The latest satellite imagery suggests iceberg A68a is in its death throes, as the once-colossal iceberg has deteriorated rapidly over the past week.
In its prime, A68a, which detached itself from Antarctica’s Larsen C ice shelf in 2017, measured 5,800 square kilometres in size, becoming one of the biggest icebergs ever recorded. At the time, it was known as iceberg A68. The lettered version came after a small piece broke off, becoming A68b, while the still-formidable and newly named A68a continued its drift.
After threatening and then parking itself to the southeast of the ecologically sensitive South Georgia island, A68a started to lose its cohesion. The iceberg is now a shadow of its former self, having disintegrated into several newly named icebergs and countless bits of floating ice.
That the iceberg is quickly disintegrating “could indicate the end of A68a’s environmental threat to South Georgia,” according to the European Space Agency. Back in November 2020, experts expressed concerns that the iceberg would lodge itself along the island’s coast, where it could menace the local wildlife, such as penguins, and the fragile critters living along the seafloor.
Having lost a large chunk in mid-December, named A68d, and its finger-like protrusion, named a68e, shortly thereafter, the iceberg is now undergoing “rapid break-up,” according to the U.S. National Ice Centre, which is responsible for tracking and naming icebergs of unusual size.
Images taken last week by the Copernicus Sentinel-1 radar mission showed that A68a had given birth to a new sizable iceberg, designated A68g, which (at the time) measured 53 kilometres at its longest point and 18 kilometres at its widest point. This calving event served to destabilise A68a even further, resulting in two more baby ‘bergs, A68h and A68i.
As these three icebergs drifted away from A68a, three more icebergs appeared, named A68j, A68k, and A68l, creating a veritable alphabet soup of icebergs. This all happened within a three day span, ending on Jan. 30. A day later, USNIC confirmed the existence of A68m, which calved from A68g. Babies having babies, I guess.
As the ESA reports, A68a now measures just 60 kilometres in length and around 23 kilometres at its widest point. Back in November, A68a measured 158 km long and 48 kilometres at its widest point, so this iceberg has lost a lot of mass in a short period of time.
The map above provided by the ESA provides a historical overview of A68’s journey from the Antarctic Peninsula to South Georgia, and its crack up. The A68 family of icebergs is now steadily drifting apart, with A68h located some 130 kilometres from South Georgia and moving in a northerly direction. Hopefully the ESA is right, and these smaller pieces no longer pose a threat to South Georgia, an overseas British territory.
Iceberg A68a’s journey appears to be over, at least as a cohesive whole. But this is the way of things, and how all icebergs eventually meet their fate.