Nature’s frozen feat: Ice circles form on Colorado River
Special to the Daily
Nature produces some amazing things. I was on the Trough Road near the Colorado River near Rancho del Rio a few days ago. Just before I crossed the bridge, I noticed some ice circles in the river.
There are basically two kinds of ice circles. Usually they form from ice floating in the river. These were different. These were composed of frozen foam. A tap with a stick broke them into many pieces. You can see a disk I broke in the vertical photo below.
Either ice chunks or foam, the process that shaped them was the same.
The foam is not pollution. It is caused by surfactants. Organic materials such as leaves fall into the water and as they decay, they release compounds called surfactants. The interaction between the water and the organic material breaks the surface tension and that allows air to more easily mix with water and creates bubbles. These bubbles congregate as natural foam.
The air temperature was 18 degrees Fahrenheit and the foam froze. The clumps of foam got caught in an eddy in the river and would spin forming a disk. They picked up more foam, but the spinning disks would also scrape against other disks keeping the round shape.