The pond surface is frozen and flat – and striped.  Somehow, the ice ended up with sinuous stripes across much of the pond.  They aren’t usually there, but sometimes they are conspicuously there, alternating in shade and sheen, meandering across and through the ice.

How do serpentine stripes form in the ice of a pond?

Does the wind make the water surface uneven as it freezes?  Does it drive rainwater into curved, parallel ridges as it freezes on ice that’s already there?  Do currents under the surface move, snake-like, in tandem below the freezing water?  Is there a combined effect of things above and things below the surface?

What causes the differences in appearance of the stripes, their brightness and reflection? Do the stripes differ in crystal structure, thickness, roughness, dissolved content, bubbles, particulates, or something else?  Perhaps if we examined the stripes closely and identified their physical differences, we would learn something about how they could have formed.

Whatever their origin, the patterns are striking, sweeping patterns generated without human planning or guidance.

Tonight, the ice is covered with water from two days of unseasonably warm weather and rain.  By morning, the temperature will drop below freezing as the wind blows.  Will there be stripes tomorrow?  We’ll see.