Deck 8: A Violent Pulse: Earthquakes

Question 1

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) in New Madrid ("hypocenter" and "epicenter" mean precisely the same thing)
B) 10 km south of New Madrid
C) 20 km beneath New Madrid
D) 200 km beneath New Madrid

Answer 1

C

Question 2

A surface along which rock on opposed sides is offset by earthquake-induced slip is called a ____________.

A) joint
B) fault
C) fold
D) wall

Answer 2

B

Question 3

The greatest earthquake ever recorded by seismographs occurred in 1960 in Chile and measured ____________ on the moment-magnitude scale.

A) 9.0
B) 9.5
C) 10.0
D) 10.5

Answer 3

B

Question 4

Body waves include ____________.

A) both S- and P-waves
B) both L- and R-waves
C) both surface and interior waves
D) P-waves only

Question 5

Geologists who specifically study earthquakes are called ____________.

A) seismologists
B) paleontologists
C) vulcanologists
D) speleologists

Question 6

Surface waves ____________.

A) travel more rapidly than body waves
B) cause most of the damage to buildings during earthquakes
C) are the first waves initially produced in an earthquake
D) are the first waves to arrive at a seismograph station after an earthquake

Question 7

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) strike-slip
D) thrust

Question 8

If,during an earthquake,a footwall slides upward relative to a hanging wall,the fault is termed ____________.

A) normal
B) reverse
C) strike-slip
D) thrust

Question 9

Which type of earthquake waves generally travels fastest?

A) interior waves
B) R-waves
C) surface waves
D) body waves

Question 10

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 on a different fault
D) all of the above

Question 11

Earthquake waves that pass through the interior of Earth are termed ____________.

A) interior waves
B) R-waves
C) surface waves
D) body waves

Question 12

The quantity of offset that occurs along a fault is termed ____________.

A) fault gouge
B) the fault gauge
C) displacement
D) accumulation

Question 13

The intersection between a fault plane and the ground surface is called the ____________.

A) dip line
B) plunge
C) fault trace
D) seismic interface

Question 14

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) normal
B) reverse
C) strike-slip
D) thrust

Question 15

Which type of earthquake wave travels fastest?

A) L-wave
B) P-wave
C) R-wave
D) S-wave

Question 16

A primary force opposing motion on all faults is ____________.

A) magnetic attraction among iron-rich minerals
B) gravity
C) friction
D) Van der Waals force

Question 17

Periods of intermittent sliding on a fault that result from the release of stress during episodes of displacement followed by stress buildup to the point that the fault is reactivated,are termed ____________.

A) chaotic faulting
B) thrust faulting
C) stick-slip behavior
D) reverse faulting

Question 18

Faulting and earthquakes are examples of ____________.

A) brittle behavior
B) ductile behavior

Question 19

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) normal
B) reverse
C) strike-slip
D) thrust

Question 20

At any point along the surface of an oblique (nonvertical)fault,the ____________.

A) hanging wall lies vertically above the footwall
B) footwall lies vertically above the hanging wall
C) hanging wall lies to the left of the footwall
D) footwall lies to the left of the hanging wall

Question 21

Vertical motion seismographs record earthquakes through the production of a squiggly diagram called a ____________.

A) wave sheet
B) seismogram
C) pictogram
D) camera lucida

Question 22

Virtually all of the deaths attributed to major earthquakes have resulted from the collapse of buildings.

Question 23

Which earthquake severity scale only takes vibration caused by the S-waves into account when estimating the size of an earthquake?

A) Richter scale
B) Mercalli scale
C) moment-magnitude scale

Question 24

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) Richter scale
B) Mercalli scale
C) moment-magnitude scale

Question 25

The point on Earth's surface directly above the point where an earthquake occurs is termed the ____________.

A) hypocenter (focus)
B) epicenter
C) eye of the fault
D) vertex

Question 26

California is the only state in the United States that experiences frequent or strong earthquakes.

Question 27

The greatest earthquake ever recorded by seismograph equipment measured ____________ on the moment-magnitude scale and had an epicenter off the coast of ____________.

A) 9.1; Indonesia
B) 9.5; Chile
C) 9.7; California
D) 9.9; Alaska

Question 28

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

Question 29

Short-term predictions of earthquake behavior ____________.

A) have saved millions of lives in the past decade alone
B) have been largely unreliable
C) are primarily based on the behavior patterns of farm animals
D) are correct approximately 50% of the time

Question 30

An earthquake with magnitude 8.0 releases ____________ the energy of an earthquake with magnitude 4.0.

A) twice
B) four hundred times
C) two hundred times
D) ten thousand times

Question 31

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 amount of change in elevation of local sea level caused by a surging wave
D) the tendency of wet, clay-rich soils to behave like a liquid during an earthquake

Question 32

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

Question 33

The point within Earth where an earthquake takes place is termed the ____________.

A) hypocenter (focus)
B) epicenter
C) eye of the fault
D) vertex

Question 34

Earthquakes are likely to occur along ____________.

A) convergent plate boundaries only
B) divergent plate boundaries only
C) transform plate boundaries only
D) all three major types of plate boundaries

Question 35

Which earthquake severity scale takes into account the type of rock that has been fractured?

A) Richter scale
B) Mercalli scale
C) moment-magnitude scale

Question 36

Intermediate and deep earthquakes occur along ____________.

A) convergent plate boundaries only
B) divergent plate boundaries only
C) transform plate boundaries only
D) all three major types of plate boundaries

Question 37

Which earthquake intensity scale assesses the effects of an earthquake on humans and human-made structures?

A) Richter scale
B) Mercalli scale
C) moment-magnitude scale

Question 38

Which earthquake severity scale varies from locality to locality for a single earthquake?

A) Richter scale
B) Mercalli scale
C) moment-magnitude scale

Question 39

On December 26,2004,a magnitude 9 earthquake generated a tsunami that devastated coastlines on the ____________ Ocean.

A) Atlantic
B) Arctic
C) Indian
D) Pacific

Question 40

How many seismic stations are necessary to find the epicenter of an earthquake?

A) one
B) two
C) three
D) four