Campus Units

Natural Resource Ecology and Management

Document Type

Article

Publication Version

Accepted Manuscript

Publication Date

1-2018

Journal or Book Title

Earth Surface Processes and Landforms

Volume

43

Issue

1

First Page

285

Last Page

297

DOI

10.1002/esp.4244

Abstract

Rock debris on the surface of ablating glaciers is not static, and is often transported across the ice surface as relief evolves during melt. This supraglacial debris transport has a strong influence on the spatial distribution of melt, and is implicated in the formation of hummocky glacial topography in deglaciated terrain. Furthermore, as icedammed lakes and ice-cored slopes become increasingly common in deglaciating watersheds, there is rising concern about hazards to humans and infrastructure posed by mass-wasting of ice-cored debris. The existing quantitative framework for describing these debris transport processes is limited, making it difficult to account for transport in mass balance, hazard assessment, and landscape development models. This paper develops a theoretical framework for assessing slope stability and gravitational mass transport in a debris-covered ice setting. Excess water pressure at the interface between ablating ice and lowering debris is computed by combining Darcy’s law with a meltwater balance. A limit-equilibrium slope stability analysis is then applied to hypothetical debris layers with end-member moisture conditions derived from a downslope meltwater balance that includes production and seepage. The resulting model system constrains maximum stable slope angles and lengths that vary with debris texture, thickness, and the rate of meltwater production. Model predictions are compared with field observations and with DEM-derived terrain metrics from two modern debris-covered glaciers on Mount Rainier, USA.

Comments

This is the peer reviewed version of the following article: Moore, P. L. (2017) Stability of supraglacial debris. Earth Surf. Process. Landforms, which has been published in final form at doi: 10.1002/esp.4244. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.

Copyright Owner

John Wiley & Sons, Ltd.

Language

en

File Format

application/pdf

Available for download on Tuesday, January 01, 2019

Published Version

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