NASA's monthly Puzzler is meant to puzzle readers; this one has the experts puzzled as well.
Every month the team at the NASA Earth Observatory website presents a Puzzler – a curious satellite or aerial image of Earth, of which readers are asked to offer up a guess or explanation.
Well, April's puzzler (pictured above) was so puzzling that even the NASA researchers were left scratching their heads. They explain:
NASA’s Operation IceBridge – the airborne mission flown annually over both polar regions – is now in its tenth year making flights over the Arctic. That’s a lot of flight hours spent mapping the region’s land ice and sea ice. But on April 14, 2018, IceBridge mission scientist John Sonntag spotted something he had never seen before.
Sonntag took the shot above from his research plane while flying over the eastern Beaufort Sea.
“We saw these sorta-circular features only for a few minutes today,” Sonntag wrote from the field. “I don’t recall seeing this sort of thing elsewhere.”
And nobody else seemed to know what they were either. So the Earth Observatory team set out to get some answers. What did the uncover? A lot of speculation.
Here are some of the reples they received.
Don Perovich, a sea ice geophysicist at Dartmouth College, remarked that the sea ice is young and growing. “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.’” The finger rafting might be evidence of a general left to right motion of the new ice as two floes collide.
“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,” says IceBridge project scientist Nathan Kurtz.
As for the holes and surrounds? “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.”
However, if you perhaps suspected something mammalian in nature, you could be getting warmer. The researchers says that the holes may have been carved out by seals to create pop-up breathing holes.
“The encircling features may be due to waves of water washing out over the snow and ice when the seals surface,” says 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.”
But then again, maybe not. Chris Polashenski, a sea ice scientist at the Cold Regions Research and Engineering Laboratory, says he's seen this before, and doesn't know for sure what they are. Yes, they could be breathing holes, but the could also be caused by convection.
Meanwhile, “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,” says Chris Shuman, a University of Maryland at Baltimore County glaciologist based at NASA’s Goddard Space Flight Center. “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.”
So just when you start to think there are no good mysteries left in the natural world, NASA comes along and tosses some puzzling ice holes into the mix. I don't know about you, but I'm going with the feel-good seals. We'll just have to wait for the next flyover and hope Sonntag gets a shot of an ice hole complete with a pop-up seal catching some air.