Chapter 10 Earthquakes

If, during an earthquake, a hanging wall slides upward relative to a footwall, the fault is termed ____________ if the fault is steep (closer to vertical than horizontal).
a. reverse
b. thrust
c. strike slip
d. normal
a. reverse
Which earthquake intensity scale assesses the effects of an earthquake on humans and human-made structures?
a. Mercalli scale
b. Richter scale
c. seismic-moment magnitude scale
a. Mercalli scale
The greatest earthquake ever recorded by seismographs occurred in 1960 in Chile and measured ____________ on the seismic-moment magnitude scale.
a. 9.0
b. 10.0
c. 10.5
d. 9.5
d. 9.5
Which of these areas of the United States would you expect to have the highest occurance of seismic activity?
a. Southeast
b. West
c. Central
d. Northeast
b. West
Faulting and earthquakes are examples of ____________.
a. ductile behavior
b. brittle behavior
b. brittle behavior
Which earthquake severity scale measures the amplitude of deflection of a seismograph pen, standardized to an idealized distance of 100 km between epicenter and seismograph?
a. Mercalli scale
b. seismic-moment magnitude scale
c. Richter scale
c. Richter scale
A primary force opposing motion on all faults is ____________.
a. gravity
b. Van der Waal’s force
c. magnetic attraction among iron-rich minerals
d. friction
d. friction
Body waves include ____________.
a. both S- and P-waves
b. P-waves only
c. both L- and R-waves
d. both surface and interior waves
a. both S- and P-waves
Virtually all of the deaths attributed to major earthquakes have resulted from the collapse of buildings.
a. false
b. true
a. false
According to the moment magnitude scale (Mw)—a magnitude 8 earthquake would be 1,000 times greater than a magnitude ____________ earthquake.
a. 9
b. 4
c. 5
d. 7
c. 5
Which earthquake severity scale varies from locality to locality for a single earthquake?
a. Richter scale
b. seismic-moment magnitude scale
c. Mercalli scale
c. Mercalli scale
The intersection between a fault plane and the ground surface is called the ____________.
a. plunge
b. seismic interface
c. fault trace
d. dip line
c. fault trace
Which earthquake severity scale takes vibration caused only by the S-waves into account when estimating the size of an earthquake?
a. seismic-moment magnitude scale
b. Mercalli scale
c. Richter scale
c. Richter scale
What geological setting(s) would you expect to produce seismic activity?
a. Rift valley
b. Basin
c. Collisional mountain belt
d. All of the above are correct
d. All of the above are correct
Medium- and deep-focus earthquakes occur along ____________.
a. convergent-plate boundaries only
b. divergent-plate boundaries only
c. transform-plate boundaries only
d. All of the above are correct.
a. convergent-plate boundaries only
On December 26, 2004, a magnitude 9 earthquake generated a tsunami that devastated coastlines on the ____________.
a. Atlantic Ocean
b. Indian Ocean
c. Arctic Ocean
d. Pacific Ocean
b. Indian Ocean
The quantity of offset that occurs along a fault is termed ____________.
a. the fault gauge
b. displacement
c. accumulation
d. fault gouge
b. displacement
Long-term prediction of earthquake behavior ____________.
a. is based on past earthquake activity
b. works on the principle that zones of past seismicity will be active in the future
c. includes the notion of seismic gaps—places where an earthquake is “overdue”
d. All of the above are correct.
d. All of the above are correct.
All discovered faults are likely to experience earthquakes in the next few hundred years.
a. false
b. true
a. false
A surface along which rock on opposed sides is offset by earthquake-induced slip is called a ____________.
a. joint
b. fold
c. wall
d. fault
d. fault
Earthquakes that occur in a band called a ____________ can be used to track the motion of subducted oceanic lithosphere.
a. Wegener belt
b. seismic gap
c. Wadati-Benioff zone
c. Wadati-Benioff zone
How can damage and injury be minimized in areas prone to seismic activity?
a. earthquake zoning
b. engineering controls
c. warning systems
d. All of the above are correct
d. All of the above are correct
Earthquake waves that pass through the interior of Earth are termed ____________.
a. body waves
b. interior waves
c. R-waves
d. surface waves
a. body waves
A coiled spring would be useful in illustrating a ____________ wave.
a. surface
b. compressional
c. shear
d. body
b. compressional
An earthquake occurs with an epicenter in the town of New Madrid, Missouri, in the interior of the North American Plate. Where might the hypocenter of this earthquake plausibly be found?
a. 20 km beneath New Madrid
b. 10 km south of New Madrid
c. in New Madrid (“hypocenter” and “epicenter” mean precisely the same thing)
d. 200 km beneath New Madrid
If a fault is nearly vertical in orientation and the two walls of rock on opposite sides slide past one another horizontally, the fault is termed ____________.
a. thrust
b. normal
c. strike slip
d. reverse
c. strike slip
Which type of fault does NOT, by definition, have a fault trace?
a. normal fault
b. reverse fault
c. blind fault
d. None of the above are correct; all faults have recognizable traces
Seismic retrofitting is the process of __________.
a. strengthening existing buildings and structures
b. mapping areas prone to earthquakes
c. predicting earthquakes
d. releasing energy
a. strengthening existing buildings and structures
At any point along the surface of an oblique (nonvertical) fault, the ____________.
a. footwall lies to the left of the hanging wall
b. hanging wall lies to the left of the footwall
c. footwall lies vertically above the hanging wall
d. hanging wall lies vertically above the footwall
d. hanging wall lies vertically above the footwall
How many seismic stations are necessary to find the epicenter of an earthquake?
a. one
b. four
c. three
d. two
c. three
Aftershocks following a major earthquake ____________.
a. may continue for days after the initial earthquake
b. are mostly much smaller than the original earthquake
c. may occur on the same fault as the original earthquake, or a different fault
d. All of the above are correct
d. All of the above are correct
Vertical motion seismographs record earthquakes through the production of a squiggly diagram called a ____________.
a. wave sheet
b. seismogram
c. camera lucida
d. pictogram
b. seismogram
Which earthquake severity scale takes into account the type of rock that has been fractured?
Select one:
a. seismic-moment magnitude scale
b. Mercalli scale
c. Richter scale
a. seismic-moment magnitude scale
Which type of earthquake has the highest velocity?
a. L-wave
b. R-wave
c. P-wave
d. S-wave
c. P-wave
The point within Earth where an earthquake takes place is termed the ____________.
a. epicenter
b. vertex
c. eye of the fault
d. hypocenter (focus)
d. hypocenter (focus)
Generally, which type of earthquake waves travel fastest?
a. body waves
b. interior waves
c. R-waves
d. surface waves
a. body waves
Faults that have moved recently or are likely to move in the future are referred to as ____________.
a. active
b. reverse
c. normal
d. passive
a. active
Earthquakes are likely to occur along ____________.
a. transform-plate boundaries only
b. divergent-plate boundaries only
c. All of the above are correct.
d. convergent-plate boundaries only
c. All of the above are correct.
If, during an earthquake, a hanging wall slides upward relative to a footwall, the fault is termed ____________ if the fault is shallow (much closer to horizontal than vertical).
a. normal
b. reverse
c. thrust
d. strike slip
c. thrust
A tsunami is ____________.
a. an earthquake-generated sea wave that can sometimes destroy coastal cities thousands of kilometers from its source
b. a sloshing of water back and forth within a lake or bay
c. the tendency of wet, clay-rich soils to behave like a liquid during an earthquake
d. the amount of change in elevation of local sea level caused by a surging wave
a. an earthquake-generated sea wave that can sometimes destroy coastal cities thousands of kilometers from its source
Surface waves ____________.
a. are the first waves to arrive at a seismograph station after an earthquake
b. produce most of the damage to buildings during earthquakes
c. travel more rapidly than body waves
d. are the first waves initially produced in an earthquake
b. produce most of the damage to buildings during earthquakes
All else being equal, an earthquake that strikes in the eastern United States would produce shaking that would be felt ____________ than one that occurred in the western United States.
a. over a lesser distance
b. over the same distance
c. over a greater distance
c. over a greater distance
The point on Earth’s surface directly above the point where an earthquake occurs is termed the ____________.
a. epicenter
b. eye of the fault
c. hypocenter (focus)
d. vertex
a. epicenter
Periods of intermittent sliding on a fault as a result of the release of stress during episodes of displacement, followed by stress buildup to the point that the fault is reactivated is termed ____________.
a. stick-slip behavior
b. chaotic faulting
c. reverse faulting
d. thrust faulting
a. stick-slip behavior
Sandy substrate is susceptible to ____________ during an earthquake.
a. liquifaction
b. displacement
c. collapse
d. faulting
a. liquifaction
Movement on a fault may occur without generating earthquakes.
a. false
b. true
b. true
Earthquakes are a result of ____________.
a. mantle upwelling
b. a sudden change in atmospheric pressure
c. lithosphere-plate movement
d. erosion
c. lithosphere-plate movement
Short-term predictions of earthquake behavior ____________.
a. are primarily based on the behavior patterns of farm animals
b. have been largely unreliable
c. are correct approximately 50% of the time
d. have saved millions of lives in the past decade alone
b. have been largely unreliable
If, during an earthquake, a footwall slides upward relative to a hanging wall, the fault is termed ____________.
a. reverse
b. normal
c. thrust
d. strike slip
b. normal
Geologists who specifically study earthquakes are called ____________.
a. speleologists
b. paleontologists
c. vulcanologists
d. seismologists
d. seismologists