The Mer de Glace is the third most important glacier in the Alps. This is an alpine glacier located on the north face of Mont Blanc. It is formed by the junction of three smaller glaciers: Glaciers Tacul, Leschaux and Talefre. It measures a total of 7 km long. Its thickness is about 200 m and its surface is 35 km2.
Since 2003, the glacier retreated 30 meters a year and the ice thickness has decreased by 8 to 10 meters per year