Glacial lake outburst floods as drivers of fluvial erosion in the Himalaya

Kristen L Cook; Christoff Andermann; Florent Gimbert; Basanta Raj Adhikari; Niels Hovius

doi:10.1126/science.aat4981

Glacial lake outburst floods as drivers of fluvial erosion in the Himalaya

Science. 2018 Oct 5;362(6410):53-57. doi: 10.1126/science.aat4981.

Authors

Kristen L Cook¹, Christoff Andermann², Florent Gimbert^{2

3}, Basanta Raj Adhikari⁴, Niels Hovius^{2

5}

Affiliations

¹ GFZ German Research Centre for Geosciences, Potsdam, Germany. klcook@gfz-potsdam.de.
² GFZ German Research Centre for Geosciences, Potsdam, Germany.
³ University of Grenoble Alpes, CNRS, IRD, Institut des Géosciences de l'Environnement (IGE), Grenoble, France.
⁴ Department of Civil Engineering, Pulchowk Campus, Institute of Engineering, Tribhuvan University, Nepal.
⁵ Institute of Earth and Environmental Science, Potsdam University, Potsdam, Germany.

PMID: 30287655
DOI: 10.1126/science.aat4981

Abstract

Himalayan rivers are frequently hit by catastrophic floods that are caused by the failure of glacial lake and landslide dams; however, the dynamics and long-term impacts of such floods remain poorly understood. We present a comprehensive set of observations that capture the July 2016 glacial lake outburst flood (GLOF) in the Bhotekoshi/Sunkoshi River of Nepal. Seismic records of the flood provide new insights into GLOF mechanics and their ability to mobilize large boulders that otherwise prevent channel erosion. Because of this boulder mobilization, GLOF impacts far exceed those of the annual summer monsoon, and GLOFs may dominate fluvial erosion and channel-hillslope coupling many tens of kilometers downstream of glaciated areas. Long-term valley evolution in these regions may therefore be driven by GLOF frequency and magnitude, rather than by precipitation.

Publication types

Research Support, Non-U.S. Gov't