A Fish Blog.com is reporting an really interesting chance encounter by a Norwegian research vessel. It appears they’ve encountered an interesting “marble iceberg“.
The iceberg seemed to be marbled. The iceberg had dark stripes or layers in between. Is it made by ice crystals with different density, or ice with different density of salt? Are the dark layers made of ice with ash; proof of volcanic activity thousand of years ago? Maybe some readers know the answer?
The origin of the amazing iceberg was being pondered by the author and commenters until Steve Warren cleared it up for everyone:
This is an iceberg containing stripes of “marine ice”. The stripes originated from crevasses in the iceberg (probably bottom-crevasses on an ice shelf) that filled with seawater which then froze. Most of the iceberg consists of bubbly bright ice which was formed by compression of snow; that’s why it has so many bubbles that make it bright; the dark stripes were formed by freezing of liquid water. We saw such striped icebergs in October 1996 near Davis Station. See my 1993 paper on green icebergs, which you can find at http://www.atmos.washington.edu/~sgw/PAPERS/1993_grenth.pdf; the stripes are mentioned briefly at the top of page 6927. We cite Wordie and Kemp (1933) who may have been the first to publish a report of striped icebergs. [Wordie had been a member of Shackleton’s Endurance expedition.]