Geologic Publications for Mount Rainier

Assessing the risk of glacial outburst floods from Emmons Glacier, Mt. Rainier, Washington

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Author(s): Logan Krehbiel, Claire Todd, Michelle Koutnik

Category: POSTER
Document Type: Poster #158-2
Publisher: Geological Society of America Abstracts with Programs
Published Year: 2017
Volume: 49
Number: 6
Pages:
DOI Identifier: 10.1130/abs/2017AM-307787
ISBN Identifier:
Keywords:

Abstract:
Mount Rainier, a stratovolcano located in the Cascade Volcanic Arc of Washington State, is home to 27 major glaciers, many of which have debris-covered ablation zones. This study analyzes Emmons Glacier supraglacial geomorphology in order to determine the risk of glacial lake outburst floods. Risk will be assessed by categorizing Emmons Glacier into one of three glacial regimes established by Benn et al. (2012). Surface slopes of six degrees or less, inefficient supraglacial drainage systems, concave-up surface elevation profiles, and slowing ice velocities can all be indicators of englacial or subglacial water storage potential. These criteria were evaluated using LiDAR data and satellite imagery. Through these analyses, we categorize Emmons Glacier as low risk for supraglacial-water storage, with potential for increasing risk in the future. While the glacier has an efficient supraglacial drainage system, we observe a concave-up longitudinal elevation profile, as well as 0.14 square miles of debris-covered surface with a slope of six degrees or less. Both of these features may promote future water storage. Additional research, including measuring glacial debris thickness and cataloging past and present water features, is needed to support our findings. If our assessment of Emmons Glacier is correct, continued ablation rates may create a positive feedback, promoting water storage, and thus increasing the risk of outburst floods.

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Suggested Citations:
In Text Citation:
Krehbiel and others (2017) or (Krehbiel et al., 2017)

References Citation:
Krehbiel, L., C. Todd, and M. Koutnik, 2017, Assessing the risk of glacial outburst floods from Emmons Glacier, Mt. Rainier, Washington: Poster #158-2, Geological Society of America Abstracts with Programs, Vol. 49, No. 6, doi: 10.1130/abs/2017AM-307787.