Which of the following describes the build up and release of stress during an earthquake?

the Modified Mercalli Scale
the elastic rebound theory
the principle of superposition
the travel time difference


The amount of ground displacement in a earthquake is called the _________ .

epicenter
dip
slip
focus


The point where movement occurred which triggered the earthquake is the _______ .

dip
epicenter
focus
strike


Which of the following sequences correctly lists the different arrivals from first to last?

P waves ... S waves .... Surface waves
Surface waves ... P waves .... S waves
P waves ... Surface waves ... S waves
S waves ... P waves .... Surface waves


How do rock particles move during the passage of a P wave through the rock?

back and forth parallel to the direction of wave travel
back and forth perpendicular to the direction of wave travel
in a rolling circular motion
the particles do not move


Detailed studies of what earthquake allowed researchers to develop the elastic rebound theory?.

the 1906 San Francisco earthquake
the 1964 Anchorage, Alaska earthquake
the 1755 Lisbon, Portugal earthquake
the 1985 Mexico CIty earthquake


How many seismograph stations are needed to locate the epicenter of an earthquake?

1
2
3
4


Earthquakes can occur with _________ faulting.

normal
reverse
thrust
all of these


Approximately what percentage of earthquakes occur at plate boundaries?

25%
50%
75%
90%


Which type of faulting would be least likely to occur along the mid-Atlantic ridge?

normal
reverse
transform
all of these could occur


How often do magnitude 8 earthquakes occur?

about 5 to 10 times per year
about once a year
about every 5 to 10 years
about every 50 to 100 years


The bulk modulus measures ______________.

the resistance to flow of a liquid
the resistance to change in color
the resistance to change in volume
the resistance to change in shape


The shear modulus measures _____________ .

the resistance to flow of a liquid
the resistance to change in shape
the resistance to change in volume of a liquid
the resistance to change in volume of a solid


If only density increases with increasing depth within the Earth, the velocity of a P wave should ___________ .

stay the same
increase
decrease


If a P wave were to go from a solid to a liquid - what would happen to its velocity?

stay the same
increase
decrease to 0.0
decrease


If an S wave were to go from a solid to a liquid - what would happen to its velocity?

stay the same
increase
decrease to 0.0
decrease


Which boundary marks a change from 100% solid to 100% liquid?

mantle ... outer core
lithosphere ... asthenosphere
crust ... mantle
none of these


Body waves consist of the:

P waves only
S waves only
P and S waves
Surface waves


With increasing travel time the difference in arrival times between the P and the S waves _________

increases
decreases
stays constant
none of the above


Earthquake A has a Richter magnitude of 7 as compared with earthquake B's 6. The amount of ground motion is one measure of earthquake intensity.

A is 10X more intense than B
A is 1000 more intense than B
Richter magnitude does not measure intensity
B is 0.01X as intense than A


In general, the most destructive earthquake waves are the __________ .

P waves
S waves
Surface waves
Q waves


Where is the focus with respect to the epicenter:

directly below the epicenter
directly above the epicenter
in the P wave shadow zone
in the S wave shadow zone




Point A, where slip initiated during the earthquake, is called the ________.

dip
epicenter
focus
scarp


Point B is called the earthquake ________.

dip
epicenter
focus
scarp


Point C is called the _________

epicenter
fault scarp
seismic wave
dip of the earthquake


What type of faulting is illustrated in this diagram?

normal
reverse
thrust
abnormal




What causes the up-and-down wiggles on the seismogram show above?

variations in air pressure
ground vibrations
tsunami waves
electromagnetic pulses


Which set of waves are probably the surface waves?

A
B
C
They are all surface waves


Which set of waves are the P waves?

A
B
C
They are all P waves


Which set of waves are the S waves?

A
B
C
They are all S waves


The difference in arrival times between which pair of waves can be used to determine the distance to the epicenter?

A and C
A and B
None of the above


How do rock particles move during the passage of a P wave through the rock?

back and forth parallel to the direction of wave travel
perpendicular to the direction of wave travel
in a rolling elliptical motion
in a rolling circular motion


How do rock particles move during the passage of a S wave through the rock?

back and forth parallel to the direction of wave travel
perpendicular to the direction of wave travel
in a rolling elliptical motion
in a rolling circular motion


Who developed the procedure used to measure the size of an earthquake?

Charles Richter
Edward Sheridan
James Hutton
Art Smith


The moment magnitude of an earthquake depends on all of the following except __.

the area of the fault break
the rigidity of the fault
the slip on the fault
the type of faulting


Which of the following measures an earthquake's intensity based on the observed effects on people and structures?

Richter scale
Modified Mercalli scale
the Centigrade scale
the moment magnitude scale


Shallow earthquakes, less than 20 km deep, are associated with _______.

convergent plate boundaries
divergent plate boundaries
transform plate boundaries
all of these


What type of faulting would be most likely to occur along transform faults?

normal faulting
reverse faulting
strike-slip faulting
all of these




What type of earthquakes would most likely occur at point A?

shallow-focus earthquakes caused by normal faulting
shallow-focus earthquakes caused by strike-slip faulting
shallow-focus earthquakes caused by thrust faulting
deep-focus earthquakes caused by thrust faulting


What type of earthquakes would most likely occur at point B?

shallow-focus earthquakes caused by normal faulting
shallow-focus earthquakes caused by strike-slip faulting
shallow-focus earthquakes caused by thrust faulting
deep-focus earthquakes caused by thrust faulting


Which of the following did not occur at a plate boundary?

New Madrid, Missouri, 1812
San Francisco, 1906
Anchorage, Alaska, 1964
Loma Prieta, California, 1989


Which of the following can be triggered by an earthquake?

tsunami
intense ground shaking
a landslide
all of these


Which of the following can trigger a tsunami?

undersea earthquakes
undersea landslides
the eruption of an oceanic volcano
all of these


Which of the following waves is the slowest?

P waves
S waves
Surface waves
tsunami


Which of the following statements is false?

Most earthquakes occur at plate boundaries
The time and location of most major earthquakes can be predicted several days in advance
Earthquakes can be caused by normal, reverse and strike-slip faulting
P waves travel faster than both S waves and Surface waves


Which of the following observations may indicate a forthcoming destructive earthquake?

An increase in the frequency of smaller earthquakes in the region
rapid tilting of the ground
rapid changes in water levels in wells
all of these


Which of the following statements best describes the state of earthquake prediction?

scientists can accurately predict the time and location of almost all earthquakes
scientists can accurately predict the time and location of about 50% of all earthquakes
scientists can accurately predict when an earthquake will occur, but not where
scientists can characterize the seismic risk of an area, but can not yet accurately predict most earthquakes

Return to the Physical Geology Home Page