Over the weekend, the Canadian Arctic’s last intact ice shelf collapsed, turning into two ice islands. Scientists say warmer air temperatures and a lack of sea ice contributed to the breakup.
“These ice shelves are able to break up now because of the lack of pressure of sea ice against the sides of these ice shelves,” Dr. Adrienne White, an ice analyst at the Canadian Ice Service with Environment and Climate Change Canada, told Digital Trends. White was monitoring satellite images along the northern coast of Ellesmere Island and the west coast of Greenland over the weekend when she noticed the Milne Ice Shelf looked very different; it had a large fracture. Over the next few days, the shelf broke into two chunks, and now they’re what’s known as ice islands. One is about 21 square miles; the other is about nine square miles.
“The winds cause the ice pack to move away from the boundaries of the ice shelf, giving it room to actually break out, and for the ice islands to drift away from the ice shelf front,” she said. NASA has a graph showing how the amount of Arctic sea ice has declined since 1979. Over the long term, warming air temperatures and possibly warming ocean temperatures can cause the shelves to thin, leaving them more fragile.
“Ice shelves are kind of a unique feature,” said White. “You can only find them, really, along the northern coast of Ellesmere Island, and there are a few in parts of Russia” and Antarctica.
Ice shelves are thick masses of ice that are connected to a coastline. They often form from glacier flow and melting sea ice that freezes onto the shelf. It can take thousands of years, said White. “It’s not something that forms over one season.” Over the millennia, they can accumulate a thickness of thousands of feet.
In 2015, Carleton University’s Water and Ice Research Laboratory sent a remotely operated vehicle to an ice channel in the Milne Ice Shelf and discovered the sediment contained many benthic (bottom-dwelling) organisms living there. That ecosystem has likely been impacted by the collapse.
As the ice islands continue to break up and move, White said the Canadian Ice Service will continue to monitor them. “ We very concerned with looking out for the safety of our ships and our coast guard fleet,” she said.
