The world's largest iceberg has calved from Antarctica over the past few days, a giant floating piece of ice close to 80 times the size of Manhattan.
The iceberg broke off the western side of the Ronne Ice Shelf in Antarctica's Weddell Sea, the European Space Agency (ESA) said Wednesday.
The iceberg is shaped like a giant ironing board, measuring around 170 kilometers (105 miles) in length and 25 kilometers (15.5 miles) in width. That makes it slightly larger than the Spanish island of Majorca, ESA said.
Iceberg calving is part of the natural cycle, with huge chunks of ice breaking off the ice shelf at regular intervals. Scientists aren't attributing this particular break-off to climate change, and instead believe it's part of the natural cycle of iceberg calving in the region.
Once it melts, the new iceberg will not lead to a sea level rise, because it was part of a floating ice shelf -- just like a melting ice cube doesn't increase the level of the drink in your glass.
That makes icebergs like this different from glaciers or ice sheets, which are found on land, and which do raise global sea levels when they break off into the ocean and melt. If Antarctica's entire ice sheet were to melt, it could raise sea levels by nearly 190 feet.
ESA said the iceberg was first spotted by Keith Makinson, a polar oceanographer with the British Antarctic Survey last week and confirmed from the US National Ice Center using ESA's Copernicus Sentinel-1 imagery.
The huge chunk of ice is now officially known as the A-76. The name might sound a bit boring for the world's largest iceberg, but it is based on science. ESA said icebergs are traditionally named from the Antarctic quadrant in which they were originally sighted, then a sequential number, then, if the iceberg breaks, a sequential letter.
An iceberg bigger than Majorca that calved off an Antarctic ice shelf has been spotted by satellites, and declared the world’s largest iceberg.
The finger-shaped iceberg, which is about 4320 square kilometres in size, isn’t thought to have been caused by anthropogenic climate change.
Named A-76, the iceberg broke off the Ronne ice shelf into the Weddell Sea in recent days, according to the European Space Agency. The area has been spared an influx of warm ocean water affecting other parts of western Antarctica, which is threatening to release huge glaciers such as one called Thwaites.
“It’s not an area that is undergoing any significant change because of global heating. The main message is it’s part of a natural cycle,” says Alex Brisbourne, a glaciologist at the British Antarctic Survey.
The tabular-shape of A-76 is typical of icebergs, and the horizontal lines on it are a sign of the stresses that caused it to break from the ice sheet, says Brisbourne. The part of the ice sheet that it calved from was floating, so the iceberg shouldn’t have any impact on sea level rise.
While A-76 is the largest iceberg in the world at the moment, it wouldn’t make the pantheon of the 10 biggest icebergs in history.
“In the grand context of things this is not humungous. Of course it’s an evolution in the ice shelf,” says Mark Drinkwater of the European Space Agency.
Drinkwater says that the Ronne ice shelf is in a fairly “steady state” where it expands after losing iceberg like this. One of its biggest calving events was in 1986, with icebergs totalling 11,000 square kilometres breaking off, followed by smaller ones in 1998, 2000 and 2015.