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East Antarctica’s Conger ice shelf – a floating platform the size of Rome – broke off the continent on March 15, 2022. Since 1970, satellite observation began to show that the tip of the shelf was disintegrating into icebergs. This is what glaciologists call calving.
Conger was already reduced to a 50km-long and 20km-wide strip attached to Antarctica’s vast continental ice sheet at one end and the ice-covered Bowman Island at the other. It was further reduced by two calving events on March 5, 7 and 6, which separated it from Bowman Island and precipitated its final collapse one week later.
The world’s largest ice shelves fringe Antarctica, extending its ice sheet into the frigid Southern Ocean. The smaller ice shelves can be found where continental glaciers meet the sea in Greenland (northern Canada) and the Russian Arctic. They can control the flow of grounded glaciers upstream to limit the loss of ice in the ocean. Conger is an example of an ice shelf that can be lost. The grounded ice that was once held behind the shelf may begin to flow faster, as the ice shelf’s restraining force is lost. This could lead to more ice falling into the ocean.
Bertie Miles/Nasa, Author provided
What caused the collapse?
Ice shelves are sometimes referred as the “safety band” of AntarcticaBecause they support the upstream flow ice from The bordering ice sheets. Very little of the Antarctic Ice Sheet melts at its surface where snow accumulates. The majority of the continent loses its ice through melting. Calving and meltingAlong the bottom of the floating ice shelves.
Bertie Miles/US Geological Survey, Author provided
The breaking and disassembly of parts from ice shelves are A natural processGenerally, ice shelves experience slow growth that is interrupted by isolated calving episodes. However, scientists have recently seen large ice shelves undergo total disintegration.
The Antarctic Peninsula, a whip-like landmas that extends from West Antarctic mainland, is home to the following: Prince Gustav ice plate (1989 to 1995), Larsen A (1995), Larsen B (2002), and Wilkins ice Shelf (2008 to 2009. Conger was once located in East Antarctica. The Cook ice Shelf was lost partially in the 1970s. These collapses suggest that the underlying environmental conditions are changing, such as the ocean and atmosphere temperatures.
It is too soon to say what triggered the collapse of the Conger ice shelf, but it appears unlikely to have been caused by melting at the surface – there are no indications of any ponds atop the ice shelf. This latest sequence of events occurred before the record-breaking air temperatures in Antarctica on March 18.
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What does the future hold?
As glaciologists, we can see the effect of global warming on Antarctica through increasing ice loss. And what happens in Antarctica is not permanent.
Bertie Miles/US Geological Survey/European Space Agency, Author provided
The global impact of the Conger Ice Shelf collapse is unlikely to be significant as the catchment area for ice into the former shelf was small. Due to its shape, Conger ice shelves was likely not to have been a significant stumbling block to the flow of ice downstream.
Global warming is making such events more probable. As more Antarctica’s ice shelves collapse, global sea level rises. The West Antarctic Ice Sheet has enough ice to raise sea level by several meters. If East Antarctica loses significant amounts of ice, the impact could be measured in the tens of metres.
Global warming is not responsible for everything that happens in the natural world. Antarctica’s natural cycle includes the release of icebergs and the waxing and wiping of ice shelves. The collapse of Conger’s ice shelf and other ice shelves is a continuation of a worrying trend that sees Antarctic ice shelves collapse one after the next.
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