Why do lakes and rivers only freeze on the surface and not all the way through?

Question

Why do lakes and rivers only freeze on the surface and not all the way through?

In: 10

Answer 1

In addition to the forementioned answers: water is heaviest at +4°C. Water freezes at 0°C, which is lighter than the +4°C water, so the ice floats on top. Once you hit a certain point that the outside temperature can’t affect the water through the thiccccc layer of ice, because the weather is not cold enough, the water stops freezing due to some laws of thermodynamics I’m not super familiar with.