Himalayan glacier lake outburst floods

A study examines the severity of glacier lake outburst floods in the Himalayas. Glacier melting in the Himalayas has created more than 5,000 glacier lakes that are dammed by potentially unstable moraines. However, some of the dams are at risk of causing glacier lake outburst floods (GLOF). Using data compiled from mapped glacier lakes and bathymetric surveys, Georg Veh and colleagues ran 5.4 billion simulations of GLOFs to estimate their contemporary potential hazard in terms of the highest water discharge expected. The GLOF hazard depends on the number of current lakes as well as the rate of historic lake outbursts, which were both highest in the Eastern Himalayas. The authors also found that GLOF hazard was approximately 3 times higher in the Eastern Himalayas than in any other Himalayan region. The 100-year GLOF has a peak discharge of roughly 15,600 cubic meters per second, which rivers in the region attain during monsoonal floods downstream. The results suggest that the frequency of glacier lake outbursts and the size of meltwater lakes are key elements in determining GLOF hazard. Further, GLOF hazard may increase in regions that have large glaciers if ice loss continues to create meltwater lakes, according to the authors.

Article #19-14898: “Hazard from Himalayan glacier lake outburst floods,” by Georg Veh, Oliver Korup, and Ariane Walz.

MEDIA CONTACT: Georg Veh, University of Potsdam, GERMANY; tel: +49-331-977-5875; email:

[email protected]

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