EGU22-752, updated on 26 Mar 2022
EGU General Assembly 2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

Increasing the episodic glacial lake outburst flood hazard in response to surge glaciers in the Karakoram

Nazir Bazai1,2,5, Peng Cui1,2,3, Paul Carling4, Hao Wang2,3, and Javed Hassan1,2,5
Nazir Bazai et al.
  • 1Institute of Mountain hazard and environment, CAS, Institute of Mountain hazard and environment, physical geography, Chengdu, China
  • 2China-Pakistan Joint Research Center on Earth Sciences, CAS-HEC, Islamabad 45320, Pakistan.
  • 3Institute of Geographic Sciences and Natural Resources Research, CAS, Beijing 100101, China
  • 4Geography and Environmental Science, University of Southampton, Southampton SO17 1BJ, UK
  • 5University of Chinese Academy of Sciences, Beijing 100039, China

In contrast to glaciers in other areas of the world, the Karakoram glaciers appear to be stable or increasing mass in response to global climate change, a phenomenon known as the 'Karakoram anomaly.' Many glaciers are experiencing irregular, frequent, and rapid frontal advances (surges), which cause natural hazards by obstructing river channels forming ice-dammed lakes, consequent outburst floods and posing threats downstream over the region. Predicting the phenomenon to protect downstream communities remains challenging around the globe. The determination of the surge characteristics, timing and evolution of lakes and GLOFs is fundamental to flood control and disaster management. This study documents 179 glacial lake outburst floods (GLOFs) that occurred from 1533 to 2020 in five major valleys. Sixty-four of the events took place after 1970, and 37 of these had remote sensing imagery that covered the GLOF formation to breaching sequence. Thirty-six glaciers were associated with GLOFS due to ice-front advance building ice barriers in rivers. The Kayger and Khurdopin glaciers are the most hazardous examples, responsible for 31.8% of major GLOFs in the Karakoram. Using a cross-correlation feature-tracking technique on remote sensing imagery, we analyzed ten surge glaciers and documented six surge events from 1990 to 2019. Results show periodic surge cycles for the Khurdopin, Kyager, Shishper, and Chilinji glaciers of c. 15–20 years, with a surge velocity in the mid-2010s higher than that of the late 1990s for all studied glaciers. The higher velocity of a glacier increases the risk of flooding downstream of the terminus because the transfer of a huge ice mass towards the terminus during the surge is a key factor for conduit development, formation and reformation of a series of ice-dammed lakes, thus determining the magnitude and frequency of outburst flood events. The response of Karakorum glaciers to global warming and climate forcing, comprising a continuum of glacier mass gain, ice thinning, and ice advance has resulted in lake formation and ice dam failures. We predict the frequency of GLOFs will increase in the future. These findings support the increasing anomalous behavior of glaciers in the Karakoram region. A conceptual model of ice-dammed lake formation and GLOF initiation in response to glacier surging is presented to synthesize the detailed observations.

How to cite: Bazai, N., Cui, P., Carling, P., Wang, H., and Hassan, J.: Increasing the episodic glacial lake outburst flood hazard in response to surge glaciers in the Karakoram, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-752,, 2022.