When a wave is too steep to support itself, the wavefront collapses creating a that advances up the shoreline

When a wave is too steep to support itself, the wavefront collapses creating a   break   that advances up the shoreline

Explanation:

When waves are tall, with a great slope that makes them unstable, they break. Braking waves might occur inshore or offshore.

Offshore: Breaking waves in the deep sea occurs when the wind speed increases so fast that they exceed the speed of the waves. These last ones acquire additional energy from the winds increasing their slopes to the point of being so unstable that the water from the crest falls forward and breaks the wave. The most influencing factor in these breaking waves is the speed of the winds.Inshore: When waves are near the shore, the scarce water deepness increases the friction of the wave with the marine bottom, and consequently, the wave´s speed decreases progressively. The wave loses energy in the friction, the wave energy is concentrated in a lower length, and the wave grows in size. As it increases, it acquires a sharper slope. As deepness decreases, the wave base loses speed, but the crest does not. As the wave crest travels faster, the frontal face of the wave becomes concave. This change in shape continues until the wave can not support itself and it breaks. The break is not produced by the friction with the bottom, but by exceeding the slope limit values.

Its in the national history museum and you can't se the original because its locked away in a vault