ice circle

A phenomenon that occurs on rivers during winter, where floating ice caught in an…A phenomenon that occurs on rivers during winter, where floating ice caught in an eddying flow will rotate around, knocking off its distant edges, forming a floating revolving circular disk, slowing turning under the influence of the underlying vortex current; when the temperature conditions are not too warm, leading to ice breakup and fragility, and not too cool, freezing over the entire surface.