Saturday, January 30, 2010

Stars In Ice

I haven't visited the Farmersville-Jackson Twp. Pond in a while and thought I'd drive over and take a walk around it late this afternoon. I found it frozen as I expected but not quite so solidly as I thought. The northeast section has snow blown across it and it's noticeably whiter than the rest. Elsewhere the ice is clear and thin.

These cattails on the northern end of the pond are brown and blasted by the cold winter wind. I've recorded a low of -8 this season (01/10) so there's been ample opportunity to do some damage. That, though, is the only sub-zero reading I've had. We had two nights (01/03 and 01/13) where we bottomed out at +1.
The ice closest to the shore is thin and nearly open, owing to the sun "heating" the sandy bottom only inches away.
But what I want you to look at in the photo above, is the "star" formations in the background. They mottle the surface in great numbers. What are they?

This "star", near the northwestern edge of the pond, is a good example. This one is a foot or more across. If I had to venture a guess, I'd say children have thrown rocks onto the thin ice and caused it to fracture in pretty patterns. Perhaps the direction of the tendrils is the same as the direction of the toss?

And yet, somehow, that doesn't seem quite a satisfactory answer. Did tossed rocks, instead, not break through the ice but sit there and warm the surface in the same way as the sandy bottom? Are the tendrils fracture lines that filled with water and expanded for the same reason?

Or is it something else entirely? I saw no rocks lying on the surface. And I remember these well from other years. In any case, we have our very own "stars in ice" and a mystery, indeed.