Mass Movements Exam Prep Chapter 15

Natural Disasters, 11e (Abbott)

Chapter 15 Mass Movements

1) External processes that increase the odds of a slope failure include ________.

A) adding mass high on a slope, as in sediment deposition

B) steepening the slope, as by fault movements

C) removing support from low on a slope, as by stream or ocean-wave erosion

D) All of these choices are correct.

2) The natural materials most commonly associated with earth failures are ________.

A) clay minerals

B) quartz

C) granite

D) basalt

E) pahoehoe

3) Clay crystals ________.

A) are very large

B) are very small

C) range from very large to very small

D) are amorphous

E) lack an ordered atomic structure

4) Freshwater passing through uplifted sediments containing quick clay changes the sea salt content leaving quick clay with all but which of the following?

A) weak structure

B) grains mostly less than 0.002-mm diameter

C) water contents commonly in excess of 50 percent

D) a higher salt content

5) The underlying cause of the Rissa, Norway, landslide was ________.

A) dissolution of salt in the soil

B) too much gypsum in the soil

C) over steepening of slopes of volcanic ash

D) freezing and thawing of piles of glacial boulders

E) layering of volcanic pyroclasts

6) Many hill-slope masses are weak due to preexisting geologic conditions such as ________.

A) ancient slide surfaces

B) rock layering dipping less than topographic slopes

C) structures within the rocks, such as fractures, ancient faults, and thin clay seams

D) All of these choices are correct.

7) The immediate causes of slope failures, such as earthquakes or heavy rainfall, are called ________.

A) triggers

B) roots

C) creators

D) sparks

E) trips

8) The sum of all the underlying causes can push a slope to the brink of failure, and then an immediate cause may trigger the movement. The immediate causes for mass movements include ________.

A) heavy rains

B) earthquakes

C) thawing of frozen ground

D) the construction projects of humans

E) All of these choices are correct.

9) In ________ masses move down and out by sliding on planes of weakness, such as faults, bedding, or clay-rich layers.

A) rock falls

B) translational slides

C) rotational slides

D) debris flows

E) struzstroms

10) Of the following types of mass movements, which can move fastest?

A) creep

B) roots

C) rock fall

D) mudflow

E) earth flow

11) The Houston-Galveston, Texas, area has been sinking due to the ________.

A) withdrawal of groundwater by pumping

B) dissolution of limestones

C) emptying of a magma chamber

D) weight of all the high-rise buildings and houses

E) dissolution of a salt layer

12) The Italian city of ________ is trying to save itself from slow subsidence and sea level rise.

A) Rome

B) Florence

C) Turin

D) Pisa

E) Venice

13) Catastrophic subsidence into sinkholes tends to occur more often in areas underlain by ________.

A) acidic freshwater flowing through limestone

B) basic freshwater flowing through limestone

C) acidic saltwater flowing through sandstone

D) basic freshwater flowing through sandstone

E) basic saltwater flowing through sandstone

14) The most likely explanation for how highly fluidized rock flows occur is that ________.

A) the jostling of fragments in the flowing mass provides energy that propagates as trapped sound waves and supports the particles, thus fluidizing the mass (acoustic fluidization)

B) water lubricates the material, allowing it to flow (hydro fluidization)

C) steam lubricates the material, allowing it to flow (aqueous fluidization)

D) the flowing mass rides on a cushion of compressed air (jetting)

E) heat generated by friction melts material within the mass, allowing it to flow (thermal fluidization)

15) Before a landslide mass begins to move downhill, it must overcome ________.

A) gravity and friction

B) inertia and gravity

C) inertia and friction

D) gravity and creep

16) The sum of the characteristics that hold a mass in place is referred to as ________.

A) shear resistance

B) cohesion

C) the normal force

D) the normal component

E) tan phi 

17) Which of the following statements is true regarding submarine mass movements?

A) They rarely occur and are not known to cause any problems.

B) There are many different kinds of submarine slope failures and they can cause major problems (e.g., tsunami).

C) They are only known to occur in subduction zones.

D) They differ from slope failures on land in that gravity plays no role underwater.

18) Which of the following is not true regarding slope failures involving snow?

A) They may be understood using the same mass-movement principles that apply to earth and rock movements.

B) They may creep, flow, slide, and fall.

C) They may be very slow or very fast.

D) They may travel from only a few meters (or less) to several kilometers.

E) The density of snow is always the same and so can be ignored when studying avalanches.

19) Most of the deaths related to snow avalanches in the United States involve ________.

A) young males engaging in winter sports in the backcountry of western states

B) people snowmobiling on snow covered roads

C) children sledding on snow-covered slopes

D) young female snowboarders at ski resorts in northeastern states

E) the elderly taking hikes in the mountains of the Pacific Northwest

20) If you are alone and get buried deeply in a snow avalanche, you will most likely ________.

A) be able to dig your way out

B) be able to dig a small cave and await rescue

C) die of suffocation

D) freeze to death

E) be dug out quickly by a rescue dog

21) Which of the following is a poor choice when trying to reduce the likelihood of a slope failure?

A) reshaping the topography by reducing the slope

B) using rock bolts to strengthen rock masses

C) adding water to the slope during a cold snap to freeze it in place

D) adding a gabion and/or a resisting mass at the toe of a slope

E) holding soil in place by using plants or netting

22) Limestone is dissolved primarily as ________ reacts with water to form a weak acid.

A) silica

B) carbon dioxide

C) nitrates

D) fluorine

E) methane

23) Creep is an ultra-slow, almost imperceptible upslope movement of the soil and lower bedrock zones. 

24) The volume of soil does not stay constant but instead swells and shrinks.

25) Clays are the least abundant of all sediments.

26) There are certain times when a hill containing clay minerals is weaker than at other times, and then gravity has a better chance of provoking a slope failure.

27) Quick clays are among the least mobile of all deposits and so provide favorable building sites.

28) Water molecules can attach their positive sides against clay minerals because clay surfaces are also positively charged.

29) Despite what some old movies show, quicksand does not suck people or other objects down.

30) The orientation of rock layering within a hill can either enhance or hinder the chances of slope failure.

31) The main types of mass movement are downward, as in falling or subsiding, or downward and outward, as in sliding and flowing.

32) The amount of water in pore spaces has no effect on mass movements of earth materials.

33) Basal failure surfaces for landslides typically are either curved in a concave-upward sense or nearly planar.

34) Land subsidence is worsened by the cessation of groundwater pumping, because the additional water that is retained underground weakens the rock, making it subside more easily.

35) Soils shrink in volume as they thaw, dry, or cool.

36) A rock at the top of a slope that starts to roll down, it is losing kinetic energy and gaining potential energy.  

37) Which of the following states has the greatest landslide potential?

A) West Virginia

B) Florida

C) Nebraska

D) Minnesota

38) Which of the following states has the lowest landslide potential?

A) West Virginia

B) Pennsylvania

C) Montana

D) Michigan

39) Which of the following is a way in which water weakens earth materials?

A) weight of water

B) absorption/adsorption

C) ability to dissolve cement

D) all of the choices are correct

40) Mass movements classified as slow, move at a rate of ________.

A) 0.3 m/sec (10 ft/sec)

B) 1.5 m/day (5 ft/day)

C) 1.5 m/year (5 ft/year)

D) 0.3 m/5 years (1 ft/5 years)

41) The debris flow of Nevados Huascarán (Peru) travelled down valleys at speeds of ________ per hour.

A) 170 km (105 mi)

B) 130 km (80 mi)

C) 200 km (124 mi)

D) 210 km (130 mi)

42) Which of the following coastal cities has subsided the most?

A) Mexico City, Mexico

B) London, England

C) Taipei, Taiwan

D) Venice, Italy