Coping with Ice

Forrest M. Mims III

Ice storms can be unpleasant, but they certainly give cause to stare in wonder at what they leave behind.

An unsual ice storm in South Texas left a thick layer of crystal clear ice atop a post in the field called Geronimo Creek Observatory where I make daily measurements of sunlight and the ozone layer.

Some folk in the region received even more ice, and the result was broken tree limbs and severed power lines. The situation would have been much worse had there been a bit more frozen rain.

The ice we received provided novel experiences for people, pets, livestock and wild animals. A little warbler found shelter just over the ground in the fork formed by a pair of cedar elms. The robins that spend winters in the woods on our place disappeared into hiding places during the iciest days. They reappeared as soon as the ice rained itself out of the trees when the temperature rose.

A neighbor's cattle and their field were coated with a beautiful layer of white. Instead of staring in admiration, the cows bawled and moaned about the frigid temperature.

Figure 1. Ice encapsulated the thorns of prickly pear cactus (Opuntia spp.) at the Mims place on Geronimo Creek, Texas, during a recent ice storm. Photograph by Forrest M. Mims III.

Most barbed wire fences and tree branches wore a form-fitted covering of glistening ice, which was much thicker on their upper sides. The exception was under the trees in the woods, where there was little ice. Apparently the branches in the canopy above intercepted nearly all the frozen rain before it could reach the lower branches.

The ice played many tricks on the plants in meadows and around the edges of the woods. It coated bluebonnet seedlings. Seed clusters from wild Maximillian sunflowers were encapsulated with nearly spherical globes of perfectly clear ice.

The large leaves of some plants were encased in ice. As the thaw occurred, the leaves sprang from their frozen traps and left behind what can only be called “ice fossils.” These short-lived creations reproduced the shape and form of each leaf infinitely better than the best ice sculptor. Most fell to the ground, where they resembled clear potato chips. Some remained frozen to neighboring stems and very much resembled transparent butterflies.

Our flock of prickly pear cactus was undaunted by the ice that decorated their sharp spines. Those thorns stood guard just as they do on hot summer days, and they performed their assignment just as efficiently when annoyed by a photographer.

"World of Science" columns are selected and sometimes revised from columns published in the San Antonio Express-News or the Seguin Gazette-Enterprise. The columns are intended for a general audience. Forrest M. Mims III and his science are featured online at www.forrestmims.org and www.sunandsky.org .