Deck 14: Deserts and Wind

Question 1

The growth of a desert by human mismanagement, or by climate change, is called ____________________.

Answer 1

desertification

Question 2

A(n) ____________________ is a broad, gently sloping depositional surface formed by merging alluvial fans.

Answer 2

bajada

Question 3

____________________ dunes are common in moist semiarid regions and along the seacoast where sparse vegetation is present to anchor the tips of the dune.

Answer 3

Parabolic

Question 4

Brief, intense local floods, called ____________________ are common following desert rainstorms.

Question 5

Long, symmetrical dunes that form as a result of two different wind directions with comparable magnitude are called ____________________ dunes.

Question 6

A(n) ____________________ is a flat-topped mountain that is smaller and more towerlike than a mesa.

Question 7

Dry, sinking air results in many of the world's deserts being located at ____ south and north latitudes.

A) 5°
B) 10°
C) 30°
D) 50°

Question 8

Death Valley is part of a vast desert region of the American West with no external drainage, known as the ____________________.

Question 9

Any region that receives less than 25 centimeters of rain per year and supports little or no vegetation is a(n) ____________________.

Question 10

A temporary desert lake that dries up during the dry season is a(n) ____________________ lake.

Question 11

The ____________________ is the semiarid zone south of the Sahara desert.

Question 12

A streambed that is dry most of the year is called a ____.

A) playa
B) spring
C) bajada
D) wash

Question 13

The steep, leeward side of a dune is called the ____________________.

Question 14

A(n) ____________________ is a continuous cover of closely packed pebbles and cobbles left behind when wind erodes smaller particles of sand and silt.

Question 15

Playa lakes often dry up due to ____ and seepage.

A) evaporation
B) condensation
C) drainage through an outlet
D) overuse by humans

Question 16

Sand grains in deserts are transported by wind close to the ground in an asymmetric jumping movement called ____________________.

Question 17

A type of desert that forms on the downwind side of a mountain range is a(n) ____________________ desert.

Question 18

Outside of the polar regions, Earth's land surface is ____ desert.

A) 50 percent
B) less than 3 percent
C) about 25 percent
D) about 10 percent

Question 19

Thick ____________________ deposits accumulated in North America during the most recent Pleistocene glacial advance from wind transporting and depositing large amounts of silt.

Question 20

The world's deserts are similar only in that they all ____.

A) receive small (less than 10 inches) amounts of rainfall each year
B) have no vegetation
C) have sandstone as the local bedrock
D) are characterized by a landscape of buttes and mesas

Question 21

Wind-scoured depressions that form in bare areas among desert plants are called ____.

A) barchan dunes
B) blowouts
C) kettles
D) playas

Question 22

The slip face is the ____ side of a dune.

A) steep
B) windward
C) gently sloping
D) flat

Question 23

The desert region that covers portions of Utah, Colorado, Arizona, and New Mexico is known as ____.

A) Death Valley
B) the Great Basin
C) the Gobi Desert
D) the Colorado Plateau

Question 24

Why is the Atacama Desert of South America dry?

A) Warm marine air encounters cool land, which absorbs moisture from the ground, creating a coastal desert.
B) Cool marine air encounters warm land and heats up, and then absorbs moisture from the ground, creating a coastal desert.
C) It is a classic example of a rain-shadow desert.
D) It is located at approximately 30 south.

Question 25

In Africa, desertification caused the ____ Desert to expand into the Sahel region.

A) Kalahari
B) Gobi
C) Sahara
D) Atacama

Question 26

What type of dune is crescent-shaped with its tips pointing downwind, and forms in rocky deserts with little sand?

A) parabolic
B) transverse
C) barchan
D) longitudinal

Question 27

Large desert rivers, like the Nile River, receive most of their water from ____.

A) ground water reserves
B) occasional, intense summer thunderstorms
C) seasonal rains
D) wetter, mountainous areas bordering the arid lands

Question 28

A(n) ____ is a flat-topped mountain that is shaped like a table.

A) bajada
B) mesa
C) dune
D) pediment

Question 29

The maximum size of particle that can generally be moved by wind is ____.

A) silt sized
B) sand sized
C) cobble sized
D) clay sized

Question 30

The largest loess deposits in the world are found in ____.

A) New York
B) the North American Great Plains
C) central China
D) the Atacama Desert in Peru

Question 31

Water vapor that condenses when rising over a mountain range is more likely to fall as rain and snow ____.

A) at 30 ° north and south latitude
B) on the downwind side of the range
C) on the windward side of the range
D) on the leeward side of the range

Question 32

Which of the following is a rain-shadow desert?

A) The Sahara Desert
B) The Atacama Desert
C) Death Valley
D) The Namib Desert

Question 33

A(n) ____ is an asymmetric mound or ridge of windblown sand.

A) alluvial fan
B) bajada
C) loess hill
D) dune

Question 34

What type of dunes form as long ridges that align perpendicularly to the prevailing wind?

A) parabolic
B) transverse
C) barchan
D) longitudinal

Question 35

Playas are often a source of economically valuable ____.

A) coal veins
B) oil wells
C) sandstones
D) salt mineral deposits

Question 36

In the Great Basin of the western United States, ____.

A) buttes and mesas are common
B) no streams flow into or away from the region
C) alluvial fans and bajadas are rare
D) sediment accumulates because streams flow into the valleys from surrounding mountains, but no streams flow out of the basin

Question 37

A(n) ____ is a broad, gently sloping erosional surface that forms along the front of desert mountains, often as a result of tectonic uplift.

A) bajada
B) pediment
C) butte
D) alluvial fan

Question 38

Vast tropical forests grow near the equator because ____.

A) rising equatorial air cools and condenses as rain
B) warm, moist air rises to form a high pressure region
C) warm moist air sinks, creating low pressure
D) rising air is heated and the moisture condenses

Question 39

Erosion by wind is ____.

A) deflation
B) saltation
C) corrosion
D) desertification

Question 40

Buttes and mesas are formed by ____.

A) abrasion by windblown silt
B) the deposition of sediment carried by rivers and streams
C) chemical weathering of less-resistant rock
D) the downcutting and lateral erosion of bedrock by rivers and streams

Question 41

Deserts around the world generally share the same characteristics and resemble one another.

Question 42

The silt that comprises the loess deposits of North America's central plains was ____.

A) blown from the Great Basin region
B) carried by glaciers from northern Canada
C) generated by continental ice sheets that ground bedrock into silt
D) weathered to silt-sized particles while being transported by wind

Question 43

Portions of Peru and Chile in the Atacama Desert receive no rainfall for a decade or more.

Question 44

Deserts never occur along coastlines.

Question 45

The slip face of a dune typically dips about 20 degrees from the horizontal.

Question 46

Washes are dry for most of the year.

Question 47

Many of the world's deserts lie at about 50° north and south of the equator.

Question 48

Pediments are generally covered by layers of gravel hundreds of meters thick.

Question 49

When moisture-laden air flows over a mountain range, it cools and loses its ability to hold moisture.

Question 50

Lithified sand dunes are called ____.

A) limestone
B) pediments
C) fossil dunes
D) plateaus

Question 51

Windblown sand is an effective agent of erosion.

Question 52

In North America, loess deposits that accumulated during the Pleistocene were deposited as far south as ____.

A) southern Mississippi
B) southern Texas
C) Florida
D) the Gulf of Mexico

Question 53

Most dunes are symmetrical.

Question 54

Migrating dunes can overrun buildings and highways.

Question 55

The Great Basin is an example of a coastal desert.

Question 56

A bajada is an erosional surface.

Question 57

Soils formed on loess areas are generally fertile.

Question 58

Loess particles stick together so effectively that they form vertical bluffs and cliffs.

Question 59

The tilted beds that are often visible in fossil dunes are ____.

A) formed by abrasion on the surface of the rock
B) formed by tectonic tilting
C) the original layers of the dune's windward face
D) the original layers of the dune's slip face

Question 60

Tectonic extension and uplift has created the mountain and valley landscape of the Great Basin. The downdropped valleys are called ____.

A) horsts
B) bajadas
C) blowouts
D) grabens

Question 61

In the desert, where is the water table commonly located?

Question 62

Describe the tectonics of the Great Basin.

Question 63

Describe the development of the Colorado Plateau.

Question 64

Describe the landscape in the desert and the effect that rain can have on the landscape.

Question 65

What kind of features do loess form?

Question 66

Describe the Gobi Desert in terms of its geographic location and its surrounding neighbors.

Question 67

Compare and contrast a bajada and pediment and how they are related.

Question 68

What is a plateau?

Question 69

What is a playa lake and a playa?

Question 70

Describe the four types of sand dunes.

Question 71

What are some factors that influence how rain and snow are unevenly distributed?

Question 72

Describe the geographic location of the Gobi Desert.

Question 73

List the three sources from which water can reach a desert.

Question 74

Which states does the Colorado Plateau encompass?

Question 75

Define loess.

Question 76

Where is the largest dune field located and how big is it?

Question 77

What kind of symmetry does a sand dune have?

Question 78

_______ percent of the world's desert area is covered by a pavement of pebbles and cobbles whereas ________ percent is covered by sand.

Question 79

The textbook mentions three different plateaus, describe each in detail.

Question 80

What is flash flooding?