Controls on the early Holocene collapse of the Bothnian Sea Ice Stream

Clason, CC, Greenwood, SL, Selmes, N, Lea, JM ORCID: 0000-0003-1885-0858, Jamieson, SSR, Nick, FM and Holmlund, P (2017) Controls on the early Holocene collapse of the Bothnian Sea Ice Stream. Journal of Geophysical Research: Earth Surface, 121 (12). pp. 2494-2513.

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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 flow line 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 modeled 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 modeled 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 nonlinear 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 modeled retreat rate less sensitive to marine forcings despite the marine setting.

Item Type:	Article
Uncontrolled Keywords:	Bothnian Sea Ice Stream, flow line modeling, Fennoscandian Ice Sheet
Depositing User:	Symplectic Admin
Date Deposited:	13 Jan 2017 10:14
Last Modified:	19 Jan 2023 07:20
DOI:	10.1002/2016JF004050
Related URLs:	Author Publisher
URI:	https://livrepository.liverpool.ac.uk/id/eprint/3005227