1. Chapter 13

2. sound light seismic heat
1. An earthquake is caused by sudden release of ___ waves when rocks fail along a geologic fault.
sound
light
seismic
heat

3. 2. The point within Earth where seismic waves originate is called the:
focus.
epicenter.
fault scarp.
fold.

4. 3. Most earthquakes are ______.
shallow focus (<70 km)
intermediate focus (70–350 km)
deep focus (350–670 km)
very deep focus (>670 km)
Earthquake foci are evenly distributed with depth

5. 4. The first seismic wave detected by a seismomograph is a:
P wave.
S wave.
Love wave.
tidal wave.

6. 5. On the seismograph below, which deflection represents the arrival of the P waves?

7. 6. On the seismograph below, which deflection represents the arrival of the S waves?

8. 7. Amplitude is measured as the height of deflection ____.B A B C D

9. 8. Which of these are body waves?
P waves
S waves
Love waves
Rayleigh waves
A and B are correct.
All of the above.

10. 9. Which type of body wave travels the fastest?
S wave
P wave
They travel at the same speed.

11. 10. Which body wave travels through solids and liquids?
S wave
P wave
They both do.

12. 11. An earthquake with a magnitude of 5 is ___ times as powerful as one with magnitude 4.
0.25 2 10
100

13. 12. Which is an index of earthquake shaking intensity?
Richter scale
moment magnitude
modified Mercalli index
All of these measure shaking.

14. 13. Modified Mercalli intensity does not linearly decrease away from the epicenter because local shaking intensity varies with:
type of rock in the local bedrock.
presence or absence of faults in the local bedrock.
thickness of the local bedrock.
All of the above.

15. 14. Where would be the least likely place to experience earthquakes?
convergent plate boundaries
divergent plate boundaries
transform plate boundaries
far from plate boundaries
earthquakes are equally likely at all locations.

16. subduction convergent
15. The deepest earthquakes are associated with what type of tectonic boundary?
divergent
transform
collision convergent
subduction convergent

17. 16. What type of earthquakes occur along mid-ocean ridges?
shallow focus (<70 km)
intermediate focus (70–350 km)
deep focus (350–670 km)
very deep focus (>670 km)
All depths occur here.

18. 17. Sea waves initiated by seismic energy from earthquakes are called:
tidal waves.
tsunamis.
liquefaction waves.
current waves.

19. 18. Earthquake forecasting is difficult to do with a high degree of precision because:
individual faults within a regional fault system have different rupture probabilities.
indicators of strain buildup are not direct indicators of rupture timing.
differentiating foreshocks, mainshocks, and aftershocks is not always possible until after the fact.
a swarm of small earthquakes can, but do not always, herald a larger event.
All of the above.

20. fire ground movement liquefaction All of the above. B and C only
19. If you were a saber-toothed cat, which of the following earthquake effects could impact you?
fire
ground movement
liquefaction
All of the above.
B and C only

21. on a former landfill site at the base of a mountain
20. If you wanted to build a multimillion dollar home in California, where should you put it?
on a sea cliff
on a former landfill site
at the base of a mountain
in the middle of a flat area