And what is worse, if the ground is starting to thaw from below, if you get a foot or two of snow on top, it insulates the ground from the freezing air, and the

And what is worse, if the ground is starting to thaw from below, if you get a foot or two of snow on top, it insulates the ground from the freezing air, and the ground temps will drive upward from below, turn the soil into a muddy mess. The same happens with rivers. A frozen river, with a heavy snowfall, will quickly thaw from below.