Heterogeneous changes of glaciers over the western Kunlun Mountains based on ICESat and Landsat-8 derived glacier inventory

摘要

Glaciers in the northwestern Qinghai-Tibet Plateau (QTP) including the Karakoram and western Kunlun Mountains (WKM) exhibited heterogeneous changes in recent years. A latest glacier inventory of the WKM region is generated by using Landsat 8/OLI images (year 2013) and SRTM3 DEM. The ICESat (Ice, Cloud, and land Elevation Satellite) elevation data in combination with the DEM is then employed to investigate glacier thickness changes. The WKM region consists of 537 glaciers (>0.02km2) with a total area of 3137km2 in 2013. Out of these, 16 groups of glaciers covering an area about 1234km2 (2013) showed varying surface elevation trends ranging from -0.4±0.20m/a to 0.7±24m/a over 2003-2008, except the serious thinning trend (-1.15±0.41m/a) detected at a surging glacier. The surging glacier (the Zhongfeng glacier) is characterized by drastic elevation variations (up to -80m) and contrasting trends over the accumulation areas due to cave-in and rapid transfer of ice to the downstream. The heterogeneous glacier behavior in the WKM region was not only exemplified in the varying mass balances of individual glaciers but also the spatial variability of elevation trends over different glacier parts (accumulationblation areas). Analysis of the heterogeneity shows that such glacier dynamics were probably associated with local glacier parameters including altitude, aspect, glacier hypsometry and ice flow. The mechanisms for the mass gain and glacier surging in the WKM region require further studies with more observations.