During my morning walk, I was taking a photograph of some ice formed from a puddle and noted the concentric rings. I know I’ve seen this before but today I wondered why they were there.
When I was home, I went online to find an explanation. As with too many things, a clear explanation was not found.
A seemingly scientific explanation is that the lines are a product of change in flow created by the prior ice sheets formed. This was describing rings found around obstacles such as rocks in a river. My example was just a puddle, but I read on. The surface current creates viscous friction, slightly melting the outer areas of the prior sheets in the process, making a ring line where the currents are going around the obstacles.
There was no flow in my puddle. No big rocks. So why rings?
There are not only ice rings but also ice discs, ice circles, ice pans, ice pancakes or ice crepes. All are a natural phenomenon that occurs in slow-moving water in cold climates.
No clear explanation for my ice-ringed puddle but I do like the image it formed. It reminds me of a topographic map.