Ch 8 Earthquakes

53. Rocks breaking at the earthquake's focus release energy in the form of: A. elastic waves B. P & S waves C. P, S, L & R waves D. surface waves E. tsunami waves

B. P & S waves

.If, during an earthquake, a hanging wall slides upward relative to a footwall, the fault is termed when the fault is steep (closer to vertical than horizontal). a. normal b. reverse c. strike-slip d. thrust

B. Reverse

The elastic rebound theory was formulated after analyzing the fault of the 1906 earthquake in San Franscisco. a. true b. false

a. true

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56. Earthquakes often occur at: A. divergent crustal plate boundaries B. convergent crustal plate boundaries C. sliding crustal plate boundaries D. subducting crustal plate boundaries E. all of the above

**e. all of the above** A. divergent crustal plate boundaries B. convergent crustal plate boundaries C. sliding crustal plate boundaries D. subducting crustal plate boundaries

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

A. Normal

Geologists who specifically study earthquakes are called: a. seismologists b. paleontologists c. vulcanologists d. speleologists

A. Seismologists

65. According the elastic rebound theory of earthquake generation: A. Stored strain in the rock is released by plastic flow, like Silly Putty, before it breaks suddenly and releases earthquake waves. B. Rock stores energy along existing fault surfaces which is released at the epicenter as the rock snaps elastically, similar to a breaking rubber band. C. Rock deforms elastically over time storing energy before breaking suddenly and releasing energy as rock masses slide past one another. D. Rock snaps as the hypocenter of the earthquake produces a crack that propagates through the crust of the earth plates causing movement which is called Plate Tectonics. E. None of the above.

A. Stored strain in the rock is released by plastic flow, like Silly Putty, before it breaks suddenly and releases earthquake waves.

77. Earthquakes or seismicity can occur for a number of reasons including: A. a sudden slip on an existing fault that has moved in the past. B. movement of magma in a volcano. C. the sudden formation of a new fault in the crust of the earth. D. a giant landslide. E. All of the above.

A. a sudden slip on an existing fault that has moved in the past. B. movement of magma in a volcano. C. the sudden formation of a new fault in the crust of the earth. D. a giant landslide. **E. All of the above.**

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

A. an earthquake generated sea wave that can sometimes destroy coastal cities thousands of kilometers from its source

.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

A. both S- and P- waves

Faulting and earthquakes are examples of a. brittle behavior b. ductile behavior

A. brittle behavior

Deep-focus earthquakes occur most frequently along ____________. A. convergent plate boundaries B. divergent plate boundaries C. transform plate boundaries D. All of the above. E. A & B only.

A. convergent plate boundaries

Medium 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

A. convergent plate boundaries only

Within the Earth, irregular convection cells within the mantle transfer heat from the core to the surface of the planet. This mechanism is one of the driving forces behind both heat transfer and the global process of ______________. A. earthquake formation B. continental drift C. seafloor spreading D. plate tectonics E. all of the above.

A. earthquake formation B. continental drift C. seafloor spreading D. plate tectonics **E. all of the above.**

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

A. hanging wal lies vertically above the footwall

The point within Earth where an earthquake takes place is termed the . a. hypocenter (focus) b. epicenter c. eye of the fault d. vertex

A. hypocenter (focus)

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 E. transform

A. normal

Which of the following is a characteristic of convergent ocean -continental plate interaction? A. progressively deeper earthquakes B. progressively shallower earthquakes C. tsunamis D. less destructive earthquakes farther inland on the continental plate E. A,C & D.

A. progressively deeper earthquakes c. tsunamis

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

A. richter scale

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

A. richter scale

What does the term elastic energy refer to? A. the gradual buildup of distant forces that slowly accumulate strain and distort the Earth's crust B. energy that is transferred through different levels in the Earth's core C. the retraction of energy from one side of the fault line to the other D. stored energy in the mantle E. the sudden release of energy in the form of L and R waves

A. the gradual buildup of distant forces that slowly accumulate strain and distort the Earth's crust

Virtually all of the deaths attributed to major earthquakes have resulted from the collapse of buildings. a. true b. false

A. true

79. The margins of the earth's crustal plates are the location of: A. zones of earthquakes. B. ocean trenches. C. volcanic belts. D. transform faults. E. All of the above.

A. zones of earthquakes. B. ocean trenches. C. volcanic belts. D. transform faults. **E. All of the above.**

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

B. 10 km south of new madrid

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

B. 9.5

The 2010 Port au Prince, Haiti earthquake and the 1989 Loma Prieta earthquake had the following in common: a. Both occurred in areas adjacent to transform plate margins. B. Both occurred in areas adjacent to convergent plate margins. C. Both were earthquakes that were killer deep focus earthquakes. D. Both were of the same magnitude M=7.0 on the Richter scale. E. A & D.

B. Both occurred in areas adjacent to convergent plate margins.

As suggested by the name "earthquake" the release of seismic energy as waves is unique to our planet and has not been found to occur in any other body of our solar system.

B. FALSE

A surface along which rock on opposed sides is offset by earthquake-induced slip is called a. joint b. fault c. fold d. wall

B. Fault

Along the San Andreas Fault in the Palmdale & Lancaster area of Southern California in the last 100+ years there has been: A. abundant seismic activity. B. a lack of seismic activity. C. numerous hot springs and volcanic activity. D. two major earthquakes, the San Fernando and Northridge earthquakes. E. More than one of the above.

B. a lack of seismic activity. (?)

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

B. cause most of the damage to buildings during earthquakes

The point on Earth's surface directly above them point where an earthquake occurs is termed the : a. hypocenter (focus) b. epicenter c. eye of the fault d. vertex

B. epicenter

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

B. have been largely unreliable

91. In what four settings do earthquakes occur? A. intraplate regions, divergent settings, convergent margins, and transform settings B. intraplate regions, subduction zones, convergent margins, and transform settings C. failed rifts, divergent settings, convergent margins, and transform settings D. hotspots, subduction zones, failed rifts, and convergent margins E. hotspots, convergent margins, divergent margins and transform margins

B. intraplate regions, subduction zones, convergent margins, and transform settings

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

B. mercalli scale

Which earthquake severity scale varies from locality to locality for a single earthquake? a. Richter scale b. Mercalli scale c. moment-magnitude scale

B. mercalli scale

Which type of earthquake wave travels fastest? a. L-wave b. P-wave c. R-wave d. S-wave

B. p- wave

98. Which of the following describes the motion of a Rayleigh wave? A. moves the ground from side to side B. rolls along the ground just as a wave rolls across a lake C. passes through the ground in one straight movement D. pushes and pulls the ground E. more than one of the above

B. rolls along the ground just as a wave rolls across a lake

Vertical motion seismographs record earthquakes through the production of a squiggly diagram called a: a. wave sheet b. seismogram c. pictogram d. camera lucida

B. seismogram

The worldwide seismic network has played an important role in human political history because seismographs detect not only the waves emitted by earthquakes but also ____________. A. the vibrations of submarines in deep water B. underground nuclear explosions C. the activities of astronauts on the Moon D. the flight paths of Scud missiles

B. underground nuclear explosions

76. An earthquake with a Richter Magnitude of 8.8 occurred in Chile on 2/27/2010. The 8.8 magnitude quake released approximately how much more energy than a 6.8 quake that occurred in Los Angeles in 1971? A. 10X B. 32X C. 100X D. 1,000X E. 32,000X

C. 100X

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

The quantity of offset that occurs along a fault is termed: a. fault gouge b. the fault gauge c. displacement d. accumulation

C. displacement

The intersection between a fault plane and the ground surface is called the: a. dip line b. plunge c. fault trace d. seismic interface

C. fault trace

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

C. friction

71. Earthquake waves propagate (travel) most rapidly through _________ A. sediment C. igneous rock B. sedimentary rock D. water E. None of the above

C. igneous rock

Earthquake waves propagate most rapidly through ____________. A. sediment B. sedimentary rock C. igneous rock D. water

C. igneous rock

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

C. indian

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

C. moment magnitude scale

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

C. stick slip behavior

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

C. strike slip

The Richter Magnitude Scale that defines earthquakes by measuring the amplitude of the largest movement of the ground as recorded by a seismograph is a logarithmic scale such that each number on the scale (1,2,3,4,5,6,etc........ ) represents a A. one fold increase in ground movement. B. thirty-two fold increase in ground movement. C. tenfold increase in ground movement D. one hundredfold increase in ground movement

C. tenfold increase in ground movement

How many seismic stations are necessary to find the epicenter of an earthquake? a. one b. two c. three d. four

C. three

83. When an earthquake occurs, where is energy released from? A. the epicenter B. the focus C. the hypocenter D. B & C E. all of the above

D. B & C b. the focus/ c. the hypocenter

Body waves include ____________. A. both S-waves and P-waves B. both surface and interior waves C. both L- and R-waves D. P-waves only as S waves cannot travel through liquids E. More than one of the above

D. P-waves only as S waves cannot travel through liquids

100. What is the full name of the intensity scale currently in use?

D. The Modified Mercalli Intensity Scale

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

D. Thrust

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

D. all three major types of plate boundaries

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 E. A & C only.

D. all three major types of plate boundaries

Surface earthquake 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 second waves to arrive at a seismograph station after an earthquake E. Only occur in earthquakes with epicenters at the near or at the surface of the earth.

D. are the second waves to arrive at a seismograph station after an earthquake

Earthquake waves that pass through the interior of Earth are termed :. a. interior waves b. R-waves c. surface waves d. body waves

D. body waves

Which type of earthquake waves generally travels fastest? a. interior waves b. R-waves c. surface waves d. body waves

D. body waves

63. The San Andreas fault A. is a transform right lateral strike-slip fault. B. marks the boundary between the Pacific Plate and the North American Plate in California. C. terminates at ocean ridges or rises. D. All of the above. E. A & B only.

a. is a transform right lateral strike-slip fault b. marks the boundary between the north american plate and pacific plate c. terminates at ocean ridges/rises

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

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**

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

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**

54. The focus and epicenter of an earthquake always coincide with one another.

a. true

90. Deep earthquakes occur in areas where oceanic crust is being actively subducted. a. true b. false

a. true

Aftershocks tend to occur in the immediate vicinity of the focus of the mainshock, whereas foreshocks spread out along the fault plane and other nearby faults. a. true b. false

a. true

Plate tectonics are useful in telling where 90% of Earth's major earthquake s are likely to occur. a. true b. false

a. true

The Wadati-Benioff Zone (WBZ) is a steeply dipping plane that corresponds to faulting associated with the subducting ocean slab. a. true b. false

a. true

99. How many seismic locations are needed to locate an epicenter?

b. 3

62. Which statement about the distribution of earthquakes on Earth is correct? A. Earthquakes are evenly distributed around the globe. B. Earthquakes occur in discrete belts or zones along plate boundaries. C. Earthquakes occur exclusively where a sudden slip on existing faults occurs. D. Earthquakes are randomly distributed around the globe and even occur in the middles of oceans and continents. E. B & C only.

b. Earthquakes occur in discrete belts or zones along plate boundaries.

All discovered faults are likely to experience earthquakes in the next few hundred years. a. TRUE b. FALSE

b. FALSE

Earthquakes whose focus or hypocenter is located under the ocean always cause tsunamis. a. true b. false

b. FALSE (not always)

51. A tsunami caused by an earthquake can A. consist of a single massive wave B. consist of more than one wave C. consist of waves of different heights D. consist of a single trough and single crest E. none of the above

b. consists of more than one wave

55. The Japan earthquake occurred along a: A. divergent plate boundary B. convergent plate boundary C. sliding plate boundary D. transform plate boundary E. emergent fault boundary

b. convergent plate boundary

57. Earthquake generated tsunamis occur where the Earth's crust is a: A. divergent plate boundary B. convergent plate boundary C. sliding plate boundary D. transform plate boundary E. emergent fault boundary

b. convergent plate boundary (subduction)

81. Any movement of the sea floor can produce a tsunami. a. true b. false

b. false

92. It is possible to predict precisely where and when an earthquake will occur. a. true b. false

b. false

Parts of plate interiors are earthquake free. a. true b. false

b. false

The motion of the P wave is up and down or side to side and the S wave pushes and pulls. a. true b. false

b. false

48. Earthquakes are caused by rock breaking at the: A. epicenter B. focus C. athenosphere D. mesosphere E. more than one of the above

b. focus

49. Tsunami waves have: a. very short wavelengths and long amplitudes B. very short amplitudes and long wavelengths C. very short periods and very high crests D. very long periods and very high crests E. more than one of the above

b. short amplitudes and long wavelengths

Shallow earthquakes occur at transform plate boundaries a. true b. false

b. true

50. Tsunami waves at sea travel up to speeds of: A. 50 mph B. 200 mph C. 500 mph D. 1000 mph E. none of the above

c. 500 mph (maybe? 100s kph)

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; all faults have recognizable traces.

c. Blind fault

Which type of fault does not, by definition, have a fault trace? A. normal fault B. reverse fault C. blind fault D. A ,B & C. E. None of the above; all faults have recognizable traces.

c. blind fault

Which of the world's major cities has suffered tremendous earthquake damage in the past not because it is located at a plate boundary (it is not), but rather because it is built atop a basin of ancient lakebed sediments that rhythmically rock back and forth when agitated by seismic waves of a characteristic frequency? a. Cairo b. los angeles c. mexico city d. tokyo

c. mexico city

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 U.S. A. over a greater distance B. over a lesser distance C. over the same distance

c. over a greater distance

The structure that is least affected (least likely to collapse) by earthquake L & R wave are: A. solid brick buildings B. solid concrete buildings C. reinforced masonry buildings D. wood frame buildings E. glass buildings with steel columns

c. reinforced masonry buildings

Faulting associated with an earthquake that shifts the seafloor and displaces the overlying water column, causing a wave: A. Body waves B. Surface waves C. Tsunami D. L & R waves E. Tidal waves

c. tsunami

52. Most of the injuries and fatalities caused by the Japan quake a. were caused by earth shaking B. were caused by earth shaking which caused buildings to collapse C. were caused by tsunami debris D. were caused by liquefaction waves E. were caused by P and S earthquake waves

c. were caused by tsunami debris

An earthquake with a magnitude of 8 as compared to an earthquake of magnitude 6 has S - waves that are _______________ times bigger. A. 1 X B. 2X C. 10X D. 100X E. 1000X

d. 100x

The Japan earthquake of 2011 had a magnitude of: a. 7.0 b. 8.5 c. 8.9 d. 9.0 e. 9.9

d. 9.0

67. Earthquake waves which pass through the interior of Earth are termed: A. interior waves B. R-waves C. surface waves D. body waves E. More than one of the above

d. body waves

87. What is the largest earthquake in a cluster called? A. the fore shock B. the P wave C. the Surface wave D. the main shock E. the after shock

d. main shock

58. The earthquake waves that cause the most damage to structures and buildings: A. P waves B. S waves C. Body waves D. Surface waves E. Refracted waves

d. surface waves

84. When an earthquake occurs in what form of energy does it travel? A. P waves B. S waves C. Surface waves D. Body waves E. all of the above

e. all of the above.

A surface along which rock on opposed sides is offset by earthquake-induced slip is called a ____________. A. joint B. convergent boundary C. divergent boundary D. wall E. fault

e. fault

Generally which type of earthquake waves travel fastest? A. interior waves B. surface waves C. R-waves D. body waves E. P-waves

e. p-waves