The nearly 100-year-old mystery of how delicate strands of glistening ice known as “hair ice” burst through rotting tree limbs has been solved by a team of researchers in Germany and Switzerland.
When the conditions are just right — such as humid winter nights with temperatures below 32 degrees Fahrenheit — hair ice forms on the rotting branches of certain trees, but up until now, the exact cause of their intriguing formation has managed to elude scientists.
According to the researchers behind the recent discovery, the growth of the fascinating ice hairs is attributed to a fungus, Exidiopsis effusa, which facilitates its growth.
Christian Matzler from the Institute of Applied Physics at the University of Bern in Switzerland, a member of the team behind the recent discovery, was quoted by the Daily Mail as having said that the researchers started investigating the phenomenon after a chance encounter with hair ice in the forest instilled a sense of “beauty” and “curiosity,” eventually leading Matzler to team up with chemist Diana Hofmann and biologist Gisela Preuß.
When we saw hair ice for the first time on a forest walk, we were surprised by its beauty (…) Sparked by curiosity, we started investigating this phenomenon, at first using simple tests, such as letting hair ice melt in our hands until it melted completely.
The team conducted a series of experiments in order to determine the properties of hair ice and in the process, managed to validate the 1918 hypothesis of Alfred Wegener, as Wegener suspected that the ice formation was linked to the presence of fungus.
According to the researchers, the driving mechanism of the phenomenon is ice segregation which, when the fungus is present, causes the ice to form like hair — study co-author Christian Matzler explained in a statement:
The same amount of ice is produced on wood with or without fungal activity, but without this activity, the ice forms a crustlike structure
Analysis of the hair ice itself showed that the melted ice contained fragments of metabolic products of the fungal activity: the complex organic compounds tannin and lignin.
