Water
A steep density gradient in a body of water can have the effect of trapping energy and preventing convection, such a gradient is employed in solar ponds. In the case of salt water, sharp gradients can lead to stratification of different concentrations of salinity. This is called a Halocline.
Read more about this topic: Density Gradient
Famous quotes containing the word water:
“Ice is an interesting subject for contemplation. They told me that they had some in the ice-houses at Fresh Pond five years old which was as good as ever. Why is it that a bucket of water soon becomes putrid, but frozen remains sweet forever? It is commonly said that this is the difference between the affections and the intellect.”
—Henry David Thoreau (1817–1862)
“When peaceful clouds were reflected in the paddies
and the water buffalo stepped surely along terraces,
maybe fathers told their sons old tales.
When bombs smashed those mirrors
there was time only to scream.”
—Denise Levertov (b. 1923)
“To be thirsty and to drink water is the perfection of sensuality rarely achieved. Sometimes you drink water; other times you are thirsty.”
—José Bergamín (1895–1983)