Deck 18: The Work of Winds and Deserts

Question 1

Agriculture and overgrazing on lands adjacent to existing deserts can cause desertification.

Answer 1

True

Question 2

Deserts are expanding through a process called desertification, destroying once productive rangeland and cropland.

Answer 2

True

Question 3

Surface creep in a desert is a type of mass wasting.

Answer 3

False

Question 4

Wind is as effective an agent of erosion and deposition as water.

Question 5

Wind transports sediment in the same way as water - as dissolved load, suspended load, and bed load.

Question 6

Even if not presently found in desert climates, all dunes originated in desert conditions.

Question 7

Barchan dunes form in low relief terrain with limited vegetation, limited sand supply, and a constant wind direction.

Question 8

Desert pavement is the result of deflation of desert surfaces.

Question 9

During the Pleistocene Epoch pluvial lakes occupied the region of Death Valley.

Question 10

Deserts are common in dry climates at low to mid latitudes.

Question 11

Mechanical weathering dominates over chemical weathering in desert regions.

Question 12

Because of the abundance of sand and dust in the desert environment, soils are generally thicker than those found in more humid environments.

Question 13

Desert landscapes are as dynamic as wetter landscapes, but change happens more slowly.

Question 14

Wind-blown sand is generally moved in

A) water
B) suspension load
C) saltating load
D) debris flows
E) A and C

Question 15

Desertification is the result of which of the following factors:

A) global warming
B) cropping marginal lands
C) overgrazing marginal lands
D) clearing of natural vegetation
E) all of the above

Question 16

Which of the following landforms are NOT formed in deserts?

A) sand dunes
B) inselbergs
C) alluvial fans
D) playa lakes
E) none of the above

Question 17

Silt- and clay-sized sediment in deserts are moved

A) by suspension
B) by saltation
C) in solution
D) by erosion

Question 18

Wind is capable of erosion by which of the following process(es)?

A) saltation
B) suspension
C) abrasion
D) deflation
E) B and C

Question 19

Ventifacts would support which of the following hypotheses?

A) wind is the major agent of erosion in deserts
B) wind-blown sediment is capable of abrasion
C) venting is a major means of erosion in deserts
D) wind is capable of scouring soft rock
E) A and B

Question 20

Ventifacts on the north-facing side of a surface stone would suggest that the prevailing direction of wind is FROM the

A) north
B) south
C) east
D) west

Question 21

Sand dunes result when

A) sand supply is plentiful
B) wind direction is consistently in one direction
C) vegetation is sparse
D) A and C
E) all of the above

Question 22

In low relief terrain with limited vegetation, limited sand supply, and a constant wind direction, which of the following dune types will develop?

A) barchan dunes
B) longitudinal dunes
C) transverse dunes
D) parabolic dunes
E) star dunes

Question 23

In low relief terrain with limited vegetation, abundant sand supply, and a constant wind direction, which of the following dune types will develop?

A) barchan dunes
B) longitudinal dunes
C) transverse dunes
D) parabolic dunes
E) star dunes

Question 24

In low relief terrain with a partial cover of vegetation, limited sand supply, and a constant wind direction, which of the following dune types will develop?

A) barchan dunes
B) longitudinal dunes
C) transverse dunes
D) parabolic dunes
E) star dunes

Question 25

The source of loess is

A) floodplains of rivers
B) deserts
C) glacial outwash
D) A and C
E) all of the above

Question 26

Which of the following combinations of desert regions are the result of climate in the mid-latitude high pressure belt?

A) the Gobi Desert, the Sahara Desert of Northern Africa, and the Arabian Desert of the Mideast
B) the Gobi Desert, the Great Basin, and the Sahara Desert of Northern Africa, and
C) the Arabian Desert of the Mideast, Patagonia, and the Atacama Desert of Chile and Peru
D) Patagonia, the Great Basin, and the Atacama Desert of Chile and Peru
E) Patagonia, the Sahara Desert of Northern Africa, and the Australian "outback"

Question 27

Which of the following combinations of desert regions are the result of being within a rainshadow?

A) the Gobi Desert, the Sahara Desert of Northern Africa, and the Arabian Desert of the Mideast
B) Patagonia, the Great Basin, and the Atacama Desert of Chile and Peru
C) the Gobi Desert, the Great Basin, and the Sahara Desert of Northern Africa, and
D) the Arabian Desert of the Mideast, Patagonia, and the Atacama Desert of Chile and Peru
E) Patagonia, the Sahara Desert of Northern Africa, and the Australian "outback"

Question 28

Deserts form in association with mountain ranges because

A) the mountains provide runoff, the primary agent of erosion in deserts
B) the mountains cause a decrease in rainfall on the downwind side or lee side
C) associated air masses are warm and dry
D) vegetation does not do well in shadows

Question 29

Desert soils are thin and patchy because

A) sand, silt, and clay are blown away
B) vegetation is sparse
C) rainfall is limited
D) chemical weathering is not dominant
E) all of the above

Question 30

Which of the following statements is accurate concerning deserts?

A) the processes and landforms in deserts are unique to deserts
B) the geologic processes operating in deserts also operate in other environments
C) the extent of deserts is constant over time and will not likely change in the future
D) deserts are an ephemeral feature, present only until vegetation can stabilize sediment

Question 31

Wind transports sediment in ___________or___________ .

Question 32

Sediment is transported by wind as ___________or ___________load.

Question 33

Long parallel ridges of sand aligned parallel to the wind direction are known as ___________ dunes.

Question 34

Long parallel ridges of sand aligned perpendicular to wind flow are known as ___________ dunes.

Question 35

___________dunes form when vegetation cover is broken by deflation and the dune tips point upwind.

Question 36

___________ are large-scale ventifacts, elongated in the direction of the wind.

Question 37

Fan-shaped landforms that develop in deserts adjacent to highlands are known as___________ ___________ .

Question 38

An isolated mountain that rises from the flat plain of a desert is known as a(n)___________ .

Question 39

Wind erodes by two processes, ___________and___________ .

Question 40

What is meant by the term "desertification"?

Question 41

Which regions are most susceptible to desertification?

Question 42

It has been estimated that approximately how much land area is converted to deserts, per year, globally?

Question 43

How does the process of surface creep occur?

Question 44

Which sized particles are usually the first to be set in motion by wind?

Question 45

During sandstorms, how high can sand be lifted into the air?

Question 46

Can the wind be a significant intercontinental agent of erosion and deposition? Explain.

Question 47

What are yardangs?

Question 48

What is desert pavement?

Question 49

What are the two different types of important landforms created by wind deposition?

Question 50

What is loess?

Question 51

Why are loess-derived soils important?

Question 52

Which of the dune types is the most mobile?

Question 53

Besides the fact that they were formed by wind, what else can dunes preserved in the rocks tell us?

Question 54

Air masses are set into motion by much the same mechanism as are plates. What is this mechanism?

Question 55

What causes the Coriolis effect?

Question 56

On average, how much rain do deserts receive per year?

Question 57

In what latitudes do most of the world's deserts lie?

Question 58

What is a common mode of mass wasting in deserts?

Question 59

What is internal drainage?

Question 60

Why is chemical weathering insignificant in deserts?

Question 61

What did the famous twenty-mule teams haul out of Death Valley?

Question 62

How were the famous borax deposits of Death Valley formed?

Question 63

What is a pediment?

Question 64

What is a bajada?

Question 65

What is a playa lake?

Question 66

How does a playa form?