Book 30, Question 26
Why does a deep lake have warm and cold layers in summer?
In summer, the Sun warms the top of a lake.
Warm water is lighter than cold water, so it floats on top. A deep lake ends up with three layers: a warm top layer, a thin middle zone where the temperature drops fast called the thermocline, and a cold dark bottom layer. The layers hardly mix, which is why a swimmer's feet can suddenly feel cold when kicking down.
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Quick answers
Why does a deep lake have warm and cold layers in summer?
Thermal stratification refers to a lake’s three main layers, each with a different temperature range.
Source: education.nationalgeographic.org
More fun facts
- The warm, shallow water of the upper layer of the lake causes plants and algae to decompose, and eventually they sink to the basin.
Sources: education.nationalgeographic.org