Deck 6: Glaciers, deserts, and Wind

Question 1

At the base of a glacier,the ice moves by ________.

A)fracturing
B)fracturing and sliding
C)sliding and ductile flow
D)ductile flow and fracturing

Answer 1

C

Question 2

________ are erosional features produced by valley/alpine glaciers.

A)Moraines
B)Cirques
C)Eskers
D)Drumlins

Answer 2

B

Question 3

The term drift ________.

A)refers only to alpine glaciers
B)refers only to moraines
C)is synonymous with the term till
D)means any sediments of glacial origin

Answer 3

D

Question 4

A(n)________ represents a former meltwater channel or tunnel in glacial ice that was filled with sand and gravel.

A)esker
B)yazoo ridge
C)valley plain
D)kettle

Question 5

If the glacial budget is balanced (accumulation equals wastage),then ________.

A)the terminus of the glacier is stationary
B)the ice front will retreat
C)the glacier will not flow downhill
D)the ice front will advance

Question 6

Abrasion and plucking generally involve what part of a glacier?

A)the internal flowage zone
B)the snout zone
C)the surface brittle zone
D)the bottom or base

Question 7

Most of an iceberg is under water because ________.

A)ice is more dense than seawater
B)seawater is more dense than ice
C)the mass of an iceberg is concentrated in the zone of wastage
D)the mass of an iceberg is concentrated in the zone of accumulation

Question 8

Ice sheets can be ________.

A)several centimeters thick
B)several meters thick
C)several kilometers thick
D)tens of kilometers thick

Question 9

What condition is most necessary to build a glacier?

A)The elevation of the area must be high enough to allow snow to fall regularly.
B)The temperature must be cold enough to cause snow to fall regularly.
C)The snow must be able to move downhill slowly.
D)More snow must fall in the winter than melts in the summer.

Question 10

How do glaciers acquire their load of sediment?

A)Sediments are deposited on glaciers by streams that flow into the glaciers.
B)Sediments are plowed up into the glacier by the front terminus of the glacier as it moves downhill.
C)Sediments are plucked off the rocks at the base and sides of the glacier.
D)Sediments fall off the cliffs surrounding the glacier and move through crevasses to the base of the glacier.
E)All of the answers describe major contributors to the glacial sediment load.

Question 11

Today,glaciers cover approximately ________ percent of the earth's surface.

A)1
B)10
C)30
D)50

Question 12

A(n)________ is likely to host a waterfall or steep rapids today.

A)outwash plain
B)hanging valley
C)striated drumlin
D)horn peak

Question 13

Crevasses (deep fractures or cracks)form because ________.

A)not all of the ice in a glacier moves downhill at the same rate in the glacier
B)as the glacier moves over irregular topography the bottom of the glacier (known as the zone of fracture)cracks and the cracks propagate upward to the surface of the glacier
C)as the glacier moves over irregular topography,the brittle upper layer or zone of fracture is subject to tension and cracks above the ductile layer
D)as the glacier moves over irregular topography,cracks can form anywhere in the glacier but they are called "crevasses" only if they are near the surface
E)there is not always the same amount of ice available in all areas so cracks form when the ice tries to move and fill in empty parts of the glacier

Question 14

A ________ forms when a block of ice is buried in drift and subsequently melts,creating a pit.

A)tarn
B)paternoster
C)kame
D)kettle

Question 15

Which one of the following applies to a valley glacier that lengthens (extends the position of its terminus downslope)over a period of many years?

A)wastage exceeds accumulation
B)accumulation exceeds wastage
C)accumulation and wastage are about equal
D)none of the above

Question 16

If you fall into a crevasse,what is the maximum depth you are likely to fall?

A)10 meters
B)25 meters
C)50 meters
D)100 meters

Question 17

Which one of the following is not true of glaciers?

A)originate on land
B)exist only in the Northern Hemisphere
C)show evidence of past or present flow
D)form from the recrystallization of snow

Question 18

Which of the following is not a major factor controlling glacial erosion?

A)ice thickness
B)rate of glacial ice movement
C)strength of the glacial ice near its base
D)character of the surface beneath the glacier

Question 19

How is sea ice different from glacial ice?

A)Sea ice is thicker than glacial ice,and sea ice floats while glacial ice does not float.
B)Sea ice is thicker than glacial ice,and both sea ice and glacial ice can float.
C)Sea ice is thinner than glacial ice,and both sea ice and glacial ice can float.
D)Sea ice is thinner than glacial ice,and sea ice floats while glacial ice does not float.

Question 20

Glacial ice sheets are the largest glaciers and they currently cover ________.

A)Antarctica,Greenland,Alaska,the Andes Mountains,the Arctic Sea,and the Alps
B)The Arctic Sea,the Alps,Greenland,Antarctica,and Alaska
C)Alaska,Antarctica,and Greenland
D)Greenland and Antarctica
E)only Antarctica

Question 21

Desert pavement is the result of ________.

A)deflation
B)abrasion by windblown sand
C)erosion by running water
D)intense chemical weathering

Question 22

Ice Age glaciers had many indirect effects.Which one of the following was not such an effect?

A)formation of mountains
B)extinction of some organisms
C)changes in some river courses
D)sea level fluctuations

Question 23

Deserts occur primarily in the Africa,Arabia,and Australia because of ________.

A)subsiding air currents
B)rising air currents
C)high temperatures
D)mountains that block the moisture and long distances from the oceans

Question 24

Inselbergs are ________.

A)insulated icebergs floating in a hot spring
B)blowouts cut from bedrock in mountainous areas
C)lithified rock formed by cementation of wind-deposited,dune sands
D)bedrock hills in a highly eroded desert landscape

Question 25

Desert and steppe lands cover about what percentage of Earth's land area?

A)10%
B)66%
C)30%
D)3%

Question 26

Our detailed knowledge of the glacial cycles and their duration is based primarily on ________.

A)ice cores
B)seafloor sediments
C)land sediments
D)climate records

Question 27

Glacial sediments or tills are characterized by ________.

A)striations
B)cirques,arêtes,and hanging valleys
C)moraines and glacial flour
D)wide variations in sizes of clasts
E)very fine-grained,highly polished clasts

Question 28

Why is wind less effective than moving water at picking up and moving materials?

A)Air is less dense than water
B)Air moves slower than water
C)Air moves faster than water
D)Air does not move very far

Question 29

Which of the following is not a typical stage in the evolution of a Basin and Range type region?

A)Water erodes the mountains and deposits sediment in the adjacent basins.
B)Alluvial fans and bajadas form along the mountain fronts.
C)Salt flats or playas and occasional playa lakes form.
D)Sediment slowly moves downhill to the sea where it is ultimately deposited.

Question 30

Permanent streams in desert regions are rare,and when they do occur,________.

A)they originate in a glacier region
B)they have numerous tributaries to keep them supplied with water as they cross the desert
C)they originate outside of the desert region and have few tributaries in the desert
D)they get their water from wadis and arroyos

Question 31

Climatologist define a "dry climate" as a climate in which ________.

A)less than 25 cm (10 in)of rain falls in a year
B)precipitation is blocked by high mountains
C)precipitation is less than expected evaporation
D)All of the answers are correct.

Question 32

Desert streams are characterized by ________.

A)increasing discharge downstream
B)decreasing discharge downstream
C)short,frequent tributaries
D)long,frequent tributaries
E)well-sorted,rounded clasts of sediment

Question 33

The major difference between floods in humid regions and in dry regions is ________.

A)in dry regions,flooding is a very slow process because there is less water
B)in dry regions,flooding is a very fast process because there are fewer plants
C)in dry regions,flooding lasts much longer than in humid regions because the water cannot soak into the baked desert soil.
D)in dry regions,flooding lasts only a short time because the water is immediately soaked up by the dry desert soil.

Question 34

Which one of the following statements is true?

A)Desert landscapes are monotonous,relatively flat areas covered to various depths with sand.
B)Deserts and dry lands are concentrated in areas of ascending air masses and relatively low atmospheric pressures.
C)Despite infrequent rainfalls,erosional and depositional features of running water are important in desert landscapes.
D)Wind is the major cause of erosion in deserts because there is little water but a lot of wind available.

Question 35

Milankovitch cycles are used to explain the cycles of cold and warm climates that characterized the Ice Ages based on ________.

A)plate tectonics and sea level rise
B)solar flares and variations in the moon's orbit over time
C)evolution of plants and animals and human impact
D)variations in the earth's orbit about the sun and precession of the earth's axis

Question 36

In a dry climate,weathering is significantly less than in a humid climate because ________.

A)wind is not a significant weathering agent
B)there is a shortage of moisture and organic acids
C)rivers are ephemeral and do not cause weathering in the desert
D)sand covers much of the rock surface and protects them from weathering in a desert

Question 37

What of the following is considered to be the most likely cause of the Quaternary Ice ages?

A)human activity releasing "greenhouse" gases
B)plate tectonics moving continents to polar regions
C)variations in the earth's orbit
D)variations in the Sun's intensity

Question 38

Which of the following did not exist prior to the Quaternary Ice ages?

A)the Mississippi River
B)the Colorado River
C)Antarctica
D)the Great Lakes
E)the arctic ocean

Question 39

If all of the ice now stored in Antarctica's glaciers melted,what would happen?

A)Sea water would become fresh enough to drink because glaciers are made of fresh water.
B)Sea level would rise flooding many coastal cities.
C)Because glacial melt water is less dense than sea water,the glacial melt will float on top of the ocean and not affect the land areas.
D)Ice bergs would float to the equatorial regions of the earth where they would lower the temperature and cause the climate to become cooler.

Question 40

Deserts and steppes occur at middle latitudes because of ________.

A)subsiding air currents
B)rising air currents
C)high temperatures
D)mountains that block the moisture and long distances from the oceans

Question 41

During the Ice Age,the climate was occasionally warmer than it is today.

Question 42

sand dune deflation blowout desert pavement

Question 43

Glaciers will not form near the equator because the Sun is too strong in that area.

Question 44

The loess deposited in many parts of the Midwest ________.

A)was once glacial outwash deposits
B)is in the form of transverse dunes
C)is uniformly thick
D)had its source in desert regions

Question 45

Arêtes,horns,and U-shaped valleys are erosional features carved from bedrock by glaciers.

Question 46

Stratified drift is sorted by glacial ice as the glacier begins to melt and drop its load of sediment.

Question 47

Melting and calving are two forms of ablation.

Question 48

horn arête lateral moraine drumlin

Question 49

loess alluvial fan playa inselberg

Question 50

Examine the words and/or phrases for each question below and determine the relationship among the majority of words/phrases. Choose the option which does not fit the pattern.

-arroyo wadi inselberg nullah

Question 51

Fiords are glacier-cut valleys that flooded as sea level rose in post-glacial times.

Question 52

Running water is an important erosional agent in many arid lands despite infrequent rainfalls.

Question 53

Moraines are the only glacial deposits composed of till.

Question 54

Till is an unsorted sediment deposited directly from the melting glacial ice; stream action is not involved.

Question 55

Examine the words and/or phrases for each question below and determine the relationship among the majority of words/phrases. Choose the option which does not fit the pattern.

-drumlin cirque esker moraine

Question 56

The North Pole is covered by glaciers.

Question 57

When a glacier is retreating,the upstream ice is still moving forward toward the downstream terminus of the glacier.

Question 58

calving zone of accumulation melting zone of wastage

Question 59

A cirque represents an erosional feature formed in what was an important accumulation zone for snow and ice at the upstream head of a glacier.

Question 60

Glaciation has only been recorded for the Quaternary period of the earth's history demonstrating that the cause of the Ice Ages is the earth's orbit moving farther from the Sun.

Question 61

Bajadas develop from coalescence of alluvial fans along fronts of mountain ranges in arid lands.

Question 62

Windblown loess,like sand,typically accumulates as mound-like dunes.

Question 63

The Basin and Range region of the western United States is an excellent example of a mountainous desert landscape.

Question 64

Which letter,S thru Z,corresponds to the object in the photo labeled "B"?

Question 65

The Colorado River is an example of a large wash.

Question 66

Which letter,S thru Z,corresponds to the object in the photo labeled "D"?

Question 67

Which letter,T thru Z,corresponds to the object in the photo labeled "A"?

Question 68

Arid and semiarid climates cover nearly one-third of Earth's land surface.

Question 69

Deserts are hot,lifeless sand-covered landscapes shaped largely by the forces of wind.

Question 70

The steeper,leeward slope of a sand dune is called the slip face.

Question 71

A playa is an intermittent lake on the floor of a desert valley.

Question 72

A(n)________ is a closed depression formed by melting of an ice block buried in a moraine or outwash plain.

Question 73

Deposits of windblown silt are called ________.

Question 74

What term denotes a glacial valley that was partly flooded as sea level rose?

Question 75

What is the name for the very large pluvial lake that once existed in northwestern Utah?

Question 76

Which letter,S thru Z,corresponds to the object in the photo labeled "C"?

Question 77

Bowl-shaped depressions in bedrock at upstream ends of alpine glacial valleys are called ________.

Question 78

What term describes open fissures in the brittle surface ice of a glacier?

Question 79

Blowouts are broad,shallow depressions excavated by deflation.

Question 80

The low,bedrock ridges and peaks of a highly eroded,basin and range,desert landscape are called ________.