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

Because Ice is less dense that water and floats upon it. Once it forms a layer of ice then the ice provides insulation to the water below it preventing it from getting cold enough to freeze.

If ice sank then we’d be in for a world of trouble. The sinking ice would not insulate the water from the freezing temperatures and more would freeze and sink until all of the water was frozen. No liquid water is not a good thing. There is a short story called “The Catalyst” (I think) that I read in elementary school that basically covered this.