A vocabulary of landscape — a landscape of words
1469 entries
glacier mouse
A glacier mouse is a ball of moss that lives loose on the surface of a glacier, growing over a small stone or a bit of grit and rolling as it goes, so that it is green on every side. The ball insulates the ice beneath it, which keeps it from melting into a pit and being stranded. Inside are springtails, tardigrades, and nematodes living in the damp, which makes each ball a small self-contained habitat traveling across a surface that has nothing else living on it.
Etymology
The English name translates the Icelandic jökla-mýs, glacier mice, given by a researcher in the 1950s for the obvious reason, which is that a field of them looks like a scattering of small animals on the ice. It is one of a handful of glaciological terms English took directly from Icelandic, alongside jökulhlaup for a glacial outburst flood.
Notes
The strangest thing about them was found by tracking individual balls with tags. They move several inches a day, they do not roll downhill as you would expect, and they move together, changing direction as a group over months, in a way nobody has explained. A single ball can be six years old or more.