Scientists are equally stunned and confused at the appearance of a massive hole in the middle of Antarctica that’s estimated to be about the size of Lake Superior, or the state of Maine, as it clocks in at 31,000 square miles. While those working on figuring out the phenomenon aren’t sure what causes it to occur, this structure actually has a name already: polynya.
A polynya is an area of open water that is surrounded by sea ice, and they can occur anywhere that floating ice is a natural occurrence. In fact, this isn’t the first polynya that has popped up in the same area, though it’s one of the most recent that scientists are better able to study because of modern technology.
The gigantic, mysterious hole “is quite remarkable,” atmospheric physicist Kent Moore told Motherboard. “It looks like you just punched a hole in the ice.”
While the origins and causation of polynyas are unknown and already has scientists working overtime to look at the incoming data, what makes this hole even more mysterious is the pattern at which it shows up. Back in the 1970s, a much larger polynya showed up in the same area, in Antarctica’s Weddell Sea, but scientists at the time weren’t able to study it much without the proper technology.
The polynya eventually went away and was unseen for four decades until last year, when it remarkably showed up again. It lasted several weeks and then went away again, but now it surfaced around September 9th of this year and scientists aren’t sure at all about the pattern, or lack thereof, that it seems to be following. What’s more is that the polynya is surprisingly far away from the edge of the sea ice, which hasn’t been observed before.
“This is hundreds of kilometres from the ice edge. If we didn’t have a satellite, we wouldn’t know it was there,” said Moore, who added that the hole was “deep in the ice pack.”
Despite everything that scientists don’t know about the polynya, there are some theories about what it will result in and what could cause it to last longer than the one that opened last year. Moore believes that the polynya could alter the existing ocean and water temperature through what’s called convection. Convection is when denser, colder water sinks to the bottom of the ocean while the warm water rushes to the surface.
“The Southern Ocean is strongly stratified. A very cold but relatively fresh water layer covers a much warmer and saltier water mass, thus acting as an insulating layer,” Dr. Mojib Latif explained to Phys.org.
This current composition could drastically change due to the size of the polynya and the increased exposure of the ocean to the warmer atmosphere, thereby driving convection. While that is one major result that some scientists can see, it works the opposite way, too; the warmer oceans could cause the polynya to stay for longer or to continue opening up in the coming years.
Moore has said that pointing to climate change as the cause of this phenomena is “premature,” but that it’s impact on the rest of the ocean cannot be denied. As it stands, on-site measurements and studies require massive amounts of effort that haven’t come through yet, but for the time being the scientists are relying on observations from satellites and deep-sea robots. The data coming from these tools are comprehensive and much more advanced than when the polynya opened up decades ago. Moore and other collaborators are compiling this data into a not-yet-published study that may take years to put together and understand.