The satellite images captured the break, about 10 years after satellite monitoring detected growth in a previously dormant crack in the ice known as Chasm-1, and about two years after a slightly smaller iceberg called A74 broke off from the same ice shelf. A cliff is a part of an ice shelf that extends from the surface below to the ocean, while an ice shelf is a piece of floating ice that extends from glaciers formed on land.
Ted Scambos, a senior scientist at the University of Colorado at Boulder, wrote in an email that the iceberg is “a huge mass of ice, about 500 billion tons … it is far from the largest iceberg ever seen. the island.”
The calving event is not expected to affect the BAS’s Halley Research Station, which was moved further inland as a precaution after Chasm-1 began growing in 2016.
However, “the new rupture puts the base about 10 miles out in the ocean, and new cracks could develop over the next few years, leading to another costly relocation of the station,” Scambos wrote. The new iceberg is expected to follow a path similar to that of the A74 to the Weddell Sea and will be named after the US National Ice Center.
Unlike some previous icebergs and collapsed ice shelves that have been linked to climate change, the IAS press release said the breakup was a “natural process” and “there is no evidence that climate change is playing a significant role”.
Instead, the cliff began to grow due to “stresses caused by the natural growth of the ice shelf,” Hilmar Gudmundsson, a glaciology researcher at Northumbria University, said in a 2019 BBC story.
Skambos compares the calving of an iceberg to a cut on a wooden board. “In this case, the chisel was a small island called MacDonald Ice Rise,” Scambos writes. “The ice was swept up against this rocky seamount by the ice flow, forcing it to break up and eventually break away from the floating ice shelf.”
“These big icebergs, sometimes as big as a small country, are magnificent. But they are just part of how the Antarctic ice sheet works,” Skambos said. “Often they have nothing to do with climate change.”
