We had a few days of highs in the 50s followed by a very fast drop in temperature and moderate winds. So these crystals grew vertically in the ponded water and were then disturbed so that they were gouged out onto the surface or pushed up under pressure similar to needled ice. If you've seen this phenomenon before I would welcome a clearer explanation of their formation! I've read through this explanation of various ice habits but the actual physical control on formation isn't clear.
Friday, March 15, 2013
Winter Oddities: Prismatic Ice Crystals
Yesterday a student in my hydrogeology course brought these unique (to me) ice crystals to my attention. They formed in the middle of our on-campus hockey rink - basically a pond of water within a simple frame covered in Tyvek. I've seen needle ice, large depth hoar crystals, and hoar frost but I haven't seen crystals of this size. Many exhibit a euhedral hexagonal prismatic morphology - as both massive and individual crystals. Looking down on the surface of the ice it looks similar to a birds-eye view of columnar basalt exposures.
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Hi John
Back in the late 70's I was living in Athens, Georgia. we had a new home and was trying to grow grass on the red soil. There was a patch of steepness that erosion was overtaking my attempts at building sod and in the Winter the moisture was seeping out of the soil. One morning I found very fine acicular crystals apparently growing out of the soil. Ice crystals that looked like from 5 or 6 feet satin spar. Of course one would wish that I had taken film, which I did not. But I had always imagined that the molecules were being added at the soil end of the prisms. My memory is weak now but I do believe that there were areas where a leaf mat was being displaced upward by the prisms and other places where the prisms were naked, some what melting from the top. From your photographs I think what I saw was more of a millimeter-scaled result with possibly thousands of prisms.
it and I have you bookmarked to check out new stuff you post . Designer lehenga
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