Deck 16: Unsafe Ground: Landslides and Other Mass Movements

Question 1

Between subaerial and submarine mass movements,we have a much better historical record of ____________.

A)subaerial movements
B)submarine movements

Answer 1

B

Question 2

One of the most problematic aspects of landslides is that large-scale,cataclysmic examples are the norm,whereas small-scale landslides are much more rare.

Answer 2

False

Question 3

____________ are likely to occur along volcanic slopes.

A)Lahars
B)Rockfalls
C)Submarine mass movements
D)Avalanches

Answer 3

A

Question 4

Which of the following types of mass movement takes place most gradually?

A)slump
B)creep
C)rock slide
D)mudflow

Question 5

Which of the following types of mass movement is least coherent (most like a liquid)?

A)slump
B)creep
C)rock slide
D)mudflow

Question 6

Geologists distinguish among different types of mass wasting based on factors such as the ____________ of the moving material and the rate of movement.

A)weight
B)color
C)compostion
D)name

Question 7

All types of mass wasting have approximately the same velocities.

Question 8

Which of the following types of mass movement is likely to move most rapidly?

A)slump
B)creep
C)rock slide
D)debris slide

Question 9

Which type of mass movement includes a large proportion of ash derived from a volcanic eruption?

A)stromboli
B)lahar
C)debris flow
D)wadi

Question 10

Strictly speaking,which of the following types of mass movement is a landslide?

A)slump
B)creep
C)rock slide
D)mudflow

Question 11

To the geologist,____________.

A)landslides and mass movements are the same thing
B)all mass movements are landslides,but not all landslides are mass movements
C)all landslides are mass movements,but not all mass movements are landslides
D)mass movements differ from landslides in that a greater mass of material moves during a mass movement than during a landslide

Question 12

Which of the following types of mass movement always travel down a curved surface?

A)slump
B)creep
C)rock slide
D)mudflow

Question 13

____________occur(s)when regolith moves slowly downslope due to freezing and thawing.

A)Avalanches
B)Slumping
C)Creep
D)Solifluction

Question 14

____________occur(s)when a semicoherent mass of material moves downslope on a failure surface.

A)Avalanches
B)Slumps
C)Creep
D)Solifluction

Question 15

Mass wasting always involves a sudden movement of material downslope.

Question 16

A ____________ may form at the head of a slump.

A)toe
B)failure surface
C)scarp
D)mass

Question 17

____________occur(s)when debris or snow mixes with air to form a chaotic cloud.

A)Avalanches
B)Slumps
C)Creep
D)Solifluction

Question 18

____________ may trigger tsunamis.

A)Lahars
B)Submarine mass movements
C)Avalanches
D)Rockfalls

Question 19

Slumps typically arrive intact at the bottom of a slope.

Question 20

____________occur(s)where thawed sediments move downslope over permafrost.

A)Avalanches
B)Slumps
C)Creep
D)Solifluction

Question 21

The immediate cause of incidents of mass movement is ____________.

A)electromagnetic attraction
B)gravitation
C)magnetism
D)friction

Question 22

Well-rounded sand has a larger angle of repose than irregularly shaped gravel.

Question 23

____________ can occur where undercutting waves remove support beneath sea cliff overhangs.

A)Landslides
B)Lahars
C)Rock falls
D)Mudslides

Question 24

The principle difference between a debris slide and a debris avalanche is the ____________.

A)shape of the path taken by the moving mass
B)grain size of the moving mass
C)debris slide contains abundant water,whereas the debris avalanche is dry
D)debris slide contains pyroclastic debris from a volcanic eruption

Question 25

The principle difference between a lahar and a mudflow is the ____________.

A)shape of the path taken by the moving mass
B)grain size of the moving mass
C)lahar contains abundant water,whereas the mudflow is dry
D)lahar contains pyroclastic debris from a volcanic eruption

Question 26

In cold,dry,mountainous climate,rock glaciers consisting of rocks held together by a smaller volume of ice can slide down slopes.

Question 27

Submarine mass movements have been found along hot-spot volcanoes and active plate boundaries.These massive slumps have been attributed to ____________.

A)subduction
B)tectonic activity
C)mantle upwelling
D)liquifaction

Question 28

Unstable slopes start to move when the ____________ force exceeds the ____________ force that holds the material in place.

A)downslope;gravity
B)resistance;downslope
C)downslope;resistance
D)gravity;resistance

Question 29

The principle difference between a debris flow and a mudflow is the ____________.

A)shape of the path taken by the moving mass
B)grain size of the moving mass
C)debris flow contains abundant water,whereas the mudflow is dry
D)debris flow contains pyroclastic debris from a volcanic eruption

Question 30

Ground shaking can transform wet sediments into liquid-like slurries in a process known as ____________.

A)liquifaction
B)slumping
C)undercutting
D)sloping

Question 31

____________ in metamorphic rock may become a failure surface.

A)Bedding planes
B)Exfoliation joints
C)Foliation planes

Question 32

Tectonic activity destabilizes the ground.

Question 33

The principle difference between a slump and a debris slide is the ____________.

A)shape of the path taken by the moving mass
B)grain size of the moving mass
C)slump contains abundant water,whereas the debris slide is dry
D)slump contains pyroclastic debris from a volcanic eruption

Question 34

Moisture among sediment grains ____________.

A)always increases the likelihood of mass wasting
B)always decreases the likelihood of mass wasting
C)can promote stability if present in small amounts,but promotes mass wasting if sediment is saturated
D)can promote stability if the grains are saturated,but a small amount being present has little effect on the likelihood of mass wasting

Question 35

The principle difference between a debris flow and a debris slide is the ____________.

A)shape of the path taken by the moving mass
B)grain size of the moving mass
C)debris flow contains abundant water,whereas the debris slide is dry
D)debris flow contains pyroclastic debris from a volcanic eruption

Question 36

Slope stability is determined by which two forces?

A)downslope and resistance
B)gravity and friction
C)resistance and gravity
D)downslope and friction

Question 37

____________ may form parallel to slope surfaces in granite and become a failure surface.

A)Bedding planes
B)Exfoliation joints
C)Foliation planes

Question 38

For dry sediments,the angle of repose is typically between ____________ and ____________ degrees.

A)10;17
B)15;22
C)20;27
D)30;37

Question 39

____________ in sedimentary rock may become a failure surface.

A)Bedding planes
B)Exfoliation joints
C)Foliation planes

Question 40

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

Question 41

Conditions such as ____________ may exacerbate a developing slump.

A)persistent rain
B)rising floodwaters
C)continuing earthquake aftershocks
D)All of the above are correct.

Question 42

Fires and deforestation may lead to slope failure.

Question 43

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

Question 44

Mass movement along coastal cliffs in southern California is so common because ____________.

A)the region is along an active margin with frequent earthquakes
B)the region is dry and the slopes support little or no vegetation
C)much of the rock in southern California is fractured
D)All of the above are correct.

Question 45

A rock slide into a reservoir triggered catastrophic flooding of the landscape below which dam?

A)Vaiont (Italy)
B)Aswan (Egypt)
C)Hoover (Nevada)
D)Glen Canyon (Arizona)

Question 46

Which type of bedrock provides the greatest risk of landslide?

A)granite
B)gneiss
C)sandstone
D)shale

Question 47

All regions are susceptible to mass movements.

Question 48

Coastal California is particularly susceptible to mass wasting because of ____________.

A)tectonic activity
B)weak substrate
C)seasonal heavy rains
D)All of the above are correct.

Question 49

____________ are surface features indicative of a developing slump.

A)Dead trees
B)Sinking foundations
C)Tilted utility poles
D)All of the above are correct.

Question 50

____________ may help prevent stabilize slopes to prevent mass wasting.

A)Revegetation
B)Regrading
C)Preventing undercutting
D)All of the above are correct.