1. Chapter 19 Review
Earthquakes

2. Movement occurs along fractures in rocks when _____.
stress equals the strength of the rocks involved
stress overcomes the strength of the rocks involved
stress is applies to the rocks involved
stress is less than the rocks involved

3. The strain which causes a material to twist is known as
stress
compression
tension
shear

4. The strain which causes a material to pull apart is known as
stress
compression
tension
shear

5. P-waves and S-waves are also known as ____.
surface waves
ground waves
body waves
first waves

6. Which point marks the epicenter of the earthquake?B C D

7. At which point will the most damage as a result of the earthquake occur?B C D

8. What is true about the focus?
It is the point where the most surface damage will occur.
It is the point where the surface waves originate and spread out.
It is the point where the waves are attracted.
It is the point of failure where the waves originate.

9. What keeps the stable part of this seismometer from moving during an earthquake?
inertia
gravity
its mass
its location

10. Which part of the seismometer does not shake during an earthquake?
the frame
the spring
the rotating drum
the pendulum and pen

11. Use the graph to answer the questions.

12. A seismogram is located 4500 miles away from the epicenter of an earthquake. What is the difference in time between when the P-waves reach the seismogram and the S-waves reach the seismogram?
5 1/2 minutes
6 minutes
10 minutes
22 minutes

13. Which type of material would be best to use for construction in an area prone to earthquakes?
Concrete
Brick
Wood
Stone

14. Organize the locations from lowest to highest hazard.
Earthquake History
Strain Buildup Rate A
many earthquakes
slow B
few earthquakes
moderate C
fast D
B, A, D, C
C, D, A, B
A, B, C, D
B, A, C, D

15. Seismologists have assessed a particular area and predict that an earthquake occurs every 17 years in that area. If the last earthquake occurred in 1998, when will the next earthquake most likely occur?
2010
2015
2017
2025

16. Over the past 250 years a city has experienced 23 earthquakes at rather regular intervals. Approximately how often have these earthquakes occurred?
every 50 years
every 10 years
every 100 years
every 5 years

17. A city is located over an active fault, but has not experienced an earthquake for a long period of time. The city is most likely located where?
over a seismic gap
in an area of low recurrence
over minimal strain accumulation
at a location of low seismic risk

18. ____ and the amount of strain released during the last quake are used in earthquake probability studies.
Seismic belts
Strain accumulation
Fault scarps
Tsunamis

19. On a seismometer, vibrations of the ground do not move the ____.
frame
spring
recording drum
suspended mass

20. A ____ fault forms as a result of horizontal compression.
blind
normal
strike-slip
reverse

21. The San Andreas Fault, a result of horizontal shear, is a ____ fault.
blind
normal
strike-slip
reverse

22. The locations of seismic belts are determined by plotting ____.
earthquake epicenters
seismic gaps
earthquake foci
epicentral distances

23. A numerical scale of earthquake magnitude that takes into account the size of the fault rupture is the ____.
Richter scale
modified Mercalli scale
moment magnitude scale
epicentral distance scale

24. formation of fault scarps. surface ruptures.
Deaths associated with earthquake deaths in sloping areas can result from
tsunamis.
landslides.
formation of fault scarps.
surface ruptures.

25. Does not pass through Earth’s liquid outer core
surface wave
P-wave
S-wave

26. Does not pass through Earth’s interior at all
surface wave
P-wave
S-wave

27. Squeezes and pulls rocks in same direction as the save travels
surface wave
P-wave
S-wave

28. Is refracted by Earth’s core
surface wave
P-wave
S-wave

29. Absence of this kind of waves results in a shadow zone
surface wave
P-wave
S-wave

30. Causes structures to sink into the ground
Liquefaction of soils
Collapse of higher, intact floors onto ground floors
Vertical motions of the seafloor during an earthquake
Natural sway of intermediate buildings equals the period of vibration of the earthquake

31. Type of structural failure called “pancaking”
Liquefaction of soils
Collapse of higher, intact floors onto ground floors
Vertical motions of the seafloor during an earthquake
Natural sway of intermediate buildings equals the period of vibration of the earthquake

32. Type of structural failure related to building height
Liquefaction of soils
Collapse of higher, intact floors onto ground floors
Vertical motions of the seafloor during an earthquake
Natural sway of intermediate buildings equals the period of vibration of the earthquake

33. Results in a tsunami Liquefaction of soils
Collapse of higher, intact floors onto ground floors
Vertical motions of the seafloor during an earthquake
Natural sway of intermediate buildings equals the period of vibration of the earthquake

34. Section of an active fault that has not experienced a significant earthquake for a long time
modified Mercalli scale
magnitude
stress
fault
tsunami
strain
seismic gap
surface wave

35. Rates earthquake intensity
modified Mercalli scale
magnitude
stress
fault
tsunami
strain
seismic gap
surface wave

36. Wave generated by vertical motions of the seafloor
modified Mercalli scale
magnitude
stress
fault
tsunami
strain
seismic gap
surface wave

37. Seismic wave that causes the ground to move in two directions
modified Mercalli scale
magnitude
stress
fault
tsunami
strain
seismic gap
surface wave

38. Forces per unit area acting on a material
modified Mercalli scale
magnitude
stress
fault
tsunami
strain
seismic gap
surface wave

39. Measure of the energy released by a quake
modified Mercalli scale
magnitude
stress
fault
tsunami
strain
seismic gap
surface wave

40. Deformation of materials in response to stress
modified Mercalli scale
magnitude
stress
fault
tsunami
strain
seismic gap
surface wave

41. Fracture in rock along which movement occurs
modified Mercalli scale
magnitude
stress
fault
tsunami
strain
seismic gap
surface wave

42. Most rocks that exist in Earth’s crust are brittle but become ductile at great depths where temperatures are cooler.
True
False

43. Seismic belts are relatively narrow and tend to follow tectonic plate boundaries.
True
False

44. If two seismic stations receive data from an earthquake, the quake’s location can be computed if P-waves, S-waves, and surface waves have been received.
True
False

45. The fact that a significant earthquake has not occurred within a seismic gap indicates that an earthquake is more likely to occur in the near future.
True
False

46. On a seismometer, the suspended mass tends to stay at rest during an earthquake because of inertia.
True
False

47. A seismometer is designed so that its frame vibrates with the movement of the ground.
True
False

48. The amount of damage done to structures as a result of an earthquake is the earthquake’s magnitude.
True
False

49. S-waves are refracted, or bent, by Earth’s outer core.
True
False