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Glacier the size of Great Britain under threat of separating from Antarctica

Channels of warm ocean water melting the ice from below threaten the stability of Thwaites glacier in western Antarctica. Photo:AFP/Getty


Glacier the size of Great Britain under threat of separating from Antarctica


By Patryk Krych | The World Daily | SEPTEMBER 11th 2020


The Thwaites glacier in the West Antarctic, nicknamed the ‘Doomsday Glacier’, has been marked by scientists as a possible global threat, as warmer channels of oceanic waters are heating it from underneath. This may lead to the country-sized glacier’s eventual separation.

The scientific findings, recently published in The Cryosphere journal, reveal the ocean floor beneath the glacier is much deeper than anyone had previously thought it would be. There are an especially high number of channel lines leading to the meeting point of the ice, and the ocean bed. The primary fear is that the glacier, noted to be the size of Great Britain, will separate from the rest of the ice shelf in turn leading to a major worldwide rising of sea levels.

Scientists say that the Thwaites glacier is extremely sensitive to climate damage, and that it has been melting for a long while now, accounting for about 4% of global sea rise levels. Over the past three decades, its loss of ice mass has increased fivefold.

Cavities, comparable to tooth decay, have been mapped by the scientists in the report all across the glacier, the size of the Grand Canyon. These cavities, the scientists fear, are allowing warmer water from underground channels to enter the glacier and exacerbate the melting process, and the global sea level rising as a direct result.

“And because they are so deep, and so wide - this allows a lot more water to get at, and melt, Thwaites' floating front as well as its ice that rests on the seabed,” said Dr Kelly Hogan from the British Antarctic Survey (BAS).

It was the BAS, along with a United States team that had traced the glacier’s seabed terrain, as well as much of the ice shelf’s very bottom levels in order to measure the gaps present. These gaps had appeared in areas that were previously grounded ice. This study was accomplished using aircraft, ship, and a robot submarine.

What they’d found was two particular cavities, about 800 metres deep, going about 10km across (six miles), a perfect passageway for warm water to invade and contribute to the glacier’s melting. While these two cavities were around 10,000 years old, the scientists found evidence of expansion, as well as relatively new fissures within the ice that had appeared somewhere in the last 30 years.

“Before we did these studies, the assumption was that all the channels are the same, but the new ones are much thinner and more dynamic. They will get bigger over time,” said Dr. Tom Jordan, an aero-geophysicist at the British Antarctic Survey, and one of the study’s lead authors. “Understanding that process and how these cavities evolve will be key to understanding how Thwaites and western Antarctica will change in the future.”

The Thwaites glacier covers around 192,000 sq km (74,000 sq miles), and if it were to collapse entirely, would add about 65cm to sea levels. Scientists aren’t sure how soon this may happen, but they know the process is under way.

“Thwaites Glacier itself is probably one of the most significant glaciers in West Antarctica, because it's so large, because we can see it's changing today,” said Dr. Jordan. “And also, we know that its bed dips down, and it gets deeper and deeper underneath the ice sheet, which means that, theoretically, you can get a process called marine ice sheet instability. And once it starts to retreat, it will just keep retreating.”

At the moment, nobody’s worried about the Thwaites breaking off from the rest of the shelf in the short or medium term, but as a long-term problem, the issue cannot be ignored. Particularly in our modern, constantly warming world where so many human actions and indecisions lead to further climate change. The UK and US teams joined to study the glacier together in 2019, and will supposedly continue their studies to try and figure out the rate of thaw, to see how and when the foreshadowed changes may occur.


By Patryk Krych | © The World Daily 2020