Question 1

Why does the removal of material at the base of a slope decrease its stability?

Accepted Answer

A)  Removing material decreases the surface tension between grains. 
B)  The force of gravity decreases,and the slope will fail. 
C)  The slope now has a much lower angle of repose. 
D)  The slope now exceeds the angle of repose of the material. 
A)  Removing material decreases the surface tension between grains. 
B)  The force of gravity decreases,and the slope will fail. 
C)  The slope now has a much lower angle of repose. 
D)  The slope now exceeds the angle of repose of the material. D

Question 2

Adding a small amount of water to a substance increases its cohesion,whereas adding a lot of water decreases its cohesion.Why?

Accepted Answer

A)  A small amount of water decreases surface tension,allowing the grains to bond together,whereas too much water will increase surface tension and force the grains away from each other. 
B)  A small amount of water increases surface tension and holds the grain together.Too much water between the grains will eliminate surface tension. 
C)  Water has a small electrostatic force that disrupts the gravitational attraction of the grains and forces them to move away from each other. 
D)  A small amount of water will precipitate cement into the pores of the material,whereas too much water will not allow that cement to form. 
A)  A small amount of water decreases surface tension,allowing the grains to bond together,whereas too much water will increase surface tension and force the grains away from each other. 
B)  A small amount of water increases surface tension and holds the grain together.Too much water between the grains will eliminate surface tension. 
C)  Water has a small electrostatic force that disrupts the gravitational attraction of the grains and forces them to move away from each other. 
D)  A small amount of water will precipitate cement into the pores of the material,whereas too much water will not allow that cement to form. B

Question 3

Which of the following landscapes is the most likely candidate for the occurrence of mass movements?

Accepted Answer

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 mountainous terrain in a humid environment 
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 mountainous terrain in a humid environment D

Question 4

Why do submarine slumps pose a hazard to people living in coastal areas?

Accepted Answer

A)  Submarine slumps can trigger other mass movements on land. 
B)  Submarine slumps can induce liquefaction of the nearby land surface. 
C)  Submarine slumps can trigger tsunamis. 
D)  Submarine slumps can trigger earthquakes. 
A)  Submarine slumps can trigger other mass movements on land. 
B)  Submarine slumps can induce liquefaction of the nearby land surface. 
C)  Submarine slumps can trigger tsunamis. 
D)  Submarine slumps can trigger earthquakes.

Question 5

Slope failures are more likely to occur in ________ than in ________.

Accepted Answer

A)  forests; deserts 
B)  mountains; deserts 
C)  deserts; mountains 
D)  deserts; forests 
A)  forests; deserts 
B)  mountains; deserts 
C)  deserts; mountains 
D)  deserts; forests

Question 6

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

Accepted Answer

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

Question 7

After finishing a new construction project,why is the first task often to install new landscaping around the area?

Accepted Answer

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. 
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.

Question 8

What is a turbidity current? How is this related to mass movements?

Accepted Answer

A turbidity current is a submarine mass

Question 9

What type of mass wasting event is beginning to form on the hillside shown in the image below?

Accepted Answer

A)  an avalanche 
B)  a debris flow 
C)  solifluction 
D)  a slump 
A)  an avalanche 
B)  a debris flow 
C)  solifluction 
D)  a slump

Question 10

The principal difference between a lahar and a mudflow is ________.

Accepted Answer

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

Question 11

Why would Florida,which receives plentiful rainfall and remains humid for a large portion of the year,be less susceptible to landslides than the California desert?

Accepted Answer

Student answers should be similar to the

Question 12

Lahars occur on ________.

Accepted Answer

A)  volcanic slopes 
B)  vertical cliff faces 
C)  undersea slopes 
D)  divergent plate boundaries 
A)  volcanic slopes 
B)  vertical cliff faces 
C)  undersea slopes 
D)  divergent plate boundaries

Question 13

________ occurs when debris or snow mixes with air to form a chaotic cloud.

Accepted Answer

A)  An avalanche 
B)  A slump 
C)  Creep 
D)  Solifluction 
A)  An avalanche 
B)  A slump 
C)  Creep 
D)  Solifluction

Question 14

Which of the following factors decreases the risk of mass movement?

Accepted Answer

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 
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 15

Why are submarine mass wasting events of concern to people living near sea level in coastal regions? (What hazard can be triggered by submarine mass wasting events?)

Accepted Answer

Submarine mass wasting events

Question 16

As shown in the figure below,________ may form parallel to slope surfaces in granite and become a failure surface.

Accepted Answer

A)  bedding planes 
B)  exfoliation joints 
C)  foliation planes 
D)  uplift planes 
A)  bedding planes 
B)  exfoliation joints 
C)  foliation planes 
D)  uplift planes

Question 17

What is the most effective means of mitigating the risk of a slope failure for the slope shown in the figure below?

Accepted Answer

A)  installing rock bolts 
B)  revegetating with new plants 
C)  installing riprap 
D)  dewatering the slope 
A)  installing rock bolts 
B)  revegetating with new plants 
C)  installing riprap 
D)  dewatering the slope

Question 18

Describe two factors that affect the resistance force and explain how they affect the stability of the slope.

Accepted Answer

Student answers may contain two of the f

Question 19

Which of the following consist(s)of large boulders placed at the base of coastal slopes?

Accepted Answer

A)  rock dams 
B)  rock sheds 
C)  riprap 
D)  retaining walls 
A)  rock dams 
B)  rock sheds 
C)  riprap 
D)  retaining walls

Question 20

Which of the following increases the risk of mass movement?

Accepted Answer

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 
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

Exam 13: Unsafe Ground: Landslides and Other Mass Movements

Why does the removal of material at the base of a slope decrease its stability?

Adding a small amount of water to a substance increases its cohesion,whereas adding a lot of water decreases its cohesion.Why?

Which of the following landscapes is the most likely candidate for the occurrence of mass movements?

Why do submarine slumps pose a hazard to people living in coastal areas?

Slope failures are more likely to occur in ________ than in ________.

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

After finishing a new construction project,why is the first task often to install new landscaping around the area?

What is a turbidity current? How is this related to mass movements?

What type of mass wasting event is beginning to form on the hillside shown in the image below?

The principal difference between a lahar and a mudflow is ________.

Why would Florida,which receives plentiful rainfall and remains humid for a large portion of the year,be less susceptible to landslides than the California desert?

Lahars occur on ________.

________ occurs when debris or snow mixes with air to form a chaotic cloud.

Which of the following factors decreases the risk of mass movement?

Why are submarine mass wasting events of concern to people living near sea level in coastal regions? (What hazard can be triggered by submarine mass wasting events?)

As shown in the figure below,________ may form parallel to slope surfaces in granite and become a failure surface.

What is the most effective means of mitigating the risk of a slope failure for the slope shown in the figure below?

Describe two factors that affect the resistance force and explain how they affect the stability of the slope.

Which of the following consist(s)of large boulders placed at the base of coastal slopes?

Which of the following increases the risk of mass movement?

The Earth in Context

The Way the Earth Works: Plate Tectonics

Patterns in Nature: Minerals

Up From the Inferno: Magma and Igneous Rocks

The Wrath of Vulcan: Volcanic Eruptions

Pages of the Earths Past: Sedimentary Rocks

Metamorphism: a Process of Change

A Violent Pulse: Earthquakes

Crags,cracks,and Crumples: Crustal Deformation and Mountain Building

Deep Time: How Old Is Old

A Biography of the Earth

Riches in Rock: Energy and Mineral Resources

Streams and Floods: the Geology of Running Water

Restless Realm: Oceans and Coasts

A Hidden Reserve: Groundwater

Dry Regions: the Geology of Deserts

Amazing Ice: Glaciers and Ice Ages

Global Change in the Earth System

Introducing Rocks

A Surface Veneer: Sediments and Soils

The Rock Cycle

The Earth’s Interior Revisited: Insights from Geophysics

Memories of Past Life: Fossils and Evolution

Ever-Changing Landscapes and the Hydrologic Cycle

Prelude: And Just What is Geology?

Filters

Slope failures are more likely to occur in than in .