Deck 4: Glacial and Arid Landscapes

Question 1

A glacier's downstream end ________.

A)is where new ice is added through compaction of snowfall
B)is in the zone of wastage
C)is where the fastest flow occurs
D)is where cirques get carved out

Answer 1

B

Question 2

In an area of alpine glaciation, sinuous, sharp-edged ridges called ________ and sharp, pyramid- like peaks called ________ are common features.

A)tarns; cirques
B)cirques; arêtes
C)arêtes; horns
D)horns; hanging valleys

Answer 2

C

Question 3

How do glaciers move?

A)They slide along their bottoms, over the bedrock beneath.
B)They flow internally, like Silly Putty.
C)Both A and B
D)Neither A nor B

Answer 3

C

Question 4

When a valley glacier leaves the mountains and enters the relative flat lands below, it may spread out to form ________.

A)an ice cap
B)a piedmont glacier
C)an ice shelf
D)a lateral moraine

Question 5

Under typical conditions, glaciers flow ________.

A)at a rate between 2 meters (6.5 feet)and 800 meters (2600 feet)per year
B)throughout the entire glacial ice mass
C)at a rate between 1.6 to 8 kilometers per hour (1 and 5 miles per hour)
D)only when the snow is falling

Question 6

Which one of the following is NOT true of glaciers?

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

Question 7

This cobble shows prominent scratches because ________.

A)it was tumbled in a stream
B)it was scraped against other rocks in a glacier
C)it was blasted by wind
D)this was its shape when it was mechanically weathered from its source rock

Question 8

Which of the following lakes formed over an immense area of the northern United States and southern Canada during the Quaternary Ice Age?

A)Lake Agassiz
B)Lake Bonneville
C)Great Salt Lake
D)Walden Pond

Question 9

________ are erosional features produced by valley (alpine)glaciers.

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

Question 10

Where do crevasses form?

A)in the zone of fracture
B)below the zone of fracture
C)at the terminus
D)in icebergs

Question 11

Which of the four lettered positions on this map-view sketch shows the location of the terminal end moraine?

A)A
B)B
C)C
D)D

Question 12

Where are drumlins formed?

A)in areas of alpine glaciation
B)in areas of ground moraine
C)in fiords
D)in areas of glacial plucking

Question 13

If accumulation exceeds ablation in a glacial budget, which of the following will happen?

A)The terminus will move downhill ("advance").
B)The terminus will shift uphill ("retreat").
C)The glacier will begin to flow uphill.
D)The glacier will melt away due to climate change.

Question 14

About what percentage of Earth's land surface is covered by deserts?

A)3%
B)15%
C)30%
D)55%

Question 15

How is desert different from steppe?

A)Steppe is more humid than desert.
B)Desert is more humid than steppe.
C)Desert occurs at subtropical latitudes, but not at mid-latitudes in continental interiors.
D)Steppe occurs at subtropical latitudes, but not at mid-latitudes in continental interiors.

Question 16

If you were on a geology field trip in an area of glacial deposition, how would you distinguish between samples of till and stratified drift?

A)with a rock hammer
B)by comparing their grain size and sorting
C)by comparing the specific gravity of the two samples
D)with hydrochloric acid

Question 17

What formed this valley's distinctive "U" shape?

A)river erosion
B)wind erosion
C)dune movement
D)glacial erosion

Question 18

Where is the world's largest ice sheet located today?

A)Greenland
B)Alaska
C)Iceland
D)Antarctica

Question 19

About what percentage of Earth's land surface was covered by glaciers during the Quaternary period?

A)3%
B)15%
C)30%
D)55%

Question 20

Which of the following is NOT a variety of moraine?

A)lateral
B)medial
C)end
D)hanging

Question 21

Cross-bedding consists of many preserved ________ resulting from moving sand dunes.

A)slip faces
B)desert pavements
C)blowouts
D)loess

Question 22

Glaciers acquire sediment through plucking from the bedrock beneath the glacier.

Question 23

Arêtes, horns, and U-shaped valleys are depositional features made of till.

Question 24

Glaciers are part of the hydrologic cycle.

Question 25

Steppes are the driest of the true desert lands.

Question 26

A rainshadow desert forms ________.

A)when dry air descends from high in the atmosphere between 20° and 30° latitude
B)in places where mountain ranges act as barriers to the movement of water vapor
C)in cold, polar regions
D)near the equator, where moist air rises (because it is hot and less dense)up, away from Earth's surface

Question 27

The most recent Ice Age occurred during the Cretaceous period.

Question 28

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

Question 29

Ephemeral streams ________.

A)are a major agent of erosion in desert regions
B)are a major agent of erosion in areas of ground moraine
C)flow all the time
D)are limited to rainshadow deserts

Question 30

Moraines are the only glacial deposits composed of till.

Question 31

Deflation may lead to ________.

A)dust storms
B)desert pavement
C)loess
D)all of the above

Question 32

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

Question 33

Bajadas develop when multiple alluvial fans grow and merge along the fronts of mountain ranges in arid lands.

Question 34

Loess consists mainly of sand-sized particles.

Question 35

Although infrequent, running water is responsible for most of the erosional work in deserts.

Question 36

The Basin and Range region of the western United States is characterized by interior drainage with streams eroding uplifted mountain blocks and depositing sediment in interior basins.

Question 37

Melting and calving are two forms of accumulation.

Question 38

A(n)________ a thick, flowing ice mass that forms over hundreds or thousands of years.

Question 39

At the Last Glacial Maximum, sea level was about 180 meters lower than it is today.

Question 40

Examine the photo. Is it true or false to say, "the dunes that deposited these cross beds were moving from the left to the right"?

Question 41

Match the items in the first column with the correct descriptions in the second column.

A)lifting and removal of loose material like soil or sediment by the wind.
B)wind-deposited sand that forms mounds or ridges.
C)a layer of coarse pebbles and cobbles that are too large to be moved by the wind overlying finer-grained sediment in desert regions.
D)preserved slip-faces that accumulate as a dune migrates.
E)shallow depressions where soil or sediment has been stripped away by the wind.
F)regions that are slightly more humid than desert.
G)wind-deposited silt.
H)the leeward side of a dune.
1)deflation
2)dunes
3)blowout
4)loess
5)slip face
6)cross-bedding
7)steppe
8)desert pavement

Question 42

A landscape dominated by U-shaped valleys and pyramid-shaped mountains is most likely formed due to ________.

Question 43

By the year 2030, it is possible that Glacier National Park in Montana will not have any ________.

Question 44

________ is drier than steppe.

Question 45

A hazard people face when crossing a glacier is falling into a(n)________, a large crack that extends through the zone of fracture.

Question 46

Desert regions that exhibit a discontinuous pattern of ephemeral streams that do not flow out of the desert to the ocean are said to have a(n)________.

Question 47

Between wind, water, and glacial ice, ________ is easily the least effective agent of erosion.

Question 48

Match the items in the first column with the correct descriptions in the second column.

A)enormous mass of ice that flows out in all directions from one or more snow-accumulation centers and completely obscures all but the highest areas of underlying terrain.
B)a stream of ice, bounded by precipitous rock walls, that flows down a mountain valley from a snow accumulation center near its head.
C)frozen seawater.
D)large, relatively flat masses of floating ice that extend seaward from the coast (where they are fed by glaciers)but remain attached to the land along one or more sides.
9)sea ice
10)ice sheet
11)alpine glacier (or "valley glacier")
12)ice shelf

Question 49

The ________ region of the United States is depicted in this image.

Question 50

Match the landscape feature with the material from which it is formed.

A)till
B)outwash
C)solid rock
13)glacial erratic
14)cirque
15)esker
16)horn
17)drumlin
18)moraine

Question 51

Examine the satellite image of Death Valley, California. (a)What province of the United States is it located within? (b)Identify the various desert landforms seen there, circle and label them, and (c)describe how each one forms. Finally, (d)describe the sequence of events to that produced this scene over time.

Question 52

Glaciers are powerful agents of erosion and deposition, and during the Quaternary Ice Age, these flowing masses of ice reshaped much of the North American continent. Discuss three of the effects of Ice Age glaciers that are NOT related to erosion or deposition.

Question 53

A(n)________ is a cone of debris that forms where an ephemeral stream emerges from the confines of the canyon. Its runoff spreads over the gentler slopes at the base of the mountains and quickly loses velocity, dumping most of its sediment load within a short distance.

Question 54

When a glacial trough is "drowned" by the sea, the result is a(n)________.

Question 55

________ form from the coalescence of multiple alluvial fans.

Question 56

Though ________ and ________ are sediments that can be picked up by the wind, ________ is too heavy, and gets left behind.

Question 57

A sinuous ridge composed of sand and gravel is a(n)________; It is a deposit made by streams flowing in tunnels within or beneath glacial ice.

Question 58

If the planet were to cool in the future, snow may begin to accumulate near the head of a glacier more rapidly than it would melt in the zone of wastage. In these circumstances, the terminus of the glacier would ________.

Question 59

Label each of the indicated Basin and Range landscape features in the boxes provided.

Question 60

The ________ period of geologic time is depicted in this image.

Question 61

Examine the aerial photograph of Death Valley, California, part of the Basin and Range province. Note that the western side of Death Valley, up against the Panamint Range, features a well-developed bajada, while the east side of the valley, up against the Amargosa Range, shows only a few isolated alluvial fans. Suggest an explanation for this asymmetry, and how you would test your hypothesis with an investigation on the ground.

Question 62

Wind is included along with gravity, water, and ice as an agent of erosion. In many national parks and other areas of natural beauty, statements are often made that credit wind as having sculpted the landscape. Briefly discuss the importance of wind as an agent of erosion and explain why such statements are probably geologically inaccurate.