However, since the early 1900s explorers have reported the perplexing existence of green icebergs around Antarctica.
The odd green icebergs have always baffled scientists, but now a new study suggests iron oxides in rock dust from Antarctica's mainland are turning some icebergs green. Warren took a core sample from a glacier near East Antarctica's Amery Ice Shelf and compared it to other green ice samples from Australian expeditions in the 1980s.
Iron is a key nutrient for phytoplankton, microscopic vegetation that kind the bottom of the marine meals internet.
If experiments prove the new theory right, it would mean green icebergs are ferrying precious iron from Antarctica's mainland to the open sea when they break off, providing this key nutrient to the organisms that support almost all marine life.More news: Valve removes Rape Day game from Steam in response to outcry
"It's like taking a package to the post office", stated Warren.
Professor Stephen Warren, the study's lead author, is a glaciologist at the University of Washington who has been studying green icebergs since 1988. "We always thought green icebergs were just an exotic curiosity, but now we think they may actually be important".
"What is most incredible is not their color but rather their clarity, because they have no bubbles", said Warren to IFLScience. Much of it covered by snow, at the far left is bubbly blue-white glacier ice. "This ice had no bubbles". The marine-ice part of such icebergs is clear, dark, and often green in color, because red or yellow particles from the seawater, in combination with the blue of ice, can shift the color to green.
Icebergs are massive chunks of ice that break off of glaciers and ice shelves and run into the ocean. However, the bottom layer of the iceberg, which is submerged in water, is made out of marine ice, which doesn't have any air pockets to reflect light.
Researchers on top of a large composite iceberg in October 1996.More news: Zinedine Zidane Rejects Offer To Return To Real Madrid
Glacier ice, originating from snowfall, flows off the Antarctic Ice Sheet to float on the ocean as ice shelves.
This frozen seawater is also known as marine ice, and it can contain organic and inorganic particles that can add some shades of green to the ice that usually comes in shades of white and blue as you know. "Subsequent measurements of low DOC values in green icebergs, together with the recent finding of large concentrations of iron in marine ice from the Amery Ice Shelf, suggest that the color of green icebergs is caused more by iron‐oxide minerals than by DOC".
Warren proposed that it was the iron oxide, which is typically found in soil and rocks, that is turning marine ice green.
Ice in seas varies in colour because of the "abundance of foreign constituents", particularly iron oxide minerals, in seawater. Warren believes the answer may lie in "glacial flour" - the powder formed from glaciers grinding over bedrock, eroding particles from the surface. This hunch will have to be confirmed by experiments that sample icebergs of different colors for their iron content and light-reflecting properties.More news: Thai court dissolves Shinawatra-linked party over botched princess bid