Post-LGM grounding line and calving front translations of the West Antarctic Ice Sheet in the Whales Deep paleo-ice-stream trough, eastern Ross Sea, Antarctica
Newly acquired multibeam data from the Whales Deep Basin show lineations that extend to the shelf break, providing documentation that the West Antarctic Ice Sheet (WAIS) extended across the entire continental shelf during the Last Glacial Maximum (LGM). Following the LGM, the grounding line retreate...
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ftlouisianastuir:oai:digitalcommons.lsu.edu:gradschool_theses-5558 2023-06-11T04:06:58+02:00 Post-LGM grounding line and calving front translations of the West Antarctic Ice Sheet in the Whales Deep paleo-ice-stream trough, eastern Ross Sea, Antarctica McGlannan, Austin James 2017-01-01T08:00:00Z application/pdf https://digitalcommons.lsu.edu/gradschool_theses/4557 https://doi.org/10.31390/gradschool_theses.4557 https://digitalcommons.lsu.edu/context/gradschool_theses/article/5558/viewcontent/McGlannanThesis_4_11_17.pdf unknown LSU Digital Commons https://digitalcommons.lsu.edu/gradschool_theses/4557 doi:10.31390/gradschool_theses.4557 https://digitalcommons.lsu.edu/context/gradschool_theses/article/5558/viewcontent/McGlannanThesis_4_11_17.pdf LSU Master's Theses West Antarctic Ice Sheet Sedimentology Diatom Geomorphology Earth Sciences text 2017 ftlouisianastuir https://doi.org/10.31390/gradschool_theses.4557 2023-05-28T19:16:52Z Newly acquired multibeam data from the Whales Deep Basin show lineations that extend to the shelf break, providing documentation that the West Antarctic Ice Sheet (WAIS) extended across the entire continental shelf during the Last Glacial Maximum (LGM). Following the LGM, the grounding line retreated approximately 60 km where it was pinned on a bathymetric high and began constructing a composite grounding zone wedge composed of seven individual wedges. Stabilization of the grounding line was thus caused by construction this composite wedge, elevating the grounding line by ~140 meters. Sedimentological data indicate that a small ice shelf with a calving front near the shelf edge formed over the outer shelf immediately after the grounding line began retreating from the shelf edge. The ice shelf broke up sometime after the fourth wedge was constructed. After construction of GZW7, the grounding line abruptly shifted ~200 km to the south where retreat slowed near the northern end of Roosevelt Island. Concomitant with grounding-line retreat, a second larger paleo Ross Ice Shelf reformed over the middle continental shelf. This large ice shelf then retreated abruptly and the present-day open water environment was established. These data indicate a complex deglaciation, which involved several discrete steps of the grounding line during the initial stages followed by a final major retreat of both the grounding line and calving front. The sedimentologic framework presented here is significant because it is a necessary step towards developing a detailed retreat chronology for this sector of the WAIS. Text Antarc* Antarctic Antarctica Ice Sheet Ice Shelf Roosevelt Island Ross Ice Shelf Ross Sea LSU Digital Commons (Louisiana State University) Antarctic Roosevelt Island ENVELOPE(-162.000,-162.000,-79.283,-79.283) Ross Ice Shelf Ross Sea West Antarctic Ice Sheet |
institution |
Open Polar |
collection |
LSU Digital Commons (Louisiana State University) |
op_collection_id |
ftlouisianastuir |
language |
unknown |
topic |
West Antarctic Ice Sheet Sedimentology Diatom Geomorphology Earth Sciences |
spellingShingle |
West Antarctic Ice Sheet Sedimentology Diatom Geomorphology Earth Sciences McGlannan, Austin James Post-LGM grounding line and calving front translations of the West Antarctic Ice Sheet in the Whales Deep paleo-ice-stream trough, eastern Ross Sea, Antarctica |
topic_facet |
West Antarctic Ice Sheet Sedimentology Diatom Geomorphology Earth Sciences |
description |
Newly acquired multibeam data from the Whales Deep Basin show lineations that extend to the shelf break, providing documentation that the West Antarctic Ice Sheet (WAIS) extended across the entire continental shelf during the Last Glacial Maximum (LGM). Following the LGM, the grounding line retreated approximately 60 km where it was pinned on a bathymetric high and began constructing a composite grounding zone wedge composed of seven individual wedges. Stabilization of the grounding line was thus caused by construction this composite wedge, elevating the grounding line by ~140 meters. Sedimentological data indicate that a small ice shelf with a calving front near the shelf edge formed over the outer shelf immediately after the grounding line began retreating from the shelf edge. The ice shelf broke up sometime after the fourth wedge was constructed. After construction of GZW7, the grounding line abruptly shifted ~200 km to the south where retreat slowed near the northern end of Roosevelt Island. Concomitant with grounding-line retreat, a second larger paleo Ross Ice Shelf reformed over the middle continental shelf. This large ice shelf then retreated abruptly and the present-day open water environment was established. These data indicate a complex deglaciation, which involved several discrete steps of the grounding line during the initial stages followed by a final major retreat of both the grounding line and calving front. The sedimentologic framework presented here is significant because it is a necessary step towards developing a detailed retreat chronology for this sector of the WAIS. |
format |
Text |
author |
McGlannan, Austin James |
author_facet |
McGlannan, Austin James |
author_sort |
McGlannan, Austin James |
title |
Post-LGM grounding line and calving front translations of the West Antarctic Ice Sheet in the Whales Deep paleo-ice-stream trough, eastern Ross Sea, Antarctica |
title_short |
Post-LGM grounding line and calving front translations of the West Antarctic Ice Sheet in the Whales Deep paleo-ice-stream trough, eastern Ross Sea, Antarctica |
title_full |
Post-LGM grounding line and calving front translations of the West Antarctic Ice Sheet in the Whales Deep paleo-ice-stream trough, eastern Ross Sea, Antarctica |
title_fullStr |
Post-LGM grounding line and calving front translations of the West Antarctic Ice Sheet in the Whales Deep paleo-ice-stream trough, eastern Ross Sea, Antarctica |
title_full_unstemmed |
Post-LGM grounding line and calving front translations of the West Antarctic Ice Sheet in the Whales Deep paleo-ice-stream trough, eastern Ross Sea, Antarctica |
title_sort |
post-lgm grounding line and calving front translations of the west antarctic ice sheet in the whales deep paleo-ice-stream trough, eastern ross sea, antarctica |
publisher |
LSU Digital Commons |
publishDate |
2017 |
url |
https://digitalcommons.lsu.edu/gradschool_theses/4557 https://doi.org/10.31390/gradschool_theses.4557 https://digitalcommons.lsu.edu/context/gradschool_theses/article/5558/viewcontent/McGlannanThesis_4_11_17.pdf |
long_lat |
ENVELOPE(-162.000,-162.000,-79.283,-79.283) |
geographic |
Antarctic Roosevelt Island Ross Ice Shelf Ross Sea West Antarctic Ice Sheet |
geographic_facet |
Antarctic Roosevelt Island Ross Ice Shelf Ross Sea West Antarctic Ice Sheet |
genre |
Antarc* Antarctic Antarctica Ice Sheet Ice Shelf Roosevelt Island Ross Ice Shelf Ross Sea |
genre_facet |
Antarc* Antarctic Antarctica Ice Sheet Ice Shelf Roosevelt Island Ross Ice Shelf Ross Sea |
op_source |
LSU Master's Theses |
op_relation |
https://digitalcommons.lsu.edu/gradschool_theses/4557 doi:10.31390/gradschool_theses.4557 https://digitalcommons.lsu.edu/context/gradschool_theses/article/5558/viewcontent/McGlannanThesis_4_11_17.pdf |
op_doi |
https://doi.org/10.31390/gradschool_theses.4557 |
_version_ |
1768379334419021824 |