The Long Journey of a Wave
All scenes › Chapter 1 Wind shakes the water
When the wind brushes past
Wind drags the surface and makes ripples
View in 3DRipples appear
When wind brushes over the sea, it drags the top layer of water a little and tiny wrinkles appear. The white streaks on screen are the wind, and the fine pattern under them is ripples. Ripples are only a few centimeters from crest to crest. What flattens the wrinkled water again is the pull of the water’s own skin.
Why?A smooth surface gives the wind almost nothing to grab. Once ripples form, the wind has something to catch on, so it can hand more push to the water. That is why ripples are the first step toward big waves.
Learn moreThe pull of the water’s skin is called surface tension. Waves shorter than about 1.7 cm crest to crest are pulled flat by surface tension; longer ones are pulled flat by gravity. Exactly how wind passes its push to the water is still being studied by scientists. The ripples on screen are drawn much larger than real ones.
- Border between ripples and waves
- 1.7 cm
- Crest-to-crest distance at the border
- about 1.7 cm
- Ripple speed there
- about 0.23 m per second
calculated from the textbook equations for water waves (linear wave theory)
View this scene in 3D →Read more
More in the series
The numbers come from the textbook equations for water waves (linear wave theory, the dispersion relation and shoaling). In the 3D view, wave heights are drawn larger; the seabed slope and the shape of breaking waves are rough sketches.