Tsunamis Uncovered

Overview

Students learn what tsunamis are, how they form, and why tectonic events can trigger them. They connect patterns in Earth’s systems to evidence from real tsunami examples.

Learning intentions

Students will be able to:

• Explain the relationship between tectonic activity and tsunami generation.
• Describe the stages of tsunami formation, from ocean disturbance to wave propagation and coastal impact.
• Use a model (diagram/sequence) to predict what might happen after a large undersea disturbance.
• Communicate scientific ideas using appropriate Earth science terminology.

Success criteria

• I can describe how sudden seafloor movement can displace large volumes of water.
• I can label and explain the steps in a tsunami sequence using a diagram.
• I can use evidence (observations from events or maps) to support my explanation.
• I can distinguish tsunamis from wind-driven waves using key features.

Curriculum links

• Earth’s structure and processes, including plate motion and earthquakes.
• Interactions within Earth systems and the way geophysical events cause changes.
• Using scientific knowledge to explain natural hazards and their impacts.
• Representing and communicating findings using models and diagrams.

Lesson structure (60 minutes)

1. 0–5 min: Hook + WALT

• Display a short, silent visual (photo/video still) of a tsunami reaching shore. Ask: “What event could cause such a wave pattern?”
• State WALT: “We Are Learning To explain how tsunamis form and how they relate to tectonic events.”

2. 5–12 min: Activate prior knowledge

• Quick class discussion: earthquakes, volcanoes, plates, and ocean waves. Record 3–4 student ideas on the board (e.g., “waves from wind” vs “waves from ocean disturbance”).
• Teacher clarifies the idea that tsunamis are not like typical waves.

3. 12–25 min: Direct instruction with diagrams

• Use a large annotated sequence diagram:
• Undersea earthquake or rapid seafloor uplift/subsidence
• Vertical displacement of the water column
• Wave propagation across the ocean
• Arrival and amplification near the coast (shoaling) and strong run-up
• Emphasise cause-and-effect and scale: energy transfer from seafloor to water, not from wind.
• Check understanding with two quick prompts: “What changes first?” and “Where does the energy come from?”

4. 25–40 min: Modelling task (small groups)

• Students work in groups of 3–4 with a tsunami sequence card set and a blank flow diagram.
• Task: arrange the steps in correct order and add 1–2 sentences to each stage explaining the mechanism.
• Provide sentence stems for students who need literacy support (e.g., “First, the seafloor … which causes the water to …”).

5. 40–50 min: Video or animation evidence

• Show a short, classroom-appropriate video segment demonstrating tsunami propagation and coastal impact.
• Students add a “evidence note” to their diagram: one observation from the video that matches their explanation.
• Pause twice to ask: “Which step does this scene show?” and “What would you expect to happen next?”

6. 50–58 min: Formative assessment (exit check)

• Students complete a quick written or diagram-based exit ticket:
• Label a simple tsunami cross-section
• Write a 3–4 step explanation linking tectonic movement to tsunami formation
• Collect for review; teacher uses a checklist aligned to success criteria.

7. 58–60 min: Closure

• Fast share: 2–3 groups read their final step explanations. Teacher reinforces common misconceptions (e.g., “tsunamis are caused by wind” or “they form only at the shoreline”).

Resources

• Tsunami sequence diagram (teacher) and blank flow-diagram sheets (student)
• Sets of tsunami “step cards” for ordering activity
• Short video/animation (no hyperlinks) showing tsunami propagation and coastal effects
• Coloured pencils/markers for labelling
• Sentence stems and word bank (e.g., seafloor, uplift, subsidence, water displacement, propagation, shoaling, run-up)
• Timer and group roles (Reader, Diagrammer, Explainer)
• Exit ticket template (label + 3–4 step explanation)
• Optional: simple physical model materials (tray + water + gel/board to represent sudden displacement) if available

Assessment

• Formative group assessment during the modelling task: correct sequencing and scientific reasoning.
• Exit ticket: ability to describe formation steps and link to tectonic events using a diagram or brief explanation.
• Observation of students’ ability to distinguish tsunamis from ordinary wind waves using key features.

Differentiation

• Use videos and diagrams to illustrate (as required), plus colour-coding for “cause” vs “effect” stages.
• Provide dyslexia-friendly options:
• Printed diagrams with large spacing and minimal text per box
• Audio recording option of the student explanation (teacher or student device) for the exit ticket
• Provide a short, structured response template with sentence stems and fewer lines to copy
• Literacy support:
• Sentence starters and word bank; allow oral explanation first, then student chooses one sentence to write.
• Extension for advanced learners:
• Add a “What factors change impact?” box to their model (e.g., earthquake magnitude, depth, coastline shape) using evidence from the video discussion.
• Encourage more precise language about vertical displacement and wave behaviour near shore (shoaling and run-up).

Extension (optional)

• Research historical tsunami events:
• In pairs, students choose one event and answer: What tectonic event caused it, where it occurred, and what evidence shows tsunami behaviour?
• Students present a 1-minute summary using a labelled diagram.