Brain freeze

​Brisk temperatures created some intricate shapes on the surface of the neighbor’s pond. The angular and almost geometrical shapes glittered as the light played off them. 

​It seemed strange to me to see such sharp angles. In most of my observations, shapes in nature tend to be more organic. 

Again, I turned to the internet to try to get a simple explanation for these formations. The information I discovered had me realizing that I should have paid more attention in chemistry class. Additionally, just like in high school my brain started to freeze up with all the flood of information. Many posts had to do with the molecular structure of water and its transition from a liquid to a solid state. 

An article by Minnesota Sea Grant Director John A. Downing posted at umn.edu titled "Lake and River Ice: Formation and Classification." added some insight.
 
“In a calm lake or pond, the first ice or ‘primary ice’ is quite clear and crystalline and is made up of hexagonal plates, needles, or sheath-like structures with large crystals oriented up-and-down,” Downing wrote. 

A post at squarespace.com provided a little more clarity for me on the subject.

 “Lake ice is crystalline and comes in a few crystal arrangements.  Various classification systems have been developed to describe them,” said the post.
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The post first listed a “simple and practical classification" from Tony Gow, a well respected glaciologist.  I’m not so sure I would have used the term simple to describe what followed. 

That list included unseeded ice, seeded ice and snow ice.
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As near as I could decipher, the ice I had been seeing was unseeded ice which Gow explained was” large crystals with a vertical C axis.”

The second classification system the post displayed was established by Bernard Michel and R. Ramseier in 1971. The system included primary ice, secondary ice, superimposed ice and agglomerate ice. 

​With this system, I believed what I had been seeing was a type of primary ice. Reading on, I found that that system included four types of primary ice.
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I started to get a headache but continued on. 

​“P1 ice forms in calm conditions at temperatures moderately below freezing.   The crystal size is large to extra-large.  It is (also) called 'large grain ice'…,” the post continued.

​According to the post, “P2 ice also forms in calm conditions but with colder temperature conditions.  It is similar to P1 ice except with more crystals that have a randomly oriented C axis.  The crystal sizes are large to very large”. 

Meanwhile, the simplest explanation I found, was the answer to the question “Why does ice on lakes and ponds sometimes freeze clear and other times not? on Quora.com.

However, it was hard for me to verify the answer by Edward Mahoney of Salt Lake City, UT.

​“Ice forms in elongated crystals. When the ice first forms on a lake or pond, it’s usually clear and you can see through it. Those first ice crystals are lying flat. They grew with their long axes oriented in the direction of least stress, parallel with the water surface,” Mahoney posted. 

​“As the surface of the water body freezes over, the ice crystals become confined. As they grow and expand there are horizontal stresses. The direction of least stress becomes vertical, rather than horizontal. The ice crystals reform themselves into larger crystals, with the long axis vertical, rather than horizontal,” he continued. 

​He also went on to describe bubble formations in ice.
 
Feeling slightly more knowledgeable and only a little less confused, I believe I might have a handle on ice identification. 

However, whether it was P1, P2 or unseeded ice, it was still a sight to see. That’s just the nature of things ‘round here.