Deck 8: A Violent Pulse: Earthquakes

Question 1

Earthquakes that occur in a band called the ___________ can be used to track the motion of subducted oceanic lithosphere.

A)Wegener belt
B)seismic gap
C)Wadati-Benioff zone
D)Richter zone

Answer 1

C

Question 2

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 ___________ fault. Refer to the following figure for an example of such a feature.

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

Answer 2

C

Question 3

Vertical motion seismographs record earthquakes by producing a squiggly diagram called a

A)wave sheet.
B)seismogram.
C)pictogram.
D)seismograph.

Answer 3

B

Question 4

At any point along the surface of any nonvertical fault, as shown in the following figure, 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 5

At a minimum, how many seismic stations are necessary to locate the epicenter of an

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

Question 6

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 7

During an earthquake, if the hanging wall slides upward relative to the footwall and if the fault is steep (closer to vertical than horizontal), then the fault is termed a ___________ fault. Refer to the following figure for an example of such a feature.

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

Question 8

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

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

Question 9

Periods of intermittent sliding on a fault because of stress release during episodes of slip, followed by stress buildup to the point that the fault is reactivated, is termed

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

Question 10

The vast majority of earthquakes occur

A)associated with isostatic rebound.
B)near hotspots.
C)along passive margins.
D)along all types of plate boundaries.

Question 11

Earthquakes often occur along

A)bedding planes.
B)terminal moraines.
C)faults.
D)river valleys.

Question 12

A primary force opposing motion on all faults is

A)covalent bonds.
B)gravity.
C)friction.
D)the Van der Waals force.

Question 13

What kind of waves travel with a compressional motion?

A)Love waves
B)Rayleigh waves
C)P-waves
D)S-waves

Question 14

The recurrence of earthquakes along a single fault is referred to as

A)stick-slip behavior.
B)elastic-rebound theory.
C)seismic repetition theory.
D)slip-transfer theory.

Question 15

Which earthquake scale is used to assess the effects of an earthquake on humans and human-made structures?

A)Richter scale
B)Mercalli scale
C)moment magnitude scale
D)surface-wave magnitude scale

Question 16

Moderate- and deep-focus earthquakes occur along ONLY

A)convergent-plate boundaries.
B)divergent-plate boundaries.
C)transform-plate boundaries.
D)hotspots.

Question 17

Generally, which type of earthquake waves travel with the slowest velocity?

A)S-waves
B)P-waves
C)surface waves
D)All earthquake waves travel at the same speed.

Question 18

The quantity of motion that occurs along a fault is termed

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

Question 19

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

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

Question 20

An increase in size of one unit of magnitude translates to ___________ times the ground motion.

A)1
B)2
C)32
D)10

Question 21

The ___________ the earthquake, the LESS severe the damage will be.

A)larger the magnitude of
B)longer the duration of
C)farther you arefrom
D)closer you are to

Question 22

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)20 km south of New Madrid
C)20 km beneath New Madrid
D)200 km north of New Madrid

Question 23

The larger the ___________ of the wave, the MORE severe the damage will be.

A)travel-time curve
B)epicenter
C)seismometer
D)amplitude

Question 24

Which of the following does NOT affect the severity of damage from an earthquake?

A)weather
B)distance
C)duration
D)magnitude

Question 25

What occurs when earthquakes cause pore pressure to increase, which in turn causes grains to separate and compact?

A)liquefaction
B)aftershocks
C)normal faults
D)landslides

Question 26

Surface waves

A)travel more rapidly than body waves.
B)produce 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 27

A tsunami is

A)a sea wave generated by a displacement of water.
B)a sloshing of water back and forth within a lake or a bay.
C)a wave caused by unusually large tidal forces.
D)the tendency of wet, clay-rich soils to behave like a liquid during an earthquake.

Question 28

According to the image below, where was the epicenter of the earthquake?

A)New York
B)Florida
C)Kansas
D)Canada

Question 29

Earthquakes can often produce ___________ by breaking gas lines

A)landslides
B)flooding
C)sinkholes
D)fires

Question 30

The Mercalli intensity scale tends to be very subjective and thus is generally only used for historical earthquakes that were near people but were not recorded by seismometers. The Mercalli scale may be considered subjective because it

A)relies on testimony from people.
B)does not take distance into account.
C)can only be used for large earthquakes.
D)cannot be used in heavily populated areas.

Question 31

Which seismic wave phase causes the ground to roll like a wave?

A)P-wave
B)S-wave
C)Rayleigh wave
D)Love wave

Question 32

According to the moment magnitude scale (Mw), a magnitude 8 earthquake would be 1,000 times greater than a magnitude ___________ earthquake.

A)9
B)5
C)7
D)4

Question 33

What is the magnitude of the earthquake shown in the image below?

A)5
B)24
C)220
D)6

Question 34

According to the following diagram, the energy released by the 1994 Northridge earthquakes was roughly the same as the energy released by

A)the H-bomb.
B)Mount St. Helens.
C)a tornado.
D)a hurricane.

Question 35

Which type of seismic wave has the fastest velocity?

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

Question 36

Which tectonic setting has the potential to create the largest earthquakes on Earth?

A)shallow thrust faults associated with a convergent boundary
B)deep focus faults associated with a convergent boundary
C)thrust faults associated with a transform boundary
D)ridge segment transform boundaries associated with divergent boundaries

Question 37

According to the image below, which seismic wave phase is likely to cause the most damage?

A)P-wave
B)S-wave
C)surface wave
D)aftershock

Question 38

The moment magnitude is based on the ___________ and ___________ of the earthquake.

A) amplitude; displacement
B) amplitude; distance
C)displacement; amount of damage
D)amount of damage; distance

Question 39

Wet and unconsolidated substrates are uniquely susceptible to ___________ during an earthquake.

A) displacement
B) collapse
C)liquefaction
D)faulting

Question 40

On December 26, 2004, a magnitude 9.3 earthquake generated a tsunami that devastated coastlines on the ___________ Ocean.

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

Question 41

Explain why tsunamis are NOT tidal waves.

Question 42

How is the Mercalli intensity scale used to determine the magnitude of an earthquake? What errors might be associated with this technique?

Question 43

Why do deep-focus earthquakes occur along convergent plate boundaries? Why do they not occur along divergent or transform boundaries?

Question 44

Making better ___________ is the best way to try to prevent earthquake damage.

A)seismometers
B)magnitude scales
C)buildings
D)seismograms

Question 45

The ___________ of a fault gives the average time between events.

A)displacement
B)exceedance probability
C)recurrence interval
D)annual probability

Question 46

Early warning systems use computers to detect a nearby earthquake and send an emergency alert to warn of the event. Which seismic phase is the system detecting when it sends the alert?

A)Love wave
B)Rayleigh wave
C)P-wave
D)S-wave

Question 47

Why is an empty field the safest place to be in an earthquake?

Question 48

Seismic retrofitting is the process of

A)predicting future earthquakes.
B)strengthening existing buildings and structures.
C)mapping areas prone to earthquakes.
D)fitting earthquake data after an event to see if it should have been predicted.

Question 49

Long-term prediction methods include(s)

A)early warning systems.
B) behavior of animals.
C)seismic risk assessment.
D)recognition of foreshocks.

Question 50

Much of the capitol city of Port-au-Prince was destroyed during the 2010 Haiti earthquake even though similarly sized earthquakes in other cities did very little damage. What caused so much damage during the Haiti earthquake?

A) A tsunami wiped out the city.
B) Landslides covered large areas.
C)The buildings were poorly built.
D)The residents did not evacuate in time.

Question 51

Earthquake ___________ is a means of deciding where the ground is stable enough to build on in earthquake-prone areas.

A)mitigation
B)zoning
C)retrofitting
D)prevention

Question 52

Describe two earthquake-related hazards.

Question 53

Why is an early warning system NOT considered a short-term earthquake prediction tool?

Question 54

Where do earthquakes occur? Please explain your answer in the context of plate tectonics.

Question 55

Compare and contrast P- and S-waves.

Question 56

What phases of matter can a P-wave travel through? An S-wave? How has this helped us to have a better understanding of the layers of our Earth?

Question 57

Evidence of a past earthquake may be found by looking for offset beds or

A)liquefaction.
B)sand volcanoes.
C)stress fractures.
D)foliation.

Question 58

Where is the best place to be in an earthquake?

A)in an empty field
B)in a brick house
C)in a doorway
D)on the beach

Question 59

What is the Moho? How was it discovered?

Question 60

S-waves are unable to pass through the Earth's outer core, which indicates that the outer core is

A)a void space within the Earth.
B)compositionally different from the mantle.
C)composed of an ultra-dense solid.
D)liquid.