Define mass wasting.

The downslope movement of

sediment and rock under the direct

influence of gravity.

A __________ is formed when vertical

incision by a stream is the primary

process, with relatively minimal mass

wasting.

slot canyon

Which of the following correctly states

the role of rivers and mass wasting in

the formation of the Grand Canyon?

The Colorado River erodes downward,

then mass-wasting processes move

material from high to low areas, then

the Colorado River transports material

downstream.

Over time, mass wasting causes

__________.

canyons to widen

What rock type is the easiest for a

river to cut through?

shale

The Gros Ventre slide is evident today

by __________.

a scar, runout area, and landslide

debris filling the valley

Which of the following is a reason the

Gros Ventre rockslide took place?

Because the river eroded material at

the valley base, there was no support

of the material upslope.

A __________ acted as a sliding surface

across which material moved downhill

during the Gros Ventre Slide.

clay layer

Heavy rainfall caused the clay to

lubricate and the sandstone to

become __________.

saturated and heavy

Which of the following statements is

true regarding the aftermath of the

Gros Ventre rockslide?

The rockslide debris dammed up the

river and formed a lake.

Creep is __________.

mass wasting by the gradual downhill

movement of sediment, influenced by

freeze-thaw or wet-dry cycles

Describe how a soil particle moves

downhill during the freeze-thaw

process.

During the freeze, a soil particle

moves at a right angle away from the

surface, and thawing causes the

particle to fall back to a slightly lower

level.

Why would trees be J-shaped?

The trunks become tilted in the

downhill direction due to creep, but

continue to grow toward the sun.

Which of the following is associated

with creep?

slow and subtle movement of material

A __________ is a common result of

creep.

broken retaining wall

Permafrost is __________.

permanently frozen ground of tundra

and subarctic climates that has

remained 0°C for two years or more

__________ is an example of mass

wasting commonly seen in the active

layer above permafrost.

Solifluction

What is name of the near-surface

layer that thaws in the summer?

the active layer

If permafrost is melted, which of the

following is a consequence?

The ground subsides because the

volume of water is less than that of

ice.

What is used to keep the Trans-Alaska

pipeline from melting permafrost?

stilts

Mass wasting is possible only with the

aid of a transportation agent such as

water, wind, or ice.

False

What non-geologic term is commonly

used to describe a sudden event in

which large volumes of material move

down steep slopes?

Landslide

What is the angle of repose?

The steepest angle at which a material

remains at rest

The 2005 mass-wasting event in La

Conchita, CA, can be classified as a

______.

debris flow