I see this on my ponds with early or late ice when the ice is thin. No springs in my ponds either although there is no doubt springs can do this. Not sure about the mechanisms of ice formation though. Maybe someone else can come on shed some light on this.
One thing I have always found curious on natural lakes is water surges under the ice. Has anyone else seen this? I have been icefishing and seen water go up and down in my icefishing hole. I'm wondering if it has anything to do with contracting ice that may cause some kind of pressure wave. We all know the cracking of the ice that I have experienced in really cold conditions can really make some noise.
