Deck 19: Glacial Systems and Landforms

Question 1

The Great Lakes of the eastern United States and Canada occupy former river valleys that were vastly enlarged and deepened by glacial erosion. ​

Answer 1

True

Question 2

Icebergs are created _____. ​

A)by freezing of sea water
B)only when a glacier is retreating
C)by plucking
D)by calving
E)by abrasion

Answer 2

D

Question 3

Greenland currently has the world's largest ice sheet. ​

Answer 3

False

Question 4

Net accumulation of a glacier results in glacial advance.

Question 5

One major reason why lakes and marshes are common in recently glaciated areas is that _____. ​

A)those areas have very humid climates
B)a huge amount of water was released by the melting of the ice
C)the glaciers carved dendritic stream systems
D)when ice disappeared, sea level dropped, leaving standing water on land
E)preexisting drainages were disrupted by glacial erosion and deposition

Question 6

During the last major glacial expansion, sea level was higher than it is today. ​

Question 7

The downslope end of a glacier is called its terminus. ​

Question 8

In cold climates, regions of permafrost are good places to build on because the ground stays frozen to the surface all year. ​

Question 9

Where two medial moraines join, they form a lateral moraine.

Question 10

What is the relationship between firn and glacial ice? ​

A)firn is produced by the melting of glacial ice
B)firn is compressed to form glacial ice
C)when air bubbles are squeezed out of glacial ice, the ice is called firn
D)firn is older
E)firn is the German word for glacial ice

Question 11

The Jurassic Period of geologic time was an interval marked by a great number of glacial fluctuations that began about 2.6 million years ago and ended around 10,000 years ago.

Question 12

Ice caps are smaller than ice sheets. ​

Question 13

Glaciers are second only to the ocean in the amount of water they contain. ​

Question 14

Which of these represents a form of glacier ablation? ​

A)calving
B)snowfall
C)freezing rain
D)crevasses
E)sleet

Question 15

Lakes that form in cirques are known as cols. ​

Question 16

Ground moraine sediments typically have a uniform grain size. ​

Question 17

Unlike the trunk glacier, tributary glaciers carve V-shaped valleys. ​

Question 18

Most of the world's glacial ice is located in _____. ​

A)Alaska
B)Iceland
C)Antarctica and Greenland
D)Canada and Switzerland
E)Russia

Question 19

Glacial ice flows from the zone of accumulation into the zone of ablation. ​

Question 20

As an ice sheet recedes and its weight on the land is removed, the land surface sinks downward by the process of isostatic rebound. ​

Question 21

Which type of glacier is the smallest? ​

A)piedmont glaciers
B)ice sheets
C)valley glaciers
D)cirque glaciers
E)ice caps

Question 22

The zone of ablation is _____. ​

A)the high latitudes
B)upslope from the cirque
C)a feature of continental glaciers, but not alpine glaciers
D)the area downslope of the equilibrium line
E)underneath the firn and snow

Question 23

Glaciers flow by _____ when the weight of the overlying ice, firn, and snow causes ice crystals at depth to arrange themselves in parallel layers that glide over each other, much like the spreading of a deck of cards. ​

A)internal plastic deformation
B)ablation
C)basal sliding
D)icefall
E)crevassing

Question 24

A valley train is a(n)_____. ​

A)string of lakes in a glaciated valley
B)deposit of till where a hanging valley entered the trunk glacier
C)first-order tributary glacier
D)depositional landform composed of glacial outwash left by braided streams
E)ice-scoured plain

Question 25

Where liquid water lubricates the base of a glacier, it can move by _____. ​

A)basal sliding
B)ablation
C)basal crevassing
D)plucking
E)calving

Question 26

Which of these features is a depositional glacial landform? ​

A)cirque
B)arête
C)esker
D)col
E)horn

Question 27

Glaciers can erode rock and sediment by the processes of _____. ​

A)corrosion and deflation
B)ablation and abrasion
C)plucking and hydraulic action
D)deflation and saltation
E)plucking and abrasion

Question 28

Eskers are _____. ​

A)large boulders of nonlocal rock
B)composed of lake sediments
C)crescent-shaped with arms pointing in the up-ice direction
D)long and narrow ridges composed of sand and gravel
E)conical hills of sorted glaciofluvial deposits

Question 29

Where ice sheets reach the ocean by flowing through fjords, the glacial ice is called a(n)_____.

A)ice cap
B)outlet glacier
C)piedmont glacier
D)end moraine
E)roche moutonnée

Question 30

A streamlined hill molded from till is termed a(n)_____. ​

A)roche moutonnée
B)arête
C)kame terrace
D)drumlin
E)bergschrund

Question 31

Crevasses are common _____. ​

A)where a glacier moves over a break in slope
B)at the base of a glacier
C)at the equilibrium line.
D)in tarns
E)in kettles

Question 32

A hanging valley _____. ​

A)is a stream valley that was adjacent to glaciers, but was never glaciated
B)marks where a glacier extended below sea level
C)blocked the flow of one or more glaciers
D)once contained a tributary glacier
E)is a glaciated valley that was later uplifted by tectonic forces

Question 33

Which of these glacial landforms are commonly associated with lakes? ​

A)kettles
B)roche moutonnées
C)horns
D)drumlins
E)eskers

Question 34

Evidence of a previous period of glaciation includes _____. ​

A)v-shaped valleys ​
B)well sorted alluvium
C)patterned ground features
D)trellis drainage patterns ​
E)outwash plains

Question 35

Two types of alpine glacier are _____. ​

A)ice caps and cirque glaciers
B)valley glaciers and cirque glaciers
C)ice sheets and piedmont glaciers
D)ice caps and piedmont glaciers
E)ice caps and valley glaciers

Question 36

Patterned ground is a feature of _____. ​

A)piedmont glaciers
B)periglacial landscapes
C)valley glaciers
D)cirque glaciers
E)ice sheets

Question 37

Which of these glacial landforms would likely provide the least amount of information about the direction of ice flow? ​

A)roche moutonnée
B)striations
C)kettles
D)recessional moraines
E)drumlins

Question 38

A glacier that is experiencing net ablation is _____. ​

A)accumulating
B)advancing
C)in equilibrium
D)retreating
E)thickening

Question 39

Sediment deposited by glacial meltwater is _____. ​

A)termed tarn
B)better sorted than till
C)termed tephra
D)composed of pure clay
E)termed roche moutonnée

Question 40

Glaciers that extend to lower elevations beyond the mouth of a canyon, spreading out over more open terrain, are called _____. ​

A)piedmont glaciers
B)cirque glaciers
C)paternoster glaciers
D)ice caps
E)plastic glaciers

Question 41

Why do continental glaciers flow? ​

Question 42

The _______________ marks the boundary between the zones of accumulation and ablation on an alpine glacier. (two words)​

Question 43

Before becoming glacial ice, compact granular snow melts and refreezes into the substance called _______________, with a density of about 0.5 grams per cubic centimeter. ​

Question 44

A(n)_______________ is a curved ridge of glacial deposits composed of material of all grain sizes located at the toe of a glacier. (two words)

Question 45

What is the difference between a glacier's zone of accumulation and zone of ablation? ​

Question 46

What are some of the ways in which glaciers lead to the formation of lakes? ​

Question 47

Glacial abrasion leaves _______________-linear scratches, grooves, and gouges-where sharp-edged rocks scrape across bedrock. ​

Question 48

Till deposited as ridges paralleling the side margins of a glacier are termed _______________(two words).

Question 49

Large boulders scattered in and on the surface of glacial deposits or on glacially scoured bedrock are called _______________ if the rock they consist of differs from the local bedrock. ​

Question 50

A pass formed when headward erosion causes two cirques to intersect, producing a low saddle in a high mountain ridge, is termed a(n)_______________..

Question 51

Sediment deposited directly by moving glacial ice is called _______________. ​

Question 52

Beyond the belts of hills that represent terminal and recessional moraines lie _______________ plains composed of meltwater deposits. These extensive areas of relatively low relief consist of glaciofluvial deposits that are sorted as they are transported by meltwater from the ice sheets.

Question 53

Describe hanging valleys and explain how they form. ​

Question 54

Glaciers that are fed by ice and snow in mountain areas and that usually occupy valleys that were previously created by stream erosion are called _______________ glaciers.

Question 55

Between each period of maximum ice advance, known as a glacial period, a warmer time called a(n)_______________ period occurred. ​

Question 56

Glacial _______________ is the process by which moving ice freezes onto loosened rocks and sediments, incorporating them into the flow.

Question 57

A deep, narrow, ocean inlet carved by glacial erosion is termed a(n)_______________. ​

Question 58

Lakes that look like prayer beads within abasin that are connected by a stream flowing down a glacially carved valley are called _______________ lakes. ​

Question 59

Explain the difference between a terminal moraine and recessional moraine and how they are formed. ​

Question 60

The upper surface of a glacier is brittle and often contains cracks called _______________. ​