MIT Technology Review @techreview
Quelccaya Glacier in Peru, seen here in 2017, is receding. The foreground rocks show signs of glacial erosion and were likely still covered 10 years ago. Each layer in the ice represents a year’s worth of snow. Annotated by geographer Carsten Braun. https://t.co/HVXHZg1emT — PolitiTweet.org