Lake Hydrography
Bottom water of lakes may feature lower level of oxygen, to the point of completely vanished dissolved oxygen (i.e., becoming anaerobic), and higher levels of chlorinity and organic-induced acidity. In many lakes, especially in the zones of continental climate, summer heating and winter cooling create strong vertical temperature gradients which oppose water intermixing, resulting in the periods of summer and winter thermal lake stratification. They are intervened by bottom water overturning, which happens in autumn (autumn overturn) and in spring (spring overturn) due to equalizing of temperature gradients and the resulting easier intermixing by wind and other sources of turbulence.
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Famous quotes containing the word lake:
“A lake is the landscape’s most beautiful and expressive feature. It is earth’s eye; looking into which the beholder measures the depth of his own nature. The fluviatile trees next the shore are the slender eyelashes which fringe it, and the wooded hills and cliffs around are its overhanging brows.”
—Henry David Thoreau (1817–1862)