Long-term analysis of glaciers and glacier lakes in the Central and Eastern Himalaya

Vibhor Agarwal; Maximillian Van Wyk de Vries; Umesh K Haritashya; Siddhi Garg; Jeffrey S Kargel; Ying-Ju Chen; Dan H Shugar

doi:10.1016/j.scitotenv.2023.165598

Long-term analysis of glaciers and glacier lakes in the Central and Eastern Himalaya

Sci Total Environ. 2023 Nov 10:898:165598. doi: 10.1016/j.scitotenv.2023.165598. Epub 2023 Jul 17.

Authors

Vibhor Agarwal¹, Maximillian Van Wyk de Vries², Umesh K Haritashya³, Siddhi Garg³, Jeffrey S Kargel⁴, Ying-Ju Chen⁵, Dan H Shugar⁶

Affiliations

¹ Department of Earth Sciences, The College of Wooster, OH, USA; Department of Geology and Environmental Geosciences, University of Dayton, OH, USA. Electronic address: agarwal.282@osu.edu.
² School of Geography and the Environment, University of Oxford, Oxford, UK; School of Environmental Sciences, University of Liverpool, Liverpool, UK; Department of Earth and Environmental Sciences, University of Minnesota, Minneapolis, USA.
³ Department of Geology and Environmental Geosciences, University of Dayton, OH, USA.
⁴ Planetary Science Institute, Tucson, AZ, USA.
⁵ Department of Mathematics, University of Dayton, OH, USA.
⁶ Water, Sediment, Hazards, and Earth-surface Dynamics (waterSHED) Lab, Department of Geoscience, University of Calgary, AB, Canada.

PMID: 37467985
DOI: 10.1016/j.scitotenv.2023.165598

Abstract

Himalayan glaciers represent both an important source of water and a major suite of geohazards for inhabitants of their downstream regions. Recent climate change has intersected with local topographic, geomorphic, and glaciological factors to drive complex patterns of glacier thinning, retreat, velocity change, and lake development. In this study, we analyze the long-term variations in surface elevation change and velocity of the glaciers in the Central and Eastern Himalaya using existing and newly generated datasets spanning 1975 to 2018. We have used modelled (e.g., debris and ice thickness) and remote sensing datasets (e.g., Corona, Hexagon, and Landsat images) to investigate the impact of debris cover and the evolution of proglacial lakes on the glacier response in the region. We found that lake-terminating glaciers (lake TGs) have significantly higher thinning, velocity, and deceleration over time than land-terminating glaciers (land TGs). Lakes have shown an overall growth of 98 % in area and 40 % in number during 1975-2017. New proglacial lakes will likely continue to develop, and existing ones will keep expanding, influencing the frontal changes and dynamics of the lake-terminating glaciers. Debris-covered glaciers have undergone similar thinning compared to clean-ice glaciers, both for lake and land TGs; however, variations exist across the ablation zones between clean and debris-covered glaciers which this study further explores using a data-driven approach. Overall, the proglacial lakes development, changes in debris coverage, and topography significantly affect the glacier responses in the regions.

Keywords: Central Himalaya; Debris cover; Eastern Himalaya; Glacier changes; Proglacial lakes.