Structural characteristics of flow units in Svalbard valley glaciers and their utility for investigating ice-dynamic changes over centennial timescales

Jennings, SJA, Hambrey, MJ, Glasser, NF, Hubbard, B, James, TD and Midgley, NG ORCID: https://orcid.org/0000-0003-0076-1785, 2024. Structural characteristics of flow units in Svalbard valley glaciers and their utility for investigating ice-dynamic changes over centennial timescales. Journal of Glaciology. ISSN 0022-1430

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Abstract

The aim of this paper is to characterise the internal structures and ice-flow history of representative valley glaciers in Svalbard, and infer from them dynamic changes over centennial timescales. Three polythermal and one cold valley glacier are investigated using field- and laboratory-based techniques, and remote sensing. Structures along flow-unit boundaries indicate that ice-flow configuration in three of the glaciers has remained stable spanning the residence time of the ice. Deformation of a flow-unit boundary in the fourth reveals an ice-flow instability, albeit one that has been maintained since its most recent advance. Macro-crystallographic, sedimentological, and isotopic analyses indicate that basal ice is elevated to the glacier surface, as shown by entrained sediments and enrichment in heavy isotopes. In narrow zones of enhanced cumulative strain, new ice facies are generated through dynamic recrystallization. The surface density of longitudinal foliation is shown to represent the relative magnitude of cumulative strain. Geometric similarities between flow-unit boundaries in Svalbard valley glaciers and larger scale longitudinal surface structures in ice sheets suggest that deformation mechanisms are common to both.

Item Type:	Journal article
Publication Title:	Journal of Glaciology
Creators:	Jennings, S.J.A., Hambrey, M.J., Glasser, N.F., Hubbard, B., James, T.D. and Midgley, N.G.
Publisher:	Cambridge University Press (CUP)
Date:	26 December 2024
ISSN:	0022-1430
Identifiers:	Number Type 10.1017/jog.2024.103 DOI 2347058 Other
Rights:	© The Author(s), 2024. Published by Cambridge University Press on behalf of International Glaciological Society. This is an Open Access article, distributed under the terms of the Creative Commons Attribution licence (http://creativecommons.org/licenses/by/4.0), which permits unrestricted re- use, distribution and reproduction, provided the original article is properly cited
Divisions:	Schools > School of Animal, Rural and Environmental Sciences
Record created by:	Laura Borcherds
Date Added:	20 Jan 2025 10:17
Last Modified:	20 Jan 2025 10:17
URI:	https://irep.ntu.ac.uk/id/eprint/52870

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