates along a fault
Romania Jan
Remember: a fault is the place where two plates meet

7. Rocks in the crust break and move apart at a point called the focus
When the plates move, the crust near the fault is squeezed and stretched
Click image for focus points
Rocks in the crust break and move apart at a point called the focus

8. Vocabulary
focus
The point where rocks in the crust break and move apart during an earthquake

9. The focus is usually less than 25 miles below the surface of Earth

10. Near epicenter of an earthquake is where the most damage occurs
Vocabulary:
epicenter
The place on the surface of Earth directly above the focus of an earthquake

11. If the focus of an earthquake is under the ocean floor, a tsunami is produced
Vocabulary:
tsunami
A giant wave produced when the focus of an earthquake is under the ocean floor

12. This huge wall of water moves across the ocean at high speed
It causes great damage when it reaches land

13. Many earthquakes take place in an area known as the Ring of Fire
Volcanoes are also common in this area

14. This chain of earthquake zones and volcanoes circles the Pacific Plate