Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Geohazard > Mass Wasting - TRIGERRING MECHANISM > Flashcards

Mass Wasting - TRIGERRING MECHANISM Flashcards

1
Q

it is the most significant factor that could trigger mass wasting

A

degree of slope

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

t or f: as the slope increases, the gravitational component acting parallel to the slope, also increases

A

T

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

when ______ becomes greater than the ______, downslope movement can occur

A

gravitational force ; frictional forces

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

the following factors may trigger mass wasting:

A

Nature of slope material;
oversteepened slopes
vegetation and climate;
earthquake and volcanic activities

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

t or f: strong and homogenous rocks are able to form stable cliffs

A

T

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what type of rock is the cliff on Yosemite Valley, California?

A

granite rock

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

how long was the rock in Yosemite Valley, California? how did it become so stable?

A

2,000 foot

interlocking mineral grains and resistance to weathering

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

t or f: frictional forces in loose sediments are higher than in solid rocks

A

F (lower)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

is the steepest angle at which a sloping surface of unconsolidated sediment is stable

A

angle of repose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

angle of repose is typically

A

<35 degrees

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

t or f: large angular fragments generate greater frictional forces compared to small, well-rounded fragments

A

T

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

can occur along bedding planes, foliation planes, fractures, and fault surfaces that are inclined in the same direction as the slope

A

slippage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

where does slippage usually occur?

A

foliation plane, bedding plane, fracture and fault surfaces

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

t or f: slippage are inclined in the opposite direction as the slope

A

F (same direction)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

in the Grand Canyon, steep cliffs develop in resistant ______ and ______, whereas broad, gentle slopes form in much weaker ______

A

limestones and sandstones;

shales

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what is daylight structure?

A

areas of high susceptibility to mass wasting because it is facing plane of weaknesses inclined to the slope

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

undercutting of stream banks results in _____ and _____

A

cutbanks and overhang

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what causes cutbanks?

A

natural migration of stream channel

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

t or f: river valleys become wider over time due to undercutting of stream banks

A

T

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

example of oversteepened slopes caused by human actvity

A

excavation of materials from hillsides in order to create a leveled surface for construction of roads, buildings, and parking lots

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

t or f: only natural processes can destabilize a slope by increasing its steepness

A

F (natural and unnatural)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

long-term average weather

A

climate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

vegetation that blankets slopes influences the fraction of _____ or ____ that ______ into the subsurface

A

rain or snow;

infiltrates

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

how does fairly dense vegetation stabilize slopes?

A

plant roots help in binding particles and loose sediments together

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

t or f: during unusually large rainstorms or rapid snowmelts, dense vegetation will increase infiltration since it reduces the ability of surface water to move downslope, therefore destabilizing the slope bc of excessive infiltration

A

T

26
Q

________ adds significant weight to a slope and reduces friction through higher pore pressures

A

excessive infiltration

27
Q

excessive infiltration reduces friction in slope because of ______

A

increased pore pressure

28
Q

vegetation vs geology:

which is more influential factor of mass wasting?

A

geology

29
Q

how does seismic waves destabilize slopes?

A

ground vibrations reduces the frictional forces within the slope material, as well as causing them to liquefy

30
Q

seismic waves also cause materials to ____, which can immediately destabilize a slope and trigger a mass wasting event

A

liquefy

31
Q

infiltrated water within slope material increases _______, which then reduces _______ between the solids

A

pore pressure ; frictional forces

32
Q

general potential causes of mass movements

A

geological
morphological
physical
anthropogenic

33
Q

give at least 3 geological causes of mass movements

A

weak material
sensitive material
weathered material
sheared material
jointed or fissured material

34
Q

give at least 3 morphological causes of mass movements

A

tectonic or volcanic uplift
glacial rebound
erosion of slope toe
erosion of lateral margins
vegetation removal

35
Q

give at least 3 physical causes of mass movements

A

intense rainfall
rapid snow melt
earthquake
volcanic eruption

36
Q

give at least 3 human causes of mass movements

A

deforestation
irrigation
mining
drawdown of reservoirs
excavation of the slope

37
Q

give at least 3 human causes of mass movements

A

deforestation
irrigation
mining
drawdown of reservoirs
excavation of the slope

38
Q

manifestations to look at when identifying landslides

A

vegetation cover;
presence of cracks or scars;
disrupted drainage pattern;
excessive soil moisture/abrupt soil moisture changes;
terrain form;
tilting of trees/posts

39
Q

morphological diagnostics

A

concave-convex;
step-like morphology;
semicircular niche;
back tilting of slope faces;
hummocky relief;
formation of cracks;
steepening of slopes;
vegetation clearances on steep scarps;
irregular linear clearances along the slope

40
Q

the sequence of a concave and convex part of the slope is associated with :

A

landslide niches and associated deposit

41
Q

a step-like morphology is related to

A

retrogressive sliding

42
Q

t or f: step-like morphology includes presence of tension scarps

A

T

43
Q

are associated with the head part of a slide with the outcrop of a failure plane

A

semicircular niche

44
Q

semicircular niche are recognizable on photographs as a ________

A

light-toned scarp with small light curved lineaments

45
Q

back tilting of slope faces indicates

A

rotational movement of slide blocks

46
Q

back tilting of slope faces appear as

A

oval or elongated depressions with imperfect drainage conditions

47
Q

irregular slope morphology. micro relief associated with shallow movements or small retrogressive slide blocks

A

hummocky relief

48
Q

hummocky relief are associated with

A

shallow movements with retrogressive slide blocks

49
Q

t or f: the coarse surface texture of hummocky terrains stand in contrast with smooth surroundings

A

T

50
Q

morphological indication of recent activity

A

formation of cracks

51
Q

crack formation occurs with _______ movements

A

sliding and toppling

52
Q

t or f: cracks appear as lineaments more or less perpendicular to the existing scar

A

F (parallel)

53
Q

morphological indication of a presence of a landslide scar

A

steepening of slopes

54
Q

it is the top of a scar and would indicate the original slope if it is connected to the tip of the landslide

A

break point

55
Q

t or f: vegetational clearances coincide with morphological steps

A

T

56
Q

______ and _____ in a slide body often lack vegetation

A

headscarps and steps

57
Q

vegetational clearances on photographs shows as

A

light-toned elongated areas at the crown or on the body of mass movement

58
Q

_____ and ____ strip parts of the slope from vegetation; leaving the flowpath _____

A

flows and avalanches;
uncovered

59
Q

t or f: slip surfaces of translational slides are uncovered with vegetation

A

T

60
Q

the denudated areas of irregular linear clearances are shown as

A

light tones, with linear pattern in direction of movement

Geohazard (25 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions