Mr Scambos said the Ronne and another vast ice shelf, the Ross, have "behaved in a stable, quasi-periodic fashion" over the past century or more.īecause the ice was already floating in the sea before dislodging from the coast, its break-away does not raise ocean levels, he said. Periodic calving of large chunks of those shelves is part of a natural cycle, and the breaking off of A-76, which is likely to split into two or three pieces soon, is not linked to climate change, said Ted Scambos, a research glaciologist at the University of Colorado. The Ronne Ice Shelf near the base of the Antarctic Peninsula is one of the largest of several enormous floating sheets of ice that connect to the continent's landmass and extend out into surrounding seas. If the iceberg breaks, a sequential letter is added. Icebergs are traditionally named from the Antarctic quadrant in which they were originally sighted, with a sequential number. 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 southern most continent.Ī68a, which was 160km long and 48km across, broke up before it could cause any damage to the abundant wildlife in the British Overseas Territory of South Georgia.Įarth'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.īut the air over Antarctica has warmed more than twice that much. The once-mighty iceberg A68a looks to be in its death throes. Last November, 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. It takes the place as the world's largest from the A-23A iceberg - approximately 3,880sq.km in size - which is also in the Weddell Sea.
The iceberg, 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 is around 170km long and 25km wide, with an area of 4,320sq.km. “Halley is made up of eight interlinked pods built on skis, which allows the pods to be easily moved in case of unstable ice or new chasms forming on the 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, the European Space Agency said.Ĭalled A-76 and roughly the shape of Manhattan in New York but more than 70 times bigger, it was picked up on satellite images and is "currently the largest berg in the world", the ESA said. “With the ice shelf deemed unsafe due to the encroaching cracks in 2017, the British Antarctic Survey closed their Halley VI Research Station and re-positioned it to a more secure location,” The ESA said.
Glaciologists are studying the area and watching rifts and chasms in the ice shelf. These included identifying tiny fragments of rock that Antarctic glaciers picked up as they scraped. (Pierre Dutrieux/Lamont-Doherty Earth Observatory) The scientists used multiple techniques to reconstruct past conditions. The glacial region that narrowly escaped being hit by the A74 iceberg is “tenuously attached” to the seabed, according to the ESA. Icebergs broken off and drifting far from the coast of Antarctica are key to the initiation of ice ages, says a new study.
If the berg had collided more violently with this piece, it could have accelerated the fracture of the remaining ice bridge, causing it to break away.”ĭespite the close shave, dangers to the Brunt Ice Shelf continue. “Had the drifting iceberg hit the unstable ice shelf with severe force, it may have triggered the release of a new 1,700 square kilometer -sized iceberg”, even bigger that the A74.ĮSA’s Mark Drinkwater said: “The nose-shaped piece of the ice shelf, which is even larger than A74 remains connected to the Brunt Ice Shelf, but barely.