Mass Wasting - PROCESSES AND CLASSIFICATION

Question 1

what is a landlside?

Answer 1

it is a downslope movement of rock or regolith near the earth’s surface due to gravity (nelson, 2006)

Question 2

mass wasting is an integral part of ______ as it move material from _____ elevations to _____ elevations

Answer 2

erosional processes ; higher elevations ; lower elevations

Question 3

what is a regolith?

Answer 3

loose unconsolidated materials sitting atop a bedrock layer

Question 4

differentiate weathering and erosion

Answer 4

weathering is the breakdown of rocks in situ, while erosion involves mobilization and transportation of weathered materials

Question 5

t or f: mass wasting are occurring continuously on all slopes, some are very slow while others occur very suddenly, often with disastrous results

Answer 5

T

Question 6

any perceptible downslope movement of rock or regolith are referred to in general as ______

Answer 6

landslide

Question 7

landslide is also known as:

Answer 7

Debris Slump

Question 8

Cherry Hills Landslide: location and date

Answer 8

August 1-3, 1999
Antipolo, Philippines

Question 9

about how many percent of the land area of the Philippines is susceptible to lanlsides?

Answer 9

up to 80%

Question 10

what was the specific mass wasting events that occurred in cherry hills landslide?

Answer 10

slump to debris flow near the base

Question 11

Village of Saint Bernard landslide location and date

Answer 11

Guinsaugon, Leyte
Feb 17, 2006

Question 12

what triggered the saint bernad village landslide?

Answer 12

two-week continuous rainfall

Question 13

at 10:26 am, an earthquake followed the saint bernard village landslide, what is the magnitude of the earthquake?

Answer 13

Mag 2.16

Question 14

t or f: part of the slope in guinsaugon leyte lansdlide was transected by the PFZ

Answer 14

T

Question 15

what mass wasting event occurred in Andap, New Bataan in 2012?

Answer 15

Debris Flow

Question 16

when was the Andap, New Bataan Mass wasting?

Answer 16

December 4, 2012

Question 17

what river was close during the Andap mass wasting

Answer 17

Mayo River

Question 18

maximum runup height of Andap new bataan mass wasting

Answer 18

1.8m

Question 19

what specific mass wasting events occurred in Guinsaugon, Leyte?

Answer 19

Rock slide to Debris avalache

Question 20

Naga City Landlside, location and date?

Answer 20

Brgy. Tinaan, Naga City, Cebu
Sept. 20, 2018

Question 21

the Naga city landslide was a combination of what processes?

Answer 21

sinkhole collapse + planar block slides + debris flow

Question 22

during the Naga City landslide, a fault was traced ______ away from the area

Answer 22

500m

Question 23

what possibly triggered Naga landslide?

Answer 23

during 2013 NBF earthquake, groundwater flow diverted through the area (with karst terrain), causing sinkhole collapse

Question 24

knowledge about the relationships between ______ and _____ can lead to better planning that can reduce ______ to such hazards

Answer 24

local geology ; mass wasting processes ; vulnerability

Question 25

states and distributions of activity of a landslide

Answer 25

active suspended reactivated inactive dormant abandoned stabilized relict

Question 26

t or f: relict landslides have undergone weathering

Answer 26

t

Question 27

t or f: cracks present in dormant landslides are indicators of another episode of mass wasting

Answer 27

T

Question 28

what are indicators that a past landslide have occurred in an area

Answer 28

concave topography sparse vegetation bulging toe / old landslide deposits at the bottom

Question 29

mass movements can be classified according to:

Answer 29

1. type of movement 2. type of material 3. relative proportion of water and mater 4. velocity (slow or rapid) 5. thickness (shallow or deep seated) 6. triggering factors

Question 30

types of material involved in mass wasting

Answer 30

rock, debris, earth, mud

Question 31

types of triggering factors of mass movements

Answer 31

earthquake induced, rainfall induced, or human induced

Question 32

t or f: for deep seated landslides, mitigation measures are of no work, evacuation should be done.

Answer 32

T

Question 33

mixture of rock, earth, plants, and mud

Answer 33

Debris

Question 34

composed of loose sediment and weathered rock fragments

Answer 34

Earth

Question 35

mixture of water and finer-sized sediments

Answer 35

mud

Question 36

regolith are composed of

Answer 36

rock fragment, sheared bedrock, weathered zone, organic soils

Question 37

solifluction is a mixture of

Answer 37

creep and flow

Question 38

two type of debris avalanches

Answer 38

hot and cold

Question 39

comprises a detachment of soil or rock from a steep slope and the more or less free and extremely rapid descent of the material

Answer 39

Fall

Question 40

_______ refers to fine-grained deposits at the bottom of a slope, while ______ refers to coarse grained deposits

Answer 40

Talus ; Scree

Question 41

the movement of fall is largely through the ____, alternated with the ______ or ______ on the slope

Answer 41

air ; bouncing or rolling

Question 42

falling will be preceded by

Answer 42

small sliding or toppling movements

Question 43

t or f: falls can also be triggered by lateral pressures (roots, ice wedging, crystallization pressures) or by lost of underlying support (erosion on cliffs)

Answer 43

T

Question 44

t or f: falls are more common in soft roxks

Answer 44

F (hard rocks)

Question 45

constitutes a failure in the support conditions of a bedrock

Answer 45

fall

Question 46

a topple is a _____ out of the slope of a mass of soil or rock about a point below the ________ of the _______

Answer 46

forward rotation ; center of gravity ; displaced mass

Question 47

this process is identical to fall, associated with very steep slopes

Answer 47

topple

Question 48

topples may lead to _____

Answer 48

sliding of the displaced mass

Question 49

toppling is mostly occurring in combination with ____

Answer 49

fall

Question 50

a moving slab of soil or bedrock that moves as a whole, remaining in contact with the underlying material

Answer 50

slide

Question 51

two types of slides

Answer 51

rotational and translational

Question 52

a slump is an example of a _____ type of slide

Answer 52

rotational

Question 53

a type of slide that have more or less circular failure surface

Answer 53

rotational slide

Question 54

a type of slide where sliding occurs along a pre-existing failure plane

Answer 54

translational slide

Question 55

t or f: rotational slides are shallower than translational slides

Answer 55

F (deeper)

Question 56

t or f: rotational slides are narrower than translational slides

Answer 56

T

Question 57

three types of translational slides

Answer 57

soil slips rock slides debris slides

Question 58

shallow translational movement in soil materials

Answer 58

soil slips

Question 59

two types of soil slips

Answer 59

sheet slide slab slide

Question 60

scale of soil slips

Answer 60

1-2m in thickness

Question 61

occurs in cohesionless, dry soils

Answer 61

sheet slides

Question 62

occurs in saturated soil materia

Answer 62

slab slides

Question 63

three types of rock slides

Answer 63

planar slides stepped slides wedge failure

Question 64

what type of rocks slide occurred in Guinsaugon, Leyte?

Answer 64

Planar slide

Question 65

a type of rock slide where movement takes place in a single failure plane

Answer 65

planar slides

Question 66

a type of rock slide where movement occurs along a number of parallel failure plane

Answer 66

stepped slides

Question 67

a type of rockslide where failure is controlled by two planes which define a wedge-shaped block loosened from the rock slope

Answer 67

wedge failure

Question 68

debris slides occur on what slopes

Answer 68

steep (25-35 degrees)

Question 69

what is a debris slide?

Answer 69

a slope debris slides off along a discontinuity with the underlying weathered rock

Question 70

movements involving great internal deformation

Answer 70

flow

Question 71

flow involves ________, where ______ dominates over _________

Answer 71

internal deformation ; inter-granular movements ; shear-surface movements

Question 72

t or f: the internal vertical velocity distribution of a flow is uniform

Answer 72

false (not uniform)

Question 73

in a flow the vertical velocity of the material near the surface is _______ than the velocity of the underlying material

Answer 73

higher

Question 74

the most common subdivision of flow is based on the _____

Answer 74

type of material

Question 75

t or f: materials in flow movement are cohesive

Answer 75

F (not cohesive)

Question 76

a type of slow moving flow

Answer 76

earthflow

Question 77

in an earth flow, the rate of internal deformation is _____

Answer 77

limited

Question 78

t or f: earthflow includes solifluction

Answer 78

T

Question 79

the saturated material in an earthflow moves ______ and forms a _____

Answer 79

sluggishly ; bulging toe

Question 80

is a type of fast moving flow

Answer 80

mudflow

Question 81

t or f: the material in mudflow is oversaturated with water

Answer 81

t

Question 82

a mudflow mostly originates from ________, dragging soil particles with it

Answer 82

overland flow in heavy rainfall

Question 83

t or f: kinetic energy in a mudflow can be so high, it could take along stones

Answer 83

T

Question 84

in a debris flow, the trapped fluid may develop _______ buoying up individual debris particles

Answer 84

high pore pressures

Question 85

t or f: dry, non-cohesive debris can move like a flow due to interparticle impacts (similar to intermolecular motion in fluid)

Answer 85

T

Question 86

a flow taking place in larger materials

Answer 86

block flow

Question 87

t or f: mudflows are common along rivers that are composed of consolidated materials plus rainfall

Answer 87

F (semi-unconsolidated)

Question 88

an extension of a cohesive mass of rock or soil combined with the general subsidence of a broken cohesive mass into a softer underlying material

Answer 88

lateral spreads

Question 89

t or f: the surface of rupture in a lateral spread is a surface of intense shear

Answer 89

F (not a surface)

Question 90

spread may result from _____ or _____ and _______

Answer 90

liquefaction or flow; extrusion of softer material

Question 91

t or f: in lateral spreads, the vertical component is more important than the horizontal component

Answer 91

False (the horizontal is more important)

Question 92

the horizontal movement of a spread is the ________

Answer 92

sliding of detached blocks over a softer material

Question 93

spread is also partly induced by _____ of the underlying material

Answer 93

plastic deformation

Question 94

what is the slowest type of mass wasting

Answer 94

creep

Question 95

fastest type of mass wasting

Answer 95

rock fall

Question 96

is the slow movement of soil or bedrock downslope owing to periodic expansion and contraction

Answer 96

creep

Question 97

what causes expansion and contraction of the slope?

Answer 97

cyclic wetting and drying or thawing and freezing

Question 98

t or f: the stresses on a slope material in a creep is to small to generate a rapid failure

Answer 98

T

Question 99

at least two different types of landslides occur together

Answer 99

complex

Question 100

what is regarded as the most dangerous geohazard?

Answer 100

landslide

Question 101

what does EGGAR stand for?

Answer 101

Engineering Geological and Geohazard Assessment Report