Lesson Title: The Power of the Wave: Understanding Tsunami Safety
Target Audience: Grades 3–7 (Adapt complexity as needed)
Time: 45–60 minutes
Learning Objectives
Students will be able to:
- Define what a tsunami is and how it is formed.
- Identify natural warning signs of an approaching tsunami.
- Explain the proper safety steps to take during a tsunami warning.
Materials
- Whiteboard/Projector
- Markers/Pens
- Handout with key vocabulary (optional)
- “Tsunami in a Tank” demonstration materials (clear plastic container, water, small flat object/board)
1. Engage: What is a Tsunami? (10 minutes)
- Start with the Name: Ask students what they know about the word “tsunami.”
- Explain that “tsunami” is a Japanese word: “tsu” means harbor, and “nami” means wave.
- Formation Analogy: Use the “Tsunami in a Tank” demonstration .
- Fill a clear container with water. Tell the students the water represents the ocean.
- Ask a student to quickly push a flat board (representing an underwater earthquake or landslide) just under the surface of the water on one end.
- Observation: A wave will travel across the tank, demonstrating how a disturbance on the ocean floor displaces a massive amount of water, creating a wave that spans the entire depth of the ocean.
- Key Point: Stress that a tsunami is not a typical surface wave (like those caused by wind) but a series of extremely long waves caused by a sudden shift on the seabed.
2. Explore: Natural Warning Signs (15 minutes)
- Discuss Warnings: Ask the students: How would you know if a tsunami was coming if you didn’t have a TV or phone?
- Introduce the Three Key Natural Signs:
- Strong, Long Earthquake Shaking: A tsunami is often generated by an earthquake. If you are near the coast and feel shaking for 20 seconds or more, move inland immediately.
- A Loud Roar: As a tsunami approaches the shore, the turbulent air and water can create a sound like a freight train or jet plane.
- The Water Pulls Back: This is the most famous sign. The ocean may dramatically and rapidly retreat, exposing the seafloor, rocks, and fish. Explain this is the trough (lowest point) of the wave arriving before the crest (highest point). This is NOT a time to explore the beach; it’s a critical warning to run!
3. Explain: Tsunami Safety Rules (15 minutes)
- Safety Rule Discussion: Create a class list of Tsunami Safety Rules.
- Rule 1: Move Inland or Uphill. When you feel a long earthquake or see the water retreat, you must immediately go to high ground—as far inland and as high up as possible. Do not wait for an official warning.
- Rule 2: Climb High. If you cannot get inland, the safest place is on the upper floors of a tall, strong concrete building.
- Rule 3: Hear the Alert. If you hear an official warning siren or see an alert on TV/phone, follow evacuation orders immediately.
- Rule 4: Stay Put. Tsunami are a series of waves. Stress that the first wave is often not the largest, and you must stay away from the coast until officials announce the danger has passed.
4. Extend: “Tsunami Evacuation Map” Activity (5-10 minutes)
- Practical Application: Draw a simple map on the board showing a coastline, a beach, a school, and a nearby tall hill.
- Scenario: Ask students to draw the safest evacuation route from the school to the high ground.
- Review: Discuss their routes and reinforce the importance of knowing their local area’s tsunami evacuation zones (if applicable).