1. Ch. 8 Earthquakes Study Guide Answers

2. 1. • In January of 2001, Kutch, in the Indian state of Gujarat, was the epicenter of a 30-second earthquake that registered 6.9 on the Richter scale. Using the table above, this earthquake would be described as _____________. • Strong

3. 2. • Look at the trends of earthquakes in the table above. Generally, based on observations of worldwide earthquakes since 1900, with each step down in earthquake magnitude, the number of earthquakes per year is about _____________. • 5-10 times greater

4. 3. • According to the table, earthquakes that register between 6.0 and 6.9 on the Richter scale occur approximately __________ times a year worldwide. • 120

5. 4. • In June 1994, an earthquake in Northern Bolivia that measured 8.2 on the Richter scale was felt all the way from South America to Canada. According to the table, what type of damage near the epicenter would have occurred with an earthquake of this intensity? • Great damage

6. 5. • What kind of deformation leads to earthquakes? • Elastic deformation

7. 6. • If a planet has a liquid core, then S waves ________________________________. • Can’t pass through the core

8. 7. • _____________________ motion causes a normal fault. • Divergent

9. 8. • The strongest earthquakes usually occur ________________________.(where) • Near convergent boundaries

10. 9. • Strike-slip faults are prominent along _____________________________ plate boundaries. • Transform

11. 10. • The footwall moves up relative to the hanging wall in _______________________ faults. • Normal

12. 11. • Most earthquakes occur along or near the edges of the Earth's _________________________________. • Tectonic plates

13. 12. • If a seismograph detects S waves shortly after it detects P waves, then the earthquake was ________________________________. • Nearby

14. 13. • ______________________ motion occurs where two tectonic plates slip past each other. • Transform

15. 14. • Shallow, moderate earthquakes are produced along ______________________________ faults. • Strike-slip

16. 15. • Studying earthquake waves currently allows seismologists to do ______________________________. • Determine when and where the earthquake started and learn about he earth’s interior

17. 16. • Which type of seismic wave can travel through solids, liquids, and gases? • P wave

18. 17. • Which seismic waves do the greatest damage? • Surface

19. 18. • Which type of seismic wave cannot travel through liquids? • S wave

20. 19. • Which type of seismic wave is also called a secondary wave? • S wave

21. 20. • Which type of seismic wave is also called a primary wave? • P wave

22. 21. • Which type of seismic wave is the most destructive? • Surface wave

23. 22. • How much more energy is released by an earthquake with a magnitude of 3.0 than by an earthquake with a magnitude of 2.0? • 10 times more energy

24. 23. • Seismologists find an earthquake's start time by comparing seismograms and noting the difference in arrival times of __________________________________. • P and S wave

25. 24. • A(n) _____________________________ is a weight placed in the roof of a building that moves to counteract the building's movement during an earthquake. • Mass damper

26. 25. • _____________________________ absorb seismic waves during an earthquake, preventing them from traveling through the building. • Base isolators