New video follows massive Antarctic ice shelf crack from the sky

Scientists with the British Antarctic Survey (BAS) have released new footage of a massive crack in Antarctica’s Larsen C Ice Shelf that is threatening to produce a glacier bigger than the state of Rhode Island, according to BBC News and USA Today reports published earlier this week.

According to the BAS, satellite data collected earlier this month shows that the crack is growing and will soon cause a glacier with an area of more than 5,000 square km (1,930 square miles) to break away and enter the Weddell Sea. The video, which was taken by an aircraft as it recovered instruments placed on the ice shelf, illustrates how dire the situation is getting.

Currently, the fissure is 175 km (109 miles) long and 400-500 meters (1312-1640 feet) wide in some places, and if it grows just 20 km (12.5 miles) more, a block of ice one-fourth the size of Wales will break off of the Larsen C Ice Shelf and enter the Waddell Sea, BBC News said. That could happen at any time, and once it does, scientists will turn their attention to the health of the ice shelf.

“Iceberg calving is a normal part of the glacier life cycle, and there is every chance that Larsen C will remain stable and this ice will regrow,” Dr. Paul Holland of the BAS said in a statement. “However, it is also possible that this iceberg calving will leave Larsen C in an unstable configuration. If that happens, further iceberg calving could cause a retreat of Larsen C.”

“We won’t be able to tell whether Larsen C is unstable until the iceberg has calved and we are able to understand the behaviour of the remaining ice,” he added. “The stability of ice shelves is important because they resist the flow of the grounded ice inland. After the collapse of Larsen B [in 2002], its tributary glaciers accelerated, contributing to sea-level rise.”

Scientists not certain that climate change is to blame

In addition to Larsen B, several other ice shelves in the Antarctic Peninsula have retreated, lost a significant amount of volume or disappeared entirely over the past few decades – including those in Prince Gustav Channel, Larsen Inlet, Wordie, Muller, Jones Channel, and Wilkins, BBC News said. The likelihood is that Larsen C will continue that ongoing trend.

The news isn’t entirely bad, however. When Larsen B calved, scientists were able to discover a wealth of never-before-seen species in the uncovered seabed, and it is likely that Larsen C would also be home to previously undiscovered organisms as well. However, while satellites would be used to keep track of the glacier, it would nonetheless pose a threat to shipping vessels all across the Southern Ocean, according to BBC News.

According to Project MIDAS, a UK-based Antarctic research project led by scientists at Swansea University that work alongside the BAS, “There is not enough information to know whether the expected calving event on Larsen C is an effect of climate change.” However, they added, there is “good scientific evidence that climate change has caused thinning of the ice shelf.”

While the 5,000 square km iceberg would be quite large, the BAS pointed out that it would not be the biggest ever recorded. In 1956, a US Navy icebreaker spotted a nearly 32,000 square km iceberg, which would make it larger than the nation of Belgium. However, the lack of satellites prevented the size of this monstrous iceberg from being verified. In 2001, an iceberg about the size of Jamaica (11,000 square km) became the largest ever recorded by satellites after it broke off from the Ross ice shelf.


Image credit: British Antarctic Survey