A huge cavern has formed in the upper part of the Glacier des Bossons in Chamonix.

So large that it’s visible from the centre of Chamonix, the cave appeared last month in the upper part of the Bossons glacier.


A old pocket of water or large crevasse?

Located not far from the Grands Mulets refuge, the scale has shocked locals, who estimate it to be more than 10m in diameter.

Geomorphologist Ludovic Ravanel has suggested the cave has been caused by an internal collapse generated by the glacier’s advance.

“The cave may be the remnant of an old pocket of water, or it could be the end of a large crevasse.

Although the size and shape of this space are intriguing, its emergence in the middle of winter is not that surprising,” said Ravanel.

It is more evidence of the many spectacular changes observed in recent years on the Bossons glacier as it responds to global warming.