In Greenland, from the largest of the remaining Arctic shelf glaciers broke off a large mass of ice with an area of about 110 square kilometers. Photos from the satellite show that the glacier 79N cracked into small parts, which is another evidence of rapid climate change occurring in Greenland, scientists say, “The air temperature in this region has risen by 3 degrees Celsius since 1980. And in 2019 and 2020 were recorded record high temperatures,” – said in an interview with the BBC researcher Jenny Turton from the German University of Erlangen – Nuremberg.
The 79N glacier is about 80 km long and 20 km wide. It is at the front of the North-East Ice Stream of Greenland, where it flows from land into the ocean and becomes floating.
At the front edge of 79N is divided in two, with one part facing north. This branch of the glacier has collapsed.
The glacier was severely damaged back in 2019, covered with deep cracks. In 2020, the situation was further aggravated by the warm summer. A branch of the glacier split into many icebergs.
Photos from the satellite clearly demonstrate that the temperature in the region has increased. This can be understood by a large number of places with melting water on the ice surface.
Water is harmful to ice massifs. It fills and widens the cracks. Water presses on them, breaking the ice to the very base. This process is called fracturing. As a result, the glacier shelf is weakening. Oceanographers have also documented an increase in seawater temperature, which is undoubtedly why the glacier is melting from below.
“79N has only recently become the largest of the remaining Arctic shelf glaciers. This happened after the Peterman glacier in Greenland significantly decreased in the period from 2010 to 2012,” – said Jason Box from the Geological Survey of Denmark and Greenland.
“The importance of 79N in the way it is attached to the inner ice cover. The point is that if the climate changes according to the forecasts, at some point this part of Greenland will lose glaciers faster than others,” he said.
Northeast Greenland’s ice flow absorbs about 15% of the internal ice cover. The stream then carries the ice either along the N79 or to the Zachariah-Iström glacier, which has already decreased significantly in size. According to Box, the N79 can last longer because it is held at the front by the islands. This makes it a little more stable. But the shelf glacier continues to melt, although it mainly happens in its land part.
“Most likely, as a result, N79 will collapse from the middle, and this, to some extent, is a unique phenomenon. It seems to me that it will not happen for another 10-20 years. But who knows,” he said in an interview with the BBC.
In July, another shelf glacier in the Arctic – the Milna glacier, located on the northern coast of the Canadian island of Ellesmere, has significantly decreased. The ice mass of 80 square kilometers. The area of its remaining part is 106 sq. km. At the beginning of the XX century, this figure was 8.6 thousand square kilometers.
Rapid ice melting in Greenland was described in a scientific report based on data obtained from satellites of German-American mission GRACE-FO. They are able to track changes in ice masses by measuring the force of gravity in these places. In fact, the satellites have measured the ice weight.
The mission determined that 2019 was a record year – then the mass of glaciers decreased by 530 billion tons. Meltwater released as a result is enough to raise the level of the world ocean by 1.5 mm.