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Large-scale reorganization and sedimentation of terrestrial ice streams during late Wisconsinan Laurentide Ice Sheet deglaciation

2009; Geological Society of America; Volume: 122; Issue: 5-6 Linguagem: Inglês

10.1130/b26476.1

1943-2674

Colm Ó Cofaigh, David J. A. Evans, I R Smith,

Geology and Paleoclimatology Research

Research Article| May 01, 2010 Large-scale reorganization and sedimentation of terrestrial ice streams during late Wisconsinan Laurentide Ice Sheet deglaciation Colm Ó Cofaigh; Colm Ó Cofaigh † 1Department of Geography, Durham University, Science Site, South Road, Durham DH1 3LE, UK †E-mail: colm.o'cofaigh@durham.ac.uk Search for other works by this author on: GSW Google Scholar David J.A. Evans; David J.A. Evans § 1Department of Geography, Durham University, Science Site, South Road, Durham DH1 3LE, UK §E-mail: d.j.a.evans@durham.ac.uk Search for other works by this author on: GSW Google Scholar I. Rod Smith I. Rod Smith # 2Geological Survey of Canada, 3303 33rd Street NW, Calgary, Alberta, T2L 2A7, Canada #E-mail: rodsmith@nrcan.gc.ca Search for other works by this author on: GSW Google Scholar Author and Article Information Colm Ó Cofaigh † 1Department of Geography, Durham University, Science Site, South Road, Durham DH1 3LE, UK David J.A. Evans § 1Department of Geography, Durham University, Science Site, South Road, Durham DH1 3LE, UK I. Rod Smith # 2Geological Survey of Canada, 3303 33rd Street NW, Calgary, Alberta, T2L 2A7, Canada †E-mail: colm.o'cofaigh@durham.ac.uk §E-mail: d.j.a.evans@durham.ac.uk #E-mail: rodsmith@nrcan.gc.ca Publisher: Geological Society of America Received: 05 Jun 2008 Revision Received: 02 Apr 2009 Accepted: 03 Apr 2009 First Online: 08 Mar 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 © 2010 Geological Society of America GSA Bulletin (2010) 122 (5-6): 743–756. https://doi.org/10.1130/B26476.1 Article history Received: 05 Jun 2008 Revision Received: 02 Apr 2009 Accepted: 03 Apr 2009 First Online: 08 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation Colm Ó Cofaigh, David J.A. Evans, I. Rod Smith; Large-scale reorganization and sedimentation of terrestrial ice streams during late Wisconsinan Laurentide Ice Sheet deglaciation. GSA Bulletin 2010;; 122 (5-6): 743–756. doi: https://doi.org/10.1130/B26476.1 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract Glacial geomorphological mapping of Shuttle Radar Topography Mission (SRTM) data from the western Canadian Prairies demonstrates that during the last (late Wisconsinan) deglaciation of the Laurentide Ice Sheet terrestrial ice streams underwent a major reorganization of their flow configuration. This reorganization involved a 90° shift in flow direction and was accompanied by a corresponding increase in the influence of topography on streaming flow. Ice streams included both topographically confined and "pure" ice streams that flowed independent of topography. Streaming flow is recorded by suites of highly elongate (>60 km long) subglacial bedforms, bounded sharply at their lateral margins by prominent moraines. Initial streaming flow was unconfined by topography but was replaced progressively, and crosscut, by younger topographically confined flows. Flow reorganization is inferred to have been caused by temporal and spatial variations in the interaction between frozen and thawed bed conditions, with thinning and shutdown of one ice stream ultimately triggering initiation of others. This highlights the role of internal glaciodynamically driven reorganization in triggering streaming flow within large ice sheets and shows that large-scale flow reorganization can occur over the time scale of a single deglaciation in terrestrial ice streams. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.