Continuous borehole optical televiewing reveals variable englacial debris concentrations at Khumbu Glacier, Nepal

Abstract

Surface melting of High Mountain Asian debris-covered glaciers shapes the seasonal water supply to millions of people. This melt is strongly influenced by the spatially variable thickness of the supraglacial debris layer, which is itself partially controlled by englacial debris concentration and melt-out. Here, we present measurements of deep englacial debris concentrations from debris-covered Khumbu Glacier, Nepal, based on four borehole optical televiewer logs, each up to 150 m long. The mean borehole englacial debris content is ≤ 0.7% by volume in the glacier’s mid-to-upper ablation area, and increases to 6.4% by volume near the terminus. These concentrations are higher than those reported for other valley glaciers, although those measurements relate to discrete samples while our approach yields a continuous depth profile. The vertical distribution of englacial debris increases with depth, but is also highly variable, which will complicate predictions of future rates of surface melt and debris exhumation at such glaciers.

Metadata

Item Type:	Article
Authors/Creators:	Miles, K.E. Hubbard, B. Miles, E.S. Quincey, D.J. Rowan, A.V. https://orcid.org/0000-0002-3715-5554 Kirkbride, M. Hornsey, J. https://orcid.org/0000-0002-5578-547X
Copyright, Publisher and Additional Information:	© The Author(s) 2021. Open Access: This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.
Dates:	Accepted: 24 November 2020 Published (online): 13 January 2021 Published: 13 January 2021
Institution:	The University of Sheffield
Academic Units:	The University of Sheffield > Faculty of Social Sciences (Sheffield) > Department of Geography (Sheffield)
Funding Information:	Funder Grant number NATURAL ENVIRONMENT RESEARCH COUNCIL NE/P00265X/1
Depositing User:	Symplectic Sheffield
Date Deposited:	12 Feb 2021 13:37
Last Modified:	12 Feb 2021 13:37
Status:	Published
Publisher:	Springer Science and Business Media LLC
Refereed:	Yes
Identification Number:	10.1038/s43247-020-00070-x
Open Archives Initiative ID (OAI ID):	oai:eprints.whiterose.ac.uk:170201

Download

Published Version

Filename: s43247-020-00070-x.pdf

Licence: CC-BY 4.0

CLICK TO DOWNLOAD

CORE (COnnecting REpositories)

Continuous borehole optical televiewing reveals variable englacial debris concentrations at Khumbu Glacier, Nepal

Abstract

Metadata

Download

Published Version

Export

Statistics