Which term best describes mature wind-generated waves that have traveled away from their generation area?

• A. Swell
• B. Surf Zone
• C. Shallow-Water Wave
• D. Seismic Sea Wave

Answer: (A)

This question tests understanding of wind-generated waves that have moved away from where they formed. When waves are produced by winds, their energy can travel long distances over open water. As these waves travel beyond the wind area, they tend to form a regular, long-period train called swell. Swell features longer wavelengths and periods, and the waves often appear smoother and more evenly spaced than the rougher, choppier sea closer to the wind sources.

The other terms don’t fit this situation: the surf zone is the nearshore region where waves break as they enter shallow water; shallow-water waves describe waves whose behavior is significantly affected by the seafloor depth, not their distance from the wind source; seismic sea waves are tsunamis caused by sea-floor disturbances, not by wind. Hence, the term that best describes mature wind-generated waves that have traveled away from their generation area is swell.