Deck 17: Glacial and Periglacial Processes and Landforms

Question 1

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.
E)cirque glaciers.

Answer 1

C

Question 2

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.
D)it is moving lower with climate change.
E)it is not affected by climate change.

Answer 2

B

Question 3

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.
E)an ice sheet

Answer 3

B

Question 4

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 5

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.
E)paternoster glacier.

Question 6

Glacial ice is

A)essentially the same as snow.
B)formed after a slow transformation process that may take a thousand years in Antarctica.
C)made of metamorphic rock.
D)generally less dense than snow and firn.
E)filled with air bubbles.

Question 7

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.
E)nunatk.

Question 8

Which of the following is true?

A)25% of glaciers in the European Alps have receded in the past 50 years.
B)Peyto Glacier has experienced significant loss of net mass balance in recent years.
C)39% of global sea level rise is coming from melting Alaskan glaciers.
D)Mt.St.Helens and Mt.Shasta have seen 37% increases in glacial mass from 1983-2007.
E)the Columbia Ice Sheet is growing in size as its snowlines move lower in elevation.

Question 9

The process of calving in the glacial environment produces

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

Question 10

Which of the following is correctly matched?

A)ice sheet - controlled by the topography
B)ice cap - completely buries the underlying landscape,but covers less than 50 000 .
C)ice field - more than 10 000 feet thick
D)ice cap - nunataks visible
E)ice field - dome shape

Question 11

The bulk of ice on Earth is in

A)North America,specifically Alaska.
B)European and Asian mountain ranges.
C)Greenland and Antarctica.
D)floating ice shelves and packs.
E)the islands of the Arctic archipelago.

Question 12

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.
E)piedmont glacier.

Question 13

Alpine glaciers include

A)ice caps,ice sheets and cirque glaciers.
B)valley glaciers and cirque glaciers
C)cirque glaciers and ice fields.
D)valley glaciers and ice sheets.
E)cirque glaciers and ice caps.

Question 14

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

A)10 percent
B)30 percent
C)50 percent
D)77 percent
E)93 percent

Question 15

Which of the following is true of valley glaciers?

A)the snowfield sources for these glaciers are usually found right at the snowline.
B)they occur in an unconfined environment-like an open plain.
C)they may range in length from 100 m to 100 km.
D)they remain stationary and do not move.
E)they are known for eroding the least amount of all glaciers.

Question 16

The type of glacier that dominates Greenland and Antarctica is

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

Question 17

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,icefield
E)piedmont glacier,ice cap,icefield

Question 18

Which of the following is true?

A)Antarctica contains more than 29 million cubic kilometers of ice.
B)71% of Earth's fresh water is frozen.
C)1)1% of Earth's land is covered by glaciers.
D)75% of European Alpine glaciers have receded in the last 50 years.
E)globally,snowlines are lower in elevation than at any other time in recorded history

Question 19

Meltponds on ice-shelf and tidewater glacier surfaces

A)represent a positive feedback mechanism caused by increasing temperatures from both the air above and the sea below.
B)have always existed and do not indicate any kind of change in Earth's temperatures.
C)cause catastrophic flooding when the ice that holds them bursts.
D)cannot be linked in any way with global climate change.
E)represent a negative feedback mechanism that might be useful for slowing global temperature increases.

Question 20

Which is true of the Peyto and an other alpine glaciers?

A)glaciers in the mountains of North America have gained on average more than 50 per year from the 1950s to today.
B)39% of global sea level rise is coming from the melting of Alaskan glaciers.
C)Peyto Glacier has retreated most years since 1965.
D)forecasts are for increased ice accumulation with global warming as more moisture becomes available to the atmosphere.
E)all Alaska glaciers gained mass since 1985.

Question 21

Small bedrock protrusions at the base of a glacier are often overrun by a process known as ________,which occurs because ________.

A)ablation ice melts when it is sufficiently compressed
B)ablation ice deforms when it is subjected to pressure
C)regelation ice melts when it is sufficiently compressed
D)regelation ice deforms when it is subjected to pressure
E)ice plucking ice deforms when it is sufficiently compressed

Question 22

Because the upper regions of a glacier flow ________ than the base of the glacier,the upper part of the glacier tends to be ________.

A)faster compressed
B)faster stretched
C)slower compressed
D)slower stretched

Question 23

Basal slip is facilitated by

A)regelation. ,the presence of water and saturated sediments.
B)presence of melt water,debris incorporated in the ice,and frozen sediments beneath.
C)saturated sediments,debris incorporated in the ice,and rebound pressure from the bed.
D)rebound pressure from the bed,regelation,and water.
E)water,rebound pressure from the bed,and geothermal heat.

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.
E)the surge line.

Question 25

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.
E)a recessional moraine.

Question 26

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.
E)surge line.

Question 27

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

A)basal slip and fracturing.
B)slight floating of the glacier and basal slip
C)fracturing and basal debris load
D)slight floating of the glacier and basal debris loading.
E)regelation and basal slip.

Question 28

Which of the following is generally true of the basal layer of a glacier?

A)it can extend about one meter above the ground surface.
B)it tends to flow more quickly 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.
E)it behaves as a brittle solid.

Question 29

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.
E)it is changed by deep freezing.

Question 30

Which of the following is correctly matched?

A)firn - zone of mass ablation
B)melting - zone of accumulation
C)net mass loss - equilibrium line
D)sublimation - zone of ablation
E)positive balance - loss greater than gain.

Question 31

Crevasses usually form as a result of

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

Question 32

Which of the following is true of compound valley glaciers?

A)they are formed by the merging of ice caps.
B)they contain medial moraines.
C)they can flow over topographic divides,such as mountains.
D)they are one type of continental glacier.
E)they develop only in the southern hemisphere.

Question 33

Which of the following is correctly matched?

A)crevasses - horizontal cracks from friction or tension
B)ice regelation - the melting and refreezing of surface ice
C)glacial ice - a metamorphic version of snow and firn
D)firn - freshly fallen snow on the ice surface
E)englacial - on the ice surface

Question 34

Glacier surges may be associated with

A)ice quakes,mass imbalance,and water pressure.
B)mass imbalance,basal debris load,and rebound pressure from the bed.
C)water pressure,rebound pressure from the bed,and basal debris load.
D)basal debris load,ice quakes,and water pressure.
E)water pressure,basal debris load,and rebound pressure from the bed.

Question 35

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.
E)greatest erosion occurs at the ice surface.

Question 36

Which of the following represents a form of glacial erosion?

A)ablation.
B)abrasion.
C)pressure release jointing.
D)hydrolysis.
E)crystallization.

Question 37

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

A)a positive net balance occurs during a cold period,and a negative net balance occurs during a warm period.
B)glacial mass is increased by evaporation,sublimation,and deflation.
C)glacial mass is increased by a combination of processes called ablation.
D)worldwide,most glaciers are showing marked net increase in mass at present.
E)where the balance is zero,the ice advances.

Question 38

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

A)1 cm per day.
B)1 metre per day.
C)tens of meters per day.
D)a few kilometers per hour.
E)a thousand metres in a day.

Question 39

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

A)less time 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)longer it has to pile much deeper.

Question 40

Snow that has a compact,granular structure is known as

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

Question 41

Unsorted and unstratified glacial deposits (not landforms)are called

A)till.
B)outwash.
C)moraine.
D)alluvium.
E)colluvium.

Question 42

The material in a glacial moraine is

A)sorted by weight.
B)sorted by size.
C)unsorted.
D)stratified.
E)cross-bedded

Question 43

Which of the following are erosional features formed by an alpine glaciers?

A)cirque,drumlin,esker
B)horn,cirque,col
C)drumlin,esker,horn
D)col,esker,moraine
E)esker,drumlin,horn

Question 44

Erosion by alpine glaciers ________ the ruggedness of the landscape.

A)increases
B)decreases
C)has no net effect on

Question 45

The material deposited behind a end moraine (i.e. ,the side on which the ice was located)forms a(n)________,whereas that deposited in front of the end moraine forms a(n)________.

A)outwash plain till plain
B)till plain outwash plain
C)esker drumlin field
D)drumlin field esker
E)marsh outwash plain

Question 46

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

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

Question 47

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
E)lateral

Question 48

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

A)terminal
B)recessional
C)medial

Question 49

The general term for all glacial deposits is

A)till.
B)outwash.
C)glacial drift.
D)alluvium.
E)colluvium.

Question 50

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
E)wide deep

Question 51

Drowned glacial valleys are known as

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

Question 52

A pyramidal peak formed in glaciated mountains is

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

Question 53

The rock material that is trapped within a glacier that is not moving

A)does not move because the glacier does not move.
B)moves by the process of regelation.
C)moves as a result of the deformation of ice.
D)moves by the process of basal sliding.
E)moves by alternating compression and tension.

Question 54

Horns and cirques are typical features in

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.
E)subtropical desert landscapes.

Question 55

A tarn is a lake in a

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

Question 56

Which of the following would be found in an alpine glacial valley?

A)paternoster lakes
B)kames
C)kettle lakes
D)esker
E)drumlins

Question 57

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

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

Question 58

Which of the following is a depositional landform created by glaciation?

A)cols
B)horns
C)U-shaped valleys
D)outwash plain of stratified drift
E)arete

Question 59

Glacial polish results from

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

Question 60

Roches moutonn es 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)glacial deformation of the bed.

Question 61

Drumlins are formed in ________,and their tapered ends point ________.

A)outwash plains upstream
B)outwash plains downstream
C)till plains upstream
D)till plains downstream

Question 62

The presence of till indicates

A)direct deposition by a glacier.
B)deposition by wind.
C)deposition by water.

Question 63

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.
E)the area directly beneath a glacier.

Question 64

Which of the following is correctly matched?

A)an erosional form - recessional moraine
B)a depositional form - nunatak
C)a depositional form - drumlin
D)a depositional form - roche moutonn .
E)an erosional form - esker

Question 65

Which of the following is associated with a glacial outwash plain?

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

Question 66

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.
E)plains of sorted material laid down by braided streams.

Question 67

The presence of stratified,or sorted,glacial sediment indicates that

A)it was deposited in terminal moraines by continental glaciers.
B)it was deposited by glacial meltwater.
C)it was deposited as till by a continental glacier.
D)it was deposited as a medial moraine.
E)it was carried on top of the glacier.

Question 68

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.
E)outwash plain.

Question 69

Which of these statements is correct?

A)periglacial regions occupy about 40 percent of Earth's land area.
B)subarctic and tundra climates ,with seasonally snow-free ground,are periglacial regions.
C)permanently frozen subsurface ground is called frostiground.
D)periglacial regions feature hot springs.
E)periglacial regions are always at latitudes higher than 66 degrees.

Question 70

Louis Agassiz developed a theory to explain the presence of boulders that differ in composition and origin from the ground on which they rest.He regarded these glacially deposited forms as

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

Question 71

Sorted glacial drift characteristic of stream-deposited material is called

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

Question 72

Areas of permafrost,ground ice,and frost action are in which climate types?

A)subarctic and tundra
B)mesothermal
C)desert
D)humid continental
E)arid

Question 73

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)roches moutonnes in isolation

Question 74

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.
E)it is always associated with water - liquid or solid.

Question 75

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

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

Question 76

Kettle holes are formed by

A)scouring.
B)abrasion.
C)ice that melts after having been buried by glacial sediments.
D)solution of limestone by glacial meltwater.
E)plucking

Question 77

Erratics are

A)strangely shaped,erratically spaced drumlins.
B)erratically spaced moraine deposits.
C)rocks that are not native to an area.
D)unusually shaped rocks.
E)winding glacial rivers.

Question 78

Which of the following is a depositional feature formed by,or in association with,a continental glacier?

A)valley train deposit
B)terminal moraine
C)lateral moraine
D)esker
E)recessional moraine

Question 79

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

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

Question 80

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