Glacier No. 4 of Sigong River over Mt. Bogda of eastern Tianshan, central Asia: thinning and retreat during the period 1962–2009

摘要: RTK-GPS data, aerial photographs and Aster images were used to quantify volume, surface elevation, terminus position area changes of Glacier No. 4 Sigong River over Mt. Bogda, Tianshan during the period from 1962 2009. elevation tongue decreased by 15 ± 8 m (0.32 0.17 a−1) ice volume loss reached 0.014 0.008 km3 (0.013 0.007 w. e.). The glacier retreated at a rate 8.0 a−1 about 0.53 km2, accounting for 15.8% in (3.33 km2). can be primarily attributed significant increase temperature this region. A comparison with field measurements other regions eastern showed obvious spatial differences magnitude changes, owing combination regional climate change topographical factors.