The last completely intact ice shelf in the Canadian Arctic collapsed, losing more than 40 percent of its area in just two days in late July, researchers said Thursday.
Milne’s ice shelf is on the border of Elsmere Island, in the sparsely populated northern Canadian territory of Nunavut.
“Above normal air temperatures, sea winds and open water in front of the ice shelf are part of the recipe for ice shelf breakup,” the Canadian Ice Service said on Twitter when it announced the loss on Sunday.
“Whole cities are that big. These are big pieces of ice, “said Luca Copeland, a glaciologist at the University of Ottawa who was part of a research team studying the ice shelf of Milne.
The shelf area has shrunk by about 80 square kilometers. By comparison, the island of Manhattan in New York covers approximately 60 square kilometers.
“It was the largest ice shelf left intact and crumbled at its base,”
The Arctic has been warming at twice the global rate for the past 30 years, due to a process known as Arctic strengthening. But this year the temperatures in the polar region were intense. The polar sea ice reached its lowest level in July in 40 years. The record heat and fires have scorched Siberian Russia.
The summer in the Canadian Arctic this year in particular was 5 degrees Celsius above the 30-year average, Copeland said.
This has threatened smaller ice caps, which can melt quickly because they do not have most of the glaciers to stay cold. As the glacier disappears, more bases are exposed, which then heat up and speed up the melting process.
“Very small, we lose them drastically,” he said, citing reviews of satellite imagery researchers. “You feel like you’re on a sinking island, chasing these functions, and these are big functions. It’s not like a tiny piece of ice that you find in your garden. “
The collapse of the ice shelf on Ellesmere Island also meant the loss of the last known epishelf lake in the northern hemisphere, a geographical feature in which the body of freshwater is stuck on the ice shelf and floats on top of ocean water.
A research camp including instruments for measuring the flow of water through the ice shelf was lost when the shelf collapsed. “Luckily, we weren’t on the ice shelf when that happened,” Derek Mueller, a researcher at Carleton University in Ottawa, said in a blog post on Aug. 2.
Ellesmere also lost his two ice caps St. Patrick Bay this summer.
“We saw them walking like someone with terminal cancer. It was only a matter of time, “said Marc Sersee, director of the National Snow and Ice Data Center (NSIDC) in Boulder, Colorado.
Serreze and other NSIDC scientists have published a study for 2017, which predicts that ice caps are likely to disappear within five years. Ice caps are believed to have formed several centuries ago.
The disappearance was confirmed last month when NASA satellite imagery in the region revealed a complete lack of snow and ice, said Serrese, who studied hats as a graduate student on his first trip to the Arctic years ago. At the time, he said, hats looked like fixed parts of geography.
“When I was there in the ’80s, I knew every square inch of those ice hats,” he said. – You have the memories. It’s like your first girlfriend. “
Meanwhile, two other Elezmer ice caps – called Murray and Simmons – are also shrinking and are likely to disappear in 10 years, Serrese said.