Since the 1900s, explorers around the globe reported of witnessing an unusual phenomenon in several parts of Antarctica: icebergs with a hint of emerald color rather than usual white or blue. These strange icebergs have baffled scientists for more than a decade. From “why do they emit the green color?” to “is this a sign of the existence of Aliens on the Earth?”, numerous theories saw the light of day. However, now we know the truth. After a decade of research, scientists are now sure that the real reason behind the unique green color and the answer reveals that they are the most vital components of the ocean.
As it turns out, iron oxide is responsible for its green hue. As per the researchers at the University of Washington in the U.S., the blue color of icebergs is because of the ability of pure ice to absorb red light more than blue light. Thus, most of the icebergs appear blue or white. This made the existence of green icebergs an unsolved mystery for over a decade. Now, glaciologists have reported that the iron oxide plays the part in turning the icebergs green. As per the study, the iron oxides present in the rock dust from Antarctica’s mainland are responsible for turning several icebergs green. Additionally, they developed this concept when Australian researchers detected significant quantities of iron present in East Antarctica’s Amery Ice Shelf.
As per the scientists, iron is a vital nutrient for phytoplankton, very small plants that are found at the bottom of the marine food web. However, iron has become rare in several areas of the ocean. If this theory is right, this means that these green icebergs are the source of iron for phytoplankton and they are transporting the iron from Antarctica’s mainland to the sea to support almost all marine life.
Stephen Warren, a glaciologist at the University of Washington as well as the main author of the study, stated, “These green icebergs acts as a delivery medium to take a package to post office. They transport iron into the oceans and melt to deliver it to phytoplankton. We have been thinking that these the green icebergs are just one of the wonders of the planet Earth but now we consider that they are of significant importance.”
In search of the answer, when scientists climbed one of such green icebergs, apart from their unique color, they were extremely clear. They had no bubbles and it was not just regular glacier ice. When the layers of snow built up and solidify as the time passes, typical glacier ice develops and forms air pockets from where light reflects. However, marine ice is darker and clearer than glacier ice as it does not have any air pockets. Thus, when researchers found these green icebergs developed from marine ice instead of glacier ice, they alleged that the impurity in the ocean must be the reason in turning the icebergs green.
Antarctica has many mysteries hidden beneath it and scientists are eager to solve them one by one. Recently, scientists solved the mystery of Blood Fall, the 100-foot stream of water that runs down the side of a glacier of color blood red. Previously, it was believed that the reason behind the redness of water is the presence of algae, which was never proved. Several people also claimed that there must be a secret, relic, underground lake. However, scientists recently proved that the red coloring is due to oxidized iron in brine saltwater. The process is similar to the dark red color that appears after rust. When iron bearing saltwater encounters oxygen, the iron oxide forms, turning the water red. Such discoveries prove that there are various scientific reasons behind the unsolved mysteries of Antarctic waters and we just have to dig little deeper and gather more facts to solve them.