BBC
A big chunk of ice has broken away from the Arctic's largest remaining ice shelf - 79N, or Nioghalvfjerdsfjorden - in north-east Greenland.
The ejected section covers about 110 square km; satellite imagery shows it to have shattered into many small pieces. The loss is further evidence say scientists of the rapid climate changes taking place in Greenland. "The atmosphere in this region has warmed by about 3C since 1980," said Dr Jenny Turton. "And in 2019 and 2020, it saw record summer temperatures," the polar researcher at Friedrich-Alexander University in Germany told BBC News. Nioghalvfjerdsfjorden is roughly 80km long by 20km wide and is the floating front end of the Northeast Greenland Ice Stream - where it flows off the land into the ocean to become buoyant. At its leading edge, the 79N glacier splits in two, with a minor offshoot turning directly north. It's this offshoot, or tributary, called Spalte Glacier, that has now disintegrated.
The Northeast Greenland Ice Stream drains about 15% of the interior ice sheet. The stream funnels its ice either down N79 or the glacial member just to the south, Zachariae Isstrom. Zachariae has already lost most of its floating ice shelf area. Prof Box said N79 could resist longer because it was penned in right at its forward end by some islands. This lends a degree of stability. But, he added, the shelf continues to thin, albeit mostly further back along the trunk. "This will likely lead to N79 disintegrating from the middle, which is kind of unique. I guess, though, that won't happen for another 10 or 20 years. Who knows?" he told BBC News. July witnessed another large ice shelf structure in the Arctic lose significant area. This was Milne Ice Shelf on the northern margin of Canada's Ellesmere Island. Eighty sq km broke free from Milne, leaving a still secure segment just 106 sq km in size. Milne was the largest intact remnant from a wider shelf feature that covered 8,600 sq km at the start of the 20th Century. The fast pace of melting in Greenland was underlined in a study last month that analysed data from the US-German Grace-FO satellites. These spacecraft are able to track changes in ice mass by sensing shifts in the pull of local gravity. They essentially weigh the ice sheet. The Grace mission found 2019 to have been a record-breaking year, with the ice sheet shedding some 530 billion tonnes. That's enough meltwater running off the land into the ocean to raise global sea-levels by 1.5mm.
This article was originally featured in BBC.