T158 Geologic Research at Mount Rainier and Other Cascade Volcanoes: Ideal Natural Laboratories for Cutting-Edge Research with Implications to Life Safety and Infrastructure Protection in the Pacific Northwest (Posters)

Monday, 23 October 2017
9:00 AM - 6:30 PM
Halls 4EF

ASSESSING THE RISK OF GLACIAL OUTBURST FLOODS FROM EMMONS GLACIER, MT. RAINIER, WASHINGTON

Paper number: T158-2
Program: Technical Sessions
Time: 9:00 AM – 6:30 PM

Authors

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.

Geological Society of America Abstracts with Programs. Vol. 49, No. 6

doi: 10.1130/abs/2017AM-307787

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