In 2011, Malcolm Davidson of the European Space Agency was flying over the Nares Strait, a channel between Greenland and Canada’s northernmost island, Ellesmere, to check the accuracy of satellite observations. He saw that broad, low-lying pieces of sea ice had jammed together to block the strait. Looking down from above, this jigsaw of ice floes looked like an arch curving across the channel. North of the arch, sea ice was backed up into the frozen Arctic Ocean. South of it, the sea was mostly free of ice.
Such “ice arches” typically form at the northern and southern ends of the strait in winter. When they break up in spring or summer, they allow sea ice to flush out of the Arctic “like a toilet,” says Davidson. In the past two decades, the arches , and in three of the years they . As a result, an estimated of ice on average now flows through the strait to melt every year.
But each ice arch is only about 20 to 50 kilometres wide. Somehow strengthening one could preserve more sea ice and reflect more sunlight away from Earth, thought Davidson.
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“If the ice bridge… could be supported in some way, then there would be less ice loss in the summer, leading to an increase in albedo in the Arctic Ocean and a cooling effect,” he says.
Development of the idea stalled after Davidson’s collaborator Marc Cornelissen, an expedition leader who wanted to investigate infilling the strait to make it shallower, died during unseasonably warm weather in April 2015.
But now, there is new interest in the idea. Last year, researchers got a to try to thicken Arctic sea ice by drilling holes and pumping seawater on top of it to freeze. Inspired by Davidson, grant recipient Arctic Reflections, a startup in the Netherlands, is investigating whether this could be applied to strengthen the ice arches.
Thickening just tens of square kilometres of ice in the Nares Strait could keep tens of thousands of square kilometres of sea ice pent up in the Arctic Ocean, according to Arctic Reflections CEO . This could potentially “stabilise” sea ice extent, which is shrinking by almost on average per year, and buy more time to cut greenhouse gas emissions. As it stands, ice could disappear from the Arctic Ocean in summertime .
“With a relatively small intervention we could have outsized impacts on Arctic sea ice,” Ypma says. “It could help postpone that blue-ocean event.”
In a field trial in Norway’s Svalbard archipelago in 2024, Arctic Reflections increased the thickness of sea ice from 90 to 116 centimetres by flooding the snow on top of the ice with a pump for making ice roads, although it’s not clear that this thickened ice can last longer in the summer.
Besides flooding the arches, the researchers could also spray them. Oil companies in the 1980s, creating “ice islands” strong enough to support drilling rigs in as little as three weeks. The “holy grail” would be to develop a wheeled drone that could drill, pump and spray autonomously, says Ypma.
Arctic Reflections has continued its trials in Qikiqtarjuaq, an Inuit village in Canada’s Arctic archipelago. Next winter it will test how much weaker artificially thickened ice is than natural ice when placed under the kind of high pressures seen in an ice arch.
Meanwhile, and at University College London are trying to model the disintegration of Nares Strait ice arches. Summer temperatures can melt and fracture the ice arches, but strong winds and ocean currents sometimes break up the ice much earlier, like a plunger unplugging a toilet. If the model can replicate these processes, it could project whether targeted ice thickening could prolong the ice arches, possibly paving the way for field trials in several years.
Farsi hopes the technique could be “like adding some cement between the pieces of the arch so that it does not collapse”.
But polar scientists are sceptical that numerous pumping platforms could operate for months each winter on shifting sea ice in one of the most remote parts of the Arctic. And at the University of Toronto, who’s authored more than a dozen studies about the Nares Strait, says the bulk of ice loss there occurs in the years when ice arches don’t form, which is expected to happen more often.
“Even if you have infinite resources… if the arches aren’t forming, then there’s nothing to thicken, so you’re losing the ice anyway,” he says. “It just doesn’t seem like it makes sense.”
Thickening the landfast ice on either shore could potentially help form an ice arch, says Ypma, but that isn’t the current focus of the research.
Much of the ice that might be pent up in the Arctic Ocean would “simply melt in place during the summer due to the warmer climate” anyway, according to at the University of Manitoba, Canada.
“Maybe you slow [ice loss] down for a while. It’s just a band-aid, though,” says at the University of Colorado Boulder. “Your energy would be much better put [toward] alternative energy sources.”
But it is still worth trying to prolong the ice, argues at the University of Manchester, UK, who is an advisor to Arctic Reflections. Directly north of the Nares Strait is the “last ice area” where summertime sea ice is expected to persist the longest, which could serve as a climate refugium for animals like polar bears, seals and walruses.
Directly south is the North Water Polynya, open water that is the in the Arctic and a crucial hunting ground for the Inuit. Ice arches help keep ice out of the polynya in winter.
“To go, ‘well, it’s inevitable what’s going to happen’… that’s not the world I want to live in,” says Evatt.
