Blauvelt, David J. and Russell, Andrew J. and Large, Andrew R.G. and Tweed, Fiona S. and Hiemstra, John F. and Kulessa, Bernd and Evans, David J.A. and Waller, Richard I. (2020) 'Controls on jökulhlaup-transported buried ice melt-out at Skeiðarársandur, Iceland : implications for the evolution of ice-marginal environments.', Geomorphology., 360 . p. 107164.
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.
|Full text:||(VoR) Version of Record|
Available under License - Creative Commons Attribution.
Download PDF (8338Kb)
|Publisher Web site:||https://doi.org/10.1016/j.geomorph.2020.107164|
|Publisher statement:||© 2020 This manuscript version is made available under the CC-BY 4.0 license https://creativecommons.org/licenses/by/4.0/|
|Date accepted:||10 March 2020|
|Date deposited:||27 March 2020|
|Date of first online publication:||24 March 2020|
|Date first made open access:||27 March 2020|
Save or Share this output
|Look up in GoogleScholar|