The TRUE scale of the world’s biggest iceberg: Enormous ‘megaberg’ that broke free last month is just under one TRILLION tonnes – 100 million times as heavy as the Eiffel Tower, scientists say
New satellite measurements reveal the true size of the world's largest iceberg.
The floating ice platform, called A23a, has an area of 1,500 square kilometers, a volume of 263 cubic kilometers and a mass of just under a trillion tons.
That makes it not only four times as big as Greater London, but no less than 100 million times as heavy as the Eiffel Tower in Paris.
A23a – which is shaped like a 'tooth' – is now being carried northwards 'at speed' by wind and ocean currents, after being on the ground for thirty years.
It drifts along the Antarctic Peninsula (which sticks out from the mainland like a tail) and should break off through rougher waters once it reaches the open ocean.
Impressive: the enormous platform of floating ice has an area of 1,500 square kilometers, a volume of 420 cubic kilometers and a mass of just under a trillion tons
That makes it not only four times as big as Greater London, but no less than 100 million times as heavy as the Eiffel Tower in Paris
According to the British Antarctic Survey (BAS), which visited A23a last week, the iceberg is moving north at a speed of about 30 miles (48 kilometers) per day.
There is a chance that the huge mountain could disrupt the feeding routines of wildlife such as penguins, for example if it is parked in an area where foraging is common.
“It depends on its trajectory, but there is potentially an impact on wildlife if it approaches any of the sub-Antarctic islands,” a BAS spokesperson told MailOnline.
A23a is the largest surviving fragment of an iceberg that broke away from the Filchner Ice Shelf in Antarctica in August 1986.
It had only moved a few hundred kilometers when it became stuck to the ocean floor, eventually remaining stationary for the next thirty years.
Icebergs 'ground' on the ocean floor when their keel (the part below the water's surface) is deeper than the depth of the water.
The European Space Agency's CryoSat satellite found that part of the iceberg's base in particular extended much deeper, acting as an anchor.
This photo from the British Antarctic Survey shows the A23a iceberg as seen from the RRS Sir David Attenborough, Antarctica, December 1, 2023
While A23a originally calved off the Filchner Ice Shelf in 1986, it remained grounded on the seabed until last month
Satellite images from the European Space Agency show the iceberg approaching Clarence Island and Elephant Island, both near the tip of the Antarctic Peninsula
Scientists revealed last month that the mountain is moving again, being carried northward by wind and ocean currents.
European Space Agency satellite images show the iceberg approaching Clarence Island and Elephant Island, both near the tip of the Antarctic Peninsula.
“A23a has started a sprint and is rapidly leaving Antarctic waters,” the agency said on December 1.
“Like most Weddell sector icebergs, A23a will likely enter the South Atlantic Ocean on a path called Iceberg Alley.”
BAS experts on board the British polar research vessel, the RRS Sir David Attenborough, took photographs of the A23a last week after it crossed its path during a 'fortunate' encounter.
The team took samples of ocean surface water around the iceberg's route to help determine what life might form around it and how the iceberg and others like it affect carbon in the ocean.
'It's amazing to see this huge mountain with your own eyes; it extends as far as the eye can see,” said Andrew Meijers, chief scientist aboard the research vessel.
To give a sense of scale, this image shows the area of the iceberg overlaid on a map of Greater London
Scientists revealed last month that the iceberg is moving again, being carried north by wind and ocean currents
American planetary scientist Lindy Elkins-Tanton, who was part of another trip to visit A23a last month, posted photos of the mountain to X.
In a messageshe said it “feels like you're sailing past a new country.”
A23a is currently the largest iceberg in the world, but this title won't last forever because all icebergs eventually fragment.
As it gets further north, water temperatures will cause A23a to thin before it breaks apart and melts completely.
The former record holder was A76, which broke away from an ice shelf in the Weddell Sea in May 2021, but has since fragmented into three pieces.