It took nearly an hour and a half of hiking to reach the entrance of this cave, which opened beneath the Arolla glacier, in the Swiss Valais. The panorama was taken at the entrance in February 2020, on an outing with the photographer Iconogone. The equipment was heavy: snowshoes, ice axes, 35 metres of rope, ascending gear and photographic equipment. Yet no passage led any deeper.
Inside the glacier cave
The cave formed a long sloping tunnel, carved into the ice by water and air currents. The process differs from the one that shapes karst cavities, which are opened in rock by erosion, a mechanical action, or by corrosion, a chemical action.
The outing took place in winter, the season when the subglacial river that ran through the cave was frozen. It was also a question of safety: in summer, many blocks of ice would collapse.
The collapse of September 2022
Since 2021, the gallery had been open from end to end. It attracted many hikers, even though it was reached off the marked trails. By the end of summer 2022, the cavity was slowly sinking and the danger was growing week by week.
The roof collapsed during the night of Monday 19 to Tuesday 20 September 2022. The heat and the melting of the Mont Collon glacier, which towers over Arolla, had weakened the ice. A slight earthquake that night may have hastened the failure. The winter of 2021-2022 was the last in which it was possible to enter the cave.
The Arolla glacier cave in pictures
The Arolla glacier cave, photo 1 of 3
The Arolla glacier cave, photo 2 of 3
The Arolla glacier cave, photo 3 of 3
Sources: 20 minutes, “Valais : la grotte de glace d’Arolla s’est effondrée” (September 2022), via Le Nouvelliste; Alpinetrek, “La grotte du glacier d’Arolla n’existe plus”
This tour is part of the catalogue of virtual tours of underground heritage.
