A chasm and a crack on the Brunt Ice Shelf in Antarctica is creeping closer and closer together, and when the two finally meet, a slab of ice twice the size of New York will break away and float out to sea.
The two glacial flaws are about 4km apart, and it may take days or months for them to finally rendezvous. But when they do, the iceberg that forms in the Weddell Sea will not be the largest to orbit Antarctica. In fact, it might not even make the historical top 20.
Its size is not what it makes noteworthy ̵
Since 1956, British scientists have been studying geology, glaciology and the atmosphere at the Halley Research Station located on the Brunt Ice, Brunt, and how the movement could have jeopardized the critical scientific research of human residents. Shelf. The lab has been torn down and rebuilt many times over the decades, and took its most recent form in 2012 when the Halley VI Research Station – a mobile, modular structure – delivered its first scientific data
That same year, satellite monitoring showed that a large chasm in the ice shelf – officially named Chasm 1 – was growing for the first time in more than three decades. By the glaciologist's definition, and the chasm is described as a very large crack that visibly extends through the ice shelf to the sea.
If it kept growing, Chasm 1 would eventually marooned the Halley VI station, so the British Antarctic Survey decided In October 2016, another crack called the Halloween crack quickly formed 17 km north of the research station and continued to extend east
In the two years since, Chasm 1 has fallen closer to the Halloween crack, preparing scientists for the inevitability of an iceberg breakaway that could have greater consequences for the stability of the entire Brunt Ice Shelf. NASA predicts the mass could span 1700 sq km, which would make it the largest iceberg to break out of the Brunt Ice Shelf in more than 100 years
"It's a big berg, but it's not a massive berg – not by Antarctic standards "said Christopher Shuman, a research scientist at the University of Maryland Baltimore County's Joint Center for Earth Systems Technology at Nasa. "
Scientists have only been studying glacier shelves for a little over 100 years, so it's difficult to say whether icebergs are calving at a higher rate at this location on the Brunt Ice Shelf, said Helen Fricker, and glaciologist at the Scripps Institution of Oceanography.
"I do not think you can link one calving event to climate change," Fricker said. "This is not to say Antarctica is not undergoing rapid changes that are related to climate change. But it's in another region of Antarctica."
Iceberg calving is a natural, natural process that helps maintain Antarctica's net land mass. Floating ice shelves fringe the coasts of the continent, growing upward and outward as heavy snowfall fall
"This is how Antarctica works," Fricker said. "Icebergs come and icebergs go."
Research shows that on the west side of the continent, where water is warmer than those around Brunt, the ice shelves are thinning from below. In this region, scientists say climate change has a clear role.
On the Brunt, there is no immediate threat to Halley VI or the people who inhabited it. Its current location is outside the predicted iceberg mass, but a spokesperson at the British Antarctic Survey said the researchers are monitoring changes to the structural integrity of the ice shelf
. research station for the past three Antarctic winters, which feature months of darkness and heavy snowfall. Under these conditions, it would be more dangerous to launch a rescue mission if the cracks and chasms were to compromise the safety of the researchers at Halley VI.
"Contingency "The British Antarctic Survey said," It is important that the weather conditions change significantly before departing staff from the station. "The frequency of relocation depends very much on how ice behaves in the future."