New photos and videos show the world’s largest iceberg, A23a, being steadily eroded as it drifts away from Antarctica.
Ocean waters form caves and arches in the colossal tooth-shaped iceberg, which measures 1,540 square kilometers – four times the area of Greater London.
Like coastal erosion of land, the waves crash against the mountain, causing the holes to grow larger and larger until the top collapses.
A23a is gradually being eroded by waves and melting due to warmer water as it drifts steadily north after 30 years of being grounded on the ocean floor.
Objects as large as the A23a must be continuously monitored after the break as they can pose a threat to ships and wildlife.
New photos show the world’s largest iceberg, A23a, being steadily eroded as it drifts away from Antarctica, complete with arches and caves
Like coastal erosion of land, waves crash against the mountain to make the holes bigger and bigger until the top collapses.
EYOS expeditionswhich arrived at A23a on Sunday, used a drone to take the last snapshots from the air.
“We saw waves of more than three to four meters high crashing into the mountain,” said expedition leader Ian Strachan. the BBC.
‘This created waterfalls of ice – a constant state of erosion.’
EYOS videographer Richard Sidey said the A23a is ‘mind-bogglingly huge’ and ‘extends as far as you can see in either direction’.
“I don’t actually think we can fathom how big it is; we can only know how big it is through science,” he said.
“It’s certainly too big to photograph.”
As the new photos show, iceberg erosion happens in a similar way to land erosion, albeit not as slowly.
The powerful waves repeatedly hit the base of the mountain, creating small holes and cracks, which grow larger over time.
These holes eventually widen, becoming caves and then larger arches, until the ‘roof’ (the top layer of ice) collapses from the lack of support below.
EYOS videographer Richard Sidey said A23a is ‘mind-bogglingly huge’ and ‘extends as far as you can see in either direction’
This shot highlights the loss of some of the iceberg’s mass. It is four times the size of Greater London, but getting smaller
EYOS Expeditions, which arrived at A23a on Sunday, used a drone to take the last snapshots from the sky
Previous expeditions have already visited the iceberg, which will eventually melt away into nothingness
This photo from the British Antarctic Survey shows a view of the A23a iceberg from the RRS Sir David Attenborough, Antarctica, Friday, December 1, 2023
This leaves small ‘piles’ which then form smaller ‘stumps’ before melting away completely.
This is a melting process that will eventually cause A23a to be lost forever, but due to its enormous size it may take some time.
According to the British Antarctic Survey (BAS), which visited A23a in December, the iceberg is moving north at a speed of about 30 miles (48 kilometers) per day.
It is now likely to be swept into an ‘iceberg alley’ – a common route for icebergs to drift towards the sub-Antarctic island of South Georgia.
There is a chance that the 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.
Impressive: The huge platform of floating ice has an area of 2,500 square kilometers, a volume of 420 cubic kilometers and a mass of just under a trillion tons – although this is gradually decreasing as it is eroded by waves and warmer ocean temperatures
A23a – which is shaped like a ‘tooth’ – is now being carried northwards at high speed by wind and ocean currents
To give a sense of scale, this image shows the area of the iceberg overlaid on a map of Greater London
It had only moved a few hundred kilometers when it became stuck on 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.
Scientists revealed in November that the mountain is moving again, being carried northward by wind and ocean currents.
A23a is currently the largest iceberg in the world, but this title won’t last forever because all icebergs eventually fragment.
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.