NASA's IceBridge air mission has been monitoring ice in the polar regions for the tenth year. But on April 14, team member John Sontag noticed something he had never seen before. The scientist took this photo from the window of a research plane flying over the Beaufort Sea.
“We only saw these circles for a few minutes. I don't remember seeing this anywhere else,”Sontag said. It is difficult to determine what it is from the photograph, therefore all the explanations of scientists are based only on assumptions.
“The sea ice here is clearly young, thin, soft and easily influenced. This is especially noticeable in the waves near the middle amoeba,”said Don Perovich, a geophysicist at Dartmouth College.
Perovich notes that there may be a general movement of the new ice sheet from left to right, as evidenced by the jagged ice layer on the right side of the image. Such layering occurs when two thin ice floes collide. As a result of the collision, blocks of ice slide over each other like lightning or interlocking fingers.
“This is definitely an area of thin ice as there is jagged ice near the holes and the gray color indicates little snow cover. I don’t know what kind of dynamics can lead to semicircular shapes surrounding the holes, I’ve never seen anything like this before,”said Nathan Kurtz, IceBridge project employee.
According to one hypothesis, the holes were made by seals to get to the surface for air. “Surrounding shapes can be caused by waves of water hitting the snow and ice as the seals come to the surface. Or it could be some kind of drainage holes that sometimes form in the ice,”said Walt Meyer, a scientist at the US National Snow and Ice Data Center.
Sea ice specialist Chris Polyashenski of the Cold Region Engineering and Research Laboratory said he had seen this before. He agrees that the seal holes are one possible version. It is equally possible that they were formed by convection.
Glaciologist Chris Schumann of the University of Maryland believes that this is the work of warm springs or groundwater flowing from mountains inland. Another option is that the warmer water from the currents of the Beaufort or the Mackenzie River finds its way to the surface in the form of a polynya.
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