Antarctica, Pine Island and Thwaites glaciers on the verge of breaking off
Environment — di Andrea Barolini
A scientific study has identified the “Achilles heel” of the Thwaites and the reason why it melts quickly compared to other glaciers.
Antarctica, Pine Island and Thwaites glaciers on the verge of breaking off
A scientific study has identified the “Achilles heel” of the Thwaites and the reason why it melts quickly compared to other glaciers.
Global warming continues to claim victims. The latest, in chronological order, are the Pine Island and Thwaites glaciers, in the Antarctic region. According to the information contained in a scientific study published by the journal Proceedings of the National Academy of Sciences (Pnas), these glacial structures, fundamental to the stability of the entire South Pole, are now on the verge of breaking off.
Pine island & Thwaites glaciers in the Antarctic are sustaining rapid damage at their most vulnerable points, leading to the breaking up of vital ice shelves with major consequences for global sea level rise.
Adaptation may now be our only choice.
cnn.com/2020/09/15/wea…
Adaptation may now be our only choice.
cnn.com/2020/09/15/wea…
Thwaites loses 80 billion tonnes of ice per year
The portions of the ice sheet that normally prevent Pine Island and Thwaites from breaking off and advancing towards the sea are showing signs of advanced melting. This would be an extremely alarming piece of news, given that – although still anchored to the Antarctic ice sheet – the partial melting of the two glaciers has already contributed 5 per cent to global sea level rise.
The dimensions of these structures are indeed gigantic. The Thwaites glacier is 600 kilometres long and 120 kilometres wide and is among those melting most rapidly. According to the BBC, it is now losing approximately 80 billion tonnes of ice every year (in the 1990s the figure was 10 billion). Were it to melt entirely, sea level rise would reach 65 centimetres.
The "apocalyptic" scenario envisaging a domino effect for the glaciers
Scientists appear to have understood the reason for this increase: beneath the Thwaites, a series of deep channels has been discovered. These allow warmer ocean water to melt the lower portion of the glacier from below. "For the first time, we have shed light on the pathways through which warm water can reach the ice sheet," explained Kelly Hogan, of the British Antarctic Survey, one of the authors of the analysis.
If Pine Island and Thwaites glaciers destabilize, its neighbors will fall apart. abcn.ws/32tT8m2
According to the study, the channels identified could reach a depth of 600 metres. "Precisely because of this length, as well as their width, they allow a great deal of water to melt the ice," the expert added. In the event of a break-off, a scenario described as "apocalyptic" could materialise, with a domino effect that could risk dragging in other significant portions of the ice sheet.