On April 17, as part of its monthly Earth Matters blog, NASA posted a satellite image of what appeared to be a sheet of ice with curious holes in them and asked everyone to guess what it is.
The photo is now revealed to be part of the eastern Beaufort Sea in the Arctic Ocean. It was taken as part of NASA's Operation IceBridge, which flies annually over both polar regions to map the region's land and sea ice.
What Are Those Circular Features?
Some parts of the image remain hard to explain, though — most especially the mysterious ice circles, which are something IceBridge mission scientist John Sonntag had never seen previously.
"We saw these sorta-circular features only for a few minutes today. I don't recall seeing this sort of thing elsewhere," Sonntag wrote during the mission.
NASA doesn't have a firm explanation of what the holes could be since it's hard to speculate with only a photograph or satellite image alone. The IceBridge mission is mainly an imaging operation and is ill-equipped to dabble in actual exploration, so needless to say that it isn't capable of going down the area and have experts examine it. So as such, here is NASA's best guess:
What NASA Thinks
Dartmouth College sea ice geophysicist Don Perovich thinks the sea ice in the picture is young.
"The ice is likely thin, soft, and mushy and somewhat pliable. This can be seen in the wave-like features in front of the middle 'amoeba.'" What's more, there might be a left-to-right motion of the new ice as indicated by the finger rafting — which occurs when two floes of thin ice collide — on the right side of the area.
"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," adds Nathan Kurtz, a project scientist from the IceBridge mission.
The circles remain a mystery, and NASA even says they're difficult to fully explain. One speculation suggests that they may have been not so much formed but gnawed out by seals to create pockets where they can habitually use to breathe. This seems more plausible when looking at similar photographs of breathing holes crafted by ring and harp seals.
"[I]t could be a sort of drainage feature that results from when the hole is made in the ice," according to National Snow and Ice Data Center scientist Walt Meier.
With only a photograph, the ice circles are an enigma that won't be explained without more in-depth missions.
Any budding glaciologists out there? What's your take on the ice circles? As always, if you have anything to share, feel free to sound them off in the comments section below!