Deck 3: Earthquake Geology, Seismology, and Engineering

Question 1

Seismic waves that travel only near the Earth's surface are of two main types: _________ waves.

A) S- and Love
B) P- and Rayleigh
C) P- and S-
D) P- and Love
E) Love and Rayleigh

Answer 1

E

Question 2

Which of the following wave types travels the slowest moving?

A) P-waves
B) S-waves
C) L waves
D) Body waves
E) They all travel with the same velocity.

Answer 2

C

Question 3

__________ waves move in a side-to-side motion propagating in a horizontal plane parallel to the Earth's surface.

A) P-
B) Rayleigh
C) Both Body and Surface Waves
D) Both Rayleigh and P-
E) Both Love and S-

Answer 3

E

Question 4

Instrumentation used to measure Earth motion are called ________ and these movements are recorded on a ___________________.

A) quakemeters;richtergraph
B) terrameters;terrachart
C) seismometers;seismograph
D) seismomgraphs;seismochart

Question 5

The point where a fault first ruptures is called the _____________.

A) epicentre
B) hypocentre
C) foreshock
D) faultcentre
E) seismocentre

Question 6

The ________ waves advance in a backward-rotating,elliptical motion.

A) S-
B) P-
C) Love
D) Rayleigh
E) None of these are correct.

Question 7

The point on the Earth's surface directly above the point where the fault first ruptures is called the ______________.

A) epicentre
B) hypocentre
C) depocentre
D) ethnocentre

Question 8

P-waves can travel through __________________.

A) gases
B) liquids
C) solids
D) a vacuum
E) gases,liquids,and solids

Question 9

Earthquakes are most commonly caused by ________________.

A) explosions of nuclear bombs
B) undersea landslides
C) meteorite impacts
D) volcanic activity
E) sudden Earth movements along faults

Question 10

The _________ waves' motion is similar to S waves,it is from side-to-side in a horizontal plane roughly parallel to the Earth's surface.

A) Rayleigh
B) P-
C) Love

Question 11

The _____ wave travels fastest and moves in a push-pull fashion of alternating pulses of compression (push)and extension (pull).

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

Question 12

Waves can be described in terms of distance or time.The distance between successive waves is the _____________.

A) waveperiod
B) wavedisplacement
C) wavemeter
D) wavefrequency
E) wavelength

Question 13

Which of the following statements about faults are correct?

A) They are surface features extending no more than 0.5 metres below the surface.
B) A fault rupture is a one-time movement that produces an earthquake.
C) A crack in the Earth across which the two slides move relative to each other.
D) They are the point on the surface directly above the epicentre.

Question 14

Using the S-P timing method,epicentres can be located using seismograms from a minimum of ______ recording stations.

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

Question 15

High-frequency waves _________ over _______ distance while low-frequency waves do the reverse.

A) attenuate;long
B) intensify;short
C) attenuate;short
D) intensify;long

Question 16

Which seismic waves have the greatest amplitude on a seismogram?

A) P-waves
B) S-waves
C) Body waves
D) Surface waves
E) They all have the same amplitude.

Question 17

_________ waves travel only through solids;on reaching liquid or gas,the wave energy is reflected back into rock or is converted to another form.

A) S-
B) P-
C) Surface waves

Question 18

The study of Earthquakes is known as __________.

A) quakology
B) terrology
C) quassology
D) collapsology
E) seismology

Question 19

The frequency of a wave is ____________________.

A) the amount of displacement of the medium through which the wave is passing
B) the number of full wave cycles passing a given point per unit time
C) the time between successive waves
D) the energy of the wave

Question 20

Velocities for _________ waves in granite are about 5.0 km/sec,but in water they slow to 1.5 km/sec.

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

Question 21

The Enriquillo-Plantain Garden fault is a part of the:

A) Caribbean tectonic plate
B) East-west trending faults that pass through Haiti
C) zone that in 2010 produces earthquake of large magnitude 9
D) zone that in 2010 produces earthquake of moderate magnitude 7
E) Caribbean tectonic plate,east-west trending faults that pass through Haiti,and the zone that in 2010 produced an earthquake of moderate magnitude 7

Question 22

Earthquake-induced ground motions cause buildings to sway.In general,the taller the structure,the _______ the amplitude of shaking in the upper floor.

A) greater
B) lesser
C) amplitude of shaking does not depend on building height

Question 23

The main difference between earthquake magnitude and intensity is ____________.

A) magnitude is measured with seismometers while intensity is measured by satellites
B) magnitude is measured with instruments while intensity is assessed by the fault size
C) intensity requires an audience while magnitude requires machines
D) intensity requires specialized machines while magnitude requires simple machines
E) None of these are correct.

Question 24

Buildings made of wood tend to ________ than a stiffer building of brick or concrete.

A) fail under compression
B) deform elastically
C) suffer brittle failure
D) none of these

Question 25

The Richter Scale is set up so that for every _______ increase in the amplitude of the recorded seismic wave,the Richter magnitude increases by one,e.g. ,from 4 to 5.

A) twofold
B) fourfold
C) tenfold
D) twentyfold
E) fiftyfold

Question 26

In Sichuan Province,China,the 2008 earthquake particularly affected:

A) roads
B) private houses
C) bridges
D) schools
E) none of these choices

Question 27

The epicentres at divergent zones follow the ______________ and appear at _______ depths.

A) stretched lithosphere;long
B) subduction zone;shallow
C) C,triple junction;long
D) thin and stretched lithosphere;shallow
E) trench zone;shallow

Question 28

Earthquakes at hot spots are generated by the ________.

A) horizontal movement of the plate above the hot spot
B) vertical movement of the plate as it's pushed up over the hot spot
C) movement of magma below the surface

Question 29

Which of the following would be the lowest on the Mercalli intensity scale?

A) high magnitude,epicentre located in unpopulated area underlain by solid rock
B) high magnitude,epicentre located in low density rural area,shorter shaking
C) shorter shaking,deep hypocentre,epicentre located in low density city
D) longer shaking,shallow hypocentre,epicentre located in densely populated city
E) high magnitude,epicentre located in unpopulated area,1 minute of shaking

Question 30

The intensity of an earthquake is influenced by all but which one of the following?

A) earthquake magnitude
B) distance from the hypocentre/epicentre
C) type of rock or sediment making up the ground surface
D) the presence of people to record their innermost feelings
E) duration of shaking

Question 31

The moment of magnitude scale is more accurate for big earthquakes because _______.

A) it includes length of duration of shaking and energy released
B) it includes fault-rupture area and energy released
C) it includes the distance from the epicentre and length of duration of shaking
D) it includes hypocentre depth and energy released
E) it includes fault-rupture area and hypocentre depth

Question 32

In earthquake prone regions buildings can be reinforced and designed to prevent the likelihood of collapse during an earthquake.Which of the following measures are not designed to prevent building collapse?

A) shear walls
B) brace walls
C) base isolation
D) brick walls
E) add buttresses

Question 33

Each year the Earth is shaken by millions of quakes most of which are __________.

A) above magnitude 8
B) between magnitude 5 and 6
C) below magnitude 2.5
D) between magnitude 3 and 5
E) between magnitude 6 and 7

Question 34

Magnitude 2 and less can be compared to _________________ and an acceleration (g)of ___________.

A) I-II Mercalli scale;less than 0.002
B) IV-V Mercalli scale;of 0.2-0.99
C) XI-XII Mercalli scale;greater than 1.0
D) I-II Mercalli scale;of 0.2
E) I-II Mercalli scale;of 0.1

Question 35

If the magnitude of an earthquake increased from 4 to 8 on the Richter scale the associated amount of energy released from a 4 to 8 magnitude increase would be ________.

A) 2.8 million times more
B) 2,050 times more
C) 200 times more
D) 40 times more
E) 4 times more

Question 36

Seismic waves were amplified at four sites with different foundation (soil)materials in Ottawa during the 2005 Charlevoix earthquake.At which site were they preferentially amplified?

A) rock
B) 10m soil
C) 1m soil
D) 50m soil
E) none of these;seismic waves are not affected by the type or thickness of the soil material

Question 37

Liquefaction in saturated and poorly consolidated soils occurs when they are shaken or subjected to rapid loading.The result is _____________.

A) water pressure decreases and soils increase their strength and stiffness
B) water pressure increases and soils lose their strength and stiffness
C) water pressure decrease and soils lose their strength and stiffness
D) water pressure increases and soils increase their strength and stiffness

Question 38

The magnitude of an earthquake is commonly measured from the __________ of ____________.

A) frequency;surface waves on a seismograph
B) wavelength;the distance between P and S waves on a seismometer
C) period;acoustic waves on a seismograph
D) amplitude;seismic waves on a seismogram

Question 39

"Megathrust earthquakes" which release enormous amounts of energy and cause widespread destruction are generated at ___________.

A) subduction zones
B) continent to continent collisions
C) transform faults
D) hot spots

Question 40

Usually,the biggest concern in designing buildings to withstand large earthquakes is the ____________ components of movement.

A) upward push from the vertical
B) downward pull from the vertical
C) sideways push from the horizontal

Question 41

The 2010 Port-au-Prince,Haiti earthquake was not on the list of the world's greatest earthquakes but it is on the list of recent earthquakes associated with the largest number of fatalities.

Question 42

Two of the largest moment magnitudes measured to date are the 2004 Sumatra event (M_S of 8.8;M_W of 9.1)and the 1960 Chile earthquake (M_S of 8.5;M_W of 9.5).

Question 43

Locate the epicentre and estimate the magnitude of an earthquake from seismogram measurements.

Question 44

The point where a fault first ruptures underground is known as the epicentre.

Question 45

The types of rock or sediment on which a structure's foundation sits are of paramount importance with respect to whether the structure will be damaged by shaking from an earthquake.

Question 46

For magnitudes above about 6,the bigger earthquake magnitude means that more people in a larger area and for a longer time will experience the intense shaking.

Question 47

Each year,the Earth is shaken by millions of earthquakes.

Question 48

The greater the resistance to compression of the materials through which P waves pass (e.g.granite),the lower the velocity of the waves passing through.

Question 49

The moment magnitude is more accurate than the classical Richter scale because it is tied directly to physical parameters such as fault-rupture area,fault slip,and energy release,and because other earthquake scales use indirect measures such as how much a seismograph needle moves.

Question 50

The S-waves can travel through liquids,solids,and gases.

Question 51

The relation between distance and damage from an earthquake seems obvious: the closer to the hypocentre/epicentre,the greater the damage,but this is not always the case.

Question 52

The velocity of an S-wave depends on the density and resistance to shearing of materials.

Question 53

With their up-and-down and side-to-side motions,S-waves shake the ground surface and can do severe damage to buildings.

Question 54

Gail Atkinson's (Canada Research Chair in Earthquake Hazards and Ground Motions)approach to mitigating earthquake risk is ____________________.

A) to predict when and where earthquakes will occur
B) to organize a large scale evacuation
C) to replace foundation material (soil material)below buildings with more earthquake resistant material
D) to destroy all buildings which are not earthquake resistant
E) to understand the expected ground motions and design buildings to withstand them

Question 55

The biggest shaking event is called the mainshock,the smaller ones before it are known as foreshocks,and the smaller ones after it are called aftershocks.

Question 56

When you compare L,S,and P waves on the graph arrival time (Y axes)versus epicentral distance (X axes),the position of L waves will be below P waves.

Question 57

The building above (Figure 3.36 in textbook)has been strengthened by

A) adding infill walls.
B) adding frames to the exterior.
C) adding a buttress.
D) isolating the building from the ground.
E) adding braces.

Question 58

Aftershocks are smaller than the mainshock in an earthquake sequence.

Question 59

Typically fewer than 20 major and great earthquakes (magnitudes of 7 and higher)each year account for more than 90 percent of the energy released by earthquakes.

Question 60

The shaking produced by Rayleigh waves causes both vertical and horizontal movement.

Question 61

Where the frequencies of seismic waves match the natural vibration frequencies of local geology and buildings,destruction may be great.

Question 62

The waveforms on the seismogram from the closest seismic station are dominated by low-frequency waves,while high-frequency waves dominate at the station farther away.

Question 63

The duration of the shaking is not a significant factor in damages suffered and lives lost.

Question 64

Earthquake magnitude scales such as the Richter scale assess the effects on people and buildings.

Question 65

High-frequency P- and S-waves will have their vibrations amplified by 1)rigid construction materials,such as brick or stone,and 2)short buildings.

Question 66

Other measures of earthquake magnitude may include the two magnitude scales,body wave scale (m_b)and surface wave scale (M_s)

Question 67

Earthquakes at divergent zones,such as the East African Rift system,are generated at shallow depth (<33km)and with magnitude 6.0 or less.