Deck 13: Glaciers and Ice Ages

Question 1

A glacier that forms in mountainous terrain is a/an __________ glacier.

A) alpine
B) continental
C) marine
D) erratic

Answer 1

A

Question 2

A glacier that covers an area of 50,000 square kilometers or more is a/an __________ __________.

Answer 2

Answer: 242

Question 3

__________ is sediment that was deposited directly by a glacier.

Answer 3

Till

Question 4

The Matterhorn is an example of a glacial __________.

Question 5

A series of tarn lakes in the valley below a cirque are called __________ lakes.

Question 6

A glacier can move as fast as __________ per day.

A) a few millimeters
B) a few centimeters
C) 15 centimeters
D) 10 to 100 meters

Question 7

The ice sheets of Greenland and Antarctica contain __________ percent of the world's ice.

A) 25
B) 75
C) 50
D) 99

Question 8

The place where glacial flow cannot keep pace with melting is called the __________.

Question 9

The most recent ice age occurred during the __________ Epoch.

Question 10

Glacial streams deposit their sediment downstream from the glacier as __________.

Question 11

The relative rates of basal slip and plastic flow depend on the __________ of the bedrock underlying the glacier and the __________ of the ice.

A) steepness, age
B) thickness, thickness
C) steepness, thickness
D) age, steepness

Question 12

A/an __________ __________ is a section in a glacier consisting of crevasses and towering pinnacles that occur in the upper 50 meters of a glacier as it flows over bedrock.

Question 13

__________ __________ is glacier movement as a viscous fluid.

Question 14

A ridge of sediment in the center of an alpine glacier that is formed when two lateral moraines merge is called a __________ __________.

Question 15

The lower elevation portion of a glacier where less snow is added in winter than melts in summer is called the __________.

A) zone of ablation
B) no-snow area
C) zone of accumulation
D) snow line

Question 16

__________ occurs when the Earth's axis circles like a wobbling top.

Question 17

A small glacial valley lying high above the floor of the main valley is called a/an __________ __________.

Question 18

__________ is a lithified glacial deposit.

Question 19

A/an __________is a massive, long-lasting accumulation of compacted snow and ice that forms on land.

Question 20

A/an __________ is a long, snake-like ridge formed as the channel deposit of a stream that flowed within or beneath a melting glacier.

Question 21

In a plastically flowing alpine glacier, the:

A) center flows slower than the sides, but the center layers move faster than the deepest layers.
B) center, sides, and deeper layers all move at the same speed.
C) center flows faster than the sides, and the center layers move faster than the deepest layers.
D) center flows faster than the sides, but the center layers move slower than the deepest layers.

Question 22

Glacial __________ form as rocks are dragged along at the base of a glacier.

A) crevasses
B) snow lines
C) cirques
D) striations

Question 23

The Pleistocene Ice Age started about __________ million years ago.

A) 0.2
B) 2
C) 20
D) 200
Multiple Choice

Question 24

Continental glaciers occur:

A) in polar regions.
B) on mountains in Antarctica only.
C) only close to the equator at very high elevations.
D) near mountain tops (at high elevations) on all continents.

Question 25

Valleys that have been carved by glaciers and have became submerged by rising sea level are called:

A) cirques.
B) horns.
C) fjords.
D) kettle lakes.

Question 26

A/an __________ is a small lake at the base of a/an __________.

A) tarn, cirque
B) tarn, crevasse
C) arête, horn
D) arête, cirque

Question 27

The higher elevation portion of a glacier where more snow accumulates in winter than melts in summer is called:

A) the zone of ablation.
B) the ablation area.
C) the zone of accumulation.
D) snow line.

Question 28

In glacial terrain, a spoon-shaped depression beneath a steep peak is a/an:

A) cirque.
B) horn.
C) arête.
D) drumlin.

Question 29

Alpine glaciers occur:

A) on flatlands in continental interiors.
B) on mountains in Antarctica only.
C) only close to the equator at very high elevations.
D) near mountain tops (at high elevations) on all continents.

Question 30

A/an __________ is an elongate hill, usually occurring in clusters, that was deposited and eroded by a glacier.

A) ground moraine
B) drumlin
C) gremlin
D) erratic

Question 31

Glaciers erode __________-shaped valleys.

A) C
B) O
C) U
D) V

Question 32

The rate of glacial movement varies with:

A) slope steepness.
B) precipitation.
C) air temperature.
D) all of the above

Question 33

Crevasses form in the:

A) lower plastic zone of a glacier.
B) lower brittle zone of a glacier.
C) brittle upper 40 meters of a glacier.
D) brittle lower 40 meters of a glacier.

Question 34

Rounded ice grains, called firn, form if:

A) snow survives through one summer.
B) snow survives through two summers.
C) it falls on basal ice.
D) it falls on ablation ice.

Question 35

An iceberg:

A) is a piece of a glacier that has broken off.
B) is a floating platform of ice where a glacier or ice sheet meet the ocean.
C) forms out of ocean water.
D) is made up snow falling on water.

Question 36

The lower end of a glacier is called the __________.

A) snow line
B) terminus
C) zone of accumulation
D) tail

Question 37

When a glacier retreats steadily, it deposits a/an __________ moraine.

A) medial
B) terminal
C) recessional
D) ground

Question 38

The __________ separates the zone of accumulation from the zone of ablation.

A) snow line
B) terminus
C) crevasse
D) ice fall

Question 39

__________ is sediment that was first transported by a glacier and then transported and deposited by a stream.

A) Bedrock
B) Till
C) Stratified drift
D) An erratic rock

Question 40

A/an __________ is a sharp, narrow ridge between two glacial valleys.

A) tarn
B) horn
C) arête
D) fjord

Question 41

Glacial striations can be used to map the flow direction of glaciers.

Question 42

Pressure from the weight of overlying ice favors melting at the base.

Question 43

Rates of glacial movement depend entirely on air temperature.

Question 44

Ice in the upper 40 meters of a glacier fractures to form crevasses.

Question 45

Cycles identified by Milutin Milankovitch are caused by changes in:

A) the Earth's tides.
B) sunspot activity.
C) the Earth's orbital parameters (eccentricity, tilt, precession).
D) mountain uplift.

Question 46

The higher-elevation part of a glacier is called the zone of ablation.

Question 47

Alpine glaciers occur only in the Northern Hemisphere.

Question 48

The greatest ice age in Earth's history occurred during the Precambrian time.

Question 49

Glaciers form U-shaped valleys.

Question 50

A smaller glacial valley that meets the main valley with a large vertical offset is called a:

A) fjord.
B) hanging valley.
C) flying valley.
D) death valley.

Question 51

Geologic evidence shows that the Earth has been cold and ice covered for about 90 percent of the past 2.5 billion years.

Question 52

Much of the northern Great Plains is covered with ground moraine, loess, or outwash.

Question 53

The Great Lakes and the Finger Lakes in New York are the result of:

A) scouring by alpine glaciers.
B) scouring by continental ice sheets.
C) ancient fjords.
D) isostasy.

Question 54

During the last glaciation, sea level:

A) dropped by about 130 m.
B) didn't change.
C) rose by about 110 m.
D) dropped by about 2 km.
True/False

Question 55

Ground moraines record the extent of continental glaciers of the most recent ice age.

Question 56

Ice is so much more viscous than water that it sorts particles into various sizes.

Question 57

During an Ice Age:

A) all of the continental land is covered by a giant continental glacier.
B) all glaciers extend into the sea and cover large portions of the oceans.
C) the high latitudes are ice covered, but there are no glaciers near the equator.
D) alpine glaciers descend into lowlands, and continental glaciers spread over the higher latitudes.

Question 58

A glacier forms wherever the amount of snow that falls in winter equals the amount that melts in summer.

Question 59

Sediment particles carried by a glacier are likely to be sharp and jagged.

Question 60

Glaciers are now shrinking in more places and at more rapid rates than at any time since scientists began keeping records.