Scientists thought this Argentine glacier was stable. Now they say it’s melting fast

An emblematic Argentinian glacier, long thought out, one of the few on earth to be relatively stable, now undergoes its “most substantial retirement during the last century”, according to new research.

The Perito Moreno glacier in the ice field of the southern Patagonia for decades has been stuck safely in a valley. But he started losing contact with the rocky substratum below, making him lose more ice with regard to the back. It is a change, illustrated in photos of dramatic timelapse since 2020, which highlights “the fragile balance of one of the best known glaciers in the world”, write the authors of the study in the journal Earth & Environment Communications.

They expect it back to several other kilometers in the coming years.

“We believe that the retirement we see now, and why it is so extreme in terms of values that we can observe, it is because it has not been stable in a climatic way for some time now, for more than a decade,” said Moritz Koch, a doctoral student to the authors of the study of Friedrich-Alexander. “Now we see this very delayed response to climate change because it is slowly but surely detaches from this physical pinning point in the central part of the glacier.”

Koch and his team did a complete job on the ground to obtain the data from their calculations. To measure the thickness of the ice, they flew over the glacier in a helicopter with a speed radar device below. They also used Sonar on the lake and satellite information from above.

Each year, hundreds of thousands of people visit Glaciar Perito Moreno, who was declared UNESCO World Heritage Site in 1981. It is a site known for “Calve” pieces of ice that fall into the Argentino lake below.

Basic physics of climate change and glaciers is intuitive: the heat melts ice, and global warming means more and faster ice cast iron, said Richard Alley, an ice scientist with the Pennsylvania State University who was not involved in the study. But a bit like a drop cup, it is more difficult to predict when and exactly how they will separate.

He said that people who deny climate change frequently point to anomalies like Perito Moreno, which do not withdraw long when most of the other glaciers were.

Even without climate change, the glaciers fluctuate a little. But if the climate was stable, the ordinary accumulation of snow and ice would compensate for melting and movement, said Erin Pettit, glaciologist at Oregon State University which was not involved in the study either.

The glacial fusion, in particular the poles, is important because it could cause a catastrophic elevation of sea level, harm and move people living in coastal and island areas. Although the changes can be locally spectacular in places like Patagonia, Alley said that the greatest concern was to use studies like this to understand “which could happen to the big” in Antarctica.

But still smaller glaciers have a powerful presence in the communities, said Pettit. The ice has cut many landscapes that people love today, and they are intimately linked to many cultures of the world. Glaciers can be a source of drinking water or, when they collapse, a destructive force leaving slots of mud in their wake.

“We lose these little pieces of ice everywhere,” said Petit. “I hope we slowly get more respect for the ice that was here, even if it’s not always there.”

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