Deck 14: Glacial and Penglacial Landscapes

Question 1

A glacier that is confined in a bowl-shaped recess is called a

A) piedmont glacier.
B) mountain glacier.
C) cirque glacier.
D) valley glacier.

Answer 1

C

Question 2

Continuous ice sheets, ice caps, and ice fields are drained on their periphery by

A) piedmont glaciers.
B) mountain glaciers.
C) outlet glaciers.
D) valley glaciers.

Answer 2

C

Question 3

The bulk of ice on Earth is sitting in

A) North America, specifically Alaska.
B) European and Asian mountain ranges.
C) Greenland and Antarctica.
D) floating ice shelves and packs.

Answer 3

C

Question 4

Which of the following is true of the snowline?

A) It increases in elevation with increasing latitude.
B) It decreases in elevation with increasing latitude.
C) It occurs at approximately the same elevation at all latitudes because the environmental lapse rate is approximately the same at all latitudes.

Question 5

A continuous mass of ice covering a large landmass is known as a

A) tidal glacier.
B) mountain glacier.
C) continental glacier.
D) valley glacier.

Question 6

The opposite of the accumulation zone in a glacier is the

A) abrasion zone.
B) equilibrium line.
C) ablation zone.
D) snow and firn area.

Question 7

A visible snowline across the surface of a glacier is called

A) an equilibrium line.
B) a medial moraine.
C) a firn line.
D) the ice line.

Question 8

A valley glacier that extends beyond the confines of its valley and coalesces with other valley glaciers along the base of a mountain range is termed

A) an ice field.
B) a piedmont glacier.
C) a cirque glacier.
D) a valley glacier.

Question 9

The process of calving produces

A) baby steers.
B) nunataks.
C) roche moutonné.
D) icebergs.
E) moraines.

Question 10

Approximately what percentage of the world's freshwater is frozen?

A) 10 percent
B) 30 percent
C) 50 percent
D) 77 percent

Question 11

In terms of areal extent, which of the following sequences is in order from most to least area covered?

A) ice sheet, ice field, ice cap
B) ice field, ice sheet, ice cap
C) ice sheet, valley glacier, piedmont glacier
D) ice sheet, ice cap, ice field

Question 12

Which of the following is false?

A) 75% of glaciers in the European Alps have receded in the past 50 years.
B) The South Cascade Glacier has lost an average of 55 cm per year from 1955-2006.
C) 25% of global sea level rise is coming from melting alpine glaciers.
D) Mt. St. Helens and Mt. Shasta have seen 37% increases in glacial mass from 1983-2005.

Question 13

The transformation of snow into glacial ice in Antarctica takes ________ than in midlatitude alpine glaciers because ________.

A) longer; less snow falls per year in polar regions
B) longer; less melting and refreezing occurs in Antarctica
C) less time; more snow falls each year in polar regions
D) less time; less melting and refreezing occurs in the midlatitudes
E) both A and B

Question 14

$\underline { \text { Snow } }$ that has a compact, granular structure is known as

A) snowflakes.
B) firn.
C) glacial ice.
D) meta-ice.

Question 15

A general term for a mass of perennial ice, resting on land or floating shelf-like in the sea adjacent to land is

A) the snowline.
B) an iceberg.
C) a glacier.
D) moraine.

Question 16

Melting and refreezing of snow acts to ________ ice density and ________ the sphericity (roundness) of the original snowflakes.

A) increase; increase
B) increase; decrease
C) decrease; increase
D) decrease; decrease

Question 17

Alpine glaciers include all of the following except

A) an ice cap.
B) a mountain glacier.
C) a cirque glacier.
D) a valley glacier.

Question 18

Why, specifically, is glacial ice analogous to a metamorphic rock?

A) It has a definite chemical composition.
B) It has a crystalline structure.
C) It forms as a result of recrystallization caused by pressure.
D) It is solid.

Question 19

Which is false regarding the South Cascade and Alaskan glaciers?

A) The Alaskan glaciers studied have lost on average more than 50km³ (12mi³) per year from the 1950s to today.
B) 9% of global sea level rise is coming from the melting of Alaskan glaciers.
C) The South Cascade Glacier has retreated every year since 1955, except 1972..
D) Water from melting Alaskan glaciers is contributing more to global sea level rise than the glaciers of Greenland.
E) The Columbia Glacier in Alaska has advanced 12 km (7.5 mi) from 1982 to 2002.

Question 20

Relative to glacial mass balance, which of the following is false?

A) A positive net balance occurs during a cold period, and a negative net balance occurs during a warm period.
B) Glacial mass is reduced by evaporation, sublimation, and deflation.
C) Glacial mass is reduced by a combination of processes called ablation.
D) Worldwide, most glaciers are showing marked net increase in mass at present.

Question 21

Which of the following is false regarding the basal layer of a glacier?

A) It can extend tens of meters above the ground surface.
B) It tends to flow more slowly than the overlying parts of the glacier.
C) It contains more debris than other parts of the glacier.
D) Crevasses form in this region of the glacier.

Question 22

Which of the following is considered to be a possible mechanism for glacier surges?

A) basal slip
B) slight floating of the glacier
C) fracturing
D) all of the above
E) A and B only

Question 23

During a glacier surge, a glacier may move forward at a speed of up to

A) 1 cm per day.
B) 1 meter per day.
C) tens of meters per day.
D) a few kilometers per hour.

Question 24

The zone where positive gains end and losses begin in the glacial mass balance is called

A) an equilibrium line.
B) medial moraine.
C) firn line.
D) the ice field line.

Question 25

Glacier surges may be associated with

A) ice quakes.
B) mass imbalance.
C) water pressure.
D) all of these
E) B and C only

Question 26

The material in a glacial moraine is

A) sorted by weight.
B) sorted by size.
C) sorted by weight and size.
D) unsorted.

Question 27

Which of the following is a continental depositional feature?

A) cirque
B) horn
C) drumlin
D) col

Question 28

A pyramidal peak formed in glaciated mountains is

A) a col.
B) an arete.
C) a horn.
D) a cirque.

Question 29

A specific landform produced by the deposition of glacial till is known as

A) glacial drift.
B) outwash.
C) a moraine.
D) alluvium.

Question 30

Glacial polish results from

A) abrasion.
B) ice plucking.
C) regelation.
D) rotation of ice about a vertical axis.

Question 31

Basal slip is facilitated by

A) regelation.
B) presence of melt water.
C) saturated sediments.
D) all of these.
E) None of these-basal ice does not move.

Question 32

A tarn is a lake in a

A) till plain.
B) horn.
C) cirque.
D) glacial valley.

Question 33

Which of the following is true of glacial movement?

A) The rate of surface motion is usually identical to the basal slip rate.
B) The internal flow just below the surface is greater than the basal flow.
C) All glaciers move just a few centimeters per year.
D) The basal ice layer does not move downslope.

Question 34

Roche moutonnées form as a result of

A) abrasion on both the stoss (upstream) and lee (downstream) side of a rocky outcrop.
B) ice plucking on both the stoss and lee side of a rocky outcrop.
C) abrasion on the stoss side and ice plucking on the lee side of a rocky outcrop.
D) ice plucking on the stoss side and abrasion on the lee side of a rocky outcrop.
E) none of these

Question 35

Horns and cirques are typical features of

A) a till plain deposited by continental glaciers.
B) a mountain range that was sculpted by alpine glaciers.
C) unsorted glacial deposits left by continental glaciers.
D) loess deposits that have been heavily sculpted by wind action.

Question 36

When two valley glaciers join together, they form a ________ at the point at which they merge.

A) terminal moraine
B) till plain
C) recessional moraine
D) medial moraine

Question 37

Which of the following are erosional landforms created by alpine glaciation?

A) drumlins
B) eskers
C) till plains
D) cols and horns

Question 38

Drowned glacial valleys are known as

A) kettle holes.
B) tarns.
C) fjords.
D) paternoster lakes.

Question 39

Crevasses usually form as a result of

A) regelation.
B) ablation.
C) deposition.
D) tensional forces.

Question 40

Unlike a stream-cut valley that assumes a characteristic ________-shape, a glacially-carved valley evidences a characteristic ________-shape.

A) U; V
B) V; U
C) flat; rounded
D) steep; shallow

Question 41

Which of the following is an alpine feature?

A) unstratified till
B) outwash plain
C) lateral moraine
D) esker
E) kame

Question 42

Which of the following is false relative to the Pleistocene ice age epoch?

A) It began 1.65 million years ago.
B) It produced ice sheets and glaciers that covered 30 percent of Earth's land area.
C) At least 18 expansions of ice occurred over Europe and North America.
D) It represents a single continuous cold spell.

Question 43

Which of the following types of moraines is oriented parallel to the direction of ice flow?

A) terminal
B) recessional
C) medial

Question 44

Thoreau's Walden Pond is an example of which of the following?

A) kame
B) kettle
C) esker
D) drumlin
E) tarn

Question 45

Which of the following is false regarding the Pleistocene ice sheets in North America?

A) At their maximum, they extended only to the present-day Canadian border.
B) Their maximum thickness was about 2 km (1.2 mi).
C) They had a drastic effect on the landscape.
D) They disappeared by 7,000 years ago.
E) The edges of the ice sheets were not even; rather, they were characterized by ice lobes that formed curved edges.

Question 46

Which of the following does $\underline { \text { not } }$ consist of stratified glacial deposits?

A) esker
B) drumlin
C) kame

Question 47

The presence of till indicates

A) direct deposition by a glacier.
B) deposition by wind.
C) deposition by water.
D) none of these

Question 48

Pluvial lakes formed in the ________ as a result of ________.

A) southwestern U.S.; melting glaciers
B) southwestern U.S.; a wetter climate and/or a climate characterized by lower evaporation rates
C) northeastern; melting glaciers
D) northeastern U.S.; a wetter climate and/or a climate characterized by lower evaporation rates
E) northeastern; ice deposited in till plains

Question 49

Drumlins look like ________ and they occur ________.

A) mesas; in isolation
B) mesas; in swarms
C) inverted spoons; in isolation
D) inverted spoons; in swarms
E) roche moutonnées; in isolation

Question 50

Louis Agassiz called glacially deposited boulders that differ in composition and origin from the ground on which they rest

A) erratics.
B) horns.
C) tarns.
D) nunataks.

Question 51

A glacial takes about ________ years to develop, whereas an interglacial requires about ________ years.

A) 1000; 100
B) 100; 1000
C) 90,000; 10,000
D) 10,000; 90,000

Question 52

Till plains refer to

A) the flat bottomland located in U-shaped glaciated valleys.
B) sorted and stratified fluvial deposits.
C) unsorted coarse deposits characterized by low, rolling relief.
D) glacial deposits that have been actively farmed by humans.

Question 53

A winding hill of sorted sand and gravel deposits is known as a/n ________ and is deposited by a/n ________ glacier.

A) drumlin; continental
B) drumlin; alpine
C) esker; alpine
D) esker; continental
E) medial moraine; alpine

Question 54

Which of the following is false?

A) A typical ice age includes periods of warming.
B) During most of Earth's history, the planet has been much cooler than it has been during the last two million years.
C) Modern humans and our immediate ancestors (Homo erectus and Homo sapiens) lived during a climate anomaly.
D) We may be living in an interglacial of an ice age.

Question 55

Sorted glacial drift characteristic of stream-deposited material is called

A) till.
B) erratic.
C) moraine.
D) stratified drift.

Question 56

A characteristic area of low, rolling relief, deranged drainage patterns, and unsorted materials is a

A) valley train.
B) lateral moraine.
C) medial moraine.
D) till plain.

Question 57

Temperatures increased ________ from the Pleistocene Epoch to the Holocene Epoch.

A) 3 degrees C (5.4 degrees F)
B) 6 degrees C (10.8 degrees F)
C) 12 degrees C (22 degrees F)
D) 25 degrees C (45 degrees F)

Question 58

Viking colonies in Iceland apparently were deserted because of a

A) rise in sea level brought about by a minor period of global warming in 14th century.
B) drop in temperature that occurred during the "Little Ice Age."
C) decline in food production.
D) both A and C
E) both B and C

Question 59

The Great Lakes of North America were created by

A) continental glaciers that carved deep troughs that filled with water.
B) continental glaciers that deposited ice in till plains.
C) cirque glaciers.
D) isostatic subsidence of the crust.

Question 60

Which of the following would $\underline { \text { not } }$ be found in an alpine glacial valley?

A) paternoster lakes
B) hanging valleys
C) waterfalls
D) esker

Question 61

Flowing soil in an area of frozen ground is known as

A) patterned ground.
B) permafrost.
C) gelifluction, or the more general term solifluction.
D) periglacial flow.

Question 62

Which of the following is true regarding permafrost?

A) It develops where soil or rock temperatures are below freezing for at least two years.
B) It is an area that is covered by glaciers.
C) The surface layer in a permafrost region never thaws-even during the warm season.
D) It occurs at a lower elevation in the midlatitudes than in the high latitudes.

Question 63

An ice cap is the most extensive form of continental glacier.

Question 64

The Matterhorn in the Swiss Alps is an example of a nunatak.

Question 65

Which of the following is $\underline { \text { not } }$ an adaptation to living in periglacial regions?

A) buildings placed directly on frozen, hard surfaces
B) water and sewage lines in elevated trays above the ground
C) raised oil pipelines above the frozen ground
D) careful maintenance of rail tracks and roadbeds in the summer

Question 66

It is now virtually certain that the dominant cause of recent ice ages is

A) the blocking of sunlight by volcanic eruptions.
B) variations in Earth-Sun orbital relationships.
C) changes in radiation output from the Sun.
D) the blocking of sunlight by galactic dust.

Question 67

Mountain summits are often characterized by a surface composed of blocks of loose rock that is known as a ________, and which forms by ________.

A) nunatak; ice plucking
B) nunatak; frost action
C) felsenmeer; ice plucking
D) felsenmeer; frost action
E) roche moutonnées; frost action

Question 68

Antarctica is colder than the Arctic because

A) of the principle of continentality.
B) Antarctica has a higher elevation.
C) both A and B
D) None of these are true-the Arctic is actually colder than Antarctica.

Question 69

Large areas of frozen ground can develop a heaved-up, circular, ice-cored mound called

A) an ice wedge.
B) ground ice.
C) a pingo.
D) a talik.

Question 70

Which of these statements is correct?

A) Periglacial regions occupy about 20 percent of Earth's land area.
B) Subarctic climate regions with seasonally snow-free ground are periglacial regions.
C) Permanently frozen subsurface ground is called permafrost.
D) Periglacial regions can sometimes feature polygonal rock formations.
E) All of these are correct.

Question 71

The term periglacial refers to

A) areas that are on top of a glacier.
B) regions that are too warm for ground ice.
C) cold-climate processes along the margins of glaciers.
D) processes and effects that existed during the last ice age but not today.

Question 72

Which of the following is false regarding research at Dome C?

A) Ice cores record climates as far back as 800,000 years.
B) The ice is 3309 m (10,856 ft) deep there.
C) The ice from MIS 11 is of great value due to the similarities to the present.
D) The ice core record contains several periods with CO₂ levels twice as high as current levels.

Question 73

Unfrozen ground in a region of discontinuous permafrost is known as

A) nunatak.
B) talik.
C) cryotic zone.
D) patterned ground.

Question 74

The Vostok ice core was used to detail

A) previous water levels.
B) CO2 levels over the past 200,000 years.
C) current oxygen levels.
D) pleistocene glacier formation.

Question 75

Glacial ice can form during the duration of a single winter season in most glacial areas.

Question 76

In an area of permafrost, subsurface water that is frozen is specifically called

A) the active layer.
B) a talik.
C) ground ice.
D) periglacial water.

Question 77

Firn has a higher density than glacial ice.

Question 78

Which of the following is true?

A) Earth's axial tilt varies through time.
B) The ellipticity of Earth's orbit varies through time.
C) Earth wobbles on its axis.
D) All of the above are true.
E) B and C only

Question 79

Glacial ice forms more quickly in polar environments than in midlatitude, alpine environments.

Question 80

Patterned ground phenomena may include

A) rocks arranged in geometric forms.
B) polygon nets.
C) circles, hummocks, and stripes of arranged rocks.
D) all of these