Erosion is carving impressive shapes into the world's largest iceberg, in what will likely be the final months of its existence.
A ship operated by the Eyos expeditions company arrived at the icy behemoth, A23a, on Sunday and found huge caves and arches carved into its icy walls. The ice giant has been hit by the warmer air and surface water it is encountering as it slowly moves away from the White Continent. Eventually it will melt and disappear. Expedition leader Ian Strachan said he saw “waves 3 or 4 meters high crashing onto the iceberg”. “These waves created ice falls and a constant state of erosion,” he explained to the BBC.
In these images taken by the Copernicus satellite the A23a iceberg is located about 200 km west of the South Orkney Islands, here partially covered by clouds
A23a broke away from the Antarctic coast in 1986, but only recently began its “great migration”. For more than 30 years it remained stuck in the Weddell Sea floor, as a gigantic “ice island” measuring approximately 4,000 km², a surface area three times the size of New York and weighing approximately 1 trillion tons.
The video of the largest iceberg in the world: 4 thousand square kilometers
The colossus is currently adrift in the Antarctic Circumpolar Current, the large body of water that circles the continent in a clockwise direction.
This current, together with westerly currents, is pushing A23a in the direction of the South Orkney Islands, which are located about 600 km northeast of the tip of the Antarctic Peninsula.
When the walls of the iceberg crumble, a submerged surface forms and buoyancy pushes it upwards.
The A23a is sailing steadily on the route of what scientists call “iceberg alley,” the main route that follows ice from the continent. The play of winds, ocean fronts and gyres will determine its precise course in the coming weeks, but many of these giant flat-topped icebergs end up passing close to the British Overseas Territory of South Georgia.
The world's largest iceberg is now leaving Antarctica and drifting
Their destiny is to fragment and dissolve until they disappear. Their legacy is in ocean life. Along the way and disappearing they drop the transported mineral nutrients. From plankton to large whales, everyone benefits from the fertilizing effect of melting icebergs.
A thick fog hangs over the A23a: it is so big that it has its own “climate”
Iceberg D28, also known by its popular name “Molar Berg,” is rising in the South Atlantic, about 200 km north of South Georgia. Although it has lost about a third of its surface area since it broke off from Antarctica's Amery Ice Shelf in 2019, D28 has managed to maintain its essential and compact shape. Could the A23a, with its square dimensions, be equally long-lived?
The D28 seen from the satellite. It has an area of about 1,000 km² and moves north of South Georgia.
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