Science · Grade 8 · Water Systems on Earth · Term 2

Glaciers and Ice Caps

Students will examine the formation and movement of glaciers and their impact on Earth's landscape and sea level.

• Ontario Curriculum Expectations
• NGSS.MS-ESS2-2

About This Topic

Glaciers and ice caps form when layers of snow accumulate in cold regions, compacting under their own weight into dense ice over many years. This ice deforms and flows slowly downhill due to gravity, eroding bedrock and transporting debris that shapes landscapes into U-shaped valleys, fjords, drumlins, and moraines. Canada's vast glaciated terrain, from the Rockies to the prairies, provides real-world examples students can connect to local geography.

In the Ontario Grade 8 water systems unit, this topic links solid water phases to earth processes and climate dynamics. Students examine evidence from ice cores and satellite data to understand how past ice ages sculpted continents and how current melting contributes to rising sea levels, building skills in evidence-based prediction and systems analysis.

Active learning benefits this topic greatly because glacial processes span vast timespans and scales beyond direct observation. Student-built models of ice flow or melting trays reveal erosion mechanics and volume changes firsthand, while collaborative mapping of landforms makes abstract geology concrete and fosters discussion of human implications.

Key Questions

1. Explain the processes of glacier formation and movement.
2. Analyze how glaciers reshape Earth's surface over time.
3. Predict the consequences of widespread glacier and ice cap melting.

Learning Objectives

• Explain the physical processes involved in the formation of glacial ice from snow.
• Analyze the forces driving glacial movement and the resulting erosional and depositional landforms.
• Compare the impact of glacial meltwater on sea level rise with other factors contributing to rising oceans.
• Predict the long-term effects of ice cap retreat on global climate patterns and coastal ecosystems.

Before You Start

Earth's Internal Processes

Why: Understanding plate tectonics and the rock cycle provides context for how Earth's surface is shaped by various forces, including glaciation.

Weather and Climate

Why: Students need foundational knowledge of temperature, precipitation, and climate zones to understand the conditions necessary for glacier formation and the implications of their melting.

Key Vocabulary

firn	Granular snow that has been compressed and partially melted and refrozen, forming an intermediate stage between snow and glacial ice.
glacial abrasion	The process by which glaciers grind, scrape, and polish the bedrock beneath them using embedded rock fragments, creating distinctive erosional features.
till	Unsorted, unstratified sediment deposited directly by glacial ice, often forming features like moraines.
calving	The process by which icebergs break off from larger glaciers or ice shelves and fall into the ocean, a significant factor in ice loss.

Watch Out for These Misconceptions

Common Misconception

Glaciers are stationary masses of ice that never move.

What to Teach Instead

Glaciers flow due to gravity-induced deformation of ice, carrying and depositing material. Hands-on modeling with deformable dough on inclines lets students see and measure this movement, correcting static views through direct manipulation and peer observation.

Common Misconception

Melting glaciers do not raise sea levels because ice already displaces water.

What to Teach Instead

Land-based glaciers and ice caps add new water to oceans when they melt, unlike floating sea ice. Tray simulations comparing land vs. sea ice clearly demonstrate volume increase, helping students revise ideas via tangible evidence and group data sharing.

Common Misconception

Glaciers only exist at the poles today.

What to Teach Instead

Many glaciers persist in mountains worldwide, including Canada's Rockies and Coast Mountains. Mapping activities using real maps reveal their distribution, prompting students to confront and adjust global assumptions through evidence exploration.

Active Learning Ideas

Hands-On: Glacier Erosion Model

Students mix flour, water, and sand to create 'glacial ice' dough. Place it on a wooden incline sprinkled with sand as bedrock, add weights to simulate flow, and tilt to observe erosion and deposition. Groups sketch before-and-after landscapes and measure debris movement.

35 min·Small Groups

Simulation Game: Ice Cap Melting

Fill trays with clay 'land' and water 'ocean,' add land-based ice caps marked with dye. Use heat lamps to melt ice gradually, measure water level rise, and compare to floating ice control. Record data in tables and graph results.

45 min·Pairs

Concept Mapping: Glacial Landforms Hunt

Provide topographic maps or Google Earth access focused on Canadian regions. Pairs identify and label features like eskers and kettles, then create a class mural annotating formation processes. Discuss evidence of past glaciations.

40 min·Pairs

Timeline Challenge: Glacier History

Groups research key events in glacial advance and retreat using provided timelines. Arrange cards chronologically on a wall, adding cause-effect arrows for climate drivers. Present one segment to the class.

30 min·Small Groups

Real-World Connections

• Glaciologists use satellite imagery and ground surveys to monitor the mass balance of glaciers in the Canadian Rockies, providing data for water resource management and hazard assessment for communities downstream.
• Engineers and urban planners in coastal cities like Vancouver consider projections of sea level rise, informed by data on glacial melt rates, when designing infrastructure and developing evacuation plans.

Assessment Ideas

Quick Check

Present students with images of different glacial landforms (e.g., U-shaped valley, drumlin, moraine). Ask them to identify the landform and briefly explain the glacial process responsible for its creation.

Discussion Prompt

Pose the question: 'If all the ice on Greenland melted, what would be the two most significant global consequences?' Facilitate a class discussion where students support their predictions with evidence about sea level rise and climate feedback loops.

Exit Ticket

Students write a short paragraph explaining how gravity causes glaciers to move and one way this movement reshapes the land. They should use at least two key vocabulary terms in their explanation.

Frequently Asked Questions

How do glaciers form and move?

Glaciers begin as snow accumulation in cold areas, compressing into firn then ice under pressure. Movement occurs via basal sliding on meltwater or internal deformation, rates from centimeters to meters daily. Students grasp this by modeling flow forces, connecting compaction demos to real satellite velocity data for deeper insight.

What landforms do glaciers create?

Glaciers carve U-shaped valleys, striations on bedrock, and deposit moraines, erratics, and outwash plains. Erosional features form from abrasion and plucking, depositional from melting. Mapping local Canadian examples helps students link textbook images to landscapes, reinforcing process-landform connections through annotation and discussion.

How does glacier melting impact sea levels?

Melting land ice adds volume to oceans, raising levels by about 58 cm per Greenland equivalent. This threatens coastal areas with flooding. Simulations with measured trays quantify this distinctly from sea ice melt, building predictive skills as students extrapolate to global data projections.

How can active learning help students understand glaciers and ice caps?

Active approaches like building flow models or melting simulations make immense scales accessible, allowing students to test variables like slope or temperature. Collaborative mapping and data graphing reveal patterns invisible in passive reading, while discussions refine explanations. These methods boost retention by 30-50% per research, turning abstract geology into memorable experiences.