Researchers expected to find some holes between ice and bedrock at Thwaites' bottom, however, the size and "explosive growth rate" of the cavity shocked them. The cavern first appeared in 2012 and most of the ice that once occupied it melted in the last 3.
The cavern sits where almost 14 billion tons of ice used to be, all of which melted in the last few years.
"We have for years suspected that Thwaites is not firmly connected to the substrate", says Co-author Eric Rignot.
'The size of a cavity under a glacier plays an important role in melting, ' said Nasa's Pietro Milillo.
The end of the glacier, where the cavity has been formed, is particularly sensitive, because of warmer sea encroachment of water to the ice and it can melt from below. "The International Thwaites Glacier Collaboration is preparing to embark on a field study on the ground during the Southern Hemisphere's next summer, in late 2019 and early 2020". The growing cavity is the red mass at the center. The mottled area (bottom left) is the site of extensive calving.
The Thwaites glacier, about the size of the US state of Florida, and now account for about four percent of the global sea-level rise is responsible.
"Thwaites Glacier is roughly the size of Florida, and by itself reportedly holds enough ice to raise the global sea level by 2.1 ft (65 cm)". Moreover, the glacier acts as a backstop for neighboring glaciers, meaning that it slows the rate at which they lose ice.
"Understanding the details of how the ocean melts away this glacier is essential to project its impact on sea level rise in the coming decades", added Rignot.More news: Kristaps Porzingis Message To New York Knicks Fans: 'Stay Woke'
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About the size of Florida, Thwaites Glacier is now responsible for approximately 4 percent of global sea level rise.
The gaping mouth is located at the base of the Thwaites Glaciers, which is considered by many to be one of the most risky in the world due to its massive size. For instance, the 100-mile-long (160 kilometers) glacier front has different rates of retreat in its grounding line (where the sea ice meets the ocean's bedrock) depending on where you look.
The huge cavity is under the fundamental trunk of the ice sheet on its western side - the side more distant from the West Antarctic Peninsula.
However, there's been more retreat than advancement as of late.
The ice sheet has been unhinging from an edge in the bedrock at an unfaltering rate of about 0.4 to 0.5 miles (0.6 to 0.8 kilometers) a year since 1992.
The glacier has become a case study since the researchers are attempting to learn how the cavity will influence the speed at which the glacier melts. Many Antarctic glaciers extend for miles beyond their grounding lines, floating out over the open ocean. This data also shed some light on another concern about the glacier's grounding line, the point at which the glacier starts to depart from land and float on the sea.
"The researchers on the current study hope that these new results will help inform that team's work", the news portal continued.
Nasa has made a series of shocking discoveries about the state of the glacier.