The world’s oceans now have a new iceberg wandering the seas. A 5,800 square kilometer segment of the Larsen C ice shelf has recently broke off and has made the ice shelf 12% smaller. Researchers say that this recent calving of the iceberg has left the size of the Larsen C at an all-time low. What does this recent break mean for the Antarctic Peninsula? According to scientists, it’s still too soon to tell.
3, 2, 1, Breakoff
Ice shelves are floating ice masses attached to massive grounded ice sheets. They are hundreds of meters thick and act as a support for glaciers. Ice shelves essentially hold back the glaciers and slow down their movement towards the sea. To get a better understanding of these ice shelves, the Antarctic Peninsula has been carefully monitored with radar images from the European Space Agency’s Sentinel-1 mission. Scientists are fortunate enough to receive data from the mission every six days.
For years, researchers observed a large crack in the Larsen C ice shelf, but in 2017 alone the ice shelf was breaking at an unusually fast rate. Between May 25 and 31, researchers found that the rift grew by 17 kilometers, which was the largest break since January. From June 24 to 27 the shelf was breaking a rate of more than 10 meters per day until finally, the new iceberg calved completely. The satellite data showed the piece of ice drifting away from the Larsen C ice shelf. The recent break believed to be one of the top 10 largest icebergs to ever be recorded.
It is not uncommon for icebergs to calve, but scientists have become intrigued with this recent break from Larsen C. Adrian Luckman, leader of the UK’s Midas project and professor at Swansea University, has been a following the state of the Antarctic ice shelf. And according to Luckman and his team, it was not a clean break. They found that the rift has branched multiple times. According to Luckman, “it is likely that [the Larsen C ice shelf] will break into smaller pieces as time goes by.”
The Fate of Larsen C
The spotlight is now on the Larsen C ice shelf to see if it can stay together, or collapse like its close neighbors, Larsen A and Larsen B. The Larsen A ice shelf surrendered in 1995 and Larsen B in 2002. But researchers believe that it’s too soon to know how the future of Larsen C will unfold. Luckman and his research team have found in previous studies that Larsen C is likely to be less stable when the iceberg calves. However, Luckman also points out that the ice shelf still has the potential to regrow. After a large iceberg calved from Larsen B, it took seven years to confirm the instability and disintegration of the ice shelf. According to Luckman, “We will have to wait years or decades to know what will happen to the remainder of Larsen C.”
There are heated debates among researchers of whether the break in Larsen C is a result of climate change. A glacier expert at the US National Ice and Snow Data Center, Twila Moon, believes that warmer ocean temperatures allow for changes on ice shelves to happen more easily than they otherwise would. This is also based on the widely accepted notion that climate change played a role in the collapse of Larsen A and Larsen B. In rebuttal, Luckman says that “It is a possibility, but recent data from the Scripps Institute of Oceanography actually show most of the shelf thickening.” It looks like we’ll just have to wait and find out.