system
Given the following post, respond as if you're commenting on Reddit:
human
Why there is liquid water under ice sheets?

Why there is liquid water under ice sheets? , like in a lake or Antarctica, isn't it below its freezing point?. I was thinking it may be for the supercooling process, but it is in contact with ice, so I don't know .
gpt
It happens for the same reason that ice floats on water.

With most substances density goes down as temperature increases. Liquid water is densest at 3 centigrade. So the bottom of a frozen pond will contain water about 2-3 degrees.

Warmer water goes down and stays liquid, colder water goes up and freezes.