Mystery of green icebergs may soon be solved

ScienceDaily | 3/4/2019 | Staff
maye (Posted by) Level 3
Click For Photo: https://www.sciencedaily.com/images/2019/03/190304121600_1_540x360.jpg

Pure ice is blue because ice absorbs more red light than blue light. Most icebergs appear white or blue when floating in seawater, but since the early 1900s explorers and sailors have reported seeing peculiar green icebergs around certain parts of Antarctica.

The green icebergs have been a curiosity to scientists for decades, but now glaciologists report in a new study that they suspect iron oxides in rock dust from Antarctica's mainland are turning some icebergs green. They formulated the new theory after Australian researchers discovered large amounts of iron in East Antarctica's Amery Ice Shelf.

Iron - Nutrient - Phytoplankton - Microscopic - Plants

Iron is a key nutrient for phytoplankton, microscopic plants that form the base of the marine food web. But iron is scarce in many areas of the ocean.

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 nearly all marine life.

Package - Post - Office - Iceberg - Iron

"It's like taking a package to the post office. 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," said Stephen Warren, a glaciologist at the University of Washington and lead author of the new study in the Journal of Geophysical Research: Oceans, a journal of the American Geophysical Union. "We always thought green icebergs were just an exotic curiosity, but now we think they may actually be important."

Warren started studying the phenomenon on an Australian expedition in 1988, when he took a core sample from a green iceberg near the Amery Ice Shelf on the coast of East Antarctica.

Ice - Emerald - Darker - Icebergs - Signal

Interestingly, the green ice he saw was a deep emerald hue much darker and clearer than that of normal icebergs -- a signal...
(Excerpt) Read more at: ScienceDaily
Wake Up To Breaking News!
Tagged:
Sign In or Register to comment.

Welcome to Long Room!

Where The World Finds Its News!