Which one of the following is NOT true of glaciers?
- originate on land
- exist only in the Northern Hemisphere (North of the equator)
- show evidence of past or present flow
- form from the recrystallization of snow
- all of the above are true facts
What happens to snowflakes as they become progressively buried within glaciers?
- they become less dense because of large amounts of trapped air
- they begin to melt as they are insulated from the cold air
- they become interlocking crystals of ice
- they can become bluish because of trapped air
- both c and d
The upper part of a glacier, the part with perennial snow and ice, is called the ___
- zone of accumulation
- zone of wastage
- zone of ablation
- recharge zone
- discharge zone
When a glacier recedes, it ___
- flows back toward its source area
- ablates faster than its volume is replenished by snowfall
- is experiencing a positive snow/ice balance
- flows faster
- accumulates faster than it ablates
Most glaciers move___.
- primarily by sliding along faults in the ice
- primarily by plastic flow or creep, like silly putty
- only by sliding along the base of the glacier
- primarily by opening up cracks or crevasses
- as a rigid block, with all parts moving in the same direction at the same velocity
Open fissures that develop in the brittle surface ice of glaciers are called:
- crevasse
- cirque
- joint
- crevice
- fault
Which of the following is NOT a type of evidence left behind by glaciers?
- scratched and polished bedrock
- scattered stones (dropstones) in fine-grained sediment
- changes in the isotopic compositions of marine shells
- V-shaped valleys
- all of the above are evidence left behind by glaciers
What is the shape of a valley formed due to glacial erosion?
- S-shaped valley
- U-shaped valley
- V-shaped valley
- Y-shaped valley
- I-shaped valley
A sharp peak that remains after cirques have cut back into a mountain from several sides is called:
- arête
- horn
- inselberg
- cirque
- tarn
Sharp bedrock ridges sculpted between two glacially eroded valleys are called:
- tarns
- cirques
- arêtes
- cairns
- moraines
A steep-sided half-bowl shaped recess carved at the head of a mountain glacial valley is called:
- fiord
- hanging valley
- arête
- cirque
- roche mountonnée
A boulder transported by a glacier that was not derived from the underlying bedrock is called:
- clast
- esker
- nunatak
- erratic
- inselberg
Depressions left in till when imbedded blocks of ice left over from a receding glacier melted are called:
- arêtes
- horns
- drumlins
- roche moutonnées
- kettles
Elongated low mounds of till formed along the sides of valley glaciers are called:
- Lateral morraine
- Proximal morraine
- Distal morraine
- Medial morraine
- Terminal morraine
What does a terminal moraine represent?
- the end of a polished and scratched segment of bedrock
- the sharp ends of a jagged ridge formed by glaciers
- the end of an ice sheet that is floating in the sea
- a pile of sediment deposited at the end of the glacier
- the final time that two glaciers come together
The end moraine marking the farthest advance of a glacier is called:
- terminal morraine
- medial morraine
- lateral morraine
- recessional morraine
- boundary morraine
The end moraine built while the end of a glacier was temporarily stationary is called:
- terminal morraine
- medial morraine
- lateral morraine
- recessional morraine
- boundary morraine
A layer of till deposited as the front of a glacier retreats is called:
- ground moraine
- outwash plain
- valley train
- recessional moraine
- esker
A streamlined hill of till that has been remolded beneath a glacier is called:
- roche moutonnée
- moraine
- drumlin
- esker
- kame
If the steep side (the "flat" end) of a drumlin is on the northeast, it indicates that the glacier advanced from:
- southwest
- southeast
- northwest
- northeast
- none of these
An S-shaped deposit formed by glacial meltwater is called:
- oscar
- moraine
- drumlin
- esker
- varve
Large quantities of meltwater that run away from the melting edge of a glacier may deposit ________.
- fluvial
- alluvial
- discharge
- outwash
- pediment
The last episode of glaciation happened:
- 5-10 thousand years ago
- 10-21 thousand years ago
- 50-60 thousand years ago
- 100-115 thousand years ago
- 2-3 million years ago
A viable hypothesis regarding the cause of ice ages MUST be able to explain:
- Why do Ice Ages occur in cyclical periods
- Why do glaciers during ice ages move towards the ocean
- Why most of the geologic time has been free from extensive ice ages
- All of the above
- Only "a" and "c" and not "b"
In 1921, Milutin Milankovitch suggested that the primary controls on the timing of glacial periods are related to:
- the motion of Earth's plates
- the emission of greenhouse gases
- variations in Earth's orbit, tilt and wobble relative to the sun
- variations in the intensity of the sun's radiation output
- variations in the circulation of water in the ocean basins
How could changes in Earth’s tilt influence global climate?
- A high angle of tilt causes snow and ice to fall off the planet
- A minimum angle of tilt causes high latitudes to receive less sunlight during the summer, causing an increase in glaciers
- A maximum angle of tilt causes Earth to reflect more sunlight into space, causing an increase in glaciers
- A high angle of tilt causes the continents to move away from the poles leading to more glaciers
- Earth's tilt does not influence global climate
A decrease in the atmospheric CO2 content cannot be the sole viable cause for the Ice Ages because:
- Atmospheric CO2 content has no influence whatsoever in global climate change
- Atmospheric CO2 content does not increase or decrease in a cyclic manner
- CO2 can only increase global temperature, not cause ice ages
- All of the above reasons are correct
- None of the above reasons are correct
Which of the following may have contributed to climatic changes related to the Ice Age?
- plate movements
- wobbling of Earth's axis
- variations in the shape of Earth's orbit
- all of these
- none of these
Which one of the following is NOT a direct effect of the last Ice Age?
- Moraines and drumlins in the Midwestern States
- The great Lakes
- The fertile soil in the Midwestern states
- The drainage pattern of the Mississippi-Missouri River system
- All of the above are direct results of the last Ice age
when the land surface slowly rises after the weight of glacial ice is removed by melting is called:
- Mountain building
- Sea level rise
- Global warming
- Isostatic rebound
- Greenhouse effect
What happens to the land surface when large ice sheets melt away?
- it subsides because there is less ice on top
- the land surface remains unchanged but seems lower because of the loss of ice
- the land flexes upward due to isostatic rebound
- the land rises because the rocks are warmer without the ice
- none of the above happens
Large lakes that developed as a result of a cooler, wetter climate during the glacial period, in areas that might be quite arid today are called:
- kettle
- cirque
- playa
- pluvial
- finger
Which one of the following statements is NOT true regarding glacial deposits?
- drift refers to any glacial deposit
- outwash deposits are layered and sorted
- till is well-sorted sediment
- erratics are rocks deposited by a glacier
- All of the above are true regarding glacial deposits