If you compare historical photos of glaciers with those taken more recently, you can see that where there was formerly ice there is now very often nothing but rock.
If you compare historical photos of glaciers with those taken more recently, you can see that where there was formerly ice there is now very often nothing but rock. Geographers, however, are less interested in the area covered by a glacier, and more interested in its mass. Researchers from FAU have now investigated all glacial areas in South America in more detail than ever before, from the tropical areas of Venezuela to the subpolar regions of Tierra del Fuego. Their two major findings are that the highest rate of mass loss is in the Patagonian icesheet, and that the glaciers in the tropics have lost considerably less mass than previously projected, although this is not the good news which it might appear at first sight. The researchers’ findings have been published in the journal Nature Climate Change.*
Surveying glaciers is nothing new. There are two methods which are used particularly often. In the first method, researchers take several measurements directly at a glacier and project the results for entire regions. This is particularly problematic when it comes to large glacial areas such as the large ice fields in Patagonia, as barely any in situ measurements are available for these areas. The other option is to take gravimetric measurements using satellites. Scientists base their measurements on the fact that gravity on Earth changes depending not only on the location but also over time. It is influenced by aspects such as the composition of the Earth’s surface, mountain ranges, movements in the core, plate movements – and, of interest for our context, when glaciers lose mass. One disadvantage of this method is that when only small areas are covered by glaciers, as is the case in the South American tropics, the satellite only receives a weak signal and the measurement is significantly less accurate.
Read more at University of Erlangen-Nuremberg
Image: The Grey Glacier is located in the Southern Patagonian Ice Field in Chile. When such outlet glaciers shrink, they first have to form a new stable front. CREDIT: FAU / Matthias Braun
