Glacier variations at Aru Co in western Tibet from 1971 to 2016 derived from remote-sensing data

ZHEN ZHANG,JUNFENG WEI,YONG ZHANG,ZONGLI JIANG,SHIYIN LIU,KUNPENG WU

doi:10.1017/jog.2018.34

Abstract

ABSTRACTTwin glaciers collapsed in 2016 near Aru Co, western Tibet and caused extreme loss to human beings. In this study, we attempted to track the dynamics of glaciers in the region, for example the glacier area and mass changes in Aru Co for the period 1971–2016, which were determined using topographic maps and Landsat images and ASTER-derived DEMs (2011–16), the Shuttle Radar Terrain Mission DEM (2000) and topographic maps (1971). Our results showed that the glacier area of Aru Co decreased by −0.4 ± 4.1% during 1971–2016. The geodetic mass-balance results showed that the glaciers in Aru Co lost mass at a rate of −0.15 ± 0.30 m w.e. a−1 during 1971–99, while they gained mass at a rate of 0.33 ± 0.61 m w.e. a−1 for the period 1999–2016. The twin glaciers experienced a larger negative mass budget than the others in the region before 1999. This process produced large amounts of meltwater, followed by a sustained increase in the meltwater on the pressure melting point, possibly in response to a period of positive mass balance (1999–2016) and then, transferred to the glacier bed until the glaciers collapsed.

Highlights

Glaciers are an important freshwater resource (Immerzeel and others, 2010), but are responsible for hazards such as glacier collapse, surges, lake outburst floods and landslides
We selected more tie points (TPs) in the snow and ice areas to increase the accuracy of image-to-image coregistration
The results showed that the mass budget of the region was negative (−0.15 ± 0.30 m w.e. a−1) before 1999, and became positive after 1999

Summary

Introduction

Glaciers are an important freshwater resource (Immerzeel and others, 2010), but are responsible for hazards such as glacier collapse, surges, lake outburst floods and landslides. Two glaciers, located in western Tibet near the Aru Co lake, collapsed on 17 July and 21 September 2016. Both collapses caused large ice avalanches, and the first killed nine herders and hundreds of animals (Tian and others, 2016). Only one similar glacier event had been reported, i.e. the Kolka/Karmadon glacier in the Russian Caucasus on 20 September 2002, which led to a huge rock and ice slide of 120 million m3 in volume and the death of more than 140 people (Huggel and others, 2005). We need to study the glacier variations in this region to better understand the mechanism of glacier collapse

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Conclusion