A tsunami is a series of waves caused by a large, sudden displacement of water. Many start with undersea earthquakes; landslides and volcanic activity can also cause them. Not every undersea earthquake does. In deep water a tsunami can be low and very fast; near shore its height and currents can become dangerous. Safety: Use only a fictional coast. This is not emergency advice; real warnings require official local guidance and adult support. Stop: Stop at the paper explanation. No water-wave experiment, coast visit, evacuation rehearsal, or real warning interpretation.

Materials: Paper; Pencil; Long paper strip 1. Draw an imaginary ocean cross-section on the strip: deep water at left, a sloping seabed toward a coast at right. Mark a small town at the coast. Label it Qualitative model, not to scale. 2. Write four cards: A: part of the seabed suddenly rises and displaces water; B: waves spread away across the ocean; C: waves interact with shallower water near a coast; D: flooding and strong currents can damage places on land. Put them in order beneath the strip. 3. Draw three wave fronts moving toward shore and label Series of waves. Add Very fast in deep ocean and Can grow near shore. Do not draw a single breaking surf wave as the only possible appearance. 4. Write two corrections: An undersea quake without enough water displacement need not cause a tsunami. The first arriving wave is not always the largest. Explain one possible effect on the imaginary town using the word could. Done: An ordered four-card mechanism, labelled ocean strip, two corrections, and one bounded coastal-effect explanation are present. Proof: Keep the sequence and strip. Note help with ordering, reading, or distinguishing normal surf from tsunami waves. Stop: Stop at the paper explanation. No water-wave experiment, coast visit, evacuation rehearsal, or real warning interpretation.