Tiny bits of iron may explain why some icebergs are green
The emerald ice may help shuttle an essential nutrient around marine food webs
By Jeremy Rehm
Scientists may have finally figured out why some icebergs are green. Iron oxides could create the emerald hue.
Icebergs often appear mostly white because light bounces off air bubbles trapped inside the ice. But pure ice — ice without air bubbles that often forms on a berg’s underside — appears blue because it absorbs longer light wavelengths (warm colors like red and orange) and reflects shorter ones (the cooler colors).
Since the 1930s, though, mysterious capsized icebergs with green undersides, nicknamed “jade bergs,” have been spotted around Antarctica.