A considerable part of the largest iceberg in the world, A-68, has been detached from this giant ice block that in 2017 detached from an ice front on the sea attached to the Antarctic Peninsula.
A-68 has an estimated area of 5,100 square kilometers. On April 16, it lost a large fragment of about 175 square kilometers and 19 kilometers long. The iceberg is currently moving north from the Antarctic Peninsula. Having entered rougher and warmer waters, he is now riding currents that should carry him into the South Atlantic.
Professor Adrian Luckman, who has been following the progress of A-68, said the new fracture could usher in the end of this frozen giant. “I am continually amazed that something so thin and fragile has lasted this long in the open sea,” the University of Swansea researcher told BBC News.
“I suspect that the final break is now beginning, but the later shards will likely be with us for years.”
Evidence of the split on Thursday came through a radar image acquired by the European Union Sentinel-1 satellite. Luckman made it public on his Twitter account.
The A-68 name comes from a classification system administered by the US National Ice Center. USA, which divides Antarctica into quadrants. Because the iceberg broke off the Larsen C ice shelf in the Weddell Sea, it obtained an “A” designation. “68” was the last number in the plus size series in that sector.
Correctly, we should refer to the iceberg as A-68A, because the subsequent breaks also have their own related name. A-68B broke off early in the existence of the main iceberg. This new portion is sure to get the A-68C designation. Was there any indication that this particular corner would slip out? “Not that I have seen it. I have been monitoring progress, but it has mainly been the wear and tear of small chips everywhere,” said Professor Luckman.
When it detached in 2017, the A-68 was about 6,000 km2 in area, with an average thickness of approximately 190 meters.
For months it seemed to anchor itself to the sea floor and did not move very far. But it finally turned and sped up as it moved north. This past southern summer, the giant freed itself from lingering sea ice clogging the Weddell Sea, a significant development because it has exposed A-68 to much larger waves. Its structure is now under more stress and more divisions should be expected.
It is currently passing through the South Orkney Islands, which form the furthest end of the Antarctic Peninsula. Currents should send it heading in the general direction of South Georgia and the South Sandwich Islands.
Anyone can guess how much longer the A-68 can maintain its current integrity. But even if it suffers from a major fragmentation event, individual ice blocks could persist throughout this decade before disappearing.