Question

Which statement correctly describes the Metalimnion?

1. The Metalimnion is the uppermost layer, characterized by warm, circulating water.
2. It lies below the Hypolimnion, acting as the transition zone to the surface water.
3. The Metalimnion forms the intermediate layer of the lake, marked by a steep fall in temperature.
4. This layer is known for its high oxygen content due to constant mixing with the atmosphere.

• A. 4 only
• B. All
• C. 2, 3
• D. 3 only

Answer 1

Answer:

D. 3 only

• The Metalimnion is the middle layer in a thermally stratified lake, situated between the upper Epilimnion and the lower Hypolimnion.

• Its defining characteristic is a rapid decrease in water temperature with increasing depth, a zone often referred to as the thermocline.

• This steep thermal gradient significantly impedes the vertical mixing of water between the Epilimnion and Hypolimnion.

• Unlike the Epilimnion, it is less directly influenced by wind mixing and atmospheric exchange, and unlike the Hypolimnion, it doesn't hold the coldest water or exhibit the most severe oxygen depletion.

• Its non-circulating nature and sharp temperature gradient are crucial features of summer stratification.