An iceberg twice the size of Stewart Island has broken off from Antarctica into the Weddell Sea, becoming the largest afloat in the world, the European Space Agency said.
The newly created iceberg, named A-76 by scientists, was spotted in satellite images captured by the Copernicus Sentinel-1 mission, the European Space Agency said in a statement.
The iceberg's surface area is 4320sq km, and measures 175km by 25km.
By comparison, Stewart Island's total land area is 1746sq km, while the Spanish island of Mallorca in the Mediterranean occupies 3640sq km.
A-76 was first detected by the British Antarctic Survey and confirmed by the US National Ice Centre based in Maryland using imagery from Copernicus Sentinel-1, consisting of two polar-orbiting satellites.
Scientists expect the iceberg to break up and its pieces will circle Antarctica for years or decades rather than drifting northward into shipping lanes.
Scientists say global warming has caused a thinning of such shelves, but they differ on whether the latest event can be blamed on climate change.
"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," Alex Brisbourne, a glaciologist at the British Antarctic Survey, said.
But, Brisbourne said, "it's big enough to influence the ocean, and the salinity of the ocean."
In July 2017, one of the biggest icebergs ever recorded, a trillion-tonne behemoth more than seven times the size of New York City, broke off Antarctica.
The iceberg, off the Larsen Ice Shelf, was 6000sq km.
Two other Antarctic ice shelves, in the northern part of the Antarctic Peninsula, collapsed in 1995 and 2002. That sped up the slide of glaciers, which contributed to sea-level rise.