Crew members of the British ship John Biscoe, while traveling through the South Orkney
Islands on March 22, 1971, spied dozens of icebergs striped and banded in black and
green. One iceberg had more than twenty vertical stripes scattered through its 100-yard
length. Other bergs had broad bands with spots of black and white.
This was only one of the many spottings of colored icebergs made by seamen. No clear
explanations have yet been made for this phenomenon. Some dark bands may be caused by
the layers of sediment embedded in the original glacier. Others point to minerals,
sediment, and algae as the reason. Upon closer inspection, however, the dark ice is
very clear with no evidence of rocky debris inside. The floating blue and green ships
of ice will remain a mystery.