Deck 15: Aeolian Processes and Arid Landscapes

Question 1

Desert pavement refers to

A)specially constructed roadbeds in dry and hot regions.
B)surfaces of concentrated pebbles and gravels.
C)deposits of silt and clay.
D)sand-covered surfaces.
E)any rock shaped by eolian erosion.

Answer 1

B

Question 2

Arid and semiarid climates cover about of Earth's surface.

A)three-fourths
B)a quarter
C)two-thirds
D)one-half
E)one-third

Answer 2

E

Question 3

The term "eolian" refers to

A)stream-related processes.
B)glacial processes in areas outside the polar regions.
C)erosion,transportation,and deposition by the wind.
D)weathering and mass movement in humid regions.
E)coastal erosion and deposition.

Answer 3

C

Question 4

The transport of small sand particles (0.07 to 0.20 mm)along the ground in a bouncing and skipping action is known as

A)deflation.
B)abrasion.
C)saltation.
D)surface creep.
E)traction.

Question 5

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

A)gibber plain
B)lag gravels
C)sand seas
D)reg desert
E)gobi

Question 6

Saltation accounts for about % of sediment transport by wind.

A)15
B)35
C)50
D)65
E)80

Question 7

The smallest features shaped by individual saltating grains are

A)ripples.
B)dunes.
C)sand seas.
D)reg deserts.
E)ventifacts.

Question 8

The sliding and rolling along the ground of particles larger than 0.5 mm is known as

A)deflation.
B)abrasion.
C)saltation.
D)surface creep.
E)traction.

Question 9

The sediment-accumulation hypothesis of desert pavement formation states

A)wind removes fine particles leaving large pebbles,gravels,and rocks,which become consolidated.
B)wind delivers fine particles that settle and wash downward as cycles of swelling and shrinking cause gravels to migrate upward.
C)water removes fine particles leaving large pebbles,gravels,and rocks,which become consolidated.
D)water delivers fine particles that settle and wash downward as cycles of swelling and shrinking cause gravels to migrate upward.
E)both wind and water remove fine particles leaving large pebbles,gravels,and rocks,which become consolidated.

Question 10

An extensive area of sand and sand dunes is known as a(n)

A)reg desert.
B)erg desert,or sand sea.
C)lag desert.
D)desert pavement.
E)gibber plain.

Question 11

The term used to describe rocks that are pitted,fluted,or polished from eolian erosion is

A)desert pavement.
B)pumice.
C)ventifacts.
D)deflation hollows.
E)dunes.

Question 12

A depression created by deflation is known as a

A)playa.
B)bolson.
C)blowout.
D)structural basin.
E)haboob.

Question 13

The deflation hypothesis of desert pavement formation states

A)wind removes fine particles leaving large pebbles,gravels,and rocks,which become consolidated.
B)wind delivers fine particles that settle and wash downward as cycles of swelling and shrinking cause gravels to migrate upward.
C)water removes fine particles leaving large pebbles,gravels,and rocks,which become consolidated.
D)water delivers fine particles that settle and wash downward as cycles of swelling and shrinking cause gravels to migrate upward.
E)both wind and water deliver fine particles that settle and wash downward as cycles of swelling and shrinking cause gravels to migrate upward.

Question 14

The grinding and shaping of rock surfaces by the "sand blasting" action of particles captured in the air is termed

A)deflation.
B)abrasion.
C)saltation.
D)deposition.
E)traction.

Question 15

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

A)solid.
B)gas.
C)plasma.
D)fluid.
E)degenerate matter.

Question 16

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

A)deflation.
B)abrasion.
C)saltation.
D)deposition.
E)traction.

Question 17

Large depressions,such as the Qattâra depression,formed as a result of

A)deflation.
B)orogeny.
C)subduction.
D)converging plates.
E)tectonic forces.

Question 18

a()Ground view b()Aerial view
Dust storms engulf Phoenix,Arizona,in 2013 (ground view)and 2016 (aerial view).
Dust storms,such as one from Arizona in 2013,are caused by downbursts associated with thunderstorms.Such storms are termed

A)playas.
B)deflation.
C)blowout depression.
D)ventifacts.
E)haboobs.

Question 19

Elongated,streamlined ridges aligned parallel to the most effective wind direction are called

A)ventifacts.
B)yardangs.
C)desert pavements.
D)alluvial rock structures.
E)terraces.

Question 20

The ability of the wind to move materials

A)exceeds that of other transporting agents,such as water and ice.
B)is small compared to other transporting agents,such as water and ice.
C)is greater than that of water because of the higher density of air compared to water.
D)increases with decreased wind speed.
E)is equal to other transporting agents,such as water and ice.

Question 21

dunes form with their tips pointing downwind,usually in areas with limited sand supply and little to no vegetation.

A)Linear
B)Barchan
C)Longitudinal
D)Transverse
E)Parabolic

Question 22

The loess deposits in Europe and North America are thought to be derived mainly from

A)alluvium,i.e.stream deposited materials.
B)ocean sediments.
C)windblown desert sediments.
D)glacial and periglacial sources.
E)deeply entrenched river channels.

Question 23

The leading cause of decline in Lake Urmia is

A)drought.
B)climate change.
C)urbanization.
D)hydroelectric production.
E)water withdrawal.

Question 24

Areas at risk of desertification Which of the following areas is at highest (very high)risk of desertification?

A)the U.S.Great Plains
B)the Sahel
C)central Canada
D)eastern China
E)central Australia

Question 25

Ephemeral channels that form in dryland climates in response to infrequent precipitation events are known as

A)arroyos.
B)hollows.
C)yardangs.
D)ventifacts.
E)alluvial fans.

Question 26

Which of the following is not a general shape upon which scientists classify dunes?

A)rectilinear
B)crescentic
C)linear
D)star
E)parabolic

Question 27

Active dunes cover approximately % of Earth's deserts.

A)10
B)27
C)45
D)63
E)80

Question 28

dunes form parallel to the prevailing wind,often extending for hundreds of kilometers in length.

A)Linear
B)Barchan
C)Longitudinal
D)Transverse
E)Star

Question 29

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

A)windward
B)leeward
C)stoss
D)top
E)bottom

Question 30

Windblown dust that accumulates into homogeneous deposits is known as

A)gobi.
B)deflation hollows.
C)yardangs.
D)desert pavement.
E)loess.

Question 31

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

A)leeward side
B)windward side
C)freedune side
D)direction opposite of dune movement
E)It is not associated with a particular side.

Question 32

Factors that influence dry climates include all the following except

A)seasonal influence of the ITCZ.
B)dry,subsiding air associated with subtropical high pressure systems.
C)location in the rain shadow of mountains.
D)cool,stabilizing ocean currents along the western margins of continents.
E)location in continental interiors.

Question 33

The vast loess deposits in China are thought to be derived mainly from

A)alluvium,i.e.stream deposited materials.
B)ocean sediments.
C)windblown desert sediments.
D)glacial and periglacial sources.
E)deeply entrenched river channels.

Question 34

Which of the following is correct regarding loess deposits?

A)They are principally composed of sands and gravels.
B)They are formed of fine-grained clays,silts and fine.
C)They are found only in the United States.
D)They form only following glacial activity.
E)They are poor agricultural soils.

Question 35

Cone-shaped deposits of sediment often found at mouth of canyons in arid and semiarid climates are called

A)deposition.
B)deltas.
C)alluvial fans.
D)clastics.
E)arroyos.

Question 36

In vegetated dune landscapes,dunes form with their tips pointing upwind.

A)Linear
B)Barchan
C)Longitudinal
D)Transverse
E)Parabolic

Question 37

The Aral Sea,once one of the four largest lakes in the world,has steadily decreased since the 1960s on account of

A)diversion of incoming rivers for irrigation.
B)climate change.
C)urbanization.
D)hydroelectric production.
E)deforestation and resulting sedimentation.

Question 38

Which of the following is not considered a cause of desertification?

A)poor agricultural practices
B)climate change
C)poor soil-moisture management
D)salinization
E)afforestation

Question 39

The general term for the land degradation in arid and semiarid regions characterized by expansions of deserts is

A)desertification.
B)woody plant encroachment.
C)eolian process.
D)deflation.
E)saltation.

Question 40

dunes are the largest in size and have multiple slipfaces produced by winds from varying directions.

A)Linear
B)Barchan
C)Longitudinal
D)Transverse
E)Star

Question 41

What are the two competing hypotheses describing the formation of desert pavement?

Question 42

are flat-topped landforms with steep slopes resulting from differential weathering.

A)Mesas
B)Inselbergs
C)Badlands
D)Arroyos
E)Alluvial fans

Question 43

A forms when individual alluvial fans coalesce.

A)star dune
B)playa
C)yardang
D)desert pavement
E)bajada

Question 44

Describe the eolian processes of deflation and abrasion.

Question 45

Weathering of sandstone alcoves used for ancient cliff dwellings An alcove in sandstone,such as that in the Cliff House at Mesa Verde,is indicative of which weathering process?

A)exfoliation
B)carbonation
C)root wedging
D)salt-crystal growth
E)hydrolysis

Question 46

What is loess? How do the loess deposits of North America and Europe vary from those in China?

Question 47

are isolated remnants of resistant rock and products of long-term weathering and erosion.

A)Mesas
B)Inselbergs
C)Badlands
D)Arroyos
E)Alluvial fans

Question 48

Dryland rugged terrain of slopes dissected by rills and gullies are known as

A)qanats.
B)arroyos.
C)badlands.
D)bajadas.
E)playas.

Question 49

A is a dry bed of an ephemeral lake a dryland region.

A)star dune
B)playa.
C)yardang
D)desert pavement
E)bajada

Question 50

Rocks of the same composition and structure found in the same area may have weathered at uneven rates due to a variety of factors.This is known as .

A)angle of repose
B)jointing
C)inertial resistance
D)denudation
E)differential weathering

Question 51

The Basin and Range Province in the western United States is an example of a landscape.

A)tensional
B)reverse
C)horst and graben
D)compressional
E)Great Plains

Question 52

A large region identifiable by several topographic or geological traits is known as a(n)

A)topographic region.
B)ecoregion.
C)physiographic province.
D)biome.
E)alluvial terrace.

Question 53

What are the mechanisms by which air moves dust and sand?

Question 54

Dune migration on the Navajo Nation in the U.S.Southwest is an example of

A)desertification.
B)woody plant encroachment.
C)eolian transport.
D)deflation.
E)saltation.

Question 55

Describe the formation of alluvial fans and bajadas.

Question 56

The coarsest materials,such as gravel,of an alluvial fan are found

A)near the mouth of the canyon.
B)at the edge of the fan.
C)throughout the whole fan.
D)within a playa.
E)at the base of the fan.

Question 57

Alluvial fans are formed as flowing water as it leaves a constricted channel.

A)gains velocity
B)changes direction
C)down cuts
D)loses velocity
E)expands.

Question 58

What is desertification? What causes it? What areas are at risk of desertification?

Question 59

Explain the formation of sand dunes.

Question 60

are steep-sided landforms resulting from the weathering and mass wasting of mesas.

A)Volcanic necks
B)Badlands
C)Dikes
D)Plugs
E)Buttes