A few ice sheets look white. Others look blue. Yet, maybe the most valuable of all show up emerald green.
In the nick of time for Saint Patrick’s Day, researchers figure they may know why some Antarctic ice shelves are green.
The reason could be iron oxide dust ground somewhere near ice sheets on the Antarctic territory. If the hypothesis holds, it implies that the green icebergs are something other than an eccentricity of the Southern Ocean. Truth be told, they may be pivotal to the movement of ocean supplements.
“It resembles taking a bundle to the mail station,” study head Stephen Warren, a glaciologist at the University of Washington, said in an announcement. “The ice shelf can deliver this iron out into the sea, and afterward dissolve and convey it to the phytoplankton that can make use of it as a supplement.”
All about the Green Icebergs
Warren has been considering the mystery of the green icy masses for over 30 years. He initially took samples from one of these emerald green icebergs in 1988, close to the Amery Ice Shelf of East Antarctica.
“When we climbed up on that icy mass, the most astounding thing was not the color yet rather the lucidity,” Warren said. “The iceberg had no bubbles. Clearly, it was not the ice from the regular glacier.”
Most glacial ice can be found in shades of white and splendid blue. The theory is that the bluer the ice, the older it is.
The green ice was likewise without a bubble, but it looked green rather than blue. Warren and his group before long discovered that the green ice came not from glaciers, however, from marine ice. That is the ice from the undersides of coasting ice sheets.
At first, the group believed that organic material stuck in the marine ice was making the ice appear green in color. Since dissolved carbon looks yellow in color, they contemplated, the addition of organic material may merge with the typical blue of the ice to make green. In any case, studies demonstrated that the green marine ice didn’t have a higher-than-normal amount of natural polluting agents.
Presently, another research finds that a different kind of polluting agent might be the underlying cause of the green ice. As indicated by a new report published Jan. 10 in the scientific Journal of Geophysical Research: Ocean, Warren, and his associates state that the marine ice found at the bottom of the Amery Ice Shelf has 500 times more iron than the frosty ice above.
This iron originates from the rocks under the Antarctic Ice Sheet. And as the glaciers move over the rocks, these rocks are ground into a fine powder. The ice-bound iron oxidizes as it touches the seawater. The subsequent iron oxide particles appear green when light disperses through them.
At the point when ice shelves sever the bigger ice shelf, they carry along this iron-rich ice with them.
The scientists will need to test more ice sheets and synthetically examine their minerals to make certain their hypothesis is right. In any case, if they are correct, the green ice shelves may be a vital transport for iron to distant in the Southern Ocean. Iron is a key supplement for the development of phytoplankton, yet it’s hard to find in the southern oceans. The icy masses may almost certainly carry the supplement a long way from shore, making possible the life to bloom where it generally wouldn’t.
“We generally thought green ice shelves were only a striking curiosity,” Warren stated, “however at this point we figure they may really be important.”