Estimation of glacier ice storage in western China constrained by field ground-penetrating Radar surveys

Abstract

Recent decades have witnessed the accelerated retreat of alpine glaciers, which likely portends a decline in the glacial ice melt on which large downstream populations rely for freshwater. Thus, estimating water storage in alpine glaciers is critical for predicting the trend of glacier melting. This study compiled a rich set of ice thickness observations for glaciers of varying sizes in western China. We here presented a first-order assessment of the various errors involved in interpreting ice thickness from ground-penetrating radar (GPR) observations. An empirical Bayesian kriging (EBK) method was used for ice thickness interpolation and volume estimation. We then established a new volume-scaling law specific to western China glaciers based on these 36 volume-area pairs. And together with the Second Chinese Glacier Inventory (SCGI), we obtain a regional volume estimate of 4451 ± 298 km3. By comparison, we believed that this result is the most reliable estimate of the total ice storage in western China and more reliably predicts gross glacier melting. However, our results show that the method of glacier division can strongly affect the total volume estimation, which previous studies ignored. This emphasizes the need for more surveyed glaciers data and more accurate glacier inventory to improve the evaluation of the climate impact on glacier melting water resources and to help ensure the future survival of these alpine glaciers.

Keywords

• Ground-penetrating radar
• Glacier thickness survey
• Glacier volume
• volume‒area scaling law
• Distributed model
• Western China