Palaeo-ice streams in the north-eastern Laurentide Ice Sheet
This thesis presents a palaeoglaciological study aimed to determine the location, geometry and temporal evolution of palaeo-ice streams of the north-easternmost Laurentide Ice Sheet. The work was accomplished through the geomorphological interpretation of satellite imagery over 3.19 x 106 km2 of the...
Main Author: | |
---|---|
Format: | Doctoral or Postdoctoral Thesis |
Language: | English |
Published: |
Institutionen för naturgeografi och kvartärgeologi (INK)
2007
|
Subjects: | |
Online Access: | http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-7116 |
id |
ftstockholmuniv:oai:DiVA.org:su-7116 |
---|---|
record_format |
openpolar |
spelling |
ftstockholmuniv:oai:DiVA.org:su-7116 2023-05-15T15:16:34+02:00 Palaeo-ice streams in the north-eastern Laurentide Ice Sheet De Angelis, Hernán 2007 application/pdf http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-7116 eng eng Institutionen för naturgeografi och kvartärgeologi (INK) Stockholm : Institutionen för naturgeografi och kvartärgeologi Dissertations from the Department of Physical Geography and Quaternary Geology, 1653-7211 No 9 http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-7116 urn:isbn:978-91-7155-509-0 info:eu-repo/semantics/openAccess ice sheet ice stream palaeo-ice sheet palaeo-ice stream glaciology palaeoglaciology Laurentide Ice Sheet Physical Geography Naturgeografi Doctoral thesis, monograph info:eu-repo/semantics/doctoralThesis text 2007 ftstockholmuniv 2023-02-23T21:39:27Z This thesis presents a palaeoglaciological study aimed to determine the location, geometry and temporal evolution of palaeo-ice streams of the north-easternmost Laurentide Ice Sheet. The work was accomplished through the geomorphological interpretation of satellite imagery over 3.19 x 106 km2 of the Canadian Arctic, using a glaciological inversion scheme. Ice streams were active in this region during most of the time between the Last Glacial Maximum and the last deglaciation. A web of ice streams and inter-ice stream areas existed. Three major ice stream networks are identified: the M'Clintock Channel, Gulf of Boothia – Lancaster Sound and Hudson Strait. The M'Clintock Channel bears the most complex landform record, comprising three generations of palaeo-ice streams. Their location was weakly controlled by the subglacial topography and their geometry was determined by frozen-bed portions of the ice sheet, thus providing evidence for pure ice streams in the Laurentide Ice Sheet. In contrast, the more pronounced relief of the Gulf of Boothia – Lancaster Sound corridor supported topographically controlled ice streams. The landform record on emerged land along Hudson Strait is insufficient to support the existence of ice streams. It is therefore proposed that ice streams were constrained within the deep parts of the strait while flanked by cold-based zones on the margins. Small transient ice streams on Baffin and Prince of Wales islands drained local remnant ice caps during the collapse of the ice sheet. Analysis of the controls on the location and flow of palaeo-ice streams suggests that the interaction between the subglacial topography and thermal state of the substrate plays a more fundamental role than the geology. It is concluded that the behaviour of ice streams cannot be explained in terms of environmental controls alone, but the complex dynamics of ice stream shear margins and onset zones must be considered. Doctoral or Postdoctoral Thesis Arctic Baffin Hudson Strait Ice Sheet Lancaster Sound Stockholm University: Publications (DiVA) Arctic Gulf of Boothia ENVELOPE(-90.657,-90.657,70.719,70.719) Hudson Hudson Strait ENVELOPE(-70.000,-70.000,62.000,62.000) Lancaster Sound ENVELOPE(-83.999,-83.999,74.218,74.218) M'Clintock ENVELOPE(-94.214,-94.214,57.802,57.802) M'Clintock Channel ENVELOPE(-102.002,-102.002,72.001,72.001) |
institution |
Open Polar |
collection |
Stockholm University: Publications (DiVA) |
op_collection_id |
ftstockholmuniv |
language |
English |
topic |
ice sheet ice stream palaeo-ice sheet palaeo-ice stream glaciology palaeoglaciology Laurentide Ice Sheet Physical Geography Naturgeografi |
spellingShingle |
ice sheet ice stream palaeo-ice sheet palaeo-ice stream glaciology palaeoglaciology Laurentide Ice Sheet Physical Geography Naturgeografi De Angelis, Hernán Palaeo-ice streams in the north-eastern Laurentide Ice Sheet |
topic_facet |
ice sheet ice stream palaeo-ice sheet palaeo-ice stream glaciology palaeoglaciology Laurentide Ice Sheet Physical Geography Naturgeografi |
description |
This thesis presents a palaeoglaciological study aimed to determine the location, geometry and temporal evolution of palaeo-ice streams of the north-easternmost Laurentide Ice Sheet. The work was accomplished through the geomorphological interpretation of satellite imagery over 3.19 x 106 km2 of the Canadian Arctic, using a glaciological inversion scheme. Ice streams were active in this region during most of the time between the Last Glacial Maximum and the last deglaciation. A web of ice streams and inter-ice stream areas existed. Three major ice stream networks are identified: the M'Clintock Channel, Gulf of Boothia – Lancaster Sound and Hudson Strait. The M'Clintock Channel bears the most complex landform record, comprising three generations of palaeo-ice streams. Their location was weakly controlled by the subglacial topography and their geometry was determined by frozen-bed portions of the ice sheet, thus providing evidence for pure ice streams in the Laurentide Ice Sheet. In contrast, the more pronounced relief of the Gulf of Boothia – Lancaster Sound corridor supported topographically controlled ice streams. The landform record on emerged land along Hudson Strait is insufficient to support the existence of ice streams. It is therefore proposed that ice streams were constrained within the deep parts of the strait while flanked by cold-based zones on the margins. Small transient ice streams on Baffin and Prince of Wales islands drained local remnant ice caps during the collapse of the ice sheet. Analysis of the controls on the location and flow of palaeo-ice streams suggests that the interaction between the subglacial topography and thermal state of the substrate plays a more fundamental role than the geology. It is concluded that the behaviour of ice streams cannot be explained in terms of environmental controls alone, but the complex dynamics of ice stream shear margins and onset zones must be considered. |
format |
Doctoral or Postdoctoral Thesis |
author |
De Angelis, Hernán |
author_facet |
De Angelis, Hernán |
author_sort |
De Angelis, Hernán |
title |
Palaeo-ice streams in the north-eastern Laurentide Ice Sheet |
title_short |
Palaeo-ice streams in the north-eastern Laurentide Ice Sheet |
title_full |
Palaeo-ice streams in the north-eastern Laurentide Ice Sheet |
title_fullStr |
Palaeo-ice streams in the north-eastern Laurentide Ice Sheet |
title_full_unstemmed |
Palaeo-ice streams in the north-eastern Laurentide Ice Sheet |
title_sort |
palaeo-ice streams in the north-eastern laurentide ice sheet |
publisher |
Institutionen för naturgeografi och kvartärgeologi (INK) |
publishDate |
2007 |
url |
http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-7116 |
long_lat |
ENVELOPE(-90.657,-90.657,70.719,70.719) ENVELOPE(-70.000,-70.000,62.000,62.000) ENVELOPE(-83.999,-83.999,74.218,74.218) ENVELOPE(-94.214,-94.214,57.802,57.802) ENVELOPE(-102.002,-102.002,72.001,72.001) |
geographic |
Arctic Gulf of Boothia Hudson Hudson Strait Lancaster Sound M'Clintock M'Clintock Channel |
geographic_facet |
Arctic Gulf of Boothia Hudson Hudson Strait Lancaster Sound M'Clintock M'Clintock Channel |
genre |
Arctic Baffin Hudson Strait Ice Sheet Lancaster Sound |
genre_facet |
Arctic Baffin Hudson Strait Ice Sheet Lancaster Sound |
op_relation |
Dissertations from the Department of Physical Geography and Quaternary Geology, 1653-7211 No 9 http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-7116 urn:isbn:978-91-7155-509-0 |
op_rights |
info:eu-repo/semantics/openAccess |
_version_ |
1766346859260936192 |