1. Introduction to Earthquakes

2. Vocabulary Seismology: the study of earthquakes
Seismologist: person who studies earthquakes

3. What are they?
Earthquakes: a shaking of the Earth caused by tectonic plate movement
Occur at the surface or deep underground
Earthquake zones: places where a lot of faults are located

4. Where do earthquakes occur?
Remember: plates move in different directions and at different speeds
They interact at faults

5. Where do earthquakes occur?
Faults- breaks in the Earth’s crust due to sliding tectonic plates
3 types: reverse, normal, strike-slip
Some earthquakes occur in faults in the middle of plates, but most occur at edges

6. Normal Fault
Divergent boundary

7. Reverse Fault
Convergent boundary

8. Strike-Slip Fault
Transverse boundary

9. When plates move, The rocks undergo deformation
2 types: plastic deformation and elastic deformation

10. Plastic Deformation Rocks bend like a piece of molded clay
Does not cause earthquakes

11. Elastic Deformation
Rocks stretch to a point, then break. When they break, they release energy
Elastic rebound: when the pieces return to their unstretched shape. Causes earthquakes!