Impact of glacier shape on the mass balance changes: A case study of Dongkemadi region, central Tibetan Plateau

The morphology of glacier is a key factor impacting the glacier mass redistributions. High-resolution digital elevation models (DEMs) provide a reliable method to explore the vertical characteristics of glacier surface elevation changes in different types. Using topographic maps from 1969 and Shuttle Radar Topography Mission (SRTM) data acquired in 2000, we calculated the surface elevation changes for 18 glaciers to generate vertical profiles of elevation difference (VPED) in the Dongkemadi region, central Tibetan Plateau. The results showed that the VPEDs vary highly among different glacier types. For valley glaciers, surface thinning at middle elevations is less than that at higher and lower elevations; for cirque glaciers, however, the maximum surface decline occurred in the middle section; whereas hanging glaciers experienced progressively less surface lowering with increasing elevation. Glacier geometry directly affects ice dynamics, which in turn dictates the VPEDs of specific glaciers. This regulation of glacier evolution can be applied to project how valley glaciers might eventually assume the VPEDs of cirque and hanging glaciers due to ongoing warming.