Massive collapse of two glaciers in western Tibet in 2016 after surge-like instability - Archive ouverte HAL Access content directly
Journal Articles Nature Geoscience Year : 2018

Massive collapse of two glaciers in western Tibet in 2016 after surge-like instability

(1) , , (1) , , (2) , , , (3) , (3, 4) , , (5) , (6) , , (7) , , , (8) , , (9)
1
2
3
4
5
6
7
8
9
Andreas Max Kääb
  • Function : Author
  • PersonId : 944279
Silvan Leinss
  • Function : Author
Yves Bühler
Stephen Evans
  • Function : Author
Perry Bartelt
  • Function : Author
Wei-An Chao
  • Function : Author
Florent Gimbert
Wanqin Guo
  • Function : Author
Jeffrey Kargel
  • Function : Author
Gregory Leonard
  • Function : Author
Désirée Treichler
  • Function : Author

Abstract

Surges and glacier avalanches are expressions of glacier instability, and among the most dramatic phenomena in the mountain cryosphere. Until now, the catastrophic collapse of a glacier, combining the large volume of surges and mobility of ice avalanches, has been reported only for the 2002 130 × 106 m3 detachment of Kolka Glacier (Caucasus Mountains), which has been considered a globally singular event. Here, we report on the similar detachment of the entire lower parts of two adjacent glaciers in western Tibet in July and September 2016, leading to an unprecedented pair of giant low-angle ice avalanches with volumes of 68 ± 2 × 106 m3 and 83 ± 2 × 106 m3. On the basis of satellite remote sensing, numerical modelling and field investigations, we find that the twin collapses were caused by climate- and weather-driven external forcing, acting on specific polythermal and soft-bed glacier properties. These factors converged to produce surge-like enhancement of driving stresses and massively reduced basal friction connected to subglacial water and fine-grained bed lithology, to eventually exceed collapse thresholds in resisting forces of the tongues frozen to their bed. Our findings show that large catastrophic instabilities of low-angle glaciers can happen under rare circumstances without historical precedent.

Dates and versions

hal-01952631 , version 1 (12-12-2018)

Identifiers

Cite

Andreas Max Kääb, Silvan Leinss, Adrien Gilbert, Yves Bühler, Simon Gascoin, et al.. Massive collapse of two glaciers in western Tibet in 2016 after surge-like instability. Nature Geoscience, 2018, 11 (2), pp.114-120. ⟨10.1038/s41561-017-0039-7⟩. ⟨hal-01952631⟩
69 View
0 Download

Altmetric

Share

Gmail Facebook Twitter LinkedIn More