Image Credit: AGU/Journal of Geophysical Research: Oceans/Kipfstuhl et al 1992
Scientists are closing in on an answer to the question of why some icebergs exhibit a distinctive green tinge.
Green icebergs have been an enduring enigma for years, but now according to a new study by researchers from the United States and Australia, these unusual chunks of ice may owe their anomalous coloration to iron oxides picked up from rock dust on the Antarctic mainland.
The idea stems from the discovery of large amounts of iron on East Antarctica's Amery Ice Shelf.
In an intriguing twist, researchers have also proposed that these green icebergs may be transporting iron out in to the ocean where it is acting as a source of nutrition for phytoplankton.
If this is true, then it could mean that green icebergs are actually very important to the food chain.
"It's like taking a package to the post office," said study lead author and glaciologist Stephen Warren from the University of Washington. "The iceberg can deliver this iron out into the ocean far away, and then melt and deliver it to the phytoplankton that can use it as a nutrient."
"We always thought green icebergs were just an exotic curiosity, but now we think they may actually be important."