Science · Grade 8

Active learning ideas

Earthquakes and Seismic Waves

Active learning works for this topic because students need to feel and see seismic waves in action to grasp abstract concepts like wave propagation and energy transfer. The hands-on demos and mapping activities let students model real-world processes, making invisible forces visible and memorable.

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

• 30–50 min
• Pairs → Whole Class
• 4 activities

Activity 01

• Case Study Analysis
• 30 min · Small Groups

Demo: Slinky Wave Types

Provide each group with a slinky. Have students stretch it and create longitudinal waves by bunching and releasing coils for P-waves, then transverse waves by shaking side-to-side for S-waves. Time wave travel across the slinky and discuss why S-waves stop at the core model (cut slinky end). Record observations in notebooks.

Explain the causes of earthquakes and the release of seismic energy.

Facilitation Tip

During the Slinky Wave Types demo, stand at the front so all students can see the wave motions side by side while you narrate the differences in direction and speed.

What to look for

Provide students with a simplified seismogram showing clear P-wave and S-wave arrival times. Ask: 'What is the time difference between the P-wave and S-wave arrival?' and 'Based on this difference, what can you infer about the earthquake's distance from the seismograph?'

• Analyze
• Evaluate
• Create
• Decision-Making
• Self-Management

Activity 02

• Case Study Analysis
• 45 min · Pairs

Hands-On: Fault Block Models

Groups layer clay or foam to build fault blocks on paper plates. Apply pressure to simulate tectonic stress, then release to observe slip and 'quake.' Measure displacement and draw before-after diagrams. Connect to real faults by viewing photos of the San Andreas.

Differentiate between P-waves, S-waves, and surface waves.

Facilitation Tip

For Fault Block Models, assign roles like ‘stress applier’ and ‘fault recorder’ to keep students engaged and clarify the cause-and-effect relationship between force and rupture.

What to look for

On an index card, have students draw a simplified diagram illustrating the difference between P-waves and S-waves. Below the diagram, they should write one sentence explaining why S-waves are useful for locating epicenters, even though P-waves arrive first.

• Analyze
• Evaluate
• Create
• Decision-Making
• Self-Management

Activity 03

• Concept Mapping
• 40 min · Pairs

Concept Mapping: Epicenter Triangulation

Distribute seismograms from three stations. Pairs calculate time differences between P- and S-waves using a provided chart, plot circles on a map based on distances, and find the overlap point as epicenter. Discuss how more stations improve accuracy.

Analyze how seismographs are used to locate earthquake epicenters.

Facilitation Tip

In Mapping: Epicenter Triangulation, provide each group with different colored markers to track their station’s data before overlaying results, making errors and corrections visible to the whole class.

What to look for

Pose the question: 'Imagine you are a scientist analyzing seismic data from an earthquake. Why is it essential to have data from at least three different seismograph stations to accurately pinpoint the epicenter?' Facilitate a brief class discussion to gauge understanding of triangulation.

• Understand
• Analyze
• Create
• Self-Awareness
• Self-Management

Activity 04

• Stations Rotation
• 50 min · Small Groups

Stations Rotation: Wave Properties

Set up stations with ropes for surface waves, springs for P/S, sand trays for liquefaction, and videos of real quakes. Groups rotate, test waves, and note damage potential. Debrief with class chart comparing wave traits.

Explain the causes of earthquakes and the release of seismic energy.

What to look for

Provide students with a simplified seismogram showing clear P-wave and S-wave arrival times. Ask: 'What is the time difference between the P-wave and S-wave arrival?' and 'Based on this difference, what can you infer about the earthquake's distance from the seismograph?'

• Remember
• Understand
• Apply
• Analyze
• Self-Management
• Relationship Skills

A few notes on teaching this unit

Teachers find that starting with the Slinky demo builds immediate buy-in because students can feel the waves and relate them to ground shaking. Avoid rushing through the fault block models; let students experiment with repeated stress cycles to internalize elastic strain. Research shows that students grasp triangulation better when they physically plot points rather than just viewing static maps.

Successful learning looks like students accurately differentiating wave types by motion and speed, explaining how plate movements create stress, and using triangulation to locate epicenters with confidence. They should connect each activity’s output to real-world earthquake behavior and hazards.

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Watch Out for These Misconceptions

• During Slinky Wave Types, watch for students assuming all waves shake the ground the same way or arrive at the same time.

  Have students time wave arrivals with stopwatches and compare motions side by side, then ask guiding questions like, ‘Which wave would you feel first on the surface, and why?’

• During Fault Block Models, watch for students thinking earthquakes happen randomly or only at volcanoes.

  Guide students to measure the angle of the block and stress applied, then map their results on a simplified plate boundary diagram to reveal predictable patterns.

• During Mapping: Epicenter Triangulation, watch for students confusing the epicenter with the focus depth.

  Have groups plot focus points below their epicenter locations on a 3D foam model, then ask them to explain why the surface point is called the epicenter.

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Methods used in this brief

• Case Study Analysis
• Concept Mapping
• Stations Rotation