Geology Exam #2

The point where movement occurred which triggered the earthquake is the _______ .
a) dip
b) epicenter
c) focus
d) strike

focus

Which of the following sequences correctly lists the different arrivals from first to last?
a) P waves ... S waves .... Surface waves
b) Surface waves ... P waves .... S waves
c) P waves ... Surface waves ... S waves
d) S waves ... P waves .... Surface waves

P waves ... S waves .... Surface waves

What happens to rock particles during the passage of a P wave through the rock?
a) they move in a rolling, circular motion
b) they change their volume parallel to the direction of wave travel
c) the do not move
d) the change their shape perpendicular to the direction of wave travel

they change their volume parallel to the direction of wave travel

Detailed studies of what earthquake allowed researchers to develop the elastic rebound
theory?.
a) the 1906 San Francisco earthquake
b) the 1964 Anchorage, Alaska earthquake
c) the 1755 Lisbon, Portugal earthquake
d) the 1985 Mexico City earthquakes

the 1906 San Francisco earthquake

How many seismograph stations are needed to locate the epicenter of an earthquake?
a) 1
b) 2
c) 3
d) 4
e) 9

3

If a P wave were to travel from a solid to a liquid - what would happen to its velocity?
a) stay the same
b) increase
c) slow down
d) decrease to zero

slow down

If an S wave were to go from a solid to a liquid - what would happen to its velocity?
a) stay the same
b) increase
c) slow down
d) decrease to zero

decrease to zero

Body waves consist of the:
a) P waves only
b) S waves only
c) P and S waves
d) Surface waves

P and S waves

With increasing distance from an epicenter, the difference in arrival times between the P and
the S waves _________
a) increases
b) decreases
c) stays constant
d) none of the preceding

increases

Earthquake A has a Richter magnitude of 7 as compared with earthquake B's 6. The amount
of ground motion is:
a) A is 2 times more
b) A is 10 times more
c) A is 32 times more
d) ground motion cannot be determined by Richter magnitude

A is 10 times more

Earthquake A has a Richter magnitude of 8 as compared with earthquake B's 6. The
amount of energy is:
a) A is 2 times more
b) A is 10 times more
c) A is 32 times more
d) A is 100 times more
e) not measured by Richter magnitude

A is 32 times more

In general, the most destructive earthquake waves are the __________ .
a) P waves
b) S waves
c) Surface waves
d) pretty much the same

Surface waves

Where is the focus with respect to the epicenter:
a) directly below the epicenter
b) directly above the epicenter
c) on the opposite side of the Earth
d) in different places depending of the magnitude

directly below the epicenter

What causes the up-and-down wiggles on the seismogram show above?
a) variations in air pressure
b) ground movement
c) tsunami waves
c) electromagnetic pulses

ground movement

Which set of waves are probably the surface waves on the seismogram above?
a) A
b) B
c) C
d) They are all surface waves

C

Which set of waves are the P waves on the seismogram above?
a) A
b) B
c) C
d) They are all P waves

A

Which set of waves are the S waves on the seismogram above?
a) A
b) B
c) C
d) They are all S waves

B

The difference in arrival times between which pair of waves can be used to determine the distance to the epicenter of an earthquake?
a) A and C
b) A and B
c) B and C
d) cannot be determined from the seismogram

A and B

Which of the following measures an earthquake's intensity based on the observed effects on people and structures?
a) Richter scale
b) Modified Mercalli scale
c) Centigrade scale
d) moment magnitude scale

Modified Mercalli scale

Which of the following can be triggered by an earthquake?
a) tsunami
b) intense ground shaking
c) a landslide
d) all of these

all of these

Which of the following waves is the slowest?
a) P waves
b) S waves
c) Surface waves
d) they all have the same velocity

Surface waves

Which of the following statements best describes the state of earthquake prediction?
a) geologists can accurately predict the time and location of almost all earthquakes
b) scientists can accurately predict the time and location of about 50% of all earthquakes
c) scientists can accurately predict when an earthquake will occur, but not where
d) scientists can characterize the seismic risk of an area, but cannot accurately predict most earthquakes

scientists can characterize the seismic risk of an area, but cannot accurately predict most earthquakes

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

focus

A primary force opposing motion on all faults is __________.
a) covalent bond
b) gravity
c) Van der Walls force
d) friction

friction

The recurrence of earthquakes along a single fault is referred to as __________.
a) stick-slip behavior
b) elastic rebound
c) seimic repetition
d) slip-transfer

stick-slip behavior

The vast majority of earthquakes occur __________.
a) along transform plate boundaries only
b) near hotspots
c) along passive margins
d) along all types of plate boundaries

along all types of plate boundaries

Earthquakes most often occur along __________.
a) bedding planes
b) floodplains
c) fault zones
d) river valleys

fault zones

Deep focus earthquakes occur only along ___________.
a) convergent plate boundaries
b) divergent plate boundaries
c) transform plate boundaries
d) hotspots

convergent plate boundaries

__________travel with a compressional motion.
a) Love waves
b) Rayleigh waves
c) P waves
d) S-waves
e) surface waves

P waves

The massive device that detects earthquake waves because it stays in place is called a _____.
a) seismogram
b) seismograph
c) seismometer
d) pictogram

seismograph

Which type of earthquake wave generally has the slowest velocity?
a) S waves
b) P waves
c) surface waves
d) all waves travel at the same speed

surface waves

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 the town of New Madrid
b) 20 miles south of New Madrid
c) 20 miles beneath New Madrid
d) 20 miles north of New Madrid

20 miles beneath New Madrid

According to the moment magnitude scale, a magnitude 8 earthquake would beabout 1,000 greater than a magnitude _____ earthquake.
a) 9
b) 7
c) 6
d) 5
e) 4

5

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

Indian

_______ occur(s) where earthquakes cause pore pressure to increase, which in turn causes grains to separate and flow.
a) Liquefaction
b) Normal faults
c) Landslides
d) Aftershocks
e) Roiling

Liquefaction

A tsunami is __________.
a) a sea wave generated by displacement of water
b) a sloshing of water back and forth within a lake or a bay
c) a wave caused by large tidal forces
d) the tendency of wet, clay-rich soils to behave like a liquid during an earthquake.

a sea wave generated by displacement of water

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 after and earthquake

produce most of the damage to buildings during earthquakes

The __________ the earthquake, the less severe the damage will be.
a) larger the magnitude of
b) shorter the duration of
c) farther you are from
d) closer you are to

farther you are from

Wet and unconsolidated substrates are uniquely susceptible to ____ during and earthquake.
a) displacement
b) collapse
c) liquefaction
d) faulting

liquefaction

Which of the following does not affect the severity of damage from and earthquake?
a) weather
b) duration
c) distance
d) magnitude

weather

Almost all very large earthquakes occur at __________.
a) transform faults
b) spreading centers
c) subduction zones
d) hotspots

subduction zones

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

zoning

Where is the best place to be if a large earthquake occurs?
a) in an empty field
b) in a brick house
c) in a large building
d) on the beach

in an empty field

An earthquake takes place when
a) movement occurs along a fault
b) elastic strain energy on the fault blocks exceeds the friction between the blocks
c) a fault reaches the surface

elastic strain energy on the fault blocks exceeds the friction between the blocks

The point at which the first movements of an earthquake appear to occur is the _____.
a) epicenter
b) resurgence point
c) liquefaction area
d) focus

focus

Which of the following measurements of an earthquake is measured by an instrument?
a) Mercalli
b) Modified Mercalli
c) Richter

Richter

An earthquake of Richter magnitude 7 will have a seismograph amplitude how much greater than one of Richter magnitude 6?
a)1/6
b) 7
c) 10
d) 32
e) 1

10

Which of the following types of mass movement often travels as a coherent mass down a curved surface?
a. slump
b. creep
c. rock slide
d. mudflow

slump

Some landslides include a mixture of loose surface soil and debris called ________.
a.bedrock
c.sully
b. regolith
d. substratum

regolith

Which of the following types of mass movement takes place most gradually?
a. slump
b. creep
c. rock slide
d. mudflow

creep

Which of the following types of mass movement is LEAST coherent (most like a fluid)?
a.slump
b.creep
c.rock slide
d.mudflow

mudflow

What type of mass movement occurs in an area with bowed tree trunks and misaligned fences?
a.rock fall
b.mudflow
c.creep
d.debris slide

creep

What type of mass movement would you expect to form in a slot canyon (steep-walled canyon)?
a.avalanche
b.rock fall
c.slump
d.lahar

rock fall

The principal difference between a debris flow and a mudflow is ________.
a.the shape of the path taken by the moving mass
b.the grain size of the moving mass
c.that a debris flow contains abundant water, whereas a mudflow is dry
d.that a debris flow contains pyroclastic debris from a volcanic eruption

the grain size of the moving mass

The ________ in the sequence of sedimentary rocks shown below may become a failure surface.
a.bedding planes
b.exfoliation joints
c.foliation planes
d.uplift planes

bedding planes

Which of the following increases the risk of mass movement?
a.adding a small amount of moisture to loose, dry sediment
b.waves breaking before they reach sea cliffs
c.flooding the sediment with water to the point of saturation
d.reducing the grade of the slope

flooding the sediment with water to the point of saturation

Which of the following would decrease the resistance force?
a.lowering the slope angle
b.draining out water
c.chemical weathering of the slope
d.adding material to the base of the hill

chemical weathering of the slope

As ________ occurs, intact rock is broken down into smaller, weaker pieces called sediment.
a. an avalanche
b. cohesion
c. solifluction
d. weathering

weathering

The immediate cause of incidents of mass movement is ________.
a.static
b.gravity
c.magnetism
d.friction

gravity

Slope failures are most likely to occur in ________ conditions.
a.dry, mountainous
b.dry, flat
c.wet, mountainous
d.wet, flat

wet, mountainous

Which type of trigger would be more likely to cause slope failure along a newly built roadway?
a.liquefaction
b.steepening the slope
c.the addition of weight
d.exposure of fresh rock

steepening the slope

Which of the following situations may lead to slope failure?
a.the addition of a small amount of water to a slope
b.installing a chain-link fence over a slope
c.undercutting a slope by a bulldozer
d.regrading a steep slope to create a gentler slope

undercutting a slope by a bulldozer

Which of the following factors decreases the risk of mass movement?
a.nearby earthquakes
b.excavation into the base of a hill
c.adding weight to the top of a hill
d.adding vegetation to the side of a hill

adding vegetation to the side of a hill

Which of the following situations is the most likely candidate for the occurrence of mass movements?
a.a flat, desert area with little vegetation
b.a gentle slope along the coastline that is across a highway from the surf zone
c.gently sloping hills in the tropics
d.a mountain terrain in a humid environment

a mountain terrain in a humid environment

Slope failures are more likely to occur in ________ than in ________.
a.forests; deserts
b.mountains; deserts
c.deserts; mountains
d.deserts; forests

mountains; deserts

Imagine you have just bought some property and notice that the trees on the slope have curved trunks. What type of landslide event do you likely have on your property?
a.solifluction
b.creep
c.Slump
d.Mudflow

creep

How can you use a landslide hazard map to help buy a piece of property?
a.to determine if there are large rivers running by the property
b.to determine if the property is in a high-risk zone for landslides
c.to determine if the property is near a high-risk flood zone
d.to determine if the property has been exposed to fires recently

to determine if the property is in a high-risk zone for landslides

After finishing a new construction project, why is the first task often to install new landscaping around the area?
a.The plants will provide nutrients for animals that will carry away the soil.
b.The roots will grow into the slope and work to keep the slope intact.
c.The plants will add additional weight to the slope and keep it stable.
d.The roots take in oxygen and release it into the soil to increase surface tension.

The roots will grow into the slope and work to keep the slope intact.

What is the most effective means of mitigating the risk of a slope failure for the slope shown in the figure below, which depicts a seashore?
a.apply shotcrete
b.revegetate with new plants
c.install riprap
d.dewater the slope

install riprap

What is the slowest type of mass wasting process?
a. rotational slump
b. creep
c. rock avalanche
d. debris flow

creep

A descending mass moving downslope as a viscous fluid of individual particles is a _____.
a. slump
b. flow
c. slide
d. fall

flow

The driving force behind all mass wasting processes is
a. presence of vegetation
b. presence of water
c. gravity
d. slope angle

gravity

Flow of water-saturated debris over impermeable material is called
a. solifluction
b. fall
c. slip
d. flow

solifluction

An apron of fallen rock fragments that accumulates at the base of a cliff is called
a. debris
b. avalanche
c. sediment
d. talus

talus

Slopes that have been stable for many years may sometimes fail catastrophically. What is a common trigger for these failures?
a. removal of vegetative cover
b. reducing the gradient of the slope
c. draining of water from the slope
d. growth of vegetation on the slope

removal of vegetative cover

A rockfall occurs whena.
a block of bedrock breaks off and falls freely from a cliff
b. rock layers are displaced slowly downslope year after year.
c. soil and debris move downslope as a viscous fluid.
d. all of these

block of bedrock breaks off and falls freely from a cliff

Movement associated with permafrost is
a. avalanches
b. solifluction
c. quicksands
d. expansive clays.

solifluction

Mass wasting processes are classified according to
a. amount of water in rock or surface material.
b. size of particles involved.
c. type of movement (kinematics).
d. all of these

all of these

One method of stabilizing slopes to prevent mass wasting is
a. build appropriately engineered retaining structures.
b. cut away the base of the slope with heavy equipment.
c. add weight to the slope.
d. make the slope steeper.

build appropriately engineered retaining structures.

The typical rate of creep movement in soils is usually
a. a centimeter per month.
b. a centimeter per week.
c. a meter per day.
d. a centimeter or less per year.

a centimeter or less per year.

Mass wasting events may be triggered by
a. melting of permafrost
b. earthquakes
c. torrential rain
d. all of these

all of these

Which of the following is a form of mass wasting?
a. a landslide
b. a rock avalanche
c. a mudflow
d. all of are forms of mass wasting

all of are forms of mass wasting

The downslope movement of material under the influence of gravity is known as
a. downslope movement
b. land sliding
c. mass wasting
d. none of these

mass wasting

Water can encourage mass flow by:
a. reducing friction between grains
b. undercutting a steep slope
c. weathering bedrock to clay minerals
d. all of the preceding

all of the preceding

A talus cone is produced by a:
a. rock fall
b. rock slides
c. mud flows
d. all of the above

rock fall

Which of the following does not promote mass movement?
a. low slopes
b. forest fires
c. heavy rainfall
d. bedding planes dipping down slope

low slopes

One of the most effective ways to stabilize a slope is to:
a. remove all excess vegetation
b. remove the toe of the slope
c. control and remove water
d. none of the preceding

control and remove water

The characteristic slope of a pile of dry sand is called the ______ .
a. angle of repose
b. strike
c. consolidation factor
d. dip

angle of repose

Damp sand has a higher angle of repose than dry sand because of _____ .
a. cementation
b. surface tension
c. partial melting
d. dissolution

surface tension

Surface tension is greatest when ________ .
a. sand is dry
b. sand is moist, but not saturated with water
c. sand is saturated with water
d. sand is over saturated with water

sand is moist, but not saturated with water

Which of the following can trigger a landslide?
a. an earthquake
b. a heavy rainstorm
c. removal of material from the base of a slope
d. all of these

all of these

During an earthquake, water-saturated sand can behave like a liquid, a process called ____ .
a. slurrification
b. solifluction
c. unconsolidation
d. liquefaction

liquefaction

What is the dominant force that causes mass movement?
a. tidal forces
b. seismic energy release
c. gravity
d. wind

gravity

Which of the following processes is not caused largely by gravity?
a. flow of glacial ice
b. movement of landslides and debris slides
c. movement of water in streams
d. all of these are strongly influenced by gravity

all of these are strongly influenced by gravity

Which of the following situations is least likely to result in mass movement?
a. a steep slope
b. a slope with loose material saturated with water
c. a slope with abundant vegetation
d. a slope consisting of fractured and deformed rock

a slope with abundant vegetation

Which of the following slopes is least stable?
a. a slope where the sedimentary layers dip parallel to the slope
b. a slope where the sedimentary layers are horizontal
c. a slope where the sedimentary layers dip perpendicular to the slope
d. all of these slopes have the same stability

a slope where the sedimentary layers dip parallel to the slope

How do geologists classify mass movements?
a. by the speed of the mass movement
b. by the nature of the material
c. by the nature of the movement
d. all of these

all of these

The total area drained by a stream and its tributaries is called the:
A) hydrologic cycle
B) divide
C) tributary area
D) drainage basin

drainage basin

The transfer of water among various reservoirs in the Earth system is:
A) the hydrologic cycle
B) hydrologic transfer mechanism
C) water table
D) none of these

the hydrologic cycle

The headwaters of a stream are always located:
A) at the terminus of the stream where it enters a standing body of water
B) at the source of the stream
C) along the longitudinal profile of the stream
D) all of these

at the source of the stream