Any ideas how this ice might have been formed?

In organizing our pictures, I found some from a walk in Brooks Woodland Preserve in Petersham MA from February. On this walk we encountered an odd and interesting ice formation. We've never seen anything like it and have no ideas how it could have been formed. It was concentric wavy-edged rings of tubes of ice. The tubes were about an inch in diameter. They did not appear to be formed around anything and were clear enough to see through. The tubes rings were held above the ground by the bits of vegetation they rested on, which were not incorporated into the ice tubes. The circumference of the outermost tube was several feet. It was not at all like the usual concentric rings of flat ice that sometimes surround a shrinking puddle in winter. It was almost like a rodent tunnel through the snow flooded and froze - except none of the tubes merged or intersected.

Any ideas how these might've formed? Several more pics are on Webshots.

Your pic #4 seems to make a very convincing arguement to that collapsed puddle concept. I'm guessing something like a rain storm came thru and the water pooled at the collapsed edges of the rings and the temperature dropped quite quickly freezing them solid. Obviously the pure ice it formed was much more structurally solid than the melting snow / thin ice layer around it dropping the "rings" edges to the forest floor.

That's a really cool and unusual photo. While i haven't see flat ice like that it does remind me of similar "lines" of ice i saw on vertical boulder faces this year that were, in my experience, an oddity. Must have been similar conditions that caused it. Glad you shared your find here and i'll be interested to see what others have to say.

ColdRiverRun said:

Your pic #4 seems to make a very convincing arguement to that collapsed puddle concept. I'm guessing something like a rain storm came thru and the water pooled at the collapsed edges of the rings and the temperature dropped quite quickly freezing them solid. Obviously the pure ice it formed was much more structurally solid than the melting snow / thin ice layer around it dropping the "rings" edges to the forest floor.

Click to expand...

Yes, it looks similar to the rings that form with a puddle refreezing as it shrinks. When we've seen that, the edges of the rings are usually flat, thin layers of ice. These were distinctly tube-shaped, as if someone froze water in a hose then stripped the hose away. We wanted to try to get a pic of a cross section but were reluctant to break the unique formation. I'm tempted to check back through weather records to see if conditions were as you suggested.