Deck 14: Mass Wasting

Question 1

A slope's shear strength is increased with the addition of an external support along the base of a slope.

Answer 1

True

Question 2

The shear strength of a slope increases with an increase in slope.

Answer 2

False

Question 3

A stable slope does not change over time.

Answer 3

False

Question 4

Shear strength of a slope is greater with higher cohesion and greater internal friction between grains.

Question 5

Shear strength of a slope decreases as the slope material is weathered.

Question 6

Overloading of a slope is not often the result of human action.

Question 7

Vegetation increases the shear strength of hillslope materials.

Question 8

A slide is distinguished from a flow in that failure occurs along distinct surfaces or planes.

Question 9

A rotational slide can change into a debris flow downslope.

Question 10

Irregular terrain is an indication that the slope was unstable in the past and would suggest that it will be stable in the future.

Question 11

Slope stability can be increased by diverting water from the slope.

Question 12

As mass wasting processes go, creep poses the greatest risk to human life.

Question 13

Creep is accurately characterized as

A) widespread in extent
B) slow moving
C) expensive relative to damages resulting from it
D) difficult to control
E) all of the above

Question 14

Which of the following does NOT tend to increase the stability of a slope?

A) decreasing slope angle
B) diverting drainage from the slope
C) maintaining or planting vegetation
D) building houses to cover the slope
E) building a retaining wall at the base of the slope

Question 15

Mass wasting could likely to occur under which of the following combinations of conditions?

A) weathered slope with poor drainage
B) during the rainy season on a recently burned slope
C) a new subdivision on the top of a hillside that experiences an earthquake
D) B or C
E) all of the above

Question 16

Among the types of slides are

A) slumps.
B) block glides.
C) mudflows.
D) A and B
E) all of the above

Question 17

Creep would be expected in

A) a humid climate
B) a semi-arid climate
C) an arid climate
D) B and C
E) any climate

Question 18

Which of the following characteristics might suggest a piece of property is susceptible to mass wasting?

A) surface springs of water
B) tilted telephone poles
C) the presence of shale
D) rolling hills
E) all of the above

Question 19

Geologists and engineers can reduce the potential for mass wasting by

A) adding external support along the base of a slope
B) not planning developments on unstable slopes
C) altering the subsurface geology
D) A and B
E) all of the above

Question 20

The Aberfan disaster could have been avoided if the tip had

A) not been located on a steep slope.
B) been located farther away from the school
C) not been located over an area of known springs
D) been made of coarser material
E) been vegetated

Question 21

___________ is the type of mass wasting responsible for the greatest amount of property damage.

Question 22

A(n) ___________is a type of mass movement that occurs along a curved surface of rupture.

Question 23

A ___________is up to 30% water, and at least 50% clay-sized particles, whereas a___________ ___________ contains less water and larger particles.

Question 24

___________ ___________ spontaneously liquefy and flow like water.

Question 25

The___________ process is the most effective mass wasting process relative to the amount of sediment moved, it is most effective and significant in a___________ climate.

Question 26

Debris flows are common in areas of___________ relief and ___________ vegetation found in climates.

Question 27

Describe the role of water in mass wasting.

Question 28

Describe the roles of bedding and slope on the potential for unstable slopes.

Question 29

Give three examples of ways in which human activity can contribute to or cause mass wasting.

Question 30

Describe how the clearing of vegetation from a hillslope changes slope stability.

Question 31

What triggered the 1970 debris flow which buried the town of Yungay, Peru?

Question 32

How is the term landslide used in geology?

Question 33

What is meant by the term "mass wasting"(or, "mass movement")?

Question 34

What is the fundamental cause of mass wastage?

Question 35

What is the angle of repose for a slope?

Question 36

What are three types of changes in a slope that can lead to mass wasting?

Question 37

How can weathering affect mass wasting?

Question 38

Briefly explain why clay is a very unstable slope material when saturated.

Question 39

What caused the failure of the large coal mining waste pile in 1966 in Aberfan, Wales?

Question 40

What is a rockfall?

Question 41

What climatic conditions seem most conducive to promoting earthflows?

Question 42

What climatic conditions seem most conducive to promoting mudflows?

Question 43

How are mudflows different from earthflows?

Question 44

Which type of mass movement moves the greatest amount of material downslope?

Question 45

What is the commonest type of complex mass movement?