Water molecules in deep ocean waves move in a circular, orbital motion.
Here's a more detailed explanation:
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Circular Orbits: As a deep-water wave passes, individual water molecules don't travel horizontally with the wave. Instead, they move in a circular path. This means a molecule rises and moves forward as the wave crest approaches, then descends and moves backward as the trough passes.
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Decreasing Orbit Size with Depth: The diameter of these circular orbits decreases exponentially with increasing depth. This means water molecules closer to the surface experience larger, more pronounced circular motion compared to those deeper down.
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Wave Base: The influence of the wave diminishes rapidly with depth. At a depth equal to approximately one-half of the wavelength (known as the wave base), the orbital motion becomes negligible. Below this point, the water is essentially undisturbed by the passing wave.
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Energy Transmission: This circular motion effectively transmits the wave's energy through the water. The water molecules themselves are not transported over long distances; instead, they act as carriers of the wave's energy as it propagates.
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Deep-Water Waves Definition: The term "deep-water wave" specifically refers to waves traveling in water deeper than one-half their wavelength. In this scenario, the seafloor does not interfere with the wave's orbital motion. If the water depth is less than half the wavelength, the wave is considered a shallow-water wave, and the motion of water molecules is different (more elliptical and flattened due to interaction with the seabed).
