Skip to main content

Research Repository

Advanced Search

Controls on the Early Holocene Collapse of the Bothnian Sea Ice Stream

Clason, C.C.; Greenwood, S.L.; Selmes, N.; Lea, J.M.; Jamieson, S.S.R.; Nick, F.M.; Holmlund, P.

Controls on the Early Holocene Collapse of the Bothnian Sea Ice Stream Thumbnail


Authors

S.L. Greenwood

N. Selmes

J.M. Lea

F.M. Nick

P. Holmlund



Abstract

New high resolution multibeam data in the Gulf of Bothnia reveal for the first time the subglacial environment of a Bothnian Sea Ice Stream. The geomorphological record suggests that increased meltwater production may have been important in driving rapid retreat of Bothnian Sea ice during deglaciation. Here we apply a well-established one-dimensional flowline model to simulate ice flow through the Gulf of Bothnia and investigate controls on retreat of the ice stream during the post-Younger Dryas deglaciation of the Fennoscandian Ice Sheet. The relative influence of atmospheric and marine forcings are investigated, with the modelled ice stream exhibiting much greater sensitivity to surface melting, implemented through surface mass balance and hydrofracture-induced calving, than to submarine melting or relative sea level change. Such sensitivity is supported by the presence of extensive meltwater features in the geomorphological record. The modelled ice stream does not demonstrate significant sensitivity to changes in prescribed ice stream width or overall bed slope, but local variations in basal topography and ice stream width result in non-linear retreat of the grounding line, notably demonstrating points of short-lived retreat slowdown on reverse bed slopes. Retreat of the ice stream was most likely governed by increased ice surface meltwater production, with the modelled retreat rate less sensitive to marine forcings despite the marine setting.

Citation

Clason, C., Greenwood, S., Selmes, N., Lea, J., Jamieson, S., Nick, F., & Holmlund, P. (2016). Controls on the Early Holocene Collapse of the Bothnian Sea Ice Stream. Journal of Geophysical Research: Earth Surface, 121(12), 2494-2513. https://doi.org/10.1002/2016jf004050

Journal Article Type Article
Acceptance Date Dec 7, 2016
Online Publication Date Dec 22, 2016
Publication Date Dec 22, 2016
Deposit Date Dec 15, 2016
Publicly Available Date Dec 15, 2016
Journal Journal of Geophysical Research: Earth Surface
Print ISSN 2169-9011
Publisher American Geophysical Union
Peer Reviewed Peer Reviewed
Volume 121
Issue 12
Pages 2494-2513
DOI https://doi.org/10.1002/2016jf004050

Files


Accepted Journal Article (2.5 Mb)
PDF

Copyright Statement
©2016. The Authors. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.





You might also like



Downloadable Citations