New estimates of HMA glacier change
Fanny, Patrick, Etienne Berthier and colleagues from Oslo University (Andreas Kääb and Désirée Treichler) have just published the study “A spatially resolved estimate of High Mountain Asia glacier mass balances from 2000 to 2016” in Nature Geoscience. They used more than 50,000 ASTER satellite images to derive digital elevation models and to track glacier thickness changes over High Mountain Asia. They provide the first consistent estimate of volume change for ~90 000 km2 of glaciers.
Their study confirms the existence of the so called “Karakoram anomaly” and, following a 2015 study by Andreas Kääb et al. refines its location: glaciers located in the West Kunlun, Karakoram and Eastern Pamir have balanced or slightly positive mass changes. The most negative mass changes are found in the Eastern Himalaya, where glaciers loose mass at rates similar to the ones in the European Alps (up to 0.62 ± 0.23 m w.e. yr-1).
These data will help to constrain glacio-hydrological models and to better understand the contribution of glaciers to stream flow and sea level rise. Nevertheless, they provide only mass balance values averaged over 16 years and therefore do not give access to the processes responsible for these changes. More field data are needed to investigate these.