The Long Journey of a Wave
From wind to beach: the journey of a wave
Wind makes ripples, ripples grow into waves, and waves become swell that crosses the ocean and breaks on a beach. All the while, the water itself mostly turns in circles where it is. Follow it in 14 scenes.
Watch from the start in 3DChapter 1 · Wind shakes the water
When wind blows over a calm sea, ripples form and grow into waves.
- 1 A sea like a mirror
With no wind, the sea is flat
View in 3D → - 2 When the wind brushes past
Wind drags the surface and makes ripples
View in 3D → - 3 When the wind keeps blowing
Ripples grow into waves, and gravity pulls the water back down
View in 3D →
Chapter 2 · Water turns in place
The wave moves forward, but the water mostly turns in circles where it is.
- 4 One red bit of water
Water does not follow the wave — it turns in a circle where it is
View in 3D → - 5 Only the shape moves on
What travels is not the water but the shape of the wave and its energy
View in 3D → - 6 Going deeper
The deeper you go, the smaller the circle — below half a wavelength, almost no motion
View in 3D →
Chapter 3 · Swell crosses the ocean
Waves from a storm line up by length and travel thousands of kilometers.
- 7 The sea in a storm
In a storm, waves of every length and direction pile on top of each other
View in 3D → - 8 Long waves go first
In deep water, long waves are faster, so the waves line up by length
View in 3D → - 9 Swell
Smooth, evenly spaced waves crossing a calm sea
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Chapter 4 · Breaking on the beach
As the seabed rises, waves slow down, grow taller and finally break.
- 10 When the seabed rises
As the seabed gets closer, circles flatten into ovals and waves slow down — try it yourself
View in 3D → - 11 Nearing the beach
The closer to the beach, the slower the waves
View in 3D → - 12 Catching up from behind
When the front slows, the waves bunch up and grow taller
View in 3D → - 13 The crest pours forward
The crest sits over deeper water, so it runs faster — it breaks when about 0.8 times the depth
View in 3D → - 14 The end of the journey
Broken waves turn into white foam that runs up the beach, and the energy is spent here
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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.