Science // Polar Regions

Glaciers & Ice Sheets

Understand how glaciers and ice sheets form and behave — snow accumulates over centuries and compresses into dense ice, glaciers flow slowly downhill under their own weight carving U-shaped valleys and depositing moraines; the Greenland and Antarctic ice sheets together hold enough ice to raise sea levels by over 65 metres; and ice cores drilled from these sheets contain trapped air bubbles that reveal Earth's climate history going back 800,000 years

Ages
9 to 11
Type
Concept
Builds on
1 topic
Leads to
2 topics

Quick check

Can the learner explain how glaciers form from layers of snow pressed into ice, how they slowly carve valleys, and that scientists drill into ice sheets to learn about Earth's climate thousands of years ago?

Ask this to see whether the topic is secure.

Topic // Mastery

What mastery looks like

What a learner can do once this topic is secure.
  • Describe how glaciers form: snow accumulates, compresses, and becomes dense ice that flows slowly under its own weight
  • Explain that the Greenland and Antarctic ice sheets hold enough water to raise sea levels dramatically if melted
  • Describe how ice cores reveal climate history through trapped air bubbles from hundreds of thousands of years ago

Topic // Map

Where this fits

What to learn first and what this topic opens up, with the reason for each link. Required links come first.
  • RequiredMust come first
  • HelpfulHelps, but not essential

Before this

1 topic
  • Ice & States of MatterRequired

    Polar Regions // Ages 7 to 9

    Must understand ice types (sea ice vs glacial ice) before learning about glacier formation in depth

You are here

Glaciers & Ice Sheets

Ages 9 to 11 // Concept

Leads to

2 topics
  • Climate Change at the PolesRequired

    Polar Regions // Ages 9 to 11

    Must understand ice sheets before learning about their mass loss

  • Earth's Frozen WaterRequired

    Polar Regions // Ages 9 to 11

    Must understand glaciers and ice sheets before the broader cryosphere concept

Topic // Research-informed

Teaching notes

From the Marble Skill Taxonomy. These notes have not been validated in classrooms, so treat them as a starting point for your own judgement.

The approach

For ages 9–11, build understanding of glaciers and ice sheets across three linked processes: (1) FORMATION — snow accumulates over centuries and compresses through firn into dense glacial ice; (2) FLOW & SCULPTING — ice deforms and moves slowly downhill under its own weight, carving U-shaped valleys and depositing moraines; (3) ICE CORES as a climate ARCHIVE — trapped air bubbles at each depth are samples of ancient atmosphere, and because newer snow buries older layers, deeper ice is older, giving a record back ~800,000 years in the deepest Antarctic cores. Emphasise the long timescales (centuries to form, millennia recorded) and the idea that ice cores are decoded evidence, not just frozen water. Learners should run and decode these processes, not only recognise labelled parts.

Common misconceptions

  • Glaciers are frozen still and never move — they flow slowly downhill under their own weight
  • Glaciers form quickly from a cold winter — they build over centuries as snow compresses into ice
  • U-shaped valleys and scattered boulders are random — they are carved and dropped by past glaciers
  • Ice cores are just frozen water — their trapped air bubbles are samples of ancient atmosphere, a climate archive
  • Shallow and deep ice are the same age — deeper ice is older, recording further back in time

Useful representations

  • Formation strip: snowflakes → firn → dense blue glacial ice
  • Glacier-as-slow-river cross-section carving a U-shaped valley and dropping moraine
  • Ice-core column with dated layers and trapped air bubbles (deeper = older)
  • 800,000-year climate graph reconstructed from core data

Teaching practices

  • Sequence formation as a process (snowfall → compaction → flow), stressing the long timescales involved
  • Use the 'ice is a very slow river' analogy to explain flow, erosion of U-shaped valleys, and moraine deposition
  • Treat ice cores as decoding a layered signal — deeper is older, each bubble a captured sample of past air
  • Show real landscape evidence (U-shaped valleys, erratics, moraines) so glacial action is read from the land
  • Connect to climate history and to the ice-sheet sea-level store from the cryosphere topic

Activities to try

  1. 1

    Run a glacier from snowfall to sculpted valley

    Why it works: A glacier is solid but not static: it is fed by compressed snow at the top and flows downhill under gravity, shaping the land by eroding valleys and depositing moraines over very long timescales.

    1. Pile successive snowfalls onto a mountain and advance a time slider through centuries, watching flakes crush into firn and then into dense blue glacial ice.
    2. Release the glacier and observe it creep downhill very slowly, like slow treacle, grinding a rounded U-shaped valley.
    3. Watch the glacier drop a ridge of rock (a moraine) at its snout, and identify where erosion and where deposition happen.
    4. Describe in your own words why the solid ice moves at all (its own great weight plus gravity cause it to deform and flow).
    5. Predict and then test: what happens if melting at the glacier's lower end (its snout) outpaces new snowfall at the top? (The ice still flows downhill, but the snout retreats uphill as the glacier shrinks.)
  2. 2

    Drill and decode an ice core

    Why it works: Ice cores are a climate archive: each trapped air bubble is a sample of the atmosphere from around when that layer sealed, and because layers accumulate over time, deeper ice records further back.

    1. Lower a drill into an ice sheet and pull up a core showing dated layers.
    2. Tap air bubbles trapped at different depths and watch a climate graph plot backward in time as each bubble's data is added.
    3. State which bubbles are recent air and which are oldest, and explain the rule: deeper ice is older.
    4. Follow the record to near the bottom and read how far back it reaches (~800,000 years in the deepest Antarctic cores).
    5. Explain in a sentence or two how a scientist could read the climate of 100,000 years ago from a stick of ice.
  3. 3

    Read glacial action from real landscapes

    Why it works: Present-day landforms are evidence of past glacial action: shapes and deposits let us read where ice flowed, eroded, and dropped its load.

    1. Examine photographs or diagrams of U-shaped valleys, scattered erratic boulders, and moraine ridges.
    2. For each feature, explain what past glacial process (erosion by flowing ice, or deposition of carried rock) created it.
    3. Contrast a U-shaped glacial valley with a V-shaped river valley and say what the shape tells you about how it formed.
    4. Explain why scattered boulders far from any cliff, especially ones made of a different rock from the ground beneath them, can be evidence that ice carried them there in the past.

Science // Polar Regions

More in Polar Regions

All 25 topics