Quiz 6b: Aeolian Processes and Arid Landscapes

true

Water is essential to the formation of a desert pavement.

Barchan - abundant sand

Which of the following dune types is incorrectly matched with the conditions necessary for its formation?

They are formed of fine-grained clays and silts

Which of the following is correct regarding loess deposits?

Clay is difficult to lift from a surface but is easy to keep suspended in the air

Which of the following statements is correct regarding the erosion and transport of clay?

sandseas

Which of the following terms is not a correct reference to a desert pavement?

leeward

Which side of a dune typically has a slope angle equal to that of the angle of repose for sand?

deflation and sheetwash

Which two processes create desert pavement?

leeward side

Relative to dune movement and form, a dune's slipface forms on which side?

blowout depression

A depression created by deflation is known as a:

1 m (3.28 in)

Abrasion is usually confined to a zone which extends up to ________ above the ground.

10 percent

Active sand dunes and sandy deserts cover approximately what percentage of continental land between 30°N and 30°S latitude?

lower, more

Because air has a ________ density than water, saltating particles in an aeolian environment strike one another with ________ force than do saltating particles in a stream.

Aeolian

Erosion, transportation, and deposition by the wind

fluid

For purposes of discussing aeolian processes, the wind acts like a

Parallel to the wind

Linear dunes and seif dunes are oriented:

At lower wind velocities; particle impact

Once particle motion is initiated, subsequent motion can be maintained ________ because of the process of ________.

Saltating particles; surface creep

Pebbles can be moved by ________ in a process known as ________ .

They are aerodynamic and cohesive

Small particles are difficult for wind to move because:

false

Soils formed from loess tend to be infertile.

true

The Sphinx in Egypt may have originally been a natural yardang that was subsequently shaped by people into its present form.

Is small compared to other erosive agents, such as water and ice

The ability of the wind to erode materials:

deflation, abrasion

The lowering of the land surface by the lifting and removal of material is termed ________ , whereas the grinding of rock surfaces with a "sandblasting" action is ________ .

deflation

The removal and lifting of individual loose particles by the wind is termed:

34 degrees

The steepest side of a dune has a maximum angle of about:

true

The wind has relatively minor effects on weathering and erosion.