The conger shelf ice of the Eastern ATARKTIS-a floating platform in the size of the half of Saarland-broke off from the mainland on March 15, 2022, as can be seen on satellite images. This development had been underway: Since the start of satellite observations in the 1970s, the tip of the Schelf has dissolved in icebergs. Glaziologists refer to such processes as calves.
The Conger Ice Shelf was already reduced to a 50-kilometre-long and 20-kilometre-wide strip connected at one end to the huge continental ice sheet of Antarctica and to ice-covered Bowman Island at the other. Two calving events on 5 and 7 March further reduced the ice shelf, broke away from Bowman Island and finally collapsed a week later.
The world's largest ice shelves border the Antarctic and extend the ice sheet into the cold Southern Ocean. Smaller ice shelves are located where the continental ice meets the sea in Greenland, northern Canada and the Russian Arctic. When an ice shelf like the Conger Ice shelf collapses, the ice lying on the ground, which was once held back behind the ice shelf, drains faster. When the braking force of the ice shelf falls away, more ice rushes into the ocean.
What brought the building down?
Ice shelf is sometimes referred to as Antarctica's "safety band" because it supports the ice flowing down from the adjacent ice sheet. Only a small part of the Antarctic ice sheet melts at the surface, where snow piles up. Instead, most of the continent is losing ice through calving and melting at the bottom of the floating ice shelf surfaces.
The breaking off and detachment of parts of the ice shelf is a natural process: ice shelf usually goes through cycles of slow growth, which are interrupted by isolated calving events. However, in recent decades, scientists have observed how several large ice shelves completely disintegrated.
Along the Antarctic Peninsula includes the Prinz Gustav Schelfeis (from 1989 to 1995), the Larsen-A (1995) and the Larsen B-Schelfeis (2002) and the Wilkins Schelfeis (2008 to 2009). In the Eastern ATARKTIS, where Cong was once, the Cook Schelfeis was partially lost in the 1970s. Overall, this series indicates that some of the environmental conditions that change are underlying, such as the temperatures of the ocean and the atmosphere.
It is still too early to say what triggered the collapse of the Conger Ice Shelf. But it seems unlikely to have been caused by melting at the surface – there is no sign of water accumulation on the ice shelf, for example. The latest sequence of events also began before the record-breaking high air temperatures measured in Antarctica on March 18, 2022.
What the future will hold
As glaciologists, we see the impact of global warming on Antarctica in the form of increasing ice loss. And what happens in Antarctica is not limited to Antarctica. The consequences of the collapse of the Conger Ice Shelf are unlikely to be of large-scale importance, as the area from which the ice flows into the former shelf is small. And because of its shape, the Conger Ice Shelf was most likely not a significant support for inland ice flow.
But due to global warming, events like this are becoming more and more likely. And as more and more ice shelves collapse around Antarctica, the loss of ice will increase, and with it the global sea level will also rise. The ice of the West Antarctic ice sheet is enough to make the sea level rise by several meters. If East Antarctica begins to lose significant amounts of ice, the impact on sea level could be measured in tens of meters.
Not everything that happens in nature is solely due to global warming. The Antarctic loses mass by the drainage of icebergs and the growing and disappearance of mischief as part of a natural cycle. What we are now experiencing with the collapse of the conger ice shelf and other shelf is the continuation of a concern of exciting trend, in which one antarctic mischief after the other breaks down across the board.
