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Controls on jökulhlaup-transported buried ice melt-out at Skeiðarársandur, Iceland: implications for the evolution of ice-marginal environments

Lookup NU author(s): David Blauvelt, Professor Andrew RussellORCiD, Professor Andy Large

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This work is licensed under a Creative Commons Attribution 4.0 International License (CC BY 4.0).


Abstract

High-magnitude jökulhlaups, glacier margin position and ice-thickness have been identified as key controls on sandur evolution. Existing models however have focused primarily on observations made during short windows of time and often do not account for the subsequent modification of proglacial landsystems by repeated jökulhlaups or post-depositional modification due to melt out over decadal time-scales. Digital Elevation Models (DEMs) were used to reconstruct the development of large depressions on Skeiðarársandur, an outwash plain in southeast Iceland. These depressions measure up to 1 km in width and up to 13 m in depth and are associated with ice bodies up to 1 km in length and up to 150 m in height emplaced during a high-magnitude jökulhlaup in 1903 and subsequently buried by jökulhlaups in 1913 and 1922. The continued melting of the Harðaskriða ice bodies over a century following their emplacement, together with subsequent repeated burial, by high-magnitude jökulhlaups demonstrates that jökulhlaups may continue to serve as important controls on sandur evolution on a decadal to centennial timescale (101 – 102 years). The Harðaskriða depressions developed only following the retreat of the glacier margin after 1945, which highlights the controls of margin position on the evolution of the sandur. Margin position and thickness of the glacier profile was seen to affect not only the distribution and thickness of sediment emplaced during jökulhaups but also the rate and pattern of melt in the decades following the decoupling of the margin from the sandur. The jökulhlaup landsystem model signatures identified at this site may provide a useful analogue for interpreting landforms and strata emplaced by glacier margin fluctuations, jökulhlaups and melt out generated by retreating continental Pleistocene ice sheets.


Publication metadata

Author(s): Blauvelt DJ, Russell AJ, Large ARG, Tweed FS, Hiemstra JF, Kulessa B, Evans DJA, Waller RI

Publication type: Article

Publication status: Published

Journal: Geomorphology

Year: 2020

Volume: 360

Print publication date: 01/07/2020

Online publication date: 24/03/2020

Acceptance date: 10/03/2020

Date deposited: 17/03/2020

ISSN (print): 0169-555X

ISSN (electronic): 1872-695X

Publisher: Elsevier

URL: https://doi.org/10.1016/j.geomorph.2020.107164

DOI: 10.1016/j.geomorph.2020.107164


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Funding

Funder referenceFunder name
GR3/10960
IPY07/13
NERC

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