Estimating the mass change of mountain glacier using a novel method based on InSAR observations

Melting glaciers have a direct contribution to sea level rise, runoff and glacier lake outburst flood disasters. Therefore, accurate estimations of glacier mass balances with high spatial (large region) and temporal (annual, seasonal) resolutions are very important. However, the estimation of glacial mass balances in mountainous regions is usually hampered by remoteness and the lack of high-precision topographic data for most mountain ranges. This study presents a novel method for estimating mass changes in mountain glaciers using InSAR data. We utilised observations of glacier surface deformation to derive changes in thickness, and then calculated the mass change. This method can accurately estimate short-term mass changes. We apply this method to the Koxkar glacier in the Tien Shan Mountain Range in China and successfully estimate the seasonal mass change. Using theoretical error and statistical error analysis, we determined that the accuracy of this method is much better than other geodetic methods. We analyse the spatial characteristics of the mass changes in the ablation zone for the first time. The results show considerable spatial and seasonal variability, which were mainly from ablation in the summer, with the greatest amount of glacial ablation reaching up to − 3872 mm water equivalent (w.e.), and from accumulation in the winter.