Recent accelerating glacier mass loss of the Geladandong Mountain, Inner Tibetan Plateau, estimated from ZiYuan-3 and TanDEM-X measurements

Abstract

The headwaters of many Asian rivers are at mountain glaciers of the Tibetan Plateau. Glacier melt-water is a non-negligible contributor of river runoff, especially for a drought year. However, the observation of mass glacier changes was scarce in recent years. Here, we estimated the recent glacier mass change of the Geladandong mountain, by differencing the digital elevation models (DEMs) produced from ZiYuan-3 images and TanDEM-X data. Moreover, we compared the SRTM-C DEM with TanDEM-X DEMs to retrieve glacier mass balances since 2000. The annual mass loss rates of -0.11 +/- 0.03 and -0.47 +/- 0.09 m w.e. yr(-1) were derived in 2000-2012 and 2012-2018, respectively. This result revealed an accelerating rate of negative glacier mass changes during recent years, which is mainly caused by the significant increase of mass loss over non-surge glaciers, rather than surge-type glaciers, which held a slight increase of mass loss. In addition, we found a pronounced discrepancy of glacier mass change between non-surge and surge-type glaciers during 2012-2018, and suggested that this difference may be caused by the heterogeneous responses of surge-type glaciers to climate variations, because of the different timing and type of surge events.