Spatial surface velocity pattern in the glaciers of Chandra Basin, Western Himalaya

Himalayan glaciers are distinct by their surface characteristics, such as debris-cover, supra/proglacial lakes, ice-cliff, and tributaries' contributions, thus complicating their surface velocity pattern and their response towards climate warming. While remote sensing and modelled surface velocity estimation are valuable on a larger scale, in situ high-resolution data is crucial to validate them. In this study, four glaciers (Batal, Sutri Dhaka, Samudra Tapu, and Gepang Gath) from Chandra Basin were monitored to measure point-wise surface displacement using a static GNSS system during 2017–2018. Among them, the highest surface velocity was observed over Samudra Tapu (∼64.3 ma⁻¹), a large and clean-type glacier, while the lowest was for Batal (∼6.2 ma⁻¹), a small and debris-covered glacier. Our study highlighted the contrasting behaviour of lake-terminating and debris-covered glaciers for the surface velocity and also emphasize the additional control of the slope, supraglacial lake, debris thickness and convergence of glacier channels on the glacier surface velocity.