In the underground abysses created by the melting of the glaciers, speleologists try to prevent tragedies such as the one caused by the collapse of the Marmolada. And one of the most experienced tells us why the hunt for extraterrestrial life also begins here

Francesco Sauro, the man of the (ice) caves

Venturing into a cave inside a glacier requires great concentration and fine hearing. Because any creak can be a sign of a widening crack, and an impending collapse. Knowing how to distinguish it from the dripping and gurgling water that comes out everywhere is essential - Photo

The guardians of the ice, here are the 150 volunteers who watch over our mountains - guard

Francesco Sauro has already found himself in the situation of suddenly stopping during a descent into an icy pit at a depth of over a hundred meters, due to a presentiment rather than a noise. And only the immediate ascent saved him from the landslide of the wall on which he was climbing. On the other hand, the glacial mills, as these underground cavities opened by the meltwater of the glaciers are called, are the most fragile that can exist. The ice that melts on the surface creates streams that carve down passages, forming networks of caves and tunnels. And when the water reaches the rocky bed, with its strength it is able to lift the glacier, making it slide forward and breaking it.

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WHAT HAPPENED ON MARMOLADA - Exactly what happened on the Marmolada last July 3, with a detachment of ice that overwhelmed and killed 11 hikers. No warning system had been able to predict this in time. 'Our models are based on satellite observations and surface monitoring, but we don't know what happens inside a glacier,' observes Sauro. 'We try to understand how much heat the infiltrating melt water brings, and how long a glacier can survive this internal erosion'.
38-year-old from Padua, Francesco Sauro has been moving through the labyrinths of the subsoil since he was a child. His parents took him to a cave when he was four years old. At 13 he made his first exploration, and at 15 he had already descended to 900 meters deep. Today, after a doctorate in geology, and almost 40 expeditions in which he has mapped one hundred kilometers of underground tunnels, from Greenland to the Amazon, he is one of the most famous speleologists in the world. 'There is nothing more ephemeral than exploring an ice cave,' he says. 'They are environments that change constantly and after a few months they no longer exist: this is their charm'.

FROM GREENLAND TO THE AMAZON - Sauro approached the glaciers in 2013, at the insistence of a glaciologist friend and photographer, Alessio Romeo, who wanted to capture the less visible effects of global warming. During a descent into the Mer de Glace glacier, under the peaks of Mont Blanc, the caver was bewitched by the blue light that dominated its depths. «The glacial caves are the only ones where the light arrives, even if in the form of an intense blue that confuses». The presence of light has increased his scientific interest in these frozen depths. Because if there is light there may also be forms of microbial life that exploit photosynthesis. 'I study underground environments with different types of rocks also to understand what could happen on other planets from the point of view of minerals and microbiology,' continues Sauro, who for years has taught courses in planetary geology at the University of Bologna. 'During my doctorate I spent my nights looking at satellite images of Mars looking for new cave entrances, and I found a lot of them,' says the speleologist.

JOURNEY TO MARS - Life on Mars is now made impossible by the absence of an atmosphere like the one that protects the Earth from ultraviolet rays. But 4 billion years ago the two planets had a similar atmosphere and if an extraterrestrial life managed to emerge then, the only place where it could later take refuge is in the depths of the glaciers and volcanoes that cover the surface of Mars. This is why Sauro has specialized in the exploration of glacial and volcanic caves. If microorganisms can withstand the temperatures and pressures that exist hundreds, if not thousands of meters deep, under an Alpine glacier or an Icelandic volcano, perhaps the same can happen on another planet.

WORKING FOR ESA - This type of activity led Francesco Sauro to work for ESA, the European Space Agency. 'With Alessio and other friends of the La Venta association we have created the Miles Beyond company which organizes training courses for astronauts. We have already formed 36, which remained for a week in a cave at a depth of over 300 meters ', concludes Sauro who has just collected in a book ( The dark continent , Il Saggiatore) his twenty-year experiences as a speleologist. The techniques for moving through space, it seems, are similar to those used by those who descend into the subterranean abyss. Also the sense of dizziness in the face of the unknown.

Source: oggi.it