Frozen Mystery

April 06, 2018

Frost_Lace_IMG_20180131_122140 (1)

Photographer: Terry Gumz 
Summary Authors: Terry Gumz; Jim Foster

April 2018 Viewer's ChoiceThe photo above shows a lacy formation of ice that I observed during a mid-winter walk in Monroe, Georgia. It sort of looks like a plastic wrap of some kind but it's indeed ice that appears to be floating amidst the blades of grass. This odd formation, about 1 1/2 in (4 cm) wide, and about 3/16 in (0.5 cm) thick, evidently formed in the early morning hours following a still night when the air temperature dropped below freezing. I noticed it in a low moist area, which was mostly shaded after the Sun came up.

It likely formed when the grass stems exuded moisture from the damp ground by capillary action, the way more recognizable frost flowers are made. When temperatures fall below 32 F (0 C) this drawn up moisture exits from a rupture in the stem (or stems) and freezes. As more moisture continues to travel up the stem, it freezes as well, pushing the ice further along and often forming very peculiar shapes. The icy structure will grow as long as moisture is available or until melted by rays of the morning Sun. Photo taken on January 31, 2018.