Melting Of The Chhota Shigri Glacier, Western Himalaya, Insensitive To Anthropogenic Emission Residues: Insights From Geochemical Evidence

Himalayan glaciers are invariably covered by supra-glacial debris. Of these glaciers, the Chhota Shigri Glacier (CSG) in the western Himalaya has minimal debris cover (3.4%), yet has a comparable melt rate to other Himalayan glaciers. Utilizing osmium isotopic composition, and major and trace element geochemistry of cryoconite, a dark colored aggregate of mineral and organic materials on the surface of the ablation zone of the CSG, we show that the surface of CSG is essentially free of anthropogenically emitted particles, contrary to many previous findings. Given this and the overall lack of debris, we conclude that the high melt rate of CSG is primarily related to the increase of the Earth's near-surface temperature linked directly to global warming. Therefore, the future meltwater supply for glacial-fed rivers originating from Lahaul and Spiti region would be most vulnerable for >50 million population living downstream and requires immediate attention.