Articles | Volume 9, issue 2
The Cryosphere, 9, 703–717, 2015

Special issue: Interactions between climate change and the Cryosphere: SVALI,...

The Cryosphere, 9, 703–717, 2015

Research article 15 Apr 2015

Research article | 15 Apr 2015

Mass changes of Southern and Northern Inylchek Glacier, Central Tian Shan, Kyrgyzstan, during ∼1975 and 2007 derived from remote sensing data

D. H. Shangguan1,2, T. Bolch2,3, Y. J. Ding1, M. Kröhnert3, T. Pieczonka3, H. U. Wetzel4, and S. Y. Liu1 D. H. Shangguan et al.
  • 1State Key Laboratory of Cryospheric Science, Cold & Arid Regions Environmental & Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China
  • 2Department of Geography, University of Zurich, 8057 Zurich, Switzerland
  • 3Institute for Cartography, Technische Universität Dresden, 01069 Dresden, Germany
  • 4GFZ German Research Centre for Geosciences, Potsdam, Germany

Abstract. Glacier melt is an essential source of freshwater for the arid regions surrounding the Tian Shan. However, the knowledge about glacier volume and mass changes over the last decades is limited. In the present study, glacier area, glacier dynamics and mass changes are investigated for the period ~1975–2007 for Southern Inylchek Glacier (SIG) and Northern Inylchek Glacier (NIG), the largest glacier system in Central Tian Shan separated by the regularly draining Lake Merzbacher. The area of NIG increased by 2.0 ± 0.1 km2 (~1.3%) in the period ~1975–2007. In contrast, SIG has shrunk continuously in all investigated periods since ~1975. Velocities of SIG in the central part of the ablation region reached ~100–120 m a−1 in 2002/2003, which was slightly higher than the average velocity in 2010/2011. The central part of SIG flows mainly towards Lake Merzbacher rather than towards its terminus. The measured velocities at the distal part of the terminus downstream of Lake Merzbacher were below the uncertainty, indicating very low flow with even stagnant parts. Geodetic glacier mass balances have been calculated using multi-temporal digital elevation models from KH-9 Hexagon (representing the year 1975), SRTM3 (1999), ALOS PRISM (2006) and SPOT-5 high-resolution geometrical (HRG) data (2007). In general, a continuous mass loss for both SIG and NIG could be observed between ~1975 and 2007. SIG lost mass at a rate of 0.43 ± 0.10 m w.e. a−1 and NIG at a rate of 0.25 ± 0.10 m w.e. a−1 within the period ~1975–1999. For the period 1999–2007, the highest mass loss of 0.57 ± 0.46 m w.e. a−1 was found for NIG, whilst SIG showed a potential moderate mass loss of 0.28 ± 0.46 m w.e. a−1. Both glaciers showed a small retreat during this period. Between ~1975 and 1999, we identified a thickening at the front of NIG with a maximum surface elevation increase of about 150 m as a consequence of a surge event. In contrast significant thinning (>0.5 m a−1) and comparatively high velocities close to the dam of Lake Merzbacher were observed for SIG, indicating that Lake Merzbacher enhances glacier mass loss.

Short summary
Glacier velocity, glacier area, surface elevation and mass changes of the Southern and Northern Inylchek Glacier were investigated by using multi-temporal space-borne data sets. The mass balance of both SIG and NIG was negative(-0.43 ± 0.10 m w.e. a-1 and -0.25 ± 0.10 m w.e. a-1) from ~1975 to 2007. The thinning at the lake dam was higher, likely caused by calving into Lake Merzbacher. Thus, glacier thinning and glacier flow are significantly influenced by the lake.