Floating about somewhere in the Antarctic are icebergs with a curious shade of green. Apart from looking pretty in a photo, these green icebergs may actually serve a crucial role in maintaining the ecosystem of the oceans.
Scientists have had their pet theories about green ice, but the study from glaciologist Stephen Warren offers a new theory. Iron oxides, the same compounds that create brown and red rust, are turning icebergs emerald.
If the theory holds, it might do more than solve a riddle. The ice-trapped iron could represent a crucial missing link in the food chain. The icebergs would get the iron during their formation, found in Antarctica's rock dust.
Then the icebergs carry that iron dust out to the ocean, where they could feed phytoplankton, the microscopic organisms that provide nourishment for types of whales, jellyfish, krill, zooplankton, and a variety of other underwater species.
(Image credit: AGU/Journal of Geophysical Research: Oceans/Kipfstuhl et al 1992)