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Two huge icebergs break off Antarctica

Two huge icebergs break off Antarctica

The ice masses drift northeast, driven by wind, tides, and currents. Fortunately, experts say they pose no immediate threat to supply routes to science stations in the area, like Italy's Mario Zucchelli or South Korea's Bogo Jang in Terra Nova Bay.

However, icebergs can pose a threat to moorings placed on the seafloor in the region that have been used by Italy's National Antarctic Program since the 1990s, and more recently by New Zealand marine scientists.

The Nansen Ice Shelf, about 50 km long and 25 km wide, developed a fracture in recent years. Ice shelves are particularly sensitive to climate change, as they can melt from hot air on the ocean surface and from warming ocean waters.

"The crack was first observed during fieldwork in 1999 and grew progressively, and then accelerated during 2014," said Massimo Frezzotti, from the Italian research organization ENEA.

As winter weather began to soften in early March this year, optical images from the Sentinel-2A satellite and radar from Sentinel-1A, along with images from the Italian Cosmo-SkyMed mission, indicated that the ice front it was only slightly attached to the platform.

By April 6, the fracture had reached about 40 km long before it cut through the portion of the ice front between Inexpressible Island to the north and the Drygalski ice tongue to the south.

Observed by NASA's Terra satellite, the rupture occurred on April 7 during persistent, strong winds offshore. Two days later, Sentinel-1A's radar confirmed the separation.

"The area of ​​the fracture was still insignificant at the beginning of 2014, but between April 2015 and March 2016 it expanded from 11.68 square km to 25.87 square km, which indicates that a rupture is coming," he said. Flavio Parmiggiani, from the ISAC-CNR research organization in Italy.

The fracture has split the ice shelf along its length, resulting in two large icebergs that are approximately 10 km and 20 km long, and 5 km in diameter. Published research indicates that icebergs are likely 250 to 270 m thick.

ABC


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