Glaciation Quiz
Questions: 16 · 10 minutes
1. A ridge containing an unsorted mixture of clay, sand, pebbles, and boulders marks the glacier's former furthest extent. How should it be identified?
A terminal moraine
An outwash plain
A drumlin
An esker
2. Beyond a former ice margin, braided meltwater streams deposited layered, relatively sorted sand and gravel. Which feature is most likely present?
An outwash plain
A till plain
A medial moraine
A cirque
3. A smaller tributary glacier once joined a deeper main glacier. After the ice melts, the tributary valley remains high above the main valley floor. What feature results?
A hanging valley
A kettle
An esker
A drumlin
4. At the base of a glacier, meltwater refreezes around fractured rock. As the ice moves, it pulls pieces away. Which erosional process is occurring?
Deposition
Abrasion
Freeze-thaw weathering alone
Plucking
5. Two neighboring cirques erode backward toward each other, leaving a narrow, sharp ridge between them. What is this ridge called?
Terminal moraine
Arête
Roche moutonnée
Till plain
6. A field of streamlined drumlins shares the same general alignment. What can their long axes most directly help researchers infer?
The maximum thickness of the former glacier
The general direction of former ice flow
The age of the bedrock beneath the glacier
The annual snowfall at the glacier's source
7. A geologist finds a valley with steep sides and a broad, relatively flat floor. Which interpretation best fits its cross-sectional shape?
It is an outwash channel built by deposited meltwater sediment
It is a V-shaped valley cut mainly by a river
It is a U-shaped valley substantially widened and deepened by a glacier
It is a narrow gorge produced mainly by vertical river erosion
8. A region slowly rises for thousands of years after a thick ice sheet melts because weight has been removed from the crust. Which process explains this?
Isostatic rebound
Sea-floor spreading
Glacial abrasion
Meltwater deposition
9. Several cirques erode into different sides of a mountain until a steep, pyramidal summit remains. Which landform has developed?
A fjord
A horn
A kame
A lateral moraine
10. A detached block of buried glacial ice melts within sediment, leaving a depression that later fills with water. What feature forms?
A tarn created by cirque erosion
A fjord flooded by seawater
A kettle lake
A ribbon lake occupying an overdeepened valley
11. Expanding snow and ice reflect more incoming sunlight, which promotes further cooling and additional ice growth. What does this describe?
A negative feedback that limits cooling
Isostatic adjustment of the crust
A positive ice-albedo feedback
Geothermal melting beneath the ice
12. A granite boulder rests in an area where the local bedrock is limestone, and evidence shows that glacial ice carried it there. What is the boulder called?
A striation
A moraine
A drumlin
A glacial erratic
13. What is the bowl-shaped hollow commonly eroded at the head of an alpine glacial valley?
Drumlin
Outwash plain
Esker
Cirque
14. Ice inside a glacier continues moving downhill, but the glacier's terminus shifts upslope over several years. What best explains this apparent retreat?
All of the glacier's ice has reversed its direction of flow
Ice loss at the terminus exceeds the supply of ice moving into it
The glacier has stopped deforming and become permanent ground ice
Snow accumulation has become greater than melting throughout the glacier
15. During a major glacial period, large volumes of water become stored in growing land-based ice sheets. What is the expected global sea-level response?
Sea level rises because ice occupies more volume than liquid water
Sea level remains unchanged because the water cycle is closed
Sea level falls because water is transferred from the oceans to land ice
Sea level rises only near continental ice sheets
16. Which set of conditions most directly allows a glacier to begin forming?
Seasonal meltwater repeatedly freezes inside exposed bedrock cracks
River ice thickens until it begins flowing across the surrounding land
A single winter produces unusually deep but completely seasonal snowfall
Snow persists for years, becomes compacted, and recrystallizes into dense ice