Lake stratification

High school (ages 12+)
Environment & Earth

Name:

Date:

Step 1 · Read the article

Open the article and read it at the level above. Then answer the questions below in your own words.

https://smallwhale.org/articles/lake-stratification

Write what each word means, using the article.

Do not copy the article. Write two things you learned, the way you would explain them to a friend.

Answers below are taken from the article’s stored facts, so they match what the student read.

1. What is the location?Global phenomenon in lakes, particularly temperate regions
2. What is the primary driver?Water's density variation with temperature, reaching maximum density at 4°C
3. Why does the top layer of a lake get warmer than the bottom?During summer, the sun heats the lake’s surface, making that water less dense so it floats on top of the cooler, denser water below.
4. How does lake stratification affect fish and plants?The bright, oxygen-rich epilimnion supports lots of tiny plants and animals that produce food for fish. The dark, cold hypolimnion has little oxygen, so only special bacteria and invertebrates can live there.

Thermal Stratification: The layering of a water body based on temperature-induced density differences.
Epilimnion: The warm, well-mixed, upper layer of a stratified lake, characterized by high light and oxygen.
Hypolimnion: The cold, dense, and often anoxic or hypoxic bottom layer of a stratified lake.
Thermocline: A transitional layer within a body of water where temperature changes rapidly with depth.