Frosty paradise

so many varieties of ice crystals

The trail through Cowee Meadows to the cabin and the beach has seen significant improvement (thank you, State Parks!), with more to come. In midNovemeber, red squirrels were belatedly and busily carrying nest material for a winter snuggery. There were a few gulls and harlequin ducks in the bay, and an intriguing pile of feathers on the trail, where a predator had plucked its prey.

For me, however, the frost patterns stole the show. The wide meadows were a truly spectacular sight, with hoar frost on every available surface. Cow parsnip was ‘flowering’, far more beautifully than in summer—every tiny sprig on the dried inflorescence wore a tuft or ruff of crystals, and every old flower head in the meadow was frost-flowering. Out near the beach, sweetgale twigs bore large frost tufts at the tip and every wee bud along the stem had its own crown of frost. Yellow-rattle stems held puffs of frost on every empty seed pod, and the arching valves of split-open fireweed seed pods made lovely patterns.

In the woods along the trail were odd, linear, fluffy-looking patches of white, some of them several inches thick. Not snow, of course, because that hadn’t yet arrived at low elevations. Most of these fluffy patches were on the ground, but a few had developed on thin, small snags. A close look revealed that all of these patches had a piece of wood underneath. Some had long, thin, frosty curls emerging in dense clusters from the sticks, while a few held crowds of shorter, thicker crystals. I think that our freezing temperatures in the middle of November caused water in the soggy sticks to freeze and expand, extruding these crystalline forms. We often see thick columns of ice being pushed up out of freezing mud in the same way, but these fuzzy, frosty sticks are much rarer.

On a previous day out on the wetlands, I noted the numerous seed heads of some fine grasses, arching over so that their frosty seed heads made a crystalline canopy. And along some mudflats next to the Mendenhall River there was a fascinating layer of very thin ice on which were traced very unusual patterns of paisley and celtic knots.

crystals-3-by-bob-armstrong
Crystals on a bud. Photo by Bob Armstrong

Looking closely at the hoar frost on bridge railings near the glacier revealed an astonishing array of forms. Even without a microscope, I could see intricate variations within the superficially uniform spikes of frost that coated the wooden rails. Some were columnar, often with candelabra-like branches. Others were composed of small, flat plates neatly stacked on their edges, or somehow held in a ladder-like arrangement. Some plates had extremely fine filaments around the edges. Still others spikes were made of angular, linear crystals lined up at right angles to each other. And so on! Next time we get a good crop of hoar frost, go and see for yourself! It’s a real visual treat.

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