Which term describes the broad process of stratifying a lake into distinct temperature layers?

• A. Epilimnion
• B. Hypolimnion
• C. Stratification
• D. Thermocline

Answer: (C)

Stratification describes the broad process by which a lake develops distinct temperature layers. When sunlight heats the surface, that water becomes warmer and less dense than the water below, so a stable vertical arrangement forms with warm, light water on top and cooler, denser water on the bottom. The upper layer is the epilimnion, the deeper cool layer is the hypolimnion, and the region where temperature changes most rapidly with depth is the thermocline. Stratification refers to the overall layering, while epilimnion and hypolimnion are the specific layers and the thermocline is the transitional boundary between them. Seasonal changes, like cooling in autumn or mixing during turnover, can disrupt stratification.