Quiz on Glaciers

Glaciers are large, slow-moving masses of what material?

• Ice ✓ (Correct answer)
• Snow
• Rock
• Sand

Source: Glaciers are solid ice formed from snow compressed over decades until it loses all air and flows like a frozen river.

What is a chunk of ice that breaks off a glacier into the sea called?

• Ice floe
• Snowdrift
• Iceberg ✓ (Correct answer)
• Glacier

Source: Roughly 90% of an iceberg hides underwater, which is exactly why the Titanic never saw it coming.

Which mountain range's glaciers feed Asia's great rivers?

• Himalayas ✓ (Correct answer)
• Andes
• Rockies
• Pyrenees

Source: Nicknamed the 'Third Pole,' these peaks supply water to nearly two billion people downstream.

Which continent holds the most glacial ice on Earth?

• Greenland
• North America
• Asia
• Antarctica ✓ (Correct answer)

Source: Antarctica locks up about 90% of the world's ice, deep enough in places to bury a stack of skyscrapers.

Glaciers carve valleys with which distinctive cross-section?

• Canyons
• V-shaped valleys
• U-shaped valleys ✓ (Correct answer)
• Plateaus

Source: Rivers cut narrow V-shapes, but a glacier bulldozes a wide U-shaped trough you can spot from space.

Deep glacier ice often appears in what surprising color?

• White
• Blue ✓ (Correct answer)
• Grey
• Yellow

Source: Dense glacier ice absorbs red light and scatters blue, giving deep crevasses their eerie sapphire glow.

What is it called when a glacier sheds icebergs at its edge?

• Calving ✓ (Correct answer)
• Eroding
• Carving
• Cracking

Source: The term 'calving' likens the glacier to a cow giving birth as huge ice slabs crash into the water.

Glaciers grow only where yearly snowfall exceeds what?

• Evaporation
• Melting ✓ (Correct answer)
• Rainfall
• Runoff

Source: A glacier is just a snow savings account: it survives only if winter deposits beat summer withdrawals.

What is the name for a vast glacier blanketing Antarctica and Greenland?

• Ice cap
• Ice sheet ✓ (Correct answer)
• Ice shelf
• Snowpack

Source: An ice sheet is any glacier bigger than 50,000 km²; today only two exist, both melting fast.

What is a ridge of rock debris bulldozed and dumped by a glacier called?

• Esker
• Drumlin
• Kame
• Moraine ✓ (Correct answer)

Source: Moraines are a glacier's leftover rubble pile, marking exactly how far the ice once reached.

Which country's coastline of glacier-carved fjords made the word famous?

• Iceland
• Switzerland
• Canada
• Norway ✓ (Correct answer)

Source: Norway's deepest fjords plunge over a kilometre down, drowned valleys gouged out by ancient ice.

Air bubbles trapped in deep ice cores preserve samples of the ancient what?

• Atmosphere ✓ (Correct answer)
• Seawater
• Volcanic ash
• Rainwater

Source: Each bubble is a time capsule, letting scientists sniff air that animals breathed 800,000 years ago.

The last great Ice Age ended roughly how long ago?

• 50,000 years
• 25,000 years
• 12,000 years ✓ (Correct answer)
• 100,000 years

Source: As the ice retreated about 12,000 years ago, humans started farming, kicking off civilization.

Glacial meltwater turns milky turquoise because it carries suspended what?

• Algae
• Clay
• Mineral salts
• Rock flour ✓ (Correct answer)

Source: Glaciers grind bedrock into ultra-fine 'rock flour' that floats in water and paints lakes a glowing teal.

What is a deep open crack in a glacier's surface called?

• Serac
• Crevasse ✓ (Correct answer)
• Moulin
• Icefall

Source: Crevasses can plunge 30 metres deep, hidden under fragile snow bridges that silently swallow unwary climbers.

What is the lower zone of a glacier, where ice is lost faster than gained, called?

• Ablation zone ✓ (Correct answer)
• Accumulation zone
• Terminal zone
• Melt basin

Source: Below the snow line lies the ablation zone, where a glacier slowly bleeds away each summer.

What is the largest glacier in the Alps, found in Switzerland?

• Gorner Glacier
• Fiescher Glacier
• Aletsch Glacier ✓ (Correct answer)
• Rhone Glacier

Source: The Aletsch holds more ice than every other Alpine glacier combined, yet it retreats about 50 metres a year.

Roughly what share of Earth's fresh water is locked inside glaciers and ice?

• About 10%
• About 30%
• About 50%
• About 70% ✓ (Correct answer)

Source: Nearly 70% of all fresh water is frozen, which is why melting ice has such an outsized effect on sea levels.

Ötzi the Iceman emerged in 1991 from a melting glacier in which mountains?

• Andes
• Caucasus
• Alps ✓ (Correct answer)
• Pyrenees

Source: Frozen for 5,300 years, Ötzi is so well preserved that scientists mapped his last meal and his tattoos.

What is it called when a glacier suddenly speeds up to many times its normal pace?

• Avalanche
• Surge ✓ (Correct answer)
• Retreat
• Collapse

Source: During a surge a sluggish glacier can gallop forward metres per day, sometimes for years on end.