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dc.contributor.author De Angelis, Hernán
dc.contributor.author Jansson, Krister N.
dc.contributor.author Alm, Göran
dc.contributor.author Glasser, Neil F.
dc.contributor.author Hättestrand, Clas
dc.contributor.author Stroeven, Arjen P.
dc.contributor.author Kleman, Johan
dc.date.accessioned 2011-05-16T11:16:11Z
dc.date.available 2011-05-16T11:16:11Z
dc.date.issued 2010-08
dc.identifier.citation De Angelis , H , Jansson , K N , Alm , G , Glasser , N F , Hättestrand , C , Stroeven , A P & Kleman , J 2010 , ' North American Ice Sheet build-up during the last glacial cycle, 115-21 kyr ' Quaternary Science Reviews , vol 29 , no. 17-18 , pp. 2036-2051 . , 10.1016/j.quascirev.2010.04.021 en
dc.identifier.issn 0277-3791
dc.identifier.other PURE: 159951
dc.identifier.other dspace: 2160/6736
dc.identifier.uri http://hdl.handle.net/2160/6736
dc.description Kleman, J., Jansson, K., De Angelis, H., Stroeven, A. P., Hättestrand, C., Alm, G., Glasser, N. F. (2010). North American Ice Sheet build-up during the last glacial cycle, 115-21 kyr. Quaternary Science Reviews, 29(17-18), 2036-2051. en
dc.description.abstract The last glacial maximum (LGM) outline and subsequent retreat pattern (21–7 kyr) of North American ice sheets are reasonably well established. However, the evolution of the ice sheets during their build-up phase towards the LGM between 115 and 21 kyr has remained elusive, making it difficult to verify numerical ice sheet models for this important time interval. In this paper we outline the pre-LGM ice sheet evolution of the Laurentide and Cordilleran ice sheets by using glacial geological and geomorphological records to make a first-order reconstruction of ice sheet extent and flow pattern. We mapped the entire area covered by the Laurentide and Cordilleran ice sheets in Landsat MSS images and approximately 40% of this area in higher resolution Landsat ETM+ images. Mapping in aerial photographs added further detail primarily in Quebec-Labrador, the Cordilleran region, and on Baffin Island. Our analysis includes the recognition of approximately 500 relative-age relationships from crosscutting lineations. Together with previously published striae and till fabric data, these are used as the basis for relative-age assignments of regional flow patterns. For the reconstruction of the most probable ice sheet evolution sequence we employ a stepwise inversion scheme with a clearly defined strategy for delineating coherent landforms swarms (reflecting flow direction and configuration), and linking these to previously published constraints on relative and absolute chronology. Our results reveal that ice-dispersal centres in Keewatin and Quebec were dynamically independent for most of pre-LGM time and that a massive Quebec dispersal centre, rivalling the LGM in extent, existed at times when the SW sector of the ice sheet had not yet developed. The oldest flow system in eastern Quebec-Labrador (Atlantic swarm had an ice divide closer to the Labrador coast than later configurations). A northern Keewatin-Central Arctic Ice Sheet existed prior to the LGM, but is poorly chronologically constrained. There is also evidence for older and more easterly Cordilleran Ice Sheet divide locations than those that prevailed during the Late Wisconsinan. In terms of ice sheet build-up dynamics, it appears that “residual” ice caps after warming phases may have played an important role. In particular, the location and size of remnant ice masses at the end of major interstadials, i.e. OIS 5c and 5a, must have been critical for subsequent build-up patterns, because such remnant “uplands” may have fostered much more rapid ice sheet growth than what would have occurred on a fully deglaciated terrain. The ice-sheet configuration during stadials would also be governed largely by the additional topography that such “residual” ice constitutes because of inherent mass balance–topography feedbacks. en
dc.format.extent 16 en
dc.language.iso eng
dc.relation.ispartof Quaternary Science Reviews en
dc.title North American Ice Sheet build-up during the last glacial cycle, 115-21 kyr en
dc.type Text en
dc.type.publicationtype Article (Journal) en
dc.identifier.doi http://dx.doi.org/10.1016/j.quascirev.2010.04.021
dc.contributor.institution Institute of Geography & Earth Sciences en
dc.contributor.institution Centre for Glaciology en
dc.description.status Peer reviewed en


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