Antarctica’s Green Icebergs Could Save the Ocean
Is it for St.Patrick's Day or are the icebergs in Antarctica have turned green? Scientists think they know why someone icebergs have indeed turned green.
It could be iron oxide dust that has been ground down by Antarctic glaciers. If this theory holds true, it means that the green icebergs can be more than just mere bizarre parts of the Antarctic ocean. They may, in fact, be more crucial to the ocean's survival.
Research head Stephen Warren, a glaciologist from the University of Washington says, "The iceberg can transport the iron deposits to the as far away as the ocean can go. When it melts, the phytoplankton can then use it as a form of nutrients."
The study about the mystery behind the green icebergs has been active for thirty years. He started to take samples from these green ice giants in 1988, from the Amery Ice Shelf in the East of Antarctica.
"When we first climbed the iceberg, it was not the distinct color that got us interested. rather, it was the clarity," Warren said. "The ice had no bubbles. It was pretty obvious then that it was not like any other iceberg in the area."
Most glacial ice comes in shades of brilliant blue and white. Typically, the ice has been identified based on their age. The bluer the ice is, the old it is. Its blue color comes from the compression of the accumulated layers of snow that pushes the bubbles out of the ice. This then reduces the scattering of the white light causing its bluish color.
The green iceberg was also bubble free, yet it surprisingly did not turn turquoise blue. Warren and his team soon found out that the green icebergs didn't come from glaciers. They came from marine ice found at the undersides of the floating ice shelves.
At first, the team thought that it was organic material that was causing the greenish color of the icebergs. However, in the Journal of Geophysical Research: Ocean, published January 10 of this year, Warren's team reported that marine ice contains more iron than the glacial ice above it. The iron deposits come from the rocks under the Antarctic Ice Sheet.
Iron oxides as it comes into contact with sea water. As a result, the iron particles take on the greenish hue, especially when light scatters through them. When the larger ice breaks off, the iron-rich parts of the ice take the brilliant color with them.
"The green icebergs were always thought of as a product of exotic curiosity," Warren said, "but now, we think that it may actually come with significant importance to ocean survival."