Climate Change

A submarine robot gives close up of Doomsday glacier, finds more trouble beneath it

It is one of the glaciers on the continent that exhibits the quickest and most unstable changes

 
By Arya Rohini
Published: Thursday 16 February 2023
Icefin is a small robotic oceanographer that allows researchers to study ice and water around and beneath ice shelves. Photo: Cornell Chronicle.__

Thwaites Glacier in Antarctica, often known as the ‘Doomsday Glacier’, is in peril as warm ocean water has entered its weak points, according to a new research.

Thwaites Glacier might contribute to a rise in sea level of more than half a metre and further destabilise the nearby glaciers, which can add another three metres to the surge, noted the study’s findings published in two papers in the journal Nature February 15, 2023. 


Also read: Receding cryosphere: What latest WMO report warns us about


Currently, the Thwaites contribute four per cent to the average sea-level rise rate of 1.5 inches per decade. Recent decades have seen an acceleration in its retreat, but scientists disagree on whether it has reached or is approaching the point at which its collapse is imminent.

In several thousand years, the sea level would rise by 10 feet if all the major glaciers in west Antarctica were to melt. Thwaites is one of the glaciers on the continent that exhibits the quickest and most unstable changes.

The glacier is experiencing one of the worst situations owing to melting brought on by rising temperatures. This might force it to break off or melt and cause a large rise in sea levels.


Watch video: Highest glacier on Mt Everest is rapidly melting


The researchers discovered new hints on how an Antarctic ice sheet is melting by deploying a submarine robot beneath it. This ice shelf in western Antarctica appears to be rapidly retreating due to mechanisms distinct from those previously thought to be at play.

Britney Schmidt, a geophysicist at Cornell University and the lead author of one of the papers said:

These new ways of observing the glacier allow us to understand that it’s not just how much melting is happening, but how and where it is happening that matters in these very warm parts of Antarctica.

The findings will assist in evaluating the threat Thwaites and other glaciers pose for long-term sea-level rise. The study is a result of the collective effort by the International Thwaites Glacier Collaboration funded by the United States and Britain.

Through a roughly 2,000-foot-deep tunnel dug in the ice, the team deployed a remotely controlled Icefin underwater robot and obtained the first up-close pictures of the crucial location.

Icefin is a small robotic oceanographer that allows researchers to study ice and water around and beneath ice shelves.

“Icefin is collecting data as close to the ice as possible in locations no other tool can currently reach,” said Washam, who led the analysis of Icefin data used to calculate melt rates.

It’s showing us that this system is very complex and requires a rethinking of how the ocean is melting the ice, especially in a location like Thwaites, Washam added.


Also read: Half of glaciers will disappear by 2100 even if world sticks to 1.5°C goal: Study


Additionally, they found that unexpected terraces and crevasses that reached deep into the ice were melting quickly. “We see crevasses and probably terraces, across warming glaciers like Thwaites. Warm water is getting into the cracks, helping wear down the glacier at its weakest points,” said Schmidt.

Glaciers are receding at unprecedented rates due to climate change and rising temperatures. Half the Earth’s glaciers will vanish by 2100, even if we adhere to the Paris Climate Agreement goal of limiting global temperature rise to 1.5 degrees Celsius above pre-industrial levels, another study published in January, 2023, warned.

Losses would be more severe, with 68 per cent of glaciers vanishing, if global warming continues at the current rate of 2.7°C. If this happens, by the end of the following century, there would be practically no glaciers left in central Europe, western Canada and the United States.

Glaciers, which hold 70 per cent of the Earth’s freshwater, currently encompass around 10 per cent of the planet’s land area.

Melting glaciers raise sea levels dramatically, jeopardising up to two billion people’s access to water and increasing the risk of natural disasters and extreme weather events like floods.

“The rapidly increasing glacier mass losses as global temperature increases beyond 1.5C stresses the urgency of establishing more ambitious climate pledges to preserve the glaciers in these mountainous regions,” the researchers wrote.

The amount of ice lost by glaciers between 1994 and 2017 was around 30 trillion tonnes and they are now melting at a pace of 1.2 trillion tonnes each year.

The glaciers in the Alps, Iceland and Alaska are some of those that are melting at the quickest rates. Global sea level rose by 21 per cent between 2000 and 2019. This was solely due to meltwater from melting glaciers and ice sheets, according to another study published in the journal Nature.

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