Salting The Seasons

A person stands in front of a large pile of road salt in a Wisconsin Department of Transportation shed.

The following is an excerpt from an excellent article on Madison-based science writer, Erik Ness’ website ‘The Lemonadist.’ The full article is available here

3/12/24 – by Erik Ness

“I think about Ice Nine on a regular basis.”

Coming in the middle of a conversation about salt pollution, this surprising detour into literary fiction by University of Wisconsin–Madison lake scientist Hilary Dugan is a little confusing at first.

A woman giving a lecture in an art gallery.
Hilary Dugan gives a talk about winter limnology to the Wisconsin. Academies of Sciences, Arts and Letters

Ice Nine was a fictional water molecule in Kurt Vonnegut’s Cat’s Cradle — a fabulist meditation on technology and religion. A mad scientist creates a version of water that freezes at room temperature. Plus it’s infectious. One drop of Ice Nine in the ocean and the whole thing seizes up.

Dugan was reading Vonnegut when she first learned about lake stratification, the way lakes settle into layers of temperatures, warm on top and cold on the bottom, and Ice Nine just stuck. “The physics of water structure lake habitat in such a unique way that … is totally unexpected,” says Dugan. “Water is this crazy molecule. Its properties make the planet what it is. If ice sank then the oceans would freeze and we wouldn’t have life.”

If you ever have the opportunity to swim in the middle of a lake in summer, take it. “You have to have actually been in a lake to experience stratification,” says Dugan. After basking in the easy surface warmth, execute a dive towards the bottom. You’ll find the water cools quickly, dramatically. The depth of the warm zone depends on how large and deep the lake is, and on how warm and windy it’s been.

Sun warms the top few feet of the water column, but that’s not the only reason it stays warm. Warm water doesn’t mix with colder, deeper water because temperature dramatically affects density. A steep boundary zone — called a thermocline — forms as a result of these density differences. All you need is a swimsuit to immerse yourself in this phenomenon of physics organizing nature.

You knew this already, mostly, because you know that ice floats. And this little detail facilitates not just cocktails and hockey but life as we know it. Unless, of course — spoiler alert for a novel that turned 60 last year — Ice Nine escapes, devastating the planet.

“That was really when it all connected,” says Dugan.  Continue reading…