Chapter 16 E3 - Mass Wasting

Question 1

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

Answer 1

mass wasting; gravity is the controlling force

Question 2

important triggering factors of mass wasting

Answer 2

saturation of the material with water; oversteepening of slopes; removal of anchoring vegetation; ground vibrations from earthquakes

Question 3

what is an important factor in determining whether a mass wasting event will occur

Answer 3

the angle of repose

Question 4

_______ assumes a shallower angle of repose than ______ do

Answer 4

fine sand; angular pebbles

Question 5

what kind of sand is more cohesive and why

Answer 5

damp sand because dampness binds sand particles so they resist movement; water-saturated sand is least cohesive because the saturated particles are separated by water

Question 6

free fall of pieces

Answer 6

a fall (mass wasting)

Question 7

material moves along a well defined surface

Answer 7

a slide (mass wasting)

Question 8

material moves like a viscous fluid

Answer 8

a flow (mass wasting)

Question 9

debris flows composed mostly of volcanic materials

Answer 9

lahars

Question 10

relatively rapid mass wasting; typically occurs on hillsides in humid regions where water saturates the soil

Answer 10

earthflow

Question 11

a special type of earthflow sometimes associated with earthquakes

Answer 11

liquefaction

Question 12

rapid movement along a curved surface; occurs along oversteepened slopes

Answer 12

slump

Question 13

slow movement of soil and regolith downhill; causes fences and utility poles to tilt

Answer 13

creep

Question 14

slow movement in areas underlain by permafrost; upper soil layer becomes saturated and slowly flows over a frozen surface below

Answer 14

solifluction