A strange, massive ice-free area, measuring approximately 31,000 square miles (approx. 80,290 square km) was recently spotted in Antarctica’s frozen sea ice. Scientists are still working to determine why the huge hole re-opened after almost 40 years, and whether climate change could have played a role.
Satellite images show a mysterious hole, nearly the size of the state of Maine or Ireland, has appeared once again in the middle of the frozen Weddell Sea, east of the Antarctic Peninsula. The finding was made last month by a group of researchers, including scientists from the University of Toronto and the Southern Ocean Carbon and Climate Observations and Modeling (SOCCOM) project, while observing the area with satellite technology.
“It looks like you just punched a hole in the ice,” Kent Moore, a professor at the University of Toronto Mississauga, told Motherboard.
The hole, known as a “polynya,” is a large ice-free area surrounded by sea ice. The Weddell Polynya was first discovered during the mid-1970s. The hole re-opened after it remained closed for around 40 years. A polynya was also formed last year, but it’s not as big as the one formed recently.
“In the depths of winter, for more than a month, we’ve had this area of open water,” said Moore, as National Geographic reported. “It’s just remarkable that this polynya went away for 40 years and then came back.”
Measured roughly 31,000 square miles at its largest, this polynya is the biggest hole ever observed in Antarctica’s Weddell Sea since the 1970s. What puzzled Moore is that this polynya is “deep in the ice pack,” and must have been formed through other unknown processes.
“This is hundreds of kilometers from the ice edge. If we didn’t have a satellite, we wouldn’t know it was there,” Moore explained.
The harsh winter in Antarctica can also make it hard for researchers to study them.
“For us this ice-free area is an important data point which we can use to validate our climate models,” says Dr. Torge Martin, meteorologist and climate modeler in the GEOMAR Research Division “Oceans Circulation and Climate Dynamics,” told MailOnline. “Its occurrence after several decades also confirms our previous calculations.”
Researchers are also trying to determine if the polynya is caused by climate change. And at this moment, Moore said it’s still “premature” to blame it on climate change. With more advanced observation tools compared to 40 years ago, researchers are hoping to find out what triggers the re-emergence of these holes.
“We’re still trying to figure out what’s going on,” said Moore.
However, they believe that the polynya will have a wider impact on the ocean’s temperature. “Once the sea ice melts back, you have this huge temperature contrast between the ocean and the atmosphere,” Moore said.
But, other than that, he added: “We don’t really understand the long-term impacts this polynya will have.”