EGU21-1086, updated on 03 Mar 2021
EGU General Assembly 2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

Intensified paraglacial slope failures due to accelerating downwasting of a temperate glacier in Mt. Gongga, Southeastern Tibet Plateau

Yan Zhong1,2, Qiao Liu1, Yong Nie1, Matthew Westoby3, Bo Zhang4, Jialun Cai4, Haijun Liao1,2, and Guoxiang Liu4
Yan Zhong et al.
  • 1Institute of Mountain Hazard and Environment, Chinese Academy of Sciences, Chengdu, China
  • 2College of Resources and Environment, University of Chinese Acedemy of Sciences, Beijing, China
  • 3Department of Geography and Environmental Sciences, Engineering and Environment, Northumbria University, Newcastle upon Tyne, UK
  • 4Department of Surveying and Geo-Informatics, Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu, China

Topographic development via paraglacial slope failure (PSF) represents a complex interplay between geological structure, climate, and glacial denudation. Where debris generated by PSFs is deposited on the surface of a glacier, this debris can increase the extent or thickness of a supraglacial debris-cover, in turn modifying glacier ablation and affecting meltwater generation. To date, little attention has been paid to intensity and frequency of PSFs and their significance as a geomorphic agent and hazard in glacierised, monsoon temperate regions of Southeast Tibet. We mapped PSFs along the 5 km-long, west-east trending ice tongue of Hailuogou Glacier (HLG), Mt. Gongga, using repeat satellite- and UAV-derived imagery between 1990 and 2020. Three types of PSF were identified: (A) rock fall, (B) slide and collapse of sediment-mantled slopes, and (C) gulley headwards erosion. We analyzed the formation, evolution and current state of these PSFs and discuss these aspects with relation to glacier dynamics and paraglacial geomorphological history. South-facing slopes (true left of HLG) showed more destabilization and higher PSF activity than north-facing slopes. We observed annual average rates of downslope sliding for type B PSFs of 1.6-2.6 cm d-1, whereas the average upward denudation rate for type C PSFs was 0.7-3.39 cm d-1. We show that type A PSFs are non-ice-contact rock collapses that occur as a long-term paraglacial response following glacier downwasting and the exposure of steep rocky cliffs and which could also be influenced by precipitation, freeze-thaw cycling, earthquakes or other factors. In contrast, type B and C PSFs are a more immediate response to recent glacier downwasting. We further argue that the accelerating downwasting of glacier are used as a preparatory or triggering factor, which could directly or indirectly cause the PSFs.

How to cite: Zhong, Y., Liu, Q., Nie, Y., Westoby, M., Zhang, B., Cai, J., Liao, H., and Liu, G.: Intensified paraglacial slope failures due to accelerating downwasting of a temperate glacier in Mt. Gongga, Southeastern Tibet Plateau, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-1086,, 2021.


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