Chapter 8 Earthquakes Essential Questions 1. What is an earthquake? 2. Explain the relationship between epicenter, focus, and faults? 3. What is the cause of earthquakes? 4. Explain the three types of seismic waves? 5. Explain the different types of faults? 6. How are earthquakes measured? 7. What are the environmental concerns associated with earthquakes? 8. What is the internal structure of the earth? 9. How was the internal structure of the earth discovered?