This image of the Weddell Sea polynya was captured on Aug. 14, 2016, by NASA’s Aqua satellite. The giant ice hole has opened up again in 2017 for the second consecutive year after being closed for four decades. (Joshua Stevens/NASA Earth Observatory )
A massive hole about the dimensions of Lake Superior has opened up in Antarctica’s ice pack and scientists want to find out what’s behind the occurrence.
“You could imagine you’re in the center of the Antarctic winter and essentially there’s sea ice so far as you can view and then, suddenly, if you are walking along, you find this huge expanse of open water,” Kent Moore, an atmospheric physicist at the University of Toronto Mississauga, told since it happens host Carol Off.
The sea ice hole, known in the scientific community by the Russian term polynya, measured 80,000 square kilometers at its peak – a little bigger than New Brunswick and a little smaller than the island of Newfoundland.
In this satellite image of the Weddell Sea polynya taken on Sept. 21, 2017, blue represents the ice’s edge. (Submitted by Kent Moore/University of Toronto Mississauga )
Researchers first spotted it via satellite in the first ’70s, when it opened up for 3 consecutive winters. Then it vanished for 40 years, Moore said, and then reappear for three weeks in 2016.
“To our great surprise, it came back this year even larger than last year,” Moore said.
It’s been open for four months up to now in 2017 “and my guess is it will remain open up for the rest of winter,” Moore added.
‘Something’s going on, but we just don’t have enough data yet to really pin it down.’
– Kent Moore, University of Toronto Mississauga
Despite its long and mysterious history, nobody’s ever seen the substantial polynya close up because it’s in that remote region of Antarctica’s Weddell Sea.
“This one is deep in the ice pack. It’s a couple of hundred kilometers away from the coast,” Moore said.
That’s part of why is it so scientifically fascinating, he said. While polynyas aren’t uncommon in the Arctic and Antarctica, they often only form close to the coast.
The Weddell Sea polynya is shown as it appeared in passive microwave satellite imagery in the 1970s. (NASA)
The going theory, Moore said, is that ocean currents are lifting warmer waters from the ocean’s depths up to the top, where it’s melting the ice.
He said the Weddell Sea polynya would end up like an “oasis in the desert” for marine mammals such as orcas and seals, so it is probably teeming with life.
“I’m sure the wildlife know about it and are using it,” he said.
An elephant seal lounges in the South Shetland Islands, Antarctica, on March 6, 2016. The Weddell Sea polynya is like ‘an oasis’ for Antarctic sea mammals, says scientist Kent Moore. (Eitan Abramovich/AFP/Getty Images)
Scientists don’t know why it’s open now after being closed for four decades – or why it’s bigger and longer-lasting than ever before.
Melting sea ice is often related to climate change, but Moore said scientists draw those conclusions based on decades worth of data.
“So two of these events happening two years in a row really isn’t a long enough kind of trend for us to say it’s the result of global warming,” he said.
“But there is something which has happened down there, which has allowed this opening to occur 2 yrs in a row. So something’s going on, but we just don’t have enough data yet to really pin it down.”
The good news is the satellites are much more powerful than they were in the ’70s, so scientists can collect a lot more data these times.
And they intend to study the region for years to come.
“We expect to see changes in the ocean, but it might take many years to see just how large those changes are and what impact they might have.”