At the last stage of melting lake ice, water penetrates the fissures in the ice’s crystal structure. The hexagonal crystals, about the size of a pencil, are loosely linked together, and float in clumps, making a tinkling noise as they grind together.
Kayaking, canoeing or rowing through it is mesmerizing. But if you’re tempted to try it, remember that the water is freezing cold, so take precautions.
Inflection Date is a term used to define a day when the thaw begins in earnest, and means the date when the mean daily temperature rises above freezing on a lasting basis. This is significant because it means there was more thawing than freezing going on. Usually, we can’t tell if the warm weather is here to stay until several more days have passed, so you aren’t likely to see a phrase like, “today is inflection day.” More often, we’ll say something more like, “it looks like the Inflection Date was last Tuesday.”
Mean Daily Temperature:
The day’s average temperature, based on official records. It is not exactly half way between the overnight low and the afternoon high. It’s in that range, of course, but the mean usually calculates out a degree or two higher.
The Glossary page on Lake of the Woods Ice Patrol is a slow-moving project. One day, it might take the form of a list of terms, with a short definition and a link to photographs. Ultimately, I’d like to have pictures of Frazzel Ice, Ice Ridges and so on. Leave a comment if you’re enthusiastic for me to get to work on it, or if you have pictures that might help.