Which term describes a progressive wave occurring at the boundary between liquids of different densities?

Which term describes a progressive wave occurring at the boundary between liquids of different densities?

• A. Internal Wave
• B. Orbit
• C. Rogue Wave
• D. Seiche

Answer: (A)

Internal waves are gravity waves that travel along density interfaces within a stratified fluid. When two layers of water have different densities, such as a lighter layer over a denser layer, the interface between them acts like a boundary that can support wave motion. If the interface is displaced, gravity acts to restore it, and the disturbance propagates horizontally along that boundary as a progressive wave. That’s exactly what this term describes—the wave moving along the boundary between liquids of different densities. An orbit refers to the circular motion of water particles in a surface wave, not to a wave at a density boundary. A rogue wave is a rare unusually large surface wave, not tied to a density interface. A seiche is a standing wave in a closed basin, not a traveling wave along a density boundary.

Internal waves are gravity waves that travel along density interfaces within a stratified fluid. When two layers of water have different densities, such as a lighter layer over a denser layer, the interface between them acts like a boundary that can support wave motion. If the interface is displaced, gravity acts to restore it, and the disturbance propagates horizontally along that boundary as a progressive wave. That’s exactly what this term describes—the wave moving along the boundary between liquids of different densities.

An orbit refers to the circular motion of water particles in a surface wave, not to a wave at a density boundary. A rogue wave is a rare unusually large surface wave, not tied to a density interface. A seiche is a standing wave in a closed basin, not a traveling wave along a density boundary.