BBC: Aerial photos from the 1940s and 1950s are being used to probe the climate history of the Antarctic Peninsula.
UK scientists are comparing the images with newly acquired data sets to assess the changes that have occurred in some of the region's 400-plus glaciers.
The old and modern information has to be very carefully aligned if it is to show up any differences reliably.
And that is a big challenge when snow and ice obscure ground features that might otherwise act as visual anchors.
But...