In this activity, students investigate the classic Earth science analogy; "Seismic waves radiate outward from an earthquake's epicenter like ripples on water". Instruction begins as student examine a discrepant, thought-provoking image that connects the unfamiliar concept of the spreading out of seismic wave to the more familiar scenario of ripples on water radiating outwards in all directions after a droplet falls onto a pool. After students have recorded their initial thoughts regarding the image, they collect observational data from experimentation with water droplets falling into a pool to either support or refute their initial ideas. As a whole class, students then watch a visualization of ground motion at various points in the US and attempt to conceptually map this visualization to relevant features from their experiments. Students reflect on seismic wave propagation by constructing an argument (claim, evidence and explanation) that either supports or refutes the initial analogy “Earthquakes… like ripples on water?”
Students will be able to
- Explain that seismic waves propagate outwards as wave fronts from the source in 3-dimensions (X, Y, & Z axes) and have a velocity
- Explain that the amplitude of seismic waves is related to the amount of energy released from the source and decreases with distance from the source
- Compare and contrast seismic waves to ripples on water.