Categories: world

The Mystery of Strange, Emerald Green Icebergs in Antarctica Might Have Finally Been Solved

Some icebergs look white. Others look blue. Ever since the 1900s, sailors and explorers have occasionally seen these strange green icebergs, or jade mountains, floating around in the gray Antarctic landscape. Their curious color has been puzzling scientists for decades; Now, we might have a plausible explanation of this phenomenon. In a paper, a team of glaciologists propose these icebergs are turning green because they contain iron oxides carried from Antarctica's mainland. If the hunch is correct, it means that jade burgers are essentially like frozen waiters, serving a crucial nutrient that supports nearly all marine life. "It's like taking a package to the post office. then melt and deliver it to the phytoplankton that can use it as a nutrient, "says the paper's lead author, glaciologist Stephen Warren from the University of Washington. " We always thought green icebergs were just an exotic curiosity, but now we think they may actually be important. " Warren started studying this phenomenon way back in 1 988, and at first, he was struck less by the color of these slabs of ice, and more by their density. Unlike normal icebergs, which are built from packed down snow, these green ones seemed to be void of any air pockets. "This ice had no bubbles," Warren explains. "It was obvious that it was not ordinary glacier ice." Analysis several green icebergs, sampled in the 1980s, Warren and his colleagues quickly realized these frozen structures did not break off a glacier like most icebergs do.…

Some icebergs look white. Others look blue.

Ever since the 1900s, sailors and explorers have occasionally seen these strange green icebergs, or jade mountains, floating around in the gray Antarctic landscape.

Their curious color has been puzzling scientists for decades; Now, we might have a plausible explanation of this phenomenon.

In a paper, a team of glaciologists propose these icebergs are turning green because they contain iron oxides carried from Antarctica’s mainland.

If the hunch is correct, it means that jade burgers are essentially like frozen waiters, serving a crucial nutrient that supports nearly all marine life.

“It’s like taking a package to the post office. then melt and deliver it to the phytoplankton that can use it as a nutrient, “says the paper’s lead author, glaciologist Stephen Warren from the University of Washington.

” We always thought green icebergs were just an exotic curiosity, but now we think they may actually be important. “

Warren started studying this phenomenon way back in 1

988, and at first, he was struck less by the color of these slabs of ice, and more by their density. Unlike normal icebergs, which are built from packed down snow, these green ones seemed to be void of any air pockets.

“This ice had no bubbles,” Warren explains. “It was obvious that it was not ordinary glacier ice.”

Analysis several green icebergs, sampled in the 1980s, Warren and his colleagues quickly realized these frozen structures did not break off a glacier like most icebergs do.

Instead the ice ocean, the frozen ocean water that clings to the underside of an Antarctic ice shelf.

Hence, their first thought was that the green color came from dissolved marine plants and animals, long ago and still floating in the water. This organic matter would be yellow in color, and if it somehow got trapped in the blue ice, it could possibly turn the whole thing green.

But when the researchers measured for organic matter, they found little difference between green ice and blue ice. Something else must be to play, but what?

The question nagged Warren for decades; a few years ago, he finally got a big lead. In 2016, a team of oceanographers led by Laura Herraiz-Borreguero from the University of Copenhagen tested an ice core taken from the Amery Ice Shelf back in 1968. At the very bottom, they found marine ice with nearly 500 times more than the glacial ice above.

Iron oxides tend to have a rusty, earthy hue to them, and they are found in rocks from Antarctica’s mainland. In fact, as glaciers flow over bedrock, they often grind these rocks to fine powder which can then make its way into the sea.

Warren and colleagues now think that this iron oxide dust is getting trapped under the ice shelf and incorporated into the marine ice. They hypothesize this is causing the stunning emerald colors, and propose a series of tests on short cores or icebergs to “confirm or dispute that hypothesis,” according to their paper.

Iron is a key nutrient for the animals that make up the base of the marine food web, like phytoplankton and microscopic plants. Nevertheless, this crucial nutrient is scarce in many parts of the ocean, and jade mountains may be one of the only sources. Which makes these jewel-colored slabs of ice really precious.

This study has been published in Journal of Geophysical Research: Oceans .

Share
Published by
Faela