EGU22-8327
https://doi.org/10.5194/egusphere-egu22-8327
EGU General Assembly 2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

Ice cliff mass-loss of debris-covered Trakarding Glacier, Rolwaling region, eastern Nepal Himalaya

Yota Sato1,2, Pascal Buri2, Evan Miles2, Marin Kneib2,3, Sojiro Sunako4, Akiko Sakai1, Francesca Pellicciotti2,5, and Koji Fujita1
Yota Sato et al.
  • 1Nagoya University, Graduate School of Environmental Studies, Nagoya, Japan
  • 2Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), Birmensdorf, Switzerland
  • 3Institute of Environmental Engineering, ETH Zurich, Zurich, Switzerland
  • 4Snow and Ice Research Center, National Research Institute for Earth Science and Disaster Resilience (NIED), Nagaoka, Japan
  • 5Department of Geography, Northumbria University, Newcastle, UK

Glaciers in High Mountain Asia have been shrinking in the recent decades. They are a valuable indicator of climate change, and their meltwater plays an important role for regional water resources. Debris-covered glaciers, which are prevalent throughout the Himalayas, exhibit complex melt processes due to their heterogeneous surface.  Previous studies have demonstrated that ice cliffs disproportionally contribute to glacier melt, but their importance at the glacier scale has been quantified for only a few sites. In this study, we exploit measurements taken since 2016 on the lake-terminating Trakarding Glacier (27.9°N, 86.5°E; 2.9 km2 spanning 4,500–5,000 m a.s.l.; ~5% ice cliff cover), eastern Nepal Himalaya, to investigate the importance of cliffs for debris-covered ice melt at the glacier scale from a remote-sensing inversion and energy-balance modeling. We generated super-high-resolution (0.2 m) terrain data from aerial photographs (UAV and helicopter-borne photogrammetry) during 2018-2019 and manually delineated ~500 ice cliffs to derive surface velocity, elevation change, and specific mass balance, providing an observational estimate of ablation across the debris-covered tongue and attributable to ice cliffs. Further we employed a process-based 3D-backwasting model to estimate continuous ice cliff mass-loss over the study period. The model calculates the energy balance of ice cliff surfaces and reproduces their evolutions (cliff expansion, shrinkage, and reburial), based on the characteristics of the glacier surface and location of individual ice cliffs. This method, forced with in-situ meteorological and terrain data and evaluated against the observed changes, provides ice cliff mass-loss from the scale of individual features to the entire Trakarding Glacier.

How to cite: Sato, Y., Buri, P., Miles, E., Kneib, M., Sunako, S., Sakai, A., Pellicciotti, F., and Fujita, K.: Ice cliff mass-loss of debris-covered Trakarding Glacier, Rolwaling region, eastern Nepal Himalaya, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-8327, https://doi.org/10.5194/egusphere-egu22-8327, 2022.