mass movement - exam 1

Question 1

the downslope movement of rock, regolith, and soil under the direct influence of gravity

Answer 1

mass movement

Question 2

cause the slope to cross the threshold from stability to instability. not the sole cause of a mass movement event, just the last factor

Answer 2

a trigger

Question 3

the steepest angle at which an accumulation of granular particles remains stable

Answer 3

angle of repose

Question 4

intense ground shaking during earthquakes can cause water saturated surface materials to lose their strength and behave as fluid like masses that flow, this process is called

Answer 4

liquefaction

Question 5

the different ways material move during mass movement

Answer 5

fall
slide
flow

Question 6

when the movement in a mass movement event involves the free fall of detached individual pieces, it is termed a

Answer 6

fall

Question 7

mass movements in which there is a distinct zone of weakness separating the side material from the more stable underlying material

Answer 7

slide

Question 8

the most rapid type of mass movement is

Answer 8

rock avalanches

Question 9

a slide in which the surface of a rupture is a concave upward curve resembling the shape of a spoon and the descending material exhibits a downward and outward rotation

Answer 9

rotational slide

Question 10

a slide in which a mass of material moves along relatively flat surfaces such as joints, faults, or bedding planes. such slides exhibit little rotation or backward tilting

Answer 10

translational slide

Question 11

the term used to describe material that moves downslope as a viscous, often turbulent, fluid

Answer 11

flow

Question 12

most flows are saturated with water and typically move as

Answer 12

lobes or tongues

Question 13

often, flows of saturated mud and debris are incorrectly labeled

Answer 13

mudslides

Question 14

the downward sliding of a mass of rock or unconsolidated material that moves as a unit along a curved surface

Answer 14

slump

Question 15

slump is an example of a

Answer 15

rotational slide

Question 16

slump commonly occurs because a slope has been

Answer 16

oversteepened

Question 17

occurs when blocks of bedrock break lose and slide down a slope

Answer 17

rockslide

Question 18

occurs when blocks of largely unconsolidated material break lose and slide down a slope

Answer 18

debris slide

Question 19

debris flows are sometimes called ____ ____ when the material is primarily fine grained

Answer 19

mud flows

Question 20

a relatively rapid type of mass movement that involves a flow of soil and regolith containing a large amount of water

Answer 20

debris flow

Question 21

debris flows composed mostly of volcanic materials on the flanks of volcanoes are called

Answer 21

lahars

Question 22

the repeated expansion and contraction of the surface material causes a net downslope migration of soil and rock particles

Answer 22

creep

Question 23

-increased water
-undercutting of slope
-human causes
-earthquakes
-volcanoes

Answer 23

factors that initiate rapid mass wasting processes

Question 24

ground that remains permanently frozen for many years

Answer 24

permafrost

Question 25

flow of water saturated soil over impermeable material

Answer 25

solifluction

Question 26

gradual downslope movement of unconsolidated material

Answer 26

creep

Question 27

classifications of mass wasting

Answer 27

-type of material
-rate of movement
-type of movement

Question 28

large angular block usually at the base of a steep slope or cliff

Answer 28

talus

Question 29

angle at which slope failure occurs

Answer 29

angle of repose

Question 30

the energy source of mass wasting

Answer 30

gravity

Question 31

term for all gravitational downslope movements of rock or debris

Answer 31

mass wasting