Mer de Glace

The glacier flows through a high Alpine valley below steep granite walls. It experiences heavy winter snowfall, warm summers and frequent freeze–thaw cycles on surrounding rock faces.

Tributary ice streams merge into a debris-streaked tongue. Moraines mark former ice levels, while thinning ice changes the connection between the glacier, valley paths and mountain infrastructure.

Its long visual record makes glacier retreat understandable to the public. It also shows how warming affects tourism, climbing access, permafrost and rockfall exposure.