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:
“It is so manifestly incompatible with those precautions for our peace and safety, which all the great powers habitually observe and enforce in matters affecting them, that a shorter water way between our eastern and western seaboards should be dominated by any European government, that we may confidently expect that such a purpose will not be entertained by any friendly power.”
—Benjamin Harrison (1833–1901)
“A little water clears us of this deed.
How easy is it then!”
—William Shakespeare (1564–1616)