Deep and Shallow

Speed depends on depth

An interactive lesson with 6 steps, about 5 minutes: you predict, drag and solve, with instant feedback on every answer. It runs in your browser and needs JavaScript.

What you’ll learn

• Deep water: $v = \sqrt{g\lambda/2\pi}$. Shallow water: $v = \sqrt{gd}$.
• Tsunamis are shallow-water waves even in the deep ocean.
• In 4 km of water, a tsunami travels at about 700 km/h.

Steps

1. Two regimes
2. Crossing the Pacific
3. Speed from period
4. How long are swells?
5. A tsunami’s speed
6. Shallow enough?