Glaciers: Rivers of Ice

Science · Polar Regions · ages 9-11

Name ______________________ Date ____________

What are the two places on Earth with giant ice sheets mentioned in this lesson?
- Greenland and Antarctica
- Iceland and Antarctica
- the Arctic Ocean and Greenland
How does snow turn into glacier ice?
- It melts and refreezes as one solid block overnight
- It piles up over years and gets pressed into dense ice
- Wind blows it into hard round ice balls
Ice cores contain trapped air bubbles that show what Earth's air was like long ago.
Circle one: True False
Look at the bar chart. About how many meters of sea level rise would Greenland and Antarctica cause together?
Answer: ______________
A glacier flows through a mountain valley for thousands of years. What shape does it most likely leave behind?
- A narrow V-shaped valley
- A wide U-shaped valley
- A perfectly flat valley with no shape
Why do scientists drill deep ice cores instead of just studying the surface of an ice sheet?
- Deeper ice holds air bubbles trapped hundreds of thousands of years ago
- Surface ice is too slippery to study safely
- Ice cores are easier to melt into drinking water
Scientists have drilled ice cores that reach ice 800,000 years old. If a new drill reaches ice that is only half that age, how many years old is that ice?
Answer: ______________
Mia says a glacier moves so slowly that it never actually changes the land underneath it. Why is she wrong?
- Only rivers can shape valleys, never ice
- Glaciers are frozen solid and cannot move at all
- Glaciers flow under their own weight and carve valleys and leave moraines over time

Answer key

For grown-ups. Fold this page away before handing over the rest.

Glaciers: Rivers of Ice W1-mt_5_kErPeeNu-s1

Greenland and Antarctica · Greenland and Antarctica both have thick ice sheets. Together they hold enough ice to raise sea levels by more than 65 meters.
It piles up over years and gets pressed into dense ice · Layers of snow pile up for years. Their weight squeezes out the air and packs the snow into dense ice.
True · Air gets trapped in bubbles as snow turns to ice. Scientists study those bubbles to learn about ancient climate.
65 · 7 meters from Greenland plus 58 meters from Antarctica adds up to about 65 meters of sea level rise.
A wide U-shaped valley · Glaciers are wide and heavy, so they scrape rock evenly on both sides, carving a U shape instead of the narrow V a river makes.
Deeper ice holds air bubbles trapped hundreds of thousands of years ago · The deeper ice formed longer ago, so drilling down lets scientists reach air bubbles trapped up to 800,000 years in the past.
400000 · Half of 800,000 years is 400,000 years. Since deeper ice is older, that ice sits higher up than the oldest layer.
Glaciers flow under their own weight and carve valleys and leave moraines over time · Even though a glacier moves slowly, its huge weight still carves valleys and drops piles of rock called moraines as it flows.