Evolution and Controls of Large Glacial Lakes in the Nepal Himalaya

Author(s)

Umesh K. Haritashya, University of DaytonFollow
Jeffrey S. Kargel, University of Colorado
Dan H. Shugar, University of Washington
Gregory J. Leonard, University of Arizona
Katherine Strattman, University of Dayton
C. Scott Watson, University of Arizona
David Shean, University of Washington
Stephan Harrison, University of Exeter
Kyle T. Mandli, Columbia University
Dhananjay Regmi, Himalayan Research Center

Document Type

Article

Publication Date

5-2018

Publication Source

Remote Sensing

Abstract

Glacier recession driven by climate change produces glacial lakes, some of which are hazardous. Our study assesses the evolution of three of the most hazardous moraine-dammed proglacial lakes in the Nepal Himalaya—Imja, Lower Barun, and Thulagi. Imja Lake (up to 150 m deep; 78.4 x 10⁶ m³ volume; surveyed in October 2014) and Lower Barun Lake (205 m maximum observed depth; 112.3 x 10⁶ m³ volume; surveyed in October 2015) are much deeper than previously measured, and their readily drainable volumes are slowly growing. Their surface areas have been increasing at an accelerating pace from a few small supraglacial lakes in the 1950s/1960s to 1.33 km² and 1.79 km² in 2017, respectively. In contrast, the surface area (0.89 km²) and volume of Thulagi lake (76 m maximum observed depth; 36.1 x 10⁶ m³; surveyed in October 2017) has remained almost stable for about two decades. Analyses of changes in the moraine dams of the three lakes using digital elevation models (DEMs) quantifies the degradation of the dams due to the melting of their ice cores and hence their natural lowering rates as well as the potential for glacial lake outburst floods (GLOFs). We examined the likely future evolution of lake growth and hazard processes associated with lake instability, which suggests faster growth and increased hazard potential at Lower Barun lake.

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ISBN/ISSN

2072-4292

Document Version

Published Version

Comments

This work was supported by the National Aeronautics and Space Administration (NASA) High Mountain Asia grant NNX16AQ62G, SERVIR Applied Science Team grant NNX12AO96G, Interdisciplinary Research in Earth Science grant NNX17AL80G, and United Nations Development Program’s Imja Lake-Lowering project. D. Shean was supported by the NASA cryosphere program (award no. NNX16AQ88G). The authors thankWojciech Marcinek, Daniel Hicks, Adil Tahir, and Charles Howard for designing and building the sonar device (‘BathyBot’) adapted for the Thulagi bathymetry survey within the School of Mechanical Engineering at the University of Leeds, and Robert Richardson and Shaun Whitehead for their guidance on the project.

DOI: https://doi.org/10.3390/rs10050798.

Copyright

Copyright © 2018 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).

Publisher

MDPI

Volume

10

Issue

5

Peer Reviewed

yes

Keywords

GLOF, glacial lake, Nepal, Himalaya, proglacial lake, moraine-dammed, glacier, remote sensing, High Mountain Asia (HMA)

eCommons Citation

Haritashya, Umesh K.; Kargel, Jeffrey S.; Shugar, Dan H.; Leonard, Gregory J.; Strattman, Katherine; Watson, C. Scott; Shean, David; Harrison, Stephan; Mandli, Kyle T.; and Regmi, Dhananjay, "Evolution and Controls of Large Glacial Lakes in the Nepal Himalaya" (2018). Geology Faculty Publications. 62.
https://ecommons.udayton.edu/geo_fac_pub/62