Deck 7: Mass Wasting and Related Hazards

Question 1

Which of the following human activities commonly causes the over-steepening of slopes, which then leads to mass wasting?

A) construction of roads
B) drilling of water wells
C) logging of trees
D) constructing high-rise buildings
E) all of the answers listed here

Answer 1

A

Question 2

Suppose that engineers are unable to keep earth materials from coming down onto a highway. In this case, which of the following would be the most economical and effective technique for reducing the hazard?

A) build a protective structure
B) install a rain sensor
C) reroute the highway
D) remove the mountain
E) close the highway during heavy rains

Answer 2

A

Question 3

Imagine a section of highway with a large outcrop of fractured rock that poses a serious rockfall hazard. Which of the following engineering controls would be the best choice for minimizing the chance of large rocks falling onto the roadway?

A) install rock bolts
B) build a retaining wall
C) cover the slope with vegetation
D) control the flow of water
E) install a mesh fence

Answer 3

A

Question 4

Which of the following best describes a mass wasting event referred to as a slide?

A) material moving down-slope along a surface
B) material tumbling through air or down a steep slope
C) material moving as a viscous fluid
D) mixture of rock and snow
E) material moving as a viscous fluid

Question 5

Which of the following best describes a mass wasting event referred to as a fall?

A) material tumbling through air or down a steep slope
B) material moving down-slope along a surface
C) material moving as a viscous fluid
D) mixture of rock and snow

Question 6

Unlike mass wasting, gradual subsidence and sudden collapse involve the movement of earth materials without any slope. Sudden collapse is typically caused by which of the following?

A) collapse of caves in limestone rock
B) collapse of underground aquifers
C) repeated eruption of steam geysers
D) repeated eruptions of volcanic ash
E) all of the answers listed here

Question 7

What best describes the way in which mass-wasting events are classified?

A) type of material and type of motion
B) volume of material and amount of damage
C) type of material and amount of damage
D) volume of material and type of motion
E) tectonic setting and amount of damage

Question 8

Which of the following forms of mass wasting involves both sliding and flowing?

A) slump
B) flow
C) slide
D) fall
E) creep

Question 9

Which of the following is a common triggering mechanism that causes slopes to fail suddenly?

A) all of the answers listed here
B) earthquakes
C) over-steepening a slope
D) heavy rainfall events
E) wildfires

Question 10

Which of the following engineering controls would be best suited to strengthen a slope that has been over-steepened by cutting into the hillside during highway construction?

A) build a retaining wall
B) install rock bolts
C) cover the slope with vegetation
D) control the flow of water
E) build a tunnel

Question 11

It is nearly impossible for scientists and engineers to predict where slope failure may occur.

Question 12

The use of engineering controls is one of the two basic methods for minimizing mass wasting hazards. Which of the following is the other basic approach used to minimize mass wasting hazards?

A) avoid building in hazard zones
B) hydrologic controls
C) government regulations
D) geologic controls
E) slope control

Question 13

Highway tunnels are very expensive, but are often times more cost effective over the long-term compared to the cost of repeated repairs and maintenance in areas where mass wasting is difficult to control.

Question 14

Which of the following best explains why excessive amounts of water can destabilize a slope?

A) increases internal pore pressure
B) causes too much vegetation growth
C) increases chemical weathering of earth materials
D) increases erosion of surface materials
E) attracts large, heavy animals

Question 15

Which of the following forms of mass wasting involves the slow, down slope movement of individual soil and rock particles?

A) creep
B) slump
C) flow
D) slide
E) fall

Question 16

Stability of earth materials on slopes depends on the balance of gravitational and frictional forces. Which of the following does NOT have a measurable effect on the balance between gravity and friction?

A) atmospheric air pressure
B) steepness of a slope
C) presence of water
D) type of rock or sediment that is making up the slope
E) types of vegetation on the slope

Question 17

Which of the following best describes why snow avalanches occur?

A) loss of friction along weak layers within a snowpack
B) high winds and drifting snow
C) low temperatures followed by warmer weather
D) melting at the contact between the snow and underlying earth material
E) loose, non-cohesive snowpack

Question 18

Which of the following earth materials is most likely to produce a vertical cliff that is fairly stable?

A) crystalline igneous rock such as granite
B) alternating layers of sedimentary sandstone and shale
C) foliated metamorphic rock such as slate
D) loose sedimentary material such as sand and clay
E) layers of basaltic (igneous) lava flows

Question 19

Which of the following best describes a mass wasting event referred to as a flow?

A) material moving as a viscous fluid
B) material tumbling through air or down a steep slope
C) material moving down-slope along a surface
D) mixture of rock and snow

Question 20

Pumping oil from the subsurface can result in subsidence.