Every month, NASA Observatory’s Earth Matters challenges viewers to describe a mysterious satellite image, the answer to which is posted on the website a week later. However, even the experts could not come up with a definitive explanation for the April Puzzler, a photo featuring mysterious ice circles in the Arctic.
John Sonntag stumbled upon the three ice holes on April 14 while flying over the eastern Beaufort Sea, about 50 miles northwest of Canada’s Mackenzie River Delta. The mission scientist for NASA’s Operation IceBridge — which has been mapping the North and South poles’ land and sea ice for a decade — reported, “we saw these sorta-circular features only for a few minutes today. I don’t recall seeing this sort of thing elsewhere.”
NASA scientists say the circles are clearly in an area where the sea ice is young and still forming. “The ice is likely thin, soft, and mushy and somewhat pliable,” said Don Perovich, a sea ice geophysicist at Dartmouth College. “This can be seen in the wave-like features in front of the middle ‘amoeba.” IceBridge project scientist Nathan Kurtz concurs, saying, "It’s definitely an area of thin ice, as you can see finger rafting near the holes and the color is gray enough to indicate little snow cover.”
However, neither expert can explain how they were formed. Kurtz admits, “I’m not sure what kind of dynamics could lead to the semi-circle shaped features surrounding the holes. I have never seen anything like that before.”
Some researchers speculate they are breathing holes carved by Arctic seals. “The encircling features may be due to waves of water washing out over the snow and ice when the seals surface,” said Walt Meier, a scientist at the National Snow and Ice Data Center. “Or it could be a sort of drainage feature that results from when the hole is made in the ice.” Chris Shuman, a University of Maryland at Baltimore County glaciologist based at NASA’s Goddard Space Flight Center, theorizes the holes could also be the result of warmer water seeping through from the Beaufort currents or the nearby Mackenzie River.
Earth Matters contestants also came up with some ideas. Among the more plausible ones were that the icy circles are remnants of meteorites, or dried-up salt lakes. However, given that even Sontag, who has seen his share of bizarre frozen phenomenon, is stumped by the icy circles, their origins are likely to remain a mystery – at least for now!