Illustration

Lake Turnover

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Background Info
For Further Exploration
Vocabulary

Background Info

Lake turnover is the process of a lake's water turning over from top (epilimnion) to bottom (hypolimnion). During the summer, the epilimnion, or surface layer, is the warmest. It is heated by the sun. The deepest layer, the hypolimnion, is the coldest. The sun's radiation does not reach this cold, dark layer.

During the fall, the warm surface water begins to cool. As water cools, it becomes more dense, causing it to sink. This dense water forces the water of the hypolimnion to rise, "turning over" the layers.

For Further Exploration

Vocabulary

Term	Part of Speech	Definition
lake	noun	body of water surrounded by land.
epilimnion	noun	surface and upper part of a lake.
hypolimnion	noun	dense bottom layer of a lake.
radiation	noun	energy, emitted as waves or particles, radiating outward from a source.
dense	adjective	having parts or molecules that are packed closely together.
lake turnover	noun	process of the dense lower layer of a lake rising to become the upper, less-dense layer.