Late Pleistocene ice export events into the Arctic Ocean from the M'Clure Strait Ice Stream, Canadian Arctic Archipelago

Stokes, C.R.; Clark, C.D.; Darby, D.A.; Hodgson, D.A.

Abstract

Rapidly-flowing sectors of an ice sheet (ice streams) can play an important role in abrupt climate change through the delivery of icebergs and meltwater and the subsequent disruption of ocean thermohaline circulation (e.g., the North Atlantic's Heinrich events). Recently, several cores have been raised from the Arctic Ocean which document the existence of massive ice export events during the Late Pleistocene and whose provenance has been linked to source regions in the Canadian Arctic Archipelago. In this paper, satellite imagery is used to map glacial geomorphology in the vicinity of Victoria Island, Banks Island and Prince of Wales Island (Canadian Arctic) in order to reconstruct ice flow patterns in the highly complex glacial landscape. A total of 88 discrete flow-sets are mapped and of these, 13 exhibit the characteristic geomorphology of palaeo-ice streams (i.e., parallel patterns of large, highly elongated mega-scale glacial lineations forming a convergent flow pattern with abrupt lateral margins). Previous studies by other workers and cross-cutting relationships indicate that the majority of these ice streams are relatively young and operated during or immediately prior to deglaciation. Our new mapping, however, documents a large (> 700 km long; 110 km wide) and relatively old ice stream imprint centred in M'Clintock Channel and converging into Viscount Melville Sound. A trough mouth fan located on the continental shelf suggests that it extended along M'Clure Strait and was grounded at the shelf edge. The location of the M'Clure Strait Ice Stream exactly matches the source area of 4 (possibly 5) major ice export events recorded in core PS1230 raised from Fram Strait, the major ice exit for the Arctic Ocean. These ice export events occur at not, vert, similar12.9, not, vert, similar15.6, not, vert, similar22 and 29.8 ka (14C yr BP) and we argue that they record vigorous episodes of activity of the M'Clure Strait Ice Stream. The timing of these events is remarkably similar to the North Atlantic's Heinrich events and we take this as evidence that the M'Clure Strait Ice Stream was also activated around the same time. This may hold important implications for the cause of the North Atlantic's Heinrich events and hints at the possibility of a pan-ice sheet response.

Citation

Stokes, C., Clark, C., Darby, D., & Hodgson, D. (2005). Late Pleistocene ice export events into the Arctic Ocean from the M'Clure Strait Ice Stream, Canadian Arctic Archipelago. Global and Planetary Change, 49(3-4), 139-162. https://doi.org/10.1016/j.gloplacha.2005.06.001

• Journal Article Type: Article
• Publication Date: 2005-12
• Deposit Date: Apr 3, 2007
• Journal: Global and Planetary Change
• Print ISSN: 0921-8181
• Electronic ISSN: 1872-6364
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 49
• Issue: 3-4
• Pages: 139-162
• DOI: https://doi.org/10.1016/j.gloplacha.2005.06.001
• Keywords: Ice stream, Laurentide Ice Sheet, Arctic Ocean, Iceberg rafted detritus (IRD).
• Public URL: https://durham-repository.worktribe.com/output/1547960