Glaciers in the Alps
Sleuthing a Victorian-era Glacial Ice 'Murder' Mystery

NASA researchers and collaborators have combined historical records, ancient ice from cores in glaciers, modern air pollution studies and a model of glacier behavior to offer an explanation of why glaciers in the Alps started retreating in the late 19th century, despite cool temperatures and ample snowfall, which should have kept them growing.  They find that soot from industrialization in Europe was deposited on the lower slopes of the glaciers, and that soot absorbed sunlight and accelerated melting.  Although pollution sources today are not the same as in the 19th century, there is still enough pollution to make the air circulation patterns visible.  This photo from summer 2012 looking south into the Bernese Alps shows how air pollution in the Alps tends to be confined to lower altitudes, concentrating the deposition of soot and dust on the lower slopes. At center left in the picture, a glacier can be seen extending from a high-altitude snow field, above the pollution layer, down into the valley where its lower reach is bathed in pollutants.  

Image credit: Peter Holy

Page Last Updated: September 3rd, 2013
Page Editor: Tony Greicius