Considering that we didn’t start getting satellites up into the atmosphere until the 1970s, it comes as no surprise that recently discovered photographs from the 1930s depicting Greenland’s glaciers are viewed as a precious scientific resource.
Rediscovered in a castle just outside of Copenhagen, Denmark, the photographs below spawn from 1930s aerial surveys of the southeast coast of Greenland. Combined with US military aerial shots taken during the Second World War and recent satellite images, Anders Bjørk at the University of Copenhagen and his colleagues have been able to observe changes at high spatial resolution from a period in which few glacier measurements have ever been found.
Analysis of the photographs have revealed that glacier retreat was as vigorous during the 1930s as it has been over the past decade, thanks in part due to a similar period of warming during the 1930s. However, whereas glaciers with a terminus in the ocean are retreating rapidly today, it was land-terminating glaciers that suffered depletion 80 years ago.