Iceberg separates from Antarctica and becomes the largest in the world
The largest iceberg on record, the B15, broke off the Ross Ice Shelf in March 2000, measuring over 4,200 square miles (11,000 square kilometers). Although it is more than double the size of the A76, said Dr Shuman, the B15 did not destabilize the Ross Ice Shelf. B15 has since fractured into several icebergs, all of which except one have melted.
According to Dr Shuman, the last significant calving on the Ronne plateau dates back to May 2000.
By studying the new iceberg, researchers hope to gain a better understanding of the overall condition of Antarctic ice shelves, said David Long, which maintains the Antarctic Iceberg Tracking Database at Brigham Young University.
“Understanding when the ice caps calve helps us understand whether some of these other more unstable ice caps might break or disintegrate,” he said. “And that would be important because, as these more unstable ice caps break apart, they can release the flow of glaciers that are held in place by the ice shelves.
While the ice shelves float on the water, the glaciers behind them lie on dry land. So if they are thrown back into the sea and melted, it would raise the sea level, he said.
The National Ice Center names and tracks Antarctic icebergs that are at least 10 nautical miles long or 20 square nautical miles wide. The center, which is operated by the Navy, Coast Guard, and National Oceanic and Atmospheric Administration, currently tracks 42 named icebergs.
The question with A76 is what will happen next.
An approximately 100-mile-long and 30-mile-wide iceberg that had broken away from the Antarctic Peninsula in 2017 sounded the alarm in November when it appeared to be on a collision course with the British island territory of Georgia from the South. This iceberg, A68a, ended up stranded off the coast of the island. If the A76 hits a similar current, it could reach the Antarctic Peninsula in a matter of months and interfere with shipping lanes there, said Christopher Readinger, head of the Ice Center’s Antarctic team.
As the A76 makes its journey, Dr Jackson said, climatologists will be watching closely – even if much of the public does not. Dr Jackson cited A68a, the iceberg that briefly threatened South Georgia.