Can you identify the holes in the sea ice pictured above? If so, let NASA know. They recently posted the image, snapped over the Beaufort Sea, as the April 2018 Puzzler on their “Earth Matters” blog. They aren’t quite sure what caused them, although they ventured a few ideas, including heat, thin ice, and even rogue seals.

The shadow of NASA's P-3 plane supporting Operation IceBridge

NASA Operation IceBridge mission scientist John Sonntag captured the baffling image from a P-3 research plane soaring over the eastern Beaufort Sea. Sonntag had never seen holes like this before; writing from the field, he said, “We saw these sorta-circular features only for a few minutes today. I don’t recall seeing this sort of thing elsewhere.”

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Before the agency revealed that the photo was from the Arctic, Internet users offered plenty of guesses as to its location – from fires in Oklahoma to the surface of Mars. User Scott Stensland came close when he guessed the circles were open water holes in ice created by ocean mammals, such as seals. Indeed, that’s similar to one answer NASA has come up with: the holes bear a resemblance to photographs of breathing holes harp seals and ring seals have created. National Snow and Ice Data Center scientist Walt Meier told NASA, “The encircling features may be due to waves of water washing out over the snow and ice when the seals surface. Or it could be a sort of drainage feature that results from when the hole is made in the ice.”

Cold Regions Research and Engineering Laboratory sea ice scientist Chris Polashenski told NASA he’d glimpsed features like these holes in the past. Seals could offer one answer; another is convection. University of Maryland at Baltimore County glaciologist Chris Shuman, who’s based at the agency’s Goddard Space Flight Center, told NASA, “This is in pretty shallow water generally, so there is every chance this is just ‘warm springs’ or seeps of ground water flowing from the mountains inland that make their presence known in this particular area. The other possibility is that warmer water from Beaufort currents or out of the Mackenzie River is finding its way to the surface due to interacting with the bathymetry, just the way some polynyas form.”

+ NASA Earth Observatory

+ Curious Circles in Arctic Sea Ice

Images via John Sonntag/Operation IceBridge/NASA and NASA/Joe MacGregor