Evolution of Mer de Glace (2007 to 2025)

Mer de Glace is the largest glacier in mainland France. Since the summer of 2021, we have been visiting Mer de Glace every summer to record its changes. The video shows the evolution of Mer de Glace (French Alps) between 2007 and 2026. As you can see here, a glacier isn't necessarily all white. A large amount of rocks are deposited on its surface due to mountain erosion: these are moraines, which give the glacier its gray color. In this video, you can see the glacier thinning and slowly moving downhill.

In 20 years, over 100 meters is lost in thickness. While its thickness reached 230 meters in 1990 at Les Echelets (the bend in the foreground), less than 60 meters remain today, enough to last about ten years… Each year Mer de Glace surprises us with the intensity of the changes, and 2026 is no exception with the formation of a stream (or meltwater channel) in the center of the glacier.

We're still looking for images to improve this timelapse 🎞️🎞️ and go back further in time. 🫵 If you have any great photos taken of the Montenvers train station in your attic and would like to participate, please share them with us!

We thank Delphine Six and the GLACIOCLIM observatory for the measurements, Compagnie du Mont Blanc for the webcam, and Jean-Michel Friedt and the IGE for the archived images.

(Measurements of lost thickness taken at Les Echelets between 2007 and 2024: -93.7 m, extrapolated to -105 m for 2026)

Bedrock altitude according to Peyaud et al. (2020) https://doi.org/10.5194/tc-14-3979-2020