Why don't lakes freeze solid?

Answer 1

Lakes freeze from the top down. Some lakes do freeze all the way to the bottom. The layer of ice and the less dense water below 4oC on the top provides an insulation to prevent the heat in the lower levels from escaping and the lower water does not freeze unless it looses this heat. A long enough, cold enough winter will remove the heat (this is simple thermodynamics) and the entire lake will freeze. Small lakes freeze faster - big lakes slower.

Answer 2

Liquid water

has a density maximum at about 4 degrees C. Therefore, as water cools at the top of the lake, the 4-degree water falls to the bottom, displacing slightly colder but less dense water. Therefore the lowest levels of water in a large lake (or ocean, or whatever) never reach freezing and such bodies of water freeze from the top down, not the bottom up.

Answer 3

Ionic bonds in water, formed when the molecule gains another electron with the presence of a second Hydrogen atom, releases exothermic heat. This stops the lake from freezing completely solid, as water molecules tend to compact as you go deeper into a body of water.

Answer 4

The entire surface of a lake may certainly become frozen during the wintertime in some areas, but unless the lake in question is fairly small, it is unlikely for a lake to freeze completely beneath the surface. The sheer volume of water in a larger, deeper lake would make it very difficult, if not impossible.

Answer 5

The salinity is so high that the lake never freezes

Answer 6

Though some rivers can freeze over, some do not. One of the reasons that a river does not freeze over is that the kinetic energy of the moving water prevents it from freezing.

Answer 7

because its impossible to freeze a whole lake?