glacier

Experts have warned that part of a glacier on the Mont Blanc massif is at risk of collapse. Authorities say about 250,000 cubic metres of ice could come down in the form of ice avalanches from the Planpincieux glacier, on the Italian side of the mountain. The mayor of Courmayeur, the closest town, decided to close roads as a precautionary measure.

A glacial gravestone will memorialise Iceland's first glacier lost to global warming and feature a poignant "letter to the future."

And is largely responsible for rising sea levels.

This isn't the first time they've been spotted