hypolimnion
Quick Summary
The hypolimnion is the deepest layer of water in a lake, located below the thermocline. This layer is characterized by cold, stagnant water that maintains a relatively uniform temperature throughout the year, except during periods of overturn.1
In stratified lakes, particularly during summer, the water column separates into distinct layers. The uppermost layer is the warm epilimnion, followed by the thermocline, a zone of rapid temperature change. Below this is the hypolimnion, which is significantly colder.23
Biological processes, such as the decomposition of organic matter sinking from the upper layers, consume oxygen in the hypolimnion. This can lead to low oxygen concentrations in this deep water layer, as it does not readily exchange with the atmosphere. The hypolimnion plays a crucial role in the lake's overall ecology and nutrient cycling.432
Ask Britannica AI about this topic
Britannica doesn't have a full article on this topic, so we've curated a list of our relevant coverage.
inland water ecosystemPermanent bodies of standing fresh water…the lower, colder layer (hypolimnion). Water circulates within but not between the layers, more vigorously within the epilimnion. The boundary between these layers is the metalimnion, a zone of rapid temperature change. With the onset of autumn, the epilimnion cools and the water becomes denser, sinking and mixing with…
Read More…the lower, colder layer (hypolimnion). Water circulates within but not between the layers, more vigorously within the epilimnion. The boundary between these layers is the metalimnion, a zone of rapid temperature change. With the onset of autumn, the epilimnion cools and the water becomes denser, sinking and mixing with…
Read More
lakeHeat transfer…portion of the lake (hypolimnion). In shallow lakes or shallow portions of large lakes, the thermocline will eventually intercept the lake bottom so that no hypolimnion exists. Normally, as the heating season progresses, the thermocline intensifies and deepens. Secondary thermoclines may develop in the epilimnion, and these will migrate…
Read More…portion of the lake (hypolimnion). In shallow lakes or shallow portions of large lakes, the thermocline will eventually intercept the lake bottom so that no hypolimnion exists. Normally, as the heating season progresses, the thermocline intensifies and deepens. Secondary thermoclines may develop in the epilimnion, and these will migrate…
Read More