Tuesday , July 27 2021

Iceberg twice as big as New York is about to break Antarctica



The precipice and the crack of the Antarctic ice shelf are getting nearer and closer to each other, and when they finally meet, the ice twice as big as the New York City will tear off and emerge into the sea.

The two ice defects are about 4 km apart and can take days or months to meet. But when they do, the iceberg that forms in the Wadell Sea will not be the largest for orbit in Antarctica. In fact, it can not even make the historic top 20.

Its size is not what makes it remarkable – what the holiday itself says about the natural process of calving in the iceberg, the way climate change can destabilize other ice shelves like Brunth, and how movement can endanger critical research, people who lived. over 60 years.

Since 1956, British scientists have studied geology, gliology, and the atmosphere at the Hallian research station on Brunth's ice shelf. The laboratory has been demolished and rebuilt many times over the past decades, with its latest form in 2012, when the Halley VI Research Station, a mobile, modular structure, provided its first scientific data.

That same year, satellite monitoring showed that a large chasm in the ice shelf – officially called Chasm 1 – was growing for the first time in more than three decades. According to the geologist's definition, the gap is described as a very large crack that visibly extends across the ice shelf to the sea.

If it continued to grow, Chasm 1 would eventually leave the Halley VI station, so the British Antarctic Research decided to move its researchers inside and at a safe distance from the gap for several months in 2016 and 2017.

But in October 2016, another crack called the Halloween Breakthrough quickly formed 17 km north of the research station and continued to extend eastward.

During these two years, Chasm 1 approached the Halloween crack, preparing the scientists for the inevitability of the iceberg, which could have greater implications for the stability of the entire ice shelf. Nasa predicts that the mass can reach 1700 sq. Km, which will make it the largest iceberg that will be part of the Brunth's Ice Shelf for more than 100 years.

"It's a big deal, but it's not a massive bargain – not Antarctic standards," says Christopher Schumann, a researcher at the Baltimore County Joint Earth Systems Center at NASA's Maryland University. "The impact on the area is that these failures have been activated again, and we are not sure why, a new rift (Halloween gap) has formed it, which was considered a very stable ice shelf."

Scientists have been studying ice shelves for just over 100 years, so it's hard to tell if icebergs are breastfeeding at a higher rate on this iceberg shelf, says Helen Fricker, a scientist at the Scripps Institute of Oceanography.

"I do not think you can link an event to climate change," Fricker said. "It does not mean that Antarctica does not undergo rapid changes that are related to climate change, but it is in another region of Antarctica."

Iceberg is a normal natural process that helps maintain Antarctica's clean ground. Floating ice shelves cover the continent's coasts, growing up and out when heavy snow falls.

"That's how Antarctica works," Fricer said. "Icebergs come to Iceberg.

Research shows that from the western side of the continent, where the waters are warmer than those around Brunth, the ice shelves are thinning down. Scientists in this region say that climate change has a clear role.

Brunth has no immediate threat to Hallius VI or to the people who live it. Its current location is outside the predicted iceberg table, but a spokesman for the British Antarctic survey said the researchers were watching changes in the structural integrity of the ice shelf.

Part of this monitoring includes a precautionary measure to shut down operations at the research station for the last three Antarctic winters, which show months of darkness and heavy snowfall. Under these circumstances, it would be more dangerous to start a rescue mission if cracks and gaps would compromise the safety of researchers in Hallius VI.

At present, staff members are about to leave for the winter of 2019.

"Unexpected contingency plans are available if ice conditions change significantly before the staff leave the station," the study said in the British Antarctic. "The station is designed to be removable, and the frequency of the transfer depends very much on the way the ice behaves in the future."


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