11 January 2024
I returned to Minihaha Creek five days after my previous visit for a run, and a look at the ice. The snow, not very deep before, has receded, and the fallen leaves arch above its surface, leaving a myriad of little cave-lets speckling the surface. I wonder if there are any organisms — macro or micro — that are adapted to take advantage of these niches.
It has been getting above freezing most days, so the crystalization has not advanced in any degree I can notice. Indeed, there has been a bit of melting, some, perhaps, wholesale melting of crystalized surfaces, but also partial melting.
The partially melted surfaces have a distinct appearance. Most noticeably, they are darker — they appear dark gray; perhaps they have sagged so that they now float on the surface of the stream, or perhaps the water has risen and presses against them from below. I have certainly noticed evidence — shelves of crystal as much as an inch above the water level — of the ebb and flow of the creek. While some of the ice initially appears as though it has melted into a homogenous sheet of ice, on closer examination, or looking from particular angles, it shows structure, ranging from a sort of refrozen mush that is bumpy with crystal fragments to a dark shadow of the same interlocking network of acicular crystals that I saw last week. I believe, though am not fully confident, that the fine structure of fractal crystalization along the edges of crystal blades has vanished. It is as though the crystalline scrimwork has been pressed into the water and smoothed with polishing paper.
I did find some places where crystalization had advanced. This was mostly underneath the low bridges that carry traffic over the creek. I imagine that the bridge both blocks insolation from above as well as providing a sort of protected area within which cold air can pool. In any case, the crystals are in full flower, their needles edged with sawteeth and etched with internal structure.
As I approach to explore, my feet break though the rim of the ice, and my crunching steps echo around the space.
