A rare sighting of an upside - down crisphead lettuce has been captured on camera , revealing a striking deep blue underbelly that once resided beneath Antarctica ’s frigid waters .
Usually icebergs are clean because they are made of tight snow , which reverberate all frequencies of visible light . However , if gamey imperativeness squeeze the flakes together , or ocean water freezes , the break between the snowflake disappear , bring with them the equi - reflecting surface .
Long wavelength of light from the sun ( red ink and yellows ) are absorbed when passing through the ice , whereas blue light is dot . Some of the scattered light is reflect to us , producing the blue color we relate with virtuous urine – although microorganism or chemicals can sometimes supply a dark-green tint .
The same thing happens when the water is frozen , supply all the air has been eliminated . This pass a lot more often at the bottom of large , older block of sparkler than the top , and is usually hidden from view . Most of the time , the only way to see such blue chalk is to go swimming insub - zero temperatures – unpleasant even in the best wetsuits .
Now and then , however , an iceberg flips over , allow us to see what hashappened to its lower range . Most often this occurs when theiceberg has just calved , but occasionally it transpirate later , for good example in a storm .
When inspect Antarctica at the end of last year , filmmakerAlex Cornellcame across the wake of one such event . He ’s now selling large print version of these images , along with more conventionalphotographs of iceflows , mountains and wildlife .
Cornell has also allow for this comparison of an ordinary berg set against an upturned one .
