Question

Which of the following statements accurately describe summer stratification in temperate lakes?

1. Summer stratification is a phenomenon where lakes develop distinct temperature layers.
2. In temperate regions, thermal stratification is rare and only occurs in very deep lakes.
3. The top meter of the water surface absorbs approximately 90% of solar radiation, leading to its significant heating.
4. Tropical lakes exhibit pronounced summer stratification due to slow mixing rates.

• A. 1, 3
• B. 3 only
• C. All
• D. 2, 4

Answer 1

Answer:

A. 1, 3

• The bottom layer, the hypolimnion, is cold, dark, and often low in oxygen due to decomposition.

• This stratification is primarily caused by increased solar intensity heating the surface and the resistance of these layers to mixing by wind.

• While common in temperate lakes, it is rare in tropical lakes where mixing is more rapid.