Ice surface-elevation change and velocity of Qingbingtan glacier No.72 in the Tomor region, Tianshan Mountains, central Asia

Abstract

Glaciers in the Tomor region of Tianshan Mountains preserve vital water resources. However, these glaciers suffer from strong mass losses in the recent years because of global warming. From 2008 to 2009, a large-scale scientific expedition has been carried out in this region. As an individual reference glacier, the tongue area of Qingbingtan glacier No. 72 was measured by the high precise Real Time Kinematic-Global Position System (RTK-GPS). In this paper, changes of the tongue area of Qingbingtan glacier No.72 has been studied based on topographic map, remote sensing image and the survey during 2008#x2013;2009 field campaign. Results indicated that the ice surface-elevation of the tongue area changed - 0.22 +/- 0.14 m a(-1) from 1964 to 2008. The estimated loss in ice volume was 0.014 +/- 0.009 km(3), which represented a similar to 20 % decrease from the 1964 volume and was equivalent to average annual mass balance of -0.20 +/- 0.12 m water equivalent for the tongue area during 1964-2008. Terminus retreated by 1852 m, approximately 41 m a(-1), with the area reduction of 1.533 km(2) (0.034 km(2) a(-1)) from 1964 to 2009. Furthermore, the annual velocity reached to similar to 70 m a(-1). Comparing with the other monitored glaciers in the eastern Tianshan Mountains, Qingbingtan glacier No.72 experienced more intensive in shrinkage, which resulted from the combined effects of climate change and glacier dynamic, providing evidence of the response to climatic warming.