World’s largest iceberg breaks off Antarctica ice shelf

A huge iceberg, the world's largest, has broken off from an ice shelf in Antarctica and is floating through the Weddell Sea.

Named "A-76" and roughly the shape of Manhattan but more than 70 times bigger, it was picked up on satellite images and is "currently the largest berg in the world", the European Space Agency said.

The iceberg is around 170 kilometres (105 miles) long and 25 kilometres wide, with an area of 4,320 square kilometres, slightly larger than the Spanish island of Majorca.

The berg, which broke off the western side of the Ronne Ice Shelf, was originally spotted by the British Antarctic Survey and confirmed using images from the Copernicus satellite.

It takes the place as the world's largest from the A-23A iceberg – approximately 3,880 square kilometres in size – which is also in the Weddell Sea.

In November last year, what was then the world's largest iceberg appeared to be on a collision course with a remote South Atlantic island home to thousands of penguins and seals, threatening to impede their ability to gather food.

The iceberg, known as A68a, had also broken off from the Larsen Ice Shelf, which has warmed faster than any other part of Earth's southernmost continent.

READ MORE: Giant iceberg on course to hit south Atlantic penguin colony

A68a, which was 160 kilometres long and 48 kilometres across, broke up before it could cause any damage to the abundant wildlife in the British Overseas Territory of South Georgia.

Ted Scambos, a research glaciologist at the University of Colorado at Boulder, said the Ronne and another vast ice shelf, the Ross, have "behaved in a stable, quasi-periodic fashion" over the past century or more. 

Because the ice was already floating in the sea before dislodging from the coast, its break-away does not raise ocean levels, he said email.

Some ice shelves along the Antarctic peninsula, farther from the South Pole, have undergone rapid disintegration in recent years, a phenomenon scientists believe may be related to global warming, according to the US National Snow & Ice Data Center. 

Earth's average surface temperature has gone up by one degree Celsius since the 19th century, enough to increase the intensity of droughts, heat waves and tropical cyclones.

But the air over Antarctica has warmed more than twice that much.

READ MORE: Massive iceberg breaks off Antarctica – but it's normal