With the first bouts of cold and clear weather gripping parts of the UK and sending temperatures subzero, now is the perfect time to keep your eyes open for hair ice. We are lucky enough to live in a narrow band (between 45o and 55o north) in which you can find this bizarre natural phenomenon.
Resembling a cross between candy floss and cobwebs, in fact most like a hair transplant from The Doc in Back to the Future, this bizarre form can be found on a dead stick or branch in a broadleaved woodland near you. And this frozen delight is even more fascinating than meets the eye.
It was only discovered a mere 98 years ago in 1918, by Alfred Wegener, and it’s taken 87 years to figure out exactly what causes it. It’s a fungus!
The formation is unique. Microscopically thin strands, only 0.02mm in diameter, which undulate and curl out from dead wood to a length of up to 20cm. What makes them unique is their ability to maintain this structure for not only hours, but days. Normally in cold but humid environments, the conditions hair ice favours, these strands would start to recrystalise, and the intricacies of the hair ice would be lost, however this does not happen.
So what stops the recrystalisation? In 2015 scientists from Germany and Switzerland discovered that a fungus, Exidiopsis effusa, was the cause of this unique formation. Whilst the exact mechanism by which the ‘hairs’ are formed is still not known, we do know that the fungus is capable of producing a re-crystalising inhibitor, much like an antifreeze, which is able to maintain these super fine structures. The exact purpose of this amazing process is still unknown but it could be to do with spore dispersal. If nothing else, it’s a beautiful treat to discover whilst out on a cold winter walk.
Where and when to find:
Any broad-leaved woodland in the UK following prolonged cold weather (temperatures just below 0oC). Hair Ice particularly favours more humid areas too and is generally found on deadwood on the forest floor but may also be found on hanging dead wood and in piled brash on woodland edges. If you are lucky enough to find any hair ice, please share your images on the BiOME Facebook page.