By AFP - Agence France Presse
The first large chunk of the world's largest iceberg breaks off
A huge chunk has broken off from the world's largest iceberg, in a possible first sign that the Antarctic giant may be crumbling, scientists told AFP on Friday.
The colossal iceberg - which is more than twice the size of Greater London and weighs almost a trillion tons - has remained largely intact since it began moving slowly north in 2020.
It has been moving towards the remote island of South Georgia in the South Atlantic, increasing the possibility of running aground in shallower waters and disrupting the feeding of baby penguins and seals.
But a piece about 19 kilometers (12 miles) long broke off, said Andrew Meijers of the British Antarctic Survey, which found the iceberg in late 2023 and has been tracking its fate via satellite ever since.
“This is the first significant and clear slice of iceberg that has appeared,” the physical oceanographer told AFP.
Soledad Tiranti, a glaciologist currently on an Argentinian exploration trip in Antarctica, also told AFP that a section had “broken off”.
The irregular chunk has an area of around 80 square kilometers (31 square miles) - huge in itself, but only a fraction of the approximately 3,360 square kilometers that remain.
Meijers said that icebergs are full of deep fractures and, although this monumental specimen has shrunk over time and lost a much smaller chunk, it has “held together very well”.
“This is a sign that these cracks are starting to break,” he said.
In the past, other mega-icebergs had disintegrated “relatively quickly over several weeks” when they started to lose large chunks, he said.
It was hard to tell whether this was “a loose tooth waiting to come out” or evidence of a much bigger change underway.
“I'm sorry to say, but it's not an exact science how these things disintegrate... it's really hard to say if this is going to disintegrate now or if it's going to hold together for longer,” said Meijers.
Known as A23a, the world's largest and oldest iceberg emerged from the Antarctic shelf in 1986.
It remained trapped for more than 30 years before finally breaking free in 2020, its heavy journey north sometimes delayed by the oceanic forces that kept it spinning in place.
This monstrous block of fresh water was being dragged by the world's most powerful oceanic “jet stream” - the Antarctic Circumpolar Current.
Meijers said that its trajectory towards South Georgia, a crucial feeding ground for seals and penguins, would probably not change because it had lost this piece.
However, if the collapse continues, it will pose “a much smaller threat to wildlife”, as feeding animals can maneuver unhindered between the smaller chunks to find food, he added.
In the past, icebergs have run aground in this location and caused significant mortality of penguin chicks and seals.
Tiranti said that the iceberg was expected to continue moving north, but its exact course depended very much on the influence of local currents on its movements.
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