Over tuna pasta, Fred and Hervé tell us about their plan for the following day: they want to look for the entry point on the eastern end of the glacier, where the water has cut a gorge into the ice. “The outflow must be gigantic,” Fred says, explaining that in summer a gigantic glacial lake, the Lac des Faverges, usually lies there. Come autumn, it suddenly vanishes when around two cubic metres of water gushes through the glacier and only reappears when it flows into the Simmental Valley. “It is as if someone pulls the plug of a gigantic bathtub.” The tranquil Simme turns into a raging river and, with the increasing size of the lake, the threat of a devastating tidal wave gets bigger each year: it has actually tripled in size over the past five years. And because the level of the glacier has dropped, the lake can no longer drain into Valais, across the ridge. The creeks there have dried up and all the water now ends up in the Bernese Oberland. Since 2011, the Lac des Faverges has been under close surveillance, so that the population can be warned in case of bursting.
Hervé and Fred are convinced that – at least at times – the corridors must be connected throughout the whole glacier; otherwise, the lake could not drain. The underground canal system expands across 3.5 horizontal kilometres and 250 vertical metres and exploring this gigantic space has long been dream of theirs. Whether or not they can make it reality remains to be seen. “You would have to do it wearing a complete diving suit because of the water level,” Hervé says. This means that from a certain depth onwards, it would probably feel like being inside the sinking Titanic, with all the corridors filled with water. We contemplate this for a little while until the cold drives us into our sleeping bags.
It’s minus 25 degrees. It’s lonely and completely silent. And it’s hard to believe that all this will disappear in the coming decades.
The Plaine Morte Glacier has retreated more than any other glacier in the Alps, even though it was doing relatively well between 1960 and 2002. Then, the amount of ice in the winter was almost identical to the amount of melt water in the summer. However, since the turn of the millennium, there has been a rapid change and there has been less and less snow on the glacier during the summer. The rule of thumb in glaciology is that in order to keep the natural balance of a glacier, at least two thirds of the icy surface need to be covered in snow throughout the year. Over the past four years, the Plaine Morte was completely bare by the end of summer. Masses of ice are laid out like a dead body waiting for an open-air burial, while vultures circle above, wearing the dress of climate change.