Region-wide glacier mass balances over the Pamir-Karakoram-Himalaya during 1999–2011

摘要

The recent evolution of Pamir-Karakoram-Himalaya (PKH) glaciers, widelyacknowledged as valuable high-altitude as well as mid-latitude climaticindicators, remains poorly known. To estimate the region-wide glacier massbalance for 9 study sites spread from the Pamir to the Hengduan Shan (easternHimalaya), we compared the 2000 Shuttle Radar Topography Mission (SRTM)digital elevation model (DEM) to recent (2008–2011) DEMs derived from SPOT5stereo imagery. During the last decade, the region-wide glacier mass balanceswere contrasted with moderate mass losses in the eastern and central Himalaya(?0.22 ± 0.12 m w.e. yr?1 to?0.33 ± 0.14 m w.e. yr?1) and larger losses in the westernHimalaya (?0.45 ± 0.13 m w.e. yr?1). Recently reported slightmass gain or balanced mass budget of glaciers in the central Karakoram isconfirmed for a larger area (+0.10 ± 0.16 m w.e. yr?1) andalso observed for glaciers in the western Pamir(+0.14 ± 0.13 m w.e. yr?1). Thus, the "Karakoram anomaly"should be renamed the "Pamir-Karakoram anomaly", at least for the lastdecade. The overall mass balance of PKH glaciers,?0.14 ± 0.08 m w.e. yr?1, is two to three times less negativethan the global average for glaciers distinct from the Greenland andAntarctic ice sheets. Together with recent studies using ICESat and GRACEdata, DEM differencing confirms a contrasted pattern of glacier mass changein the PKH during the first decade of the 21st century.