Deck 17: Glaciers and Glaciation

Question 1

How much of Earths land surface is currently covered by glacial ice?

A)<1%
B)10%
C)25%
D)45%

Answer 1

B

Question 2

Glaciers can deform internally to behave like a plastic material and flow because ________.

A)the bonds between successive layers of ice are weaker than those within a single layer, allowing the glacier to slip like a stack of cards
B)there are layers of pure liquid water between the annual layers of ice
C)there are layers of air between the layers of ice
D)there are round rock particles within the ice that act like little ball bearings

Answer 2

A

Question 3

Who co-discovered Canada's first diamond mine in the Northwest Territories?

A)Charles Fipke and Stuart Blusson
B)Louis Agassiz and Ignaz Venetz
C)Paul Hoffman and Guy Narbonne
D)Milutin Milankovitch and James Croll

Answer 3

A

Question 4

The bottom or downward tip of a crevasse marks the ________.

A)boundary between parts of the glacier moving by basal sliding and crevassal slip
B)boundary between the basal sliding and external flowage zones
C)bottom of the basal sliding zone
D)top of the internal deformation and flowage zone, and the base of the brittle zone of fracture

Question 5

Ice masses that entirely cover uplands and plateaus such as the islands in Nunavut or Vatnajukull in Iceland are called ________.

A)alpine glaciers
B)crevasse splays
C)ice caps
D)ice sheets

Question 6

Where is the world's second largest continental ice sheet?

A)Iceland
B)Greenland
C)Antarctica
D)Siberian Russia

Question 7

What physical property of H?O allows glaciers to flow, particularly by basal slip?

A)dipole forces
B)pressure melting
C)spontaneous recrystallization to the cubic structure
D)high viscosity

Question 8

When glaciers suddenly speed up and move at up to 100 times their normal rate, this is called a ________.

A)galumph
B)luge
C)splurge
D)surge

Question 9

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

A)Greenland
B)Siberian Russia
C)Iceland
D)Antarctica

Question 10

Where is the equilibrium line on a glacier?

A)at about 150 metres depth
B)below the zone of wastage
C)where the zone of accumulation meets the zone of ablation
D)beneath the terminal moraine

Question 11

Which one of the following statements concerning glaciers is false?

A)Ice sheets are larger than ice caps.
B)Piedmont glaciers form on lowlands at the base of mountainous terrain.
C)The volume of water tied up in the Antarctic ice sheet is about the same as the total discharge of the Amazon River in one year.
D)Long, extended, alpine glaciers occupied valleys in most high elevation and high latitude, mountainous areas in the United States, Canada, and Europe at one or more times during the past two million years.

Question 12

Which process occurs where a glacier enters the sea?

A)kaming
B)calving
C)surging
D)salinization

Question 13

During ice-age times when glaciers are present, water is typically stored as glacial ice and removed from the hydrologic cycle for ________.

A)less than a few months
B)up to several years
C)tens to thousands of years
D)hundreds of millions of years

Question 14

The main direct geologic effect(s)of glaciers is (are)to ________.

A)erode the continental landscape and to transport and deposit sediments
B)reduce high latitude marine sedimentation by reducing biologic productivity
C)warm the global climate by absorbing more solar radiation
D)raise global sea level by depressing the crust

Question 15

At what depth or thickness of ice does glacial ice make the transition from brittle fracture to plastic flow?

A)1 metre
B)5 metres
C)10 metres
D)50 metres

Question 16

Approximately how much of an iceberg protrudes above waterline?

A)0)1%
B)3%
C)15%
D)90%

Question 17

When glaciers suddenly move forward they are said to ________.

A)calve
B)lunge
C)purge
D)surge

Question 18

________ is one of the three ways a glacier can move over its bed.

A)Basal slip
B)Crevassal slip
C)Frost heaving
D)Morainal sliding

Question 19

Compared to earlier or subsequent streams in the same valleys, alpine glaciers move ________ but carry ________ sediment.

A)a little slower; only finer
B)faster; less
C)mainly in the winter; mostly very coarse
D)very much slower; more

Question 20

Where would you likely find glaciers that could only move by plastic flow above the bed?

A)in polar regions or with extreme cold where ice is frozen to the bedrock
B)in high elevation tropical settings
C)near the terminus of any ice sheet
D)on ice shelves

Question 21

What does it mean when the terminus of a glacier has been stationary for several years?

A)The local glacial budget is in equilibrium.
B)The glacier is still frozen but has quit moving.
C)The glacier is storing up energy preparing to surge forward.
D)Global warming has ceased.

Question 22

The focal point of a valley glacier's growth is a bowl shaped depression called a ________.

A)cirque
B)downer
C)kettle lake
D)nest

Question 23

Headward erosion by alpine glaciers on two sides of a mountain ridge can remove enough rock to intersect forming a pass called a ________.

A)col
B)cirque
C)monument
D)tarn

Question 24

Which of the following is often associated with a cirque basin in high, mountainous terrain?

A)saline lake
B)kettle
C)tarn lake
D)arête pond

Question 25

An ice carved, asymmetrical bedrock knob with the steep side downhill is called a ________.

A)drumlin
B)kame
C)nunatak
D)roche moutonnée

Question 26

A horn is made of ________.

A)rock
B)till
C)sand and gravel
D)mud

Question 27

How do most icebergs in the North Atlantic Ocean originate?

A)by calving of large tidewater glaciers on Greenland
B)as ice shelves that float northward from Antarctica
C)as masses of sea ice that float southward from the Arctic Ocean through Davis Strait
D)as calved blocks of glacial ice that float northward from Antarctica

Question 28

A ________ is an erosional feature specifically produced by alpine glaciation.

A)lateral moraine
B)kame
C)V-shaped valley
D)U-shaped valley

Question 29

The steep, triangular shaped cliffs that flank hanging valleys are called ________.

A)arêtes
B)faceted nunataks
C)lateral moraines
D)truncated spurs

Question 30

A ________ is a glacier-cut valley that was partly flooded as sea level rose.

A)kettle lake
B)fjord
C)arête
D)tarn

Question 31

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

A)truncated spur
B)hanging valley
C)striated drumlin
D)horn

Question 32

A fjord is ________.

A)a stream valley deepened by glacial erosion, that floods as sea level rises
B)a glacier-cut valley that is dammed by an end moraine and a large lake is formed
C)a glacier-cut valley which sinks below sea level due to glacial rebound after the ice melts
D)a large, kettle-pocked moraine left as an island when sea level rises following melting of the ice

Question 33

Which phrase best describes what would likely happen during the retreat of a valley glacier?

A)A line of stakes across the glacier would be gradually lowered to the valley floor directly beneath where they were originally placed.
B)A line of stakes across the glacier would continue to move down valley as the terminus of the glacier slowly retreated.
C)A line of stakes would retreat slowly up valley as the ice withdraws to its source region.
D)Who cares? The beer would get too warm!

Question 34

A ________ cross-valley profile is typical of canyons and valleys eroded and deepened by alpine or valley glaciers.

A)U
B)Y
C)V
D)S

Question 35

A cirque is made of ________.

A)rock
B)till
C)sand and gravel
D)mud

Question 36

________ are erosional features produced by valley/alpine glaciers.

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

Question 37

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 basal, sliding zone

Question 38

As a glacier advances over a fractured bedrock surface, it loosens, lifts, and incorporates blocks of rock in a process called ________.

A)frost wedging
B)hydraulic lifting
C)plucking
D)striation

Question 39

Which of the following glacial features would typically be found in close proximity?

A)cirque and terminal moraine
B)outwash plain and horn
C)hanging valley and truncated spur
D)drumlin and fjord

Question 40

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

A)wastage exceeds accumulation
B)accumulation exceeds wastage
C)accumulation and wastage are about equal; the older ice moves farther
D)the glacier experiences no accumulation or wastage

Question 41

Which of the following best describes the term glacial drift?

A)floating of icebergs southward from the north polar seas
B)slow, plastic flow in the brittle zone of a glacier
C)the sedimentary deposits of outwash and till
D)the slow, southward advance of the continental ice sheets over Canada and North America during the Pleistocene

Question 42

All of the following descriptions apply to stratified drift (not till)except for ________.

A)rock flour deposited directly from advancing ice
B)commonly layered, well sorted sand and gravel beds
C)deposited in advance of the ice front on outwash plains, in glacial lakes, or fjords
D)deposited or redeposited by glacial meltwater

Question 43

Drumlin fields contain ________.

A)smooth, tapering, asymmetric ridges of till usually formed and shaped beneath a continental ice sheet
B)bowl-shaped depressions eroded largely by frost action and glacial plucking
C)mounds of outwash deposited by meltwater streams at the snout of a glacier
D)smooth, striated, bedrock ridges shaped and polished by a glacier's erosive action

Question 44

What type of moraine is formed by the merging of two lateral moraines at a junction of two valley glaciers?

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

Question 45

The big quartzite rock sitting on the prairie at Okotoks, Alberta, and similar, smaller blocks strung out over 600 kilometres from their eroded bedrock source near Mt.Edith Cavell in Jasper National Park, make up ________.

A)a glacial lineation
B)a lateral moraine
C)an erratics train
D)Alberta's most profound political contribution

Question 46

A(n)________ is similar in appearance to a sinkhole of a karst area.

A)moraine
B)esker
C)cirque
D)kettle

Question 47

The oldest extensive glacial deposits preserved in: Finland, North America, South Africa, and Western Australia occurred ________ years ago, which ________ took for evidence of his ________ hypothesis.

A)11,000; Lancelot du Lac; Big Tilt
B)2)3 million; Mikhail Budyko; Big Chill
C)250 million; Alfred Wegener; Continental Drift
D)2)3 billion; Paul Hoffman; Snowball Earth

Question 48

Which one of the following statements concerning glacial deposits is false?

A)Till is deposited directly from the ice; outwash is deposited by meltwater streams.
B)Glacial erratics are blocks of rock that are too large for the glacier to move.
C)Tills are poorly sorted and their fragments are mostly angular.
D)Outwash is mainly stratified sand and gravel.

Question 49

A moraine is primarily made of ________.

A)till
B)outwash
C)rock
D)mud

Question 50

A ________ forms when stagnant, glacial ice melts after being buried by till or outwash.

A)tarn
B)kettle
C)drumlin
D)horn

Question 51

Which one of the following is not normally a feature of glaciated, alpine terrains?

A)horn
B)arête
C)lateral moraine
D)drumlin

Question 52

________ is a gently rolling sheet of till with an irregular surface deposited under the weight of a glacier.

A)Terminal moraine
B)Outwash blanket
C)Kame sheet
D)Ground moraine

Question 53

A drumlin is usually made of ________.

A)till
B)sand and gravel
C)rock
D)mud

Question 54

A(n)________ would likely be situated next to a large end moraine.

A)cirque
B)fjord
C)horn
D)outwash plain

Question 55

________ are both deposited by meltwater streams.

A)Terminal moraines and cirques
B)Outwash plains and valley trains
C)Valley moraines and ice sheet trains
D)Recessional kettles and erratics

Question 56

Boulders that are lithologically different than the local bedrock (like a loose Precambrian gneiss found sitting on top of bedded Paleozoic limestones)are called ________.

A)come from aways
B)ecstatics
C)erratics
D)transportees

Question 57

A(n)________ is a depositional feature composed primarily of till and usually associated with continental glaciation.

A)cirque
B)moraine
C)drumlin
D)outwash deposit

Question 58

Diamond-bearing kimberlites occur in the Northwest Territories, Saskatchewan and Ontario.What type of glacial deposit would be most useful for tracing kimberlite cobbles and minerals directly to their bedrock source area?

A)kames
B)kame terraces
C)lateral or medial moraines formed by alpine valley glaciers
D)end or ground moraine formed by a continental ice sheet

Question 59

What glacial landform is responsible for a large portion of the water resources for greater metropolitan Toronto?

A)the remnants of glacial Lake Bonneville
B)the drumlin field near Guelph and Peterborough
C)the Oak Ridges moraine and its included channel fills of coarse glacial outwash
D)pingoes and blocks of buried ice mined from glacial sediments between Toronto and Muskoka

Question 60

An erratic is made of ________.

A)rock
B)till
C)sand and gravel
D)mud

Question 61

Which glacial landform was originally deposited as a fan against glacial ice or within depressions on the ice surface?

A)end moraines
B)valley trains
C)kames
D)ground moraines

Question 62

During the maximum extent of the last Ice Age, which region remained free of ice cover?

A)northern Siberia
B)Greenland and Iceland
C)southern Ontario
D)central Yukon an portions of central and western Alaska

Question 63

An ice contact deposit is classified by its ________.

A)age
B)grain size
C)internal stratification
D)shape

Question 64

The ________ was the most recent Pleistocene glacial episode in North America.

A)Dakotan
B)Kansan
C)Indianan
D)Wisconsinan

Question 65

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

A)drumlin
B)esker
C)kettle
D)valley train

Question 66

Which was not true during the height of last Ice Age?

A)One could have walked from France to Britain.
B)One could have walked from SE Asia to Indonesia.
C)One could have walked or paddled a small boat from Siberia to Alaska.
D)The continent of Atlantis was above sea level in the mid-Atlantic Ocean.

Question 67

When did Earth's climate deteriorate enough to start this current cycle of glaciations in Antarctica?

A)10,000 years ago
B)17,000 years ago
C)about 2.4 million years ago
D)> 30 million years ago

Question 68

Which one of the following prominent features were significantly larger than at present day during the Pleistocene glacial episodes?

A)terminal moraines of continental ice sheets that moved south from Canada
B)the Great Lakes and Lake Agassiz
C)horns, arêtes, and cirques produced by alpine glaciation
D)subaerial fan deltas covering more extensive coastal plains

Question 69

Who was the first scientist to hypothesize and promote the idea of a great Pleistocene Ice Age with extensive and far reaching effects?

A)Louis Agassiz
B)Paul Hoffman
C)Milutin Milankovitch
D)Alley Oop

Question 70

What was the maximum lowering of sea level during the last Ice Age?

A)-100 metres
B)-20 metres
C)-38 metres
D)-85 metres

Question 71

Kame terraces were originally deposited ________.

A)under water along a floating ice shelf
B)as a broad band behind the advancing ice front of a continental ice sheet
C)in meltwater channels perpendicular to a melting continental ice front
D)along the sides of a glacial valley

Question 72

Which of the following is the correct listing of the classical North American glacial stages from oldest to youngest?

A)Indianan, Kansan, Nebraskan, Ohioan
B)Kansan, llinoian, Iowan, Dakotan
C)Nebraskan, Indianan, Illinoian, Wisconsinan
D)Nebraskan, Kansan, Illinoian, Wisconsinan

Question 73

What was the most far reaching effect of the Ice Age on the world's oceans?

A)Global sea levels dropped about 100 metres.
B)The seas got about -7° C cooler on average over the whole planet.
C)It was too cold for phytoplankton to live in the seas.
D)The seas got much less saline because of all the melting icebergs.

Question 74

An esker is made of ________.

A)sand and gravel
B)rock
C)till
D)mud

Question 75

Upon what evidence did Agassiz base his ice age theory?

A)astronomical calculations for cyclic variations in Earth's orbit
B)glacial landscapes in the Swiss Alps that extended far beyond existing ice fronts
C)spectroscopic measurements for variations in the solar output
D)stacks of glacial drift with intervening "warm period" soil horizons

Question 76

All of the following landforms and geologic features are direct products of glacial erosion except for ________.

A)truncated spur
B)kame terraces
C)striated bedrock
D)horn

Question 77

Independent of any local scale erosion or deposition, thick accumulations of ice load the crust and upper mantle ________.

A)causing the crust to subside
B)causing the crust to drift laterally, instigating major tectonic motions
C)causing the crust to rise up with an immediate elastic rebound
D)causing the crust to thrust and fold like in a mountain building event

Question 78

The ________ is not the name of a Pleistocene glacial episode in North America.

A)Manitoban
B)Kansan
C)Illinoian
D)Nebraskan

Question 79

During the peak of the last Ice Age circa 20,000 years ago, the total volume of glacial ice was about ________ km³, or about ________ times its present amount.

A)7 thousand; 55
B)25 million; 100
C)70 million; 2.8
D)2)42 X 10¹²; a million

Question 80

During the peak of the last Ice Age, continental land area was larger and you could have walked across the English Channel because ________.

A)the continents expanded as they got colder
B)there was so much ice that the global sea level was about 100 metres lower than now
C)sea floor spreading hadn't separated England from France yet
D)the polar ice caps flattened Earth so much that the continents were higher