Ice Puppy 112

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On Flat Lake Time
- a Modern Survivor's Guide to Living off the Road System in Alaska - © 2006-2008 Larry Taylor

The Origin of Ice Puppy 112

            On November 3, 2005 I was spending my first freeze-up marooned, by choice, at our cabin on Flat Lake since we moved here full time. The lake had been freezing for three days. I was attending to projects, putting shelves in the pantry, and still relaxing from having co-organized a regional meeting of chemists in Fairbanks that summer.
            That morning I took a picture of the lake from the front window at first light at 8:30 AM. It was a mirror surface, but looked slightly frosted. During a break at about 2 PM I was attracted to bright glints of sunlight reflecting from something that appeared to be spread over the entire frozen surface of the lake.
             I walked down to the shore, out onto our dock, and found that the glints were coming from the flat planes in clumps of ice crystals. The crystals were about two inches in diameter and separated from each other by five to six inches of the clear, black surface of the lake ice.
             As I ran back up to the cabin to get my camera and tripod, I thought about keeping the camera steady by using the shutter time-delay so that my pulse wouldn’t cause any blurring. Back on the dock, I put my foot on the ice and tested its strength. It seemed solid enough, so I carefully stood on it, and it held with no apparent deflection. The ice was so clear that I couldn’t see how thick it was, and there were no cracks or bubbles in it to give that perspective. It was like a microscopist’s dark field, with the ice crystals on it visible only due to light from the sides, with no light from underneath the ice “stage.” The crystals looked as though they were falling through space, though they had obviously grown in situ.

            I started photographing the crystals from various angles, moving from crystal to crystal, marveling at the unique structure of each, as though each had a personality all its own. I got a little too "focused" on this pursuit of beauty and in a few minutes looked up and realized I was some fifteen feet away from the dock, but the lake ice was still firm.
            That winter our neighbors, Don and Marcia Oswald, were the only other people on the north shore staying during freeze-up. Don walked out on the ice while I was photographing. Then we knew it could support two people. He called the crystals Ice Puppies.
             As I enlarged the Ice Puppy photos, I wondered at their chemistry. Water freezes in a hexagonal close packed lattice with the six hexagonal faces on the “a” planes and, perpendicular to those, an axis of symmetry called the “c” plane, flat on the top and bottom of this six sided block, as in Diagram 1.

Diagram 1. Basic hexagonal close packed ice crystal structure

The first scientific studies of ice crystals were done by a nuclear engineer, Ukichiro Nakaya, at Hokkaido University in Japan in the 1930s. He determined the temperature ranges for the growth of the different ice crystal shapes on rabbit hair in a humid stream of air, as depicted here in Table 1. (Mariana Gosnell, Ice, Knopf, 2005, p. 422)

Table 1. Temperature Effects on Ice Crystal Formation

Temperature Range (ºF)	Ice Crystal Morphology
32 to 27	“a” axis thin hexagonal plates
27 to 23	“c” axis needles
23 to 18	“c” axis hollow columns
18 to 10	“a” axis hexagonal plates
10 to 3	“a” axis fern shape stars
3 to -13	“a” axis hexagonal plates
-13 to -58	“c” axis hollow columns

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