Deck 12: Glaciers and Glaciation

Question 1

Glaciers with a positive budget are advancing glaciers.

Answer 1

True

Question 2

Where glaciers exist they are far more effective agents of erosion, transportation, and deposition than running water.

Answer 2

True

Question 3

Glaciers in temperate climates may have crevasses that extend to their base.

Answer 3

False

Question 4

During the most recent ice age, sea level was at least 100 meters lower than at present.

Question 5

Support is growing for the idea that a late Precambrian ice sheet was so extensive that the surface of the world ocean was frozen.

Question 6

Glaciers are part of the hydrosphere.

Question 7

Unsorted and unlayered rock debris carried or deposited by glaciers is called till.

Question 8

A U-shaped valley (in cross section) is characteristic of glacial erosion.

Question 9

Tillite is lithified till.

Question 10

Bodies of till shaped into streamlined hills are called drumlins.

Question 11

Striations and grooves in bedrock indicate the direction of ice movement.

Question 12

An esker is a long sinuous ridge of ice.

Question 13

The primary control of glacial-interglacial episodes seems to be variation in the Earth's orbit and inclination to the sun.

Question 14

Two layers of sediment representing one year of deposition in a lake are called a varve.

Question 15

The two types of glaciated terrain on the Earth's surface are alpine and valley.

Question 16

A large trunk glacier erodes downward more rapidly and carves a deeper valley than do smaller tributary glaciers.

Question 17

The compacted mass of granular snow, transitional between snow and ice, is called firn.

Question 18

An end moraine marks the final edge of a receding glacier just before the glacier melts away entirely.

Question 19

Glaciers in temperate climates tend to move slower than those in colder regions.

Question 20

The thicker part of a glacier will flow slower than where it is thinner.

Question 21

If all ice sheets were to melt, sea level would _____.

A) rise by as much as 40 meters
B) fall by as much as 17 meters
C) rise by over 60 meters
D) fall by over 130 meters
E) remain unchanged

Question 22

Under the influence of gravity a glacier moves down valley and eventually __.

A) flows back toward its source area
B) ablates
C) evaporates
D) goes underground
E) accumulates

Question 23

A(n) _____ -shaped valley (in cross section) is characteristic of glacial erosion.

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

Question 24

What caused the glacial ages?

A) changes in the atmosphere
B) changes in the positions of the continents
C) changes in circulation of sea water
D) All of the above have contributed to the glacial ages.
E) The cause is unknown at this time.

Question 25

___ are the product of past glaciations.

A) The Ohio and Missouri Rivers
B) The Appalachian Mountains
C) The Great Lakes
D) The Gulf of Mexico and Caribbean Sea
E) The high plains

Question 26

The central portion of a valley glacier moves _____ the sides.

A) slower than
B) faster than
C) at the same rate as

Question 27

The upper part of a glacier, the part with perennial snow and ice, is called the __.

A) zone of accumulation
B) zone of wastage
C) zone of ablation
D) recharge zone
E) discharge zone

Question 28

The longest ice core drilled was obtained at ____, Antarctica, in the 1990s.

A) McMurdo
B) Vostok
C) Palmer
D) the south pole
E) the geographic center

Question 29

Above the rigid zone, glacial ice movement is due to __.

A) sliding along faults in the ice
B) passive riding of the ice on the glacier
C) sliding along the base of the glacier
D) opening of cracks or crevasses
E) melting

Question 30

When an ice block that was buried in sediment finally melts a depression called a ___ forms.

A) arête
B) horn
C) drumlin
D) roche mountonnée
E) kettle

Question 31

____ are landscape features that indicate a mountainous area has been glaciated.

A) Cirques, horns, and arêtes
B) Drumlins, eskers, and kames
C) Horns, drumlins, and tillite
D) Crevasses, cirques, and kames
E) Erratics, moraines, and kettles

Question 32

A large trunk glacier carves a deeper valley than smaller tributaries. After the glacier disappears the tributary valley remains as _____ high above the main valley.

A) a fiord
B) a hanging valley
C) an arête
D) a cirque
E) a roche mountonnée

Question 33

A(n) _______ is a mass of ice that is not restricted to a valley but covers large areas of land.

A) ice sheet
B) moraine
C) tarn
D) arête
E) col

Question 34

Bodies of till shaped into streamlined hills are called ___.

A) kames
B) moraines
C) drumlins
D) eskers
E) kettles

Question 35

A(n) ______ is a steep-sided half-bowl shaped recess carved at the head of a mountain glacial valley.

A) fiord
B) hanging valley
C) arête
D) cirque
E) roche mountonnée

Question 36

Sharp ridges called ___ separate adjacent glacially carved valleys.

A) tarns
B) cirques
C) arêtes
D) cairns
E) moraines

Question 37

Glaciers can be considered as _______ of fresh water for future use.

A) climate characteristics
B) erosional basins
C) indicators of climate change
D) deposits
E) artesian aquifers

Question 38

A(n) _____ is a coastal inlet that is formed by a drowned glacial carved valley.

A) nunatak
B) fiord
C) inselberg
D) monadnock
E) hanging valley

Question 39

A(n) ____ is a long sinuous ridge of water-deposited cross-bedded and well-sorted sediment deposited by a stream that flowed within or under a glacier.

A) tarn
B) moraine
C) drumlin
D) esker
E) varve

Question 40

A worldwide decrease of at least _____ $\degree$ C in temperature would bring about a new glacial age.

A) 50
B) 25
C) 10
D) 5
E) 1

Question 41

Once a glacier is gone the land begins to uplift slowly to its pre-glacial height, a process called ____.

A) metamorphism
B) subduction
C) volcanism
D) crustal rebound
E) ocean basins

Question 42

The theory of _____ states that at times in the past, colder climates prevailed during which much more of the land surface was glaciated than at present time.

A) ice accumulation
B) glacial ages
C) climate change
D) Milankovitch
E) Vostock

Question 43

The down-valley part of a glacier is the ____, where melting, evaporation, and calving take place.

A) zone of accumulation
B) zone of replenishment
C) zone of ablation
D) recharge zone
E) discharge zone

Question 44

If the terminus of a glacier remains stationary for a few years a distinct _______ may form.

A) roche mountonnée
B) ground moraine
C) recessional moraine
D) lateral moraine
E) medial moraine

Question 45

___ moraines are elongate low mounds of till that form along the sides of valley glaciers.

A) Lateral
B) Proximal
C) Distal
D) Medial
E) Terminal

Question 46

A glacier will flow faster where it is steeper and _____.

A) thinner
B) has more firn
C) younger
D) thicker
E) older

Question 47

Where tributary glaciers come together the adjacent lateral moraines join to form a ______ moraine.

A) lateral
B) distal
C) proximal
D) medial
E) terminal

Question 48

The _____ is the end of a glacier.

A) ablation limit
B) snow line
C) terminus
D) zone of ending

Question 49

A(n) _____ is the sharp peak that remains after cirques have cut back into a mountain on several sides.

A) arête
B) horn
C) inselberg
D) cirque
E) tarn

Question 50

If a moving glacier reaches a body of water ______ float free.

A) crystals
B) icebergs
C) calves
D) infants
E) end moraines

Question 51

______ gives us more evidence of the beginning and ending times of glacial episodes than the direct study of glacial deposits.

A) Location of meteorites on the Antarctica ice sheet
B) Sea level changes
C) Folklore
D) Deep ocean sediment
E) Satellite imagery

Question 52

A(n) ___ is a lake occupying a bedrock depression excavated by a glacier.

A) kettle
B) pothole
C) blowout
D) monadnock
E) tarn

Question 53

The sediment deposited by debris-laden melt water is called _______.

A) fluvial
B) alluvial
C) discharge
D) outwash
E) pediment

Question 54

Open fissures called ___ develop in the brittle surface ice of glaciers.

A) crevasses
B) cirques
C) joints
D) arêtes
E) thalwegs

Question 55

A(n) ___________ is an ice-transported boulder that was not derived from the underlying bedrock.

A) clast
B) esker
C) nunatak
D) erratic
E) inselberg

Question 56

The boundary between the zone of accumulation and the zone of ablation is an irregular line called the _____.

A) equipotential surface
B) equilibrium line
C) balancing line
D) break-even curve
E) snow line

Question 57

As ice retreats by melting back, the rock debris carried by the glacier is deposited to form a relatively thin layer of till called a(n) ___________.

A) esker
B) ground moraine
C) drumlin
D) end moraine
E) erratic

Question 58

Two layers of sediment resulting from one year's deposition in a glacial lake are called ___.

A) cross beds
B) ripples
C) varves
D) contourites
E) turbidites

Question 59

The grinding of rock against rock by a glacier produces a very fine sediment called ____.

A) tillite
B) till
C) rock flour
D) rock dust
E) glacier mist