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.