6th grade quiz: EARTHQUAKES Study Sheet 1. What does the term “plastic” mean when describing the upper mantle? 2. What is a fault? 3. Describe “stick-slip motion” and tell what it causes. 4. What kind of energy builds up when the crust of two plates are stuck while the upper mantle keeps moving? 5. What is the point below the surface where rock breaks causing an earthquake called? 6. What do we call the point on the Earth’s surface during an earthquake where the seismic waves are the strongest? 7. Where do shallow focus earthquakes occur? 8. Where do deep focus earthquakes occur? 9. What is a “slickensides”? 10. Why is it better to have frequent earthquakes along a transform plate boundary than seldom? 11. Why do aftershocks occur? 12. What is an instrument that measures seismic waves called? 13. How do seismologists locate the epicenter of an earthquake? 14. Which scale rates an earthquake by the size of its seismic waves? 15. Which scale rates the damage suffered by buildings, the ground and people during a quake?