Why do ocean waves break as they approach the shore?

Is it because of the principle of superposition. Would it be described as constructive or destructive interference? I believe it's constructive interference as the two waves combine the amplitude is large which causes the wave to topple over. Is this a fair assertion?

It is not inteference. It has to do with momentum and wave speed. As the depth gets shallower, the slower wave speed at the bottom (friction) allows the top of the wave to get ahead, and momentum carries it over and it falls ahead of the wave.

Yes, the breaking of ocean waves as they approach the shore can be explained by the principle of superposition and the concept of interference.

When a wave approaches the shore, water depth decreases, causing the wave to interact with the sea bottom. As a result, the wave slows down at the bottom while the top continues moving at its original speed, causing the wave crest to become steeper. This steepening process is influenced by the superposition of the incident wave and the reflected wave due to the shore.

Now, regarding your question about constructive or destructive interference, it is actually a combination of both. Initially, as the wave approaches the shore, there is constructive interference between the incident wave and the reflected wave. The two waves combine, resulting in an increase in amplitude. This is the part where the wave gets taller or steeper.

However, as the wave continues to break, destructive interference comes into play. The wave's forward momentum causes the top part to continue moving forward and toppling over, while the bottom part slows down, creating a breaking effect. So, it starts with constructive interference, but as the wave steepens and collapses, destructive interference occurs.

Hence, your assertion about the constructive interference leading to a larger amplitude, causing the wave to break, is partially correct. It is a combination of constructive and destructive interference that ultimately leads to the breaking of the wave as it approaches the shore.