Chapter 9

Question 1

The term “mass wasting” refers to the improper use of Earth materials in a manner that is in conflict with the principles of conservation and environmental stewardship. (T/F)

Answer 1

False

Question 2

The driving force for mass wasting is gravity. (T/F)

Answer 2

True

Question 3

When soil is saturated with water it becomes heavier and less viscous and is more likely to flow downslope. (T/F)

Answer 3

True

Question 4

Creep is very slow downslope movement of soil. (T/F)

Answer 4

True

Question 5

They type of material involved doesn’t matter in how a mass wasting event is classified. (T/F)

Answer 5

False

Question 6

The term “debris,” implies that coarse-grained fragment predominates in the soil. (T/F)

Answer 6

True

Question 7

Landslides are natural phenomena that humans can either cause or prevent. (T/F)

Answer 7

True

Question 8

Within the United States, fewer people have died as a result of landslides than other geological hazards, such as earthquakes and tornadoes. (T/F)

Answer 8

False

Question 9

Humans car trigger earthflows by adding water to soil from septic systems or by over watering lawns. (T/F)

Answer 9

True

Question 10

A mudflow is a flowing mixture of soil and water usually moving down a channel. (T/F)

Answer 10

True

Question 11

In cold climates freezing and thawing contribute to downslope soil movement. (T/F)

Answer 11

True

Question 12

Resistance to movement or deformation of soil is called ___.

Answer 12

shear strength

Question 13

In a translational slide, the descending mass ___.

Answer 13

moves along a plane approximately parallel to the slope of the surface

Question 14

A ___ involves movement along a curved surface.

Answer 14

rotational slide

Question 15

When soil is saturated with water ___ increases.

Answer 15

pore pressure

Question 16

___ commonly trigger mass wasting events

Answer 16

Earthquakes

Question 17

Shear strength ___.

Answer 17

is the total force/stress resisting movement

Question 18

Two factors that contribute significantly to soil creep are water in the soil and ___.

Answer 18

freeze-thaw climates

Question 19

When a stream, wave action, or excavation by humans undercuts the base of a slope, slope failure may occur because ___.

Answer 19

downslope support of the slop materials will have been reduced or eliminated

Question 20

Mudflows are ___ likely to occur in areas not protected by vegetation

Answer 20

more

Question 21

Mudflows are ___ likely to occur in arid regions than in wet climates.

Answer 21

more

Question 22

Which of the following factors are how geologists, engineers, and others classify mass wasting?

Answer 22

rate of movement, type of materials, and type of mevement

Question 23

An apron of fallen rock fragments called ___ is generally found at the base of a slope affected by rockfall.

Answer 23

talus

Question 24

The rate of movement in creep is usually ___.

Answer 24

a centimeter or less per year

Question 25

One way to prevent slope failure is to ___.

Answer 25

drain ground water from the slope regrade the slope so that it is more gently inclined pin the rock onto the slope with rock bolts or other devices retain or establish vegetation to protect the slope

Question 26

Assuming that all other conditions are identical, a slope that is ___ is more stable.

Answer 26

more gently inclined

Question 27

Among techniques used to prevent rockfalls along highways is to ___.

Answer 27

cover with a shed spray the exposed roadslide with cement remove slide-prone rock step the slope back

Question 28

A ___ is a general term that tells nothing about the processes involved.

Answer 28

landslide