Saturday, 4 January 2014

Ice phenomenon follow-up

Since I posted the pics of the "Angel Hair" ice in Kielder on Boxing day I've researched some more and appear to have found some definitive explanations.  There's a professor at Illinois State University who has become obsessed with ice formations and by following links from his blog I found a German article, fortunately with English summary sections.  The conclusions seem to be:

*  This type of ice is formally called Haareis or Hair Ice
*  It is caused by the presence of winter-active fungi in decaying hardwood
*  It only forms where the bark has been lost from dead twigs/branches
*  CO2 released by the fungi forces water, plus some organic material, out through small channels in the dead wood
*  The organic material acts as a freezing catalyst for rapid ice formation near the exit points
*  Thus happens at temperatures only slightly below zero
*  Experimentally, if the fungi are killed the ice formation no longer happens

Hair Ice is reported from various places in Europe and also from the Pacific North West of the USA


  1. Excellent Richard, I must keep a look out for it during the next cold spell...

  2. Fascinating! I would not thought that there would have been an organic component in such cold conditions