On the extent and thickness of the Innuitian Ice Sheet: a postglacial-adjustment approach
There is at present a controversy concerning the extent and thickness of the Innuitian Ice Sheet during the last glacial maximum (ca. 18 000 BP). Here, both a thick, extensive Innuitian Ice Sheet and a thin, limited ice sheet are isostatically modelled by employing disc-shaped elements and a radiall...
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Canadian Science Publishing
1991
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Online Access: | http://dx.doi.org/10.1139/e91-022 http://www.nrcresearchpress.com/doi/pdf/10.1139/e91-022 |
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crcansciencepubl:10.1139/e91-022 2023-12-17T10:29:42+01:00 On the extent and thickness of the Innuitian Ice Sheet: a postglacial-adjustment approach Tushingham, A. M. 1991 http://dx.doi.org/10.1139/e91-022 http://www.nrcresearchpress.com/doi/pdf/10.1139/e91-022 en eng Canadian Science Publishing http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining Canadian Journal of Earth Sciences volume 28, issue 2, page 231-239 ISSN 0008-4077 1480-3313 General Earth and Planetary Sciences journal-article 1991 crcansciencepubl https://doi.org/10.1139/e91-022 2023-11-19T13:38:37Z There is at present a controversy concerning the extent and thickness of the Innuitian Ice Sheet during the last glacial maximum (ca. 18 000 BP). Here, both a thick, extensive Innuitian Ice Sheet and a thin, limited ice sheet are isostatically modelled by employing disc-shaped elements and a radially symmetric Maxwellian Earth. The predicted relative sea-level curves for both models are compared with new data from Thores River, northernmost Ellesmere Island, and data from 29 other sites located in and around the Queen Elizabeth Islands. The data from Thores River are presented as an illustrative case study that particularly emphasizes the difficulty of relating sample elevations to ancient sea levels in this region. At all 30 sites, the relative sea-level data overwhelmingly favour the thick, extensive ice model. The hypothesis of tectonic uplift to explain the high raised beaches (> 100 m) found on Ellesmere Island and elsewhere in the region is rejected. The residual uplift of the thin, limited model is not spatially coherent, nor is it likely that tectonic uplift would exactly mimic the distinctive postglacial uplift. To reconcile geomorphological evidence (in the form of the preservation of preglacial maximum sediments and the general lack of glacial deposits) and the presence of high raised beaches, it is proposed that the Innuitian Ice Sheet was for part, possibly most, of its history a cold-based ice sheet (i.e., frozen to its bed). Article in Journal/Newspaper Ellesmere Island Ice Sheet Queen Elizabeth Islands Canadian Science Publishing (via Crossref) Ellesmere Island Thores River ENVELOPE(-72.677,-72.677,82.602,82.602) Canadian Journal of Earth Sciences 28 2 231 239 |
institution |
Open Polar |
collection |
Canadian Science Publishing (via Crossref) |
op_collection_id |
crcansciencepubl |
language |
English |
topic |
General Earth and Planetary Sciences |
spellingShingle |
General Earth and Planetary Sciences Tushingham, A. M. On the extent and thickness of the Innuitian Ice Sheet: a postglacial-adjustment approach |
topic_facet |
General Earth and Planetary Sciences |
description |
There is at present a controversy concerning the extent and thickness of the Innuitian Ice Sheet during the last glacial maximum (ca. 18 000 BP). Here, both a thick, extensive Innuitian Ice Sheet and a thin, limited ice sheet are isostatically modelled by employing disc-shaped elements and a radially symmetric Maxwellian Earth. The predicted relative sea-level curves for both models are compared with new data from Thores River, northernmost Ellesmere Island, and data from 29 other sites located in and around the Queen Elizabeth Islands. The data from Thores River are presented as an illustrative case study that particularly emphasizes the difficulty of relating sample elevations to ancient sea levels in this region. At all 30 sites, the relative sea-level data overwhelmingly favour the thick, extensive ice model. The hypothesis of tectonic uplift to explain the high raised beaches (> 100 m) found on Ellesmere Island and elsewhere in the region is rejected. The residual uplift of the thin, limited model is not spatially coherent, nor is it likely that tectonic uplift would exactly mimic the distinctive postglacial uplift. To reconcile geomorphological evidence (in the form of the preservation of preglacial maximum sediments and the general lack of glacial deposits) and the presence of high raised beaches, it is proposed that the Innuitian Ice Sheet was for part, possibly most, of its history a cold-based ice sheet (i.e., frozen to its bed). |
format |
Article in Journal/Newspaper |
author |
Tushingham, A. M. |
author_facet |
Tushingham, A. M. |
author_sort |
Tushingham, A. M. |
title |
On the extent and thickness of the Innuitian Ice Sheet: a postglacial-adjustment approach |
title_short |
On the extent and thickness of the Innuitian Ice Sheet: a postglacial-adjustment approach |
title_full |
On the extent and thickness of the Innuitian Ice Sheet: a postglacial-adjustment approach |
title_fullStr |
On the extent and thickness of the Innuitian Ice Sheet: a postglacial-adjustment approach |
title_full_unstemmed |
On the extent and thickness of the Innuitian Ice Sheet: a postglacial-adjustment approach |
title_sort |
on the extent and thickness of the innuitian ice sheet: a postglacial-adjustment approach |
publisher |
Canadian Science Publishing |
publishDate |
1991 |
url |
http://dx.doi.org/10.1139/e91-022 http://www.nrcresearchpress.com/doi/pdf/10.1139/e91-022 |
long_lat |
ENVELOPE(-72.677,-72.677,82.602,82.602) |
geographic |
Ellesmere Island Thores River |
geographic_facet |
Ellesmere Island Thores River |
genre |
Ellesmere Island Ice Sheet Queen Elizabeth Islands |
genre_facet |
Ellesmere Island Ice Sheet Queen Elizabeth Islands |
op_source |
Canadian Journal of Earth Sciences volume 28, issue 2, page 231-239 ISSN 0008-4077 1480-3313 |
op_rights |
http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining |
op_doi |
https://doi.org/10.1139/e91-022 |
container_title |
Canadian Journal of Earth Sciences |
container_volume |
28 |
container_issue |
2 |
container_start_page |
231 |
op_container_end_page |
239 |
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1785582156380110848 |