A subglacial hydrologic drainage hypothesis for silt sorting and deposition during retreat in Pine Island Bay
Late Holocene sediment deposits in Pine Island Bay, West Antarctica, are hypothesized to be linked to intensive meltwater drainage during the retreat of the paleo-Pine Island Ice Stream after the Last Glacial Maximum. The uppermost sediment units show an abrupt transition from ice-proximal debris to...
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Cambridge University Press
2019
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Online Access: | https://doi.org/10.1017/aog.2019.44 https://doaj.org/article/fe4ff82228f945a7a800c7fe33df29b8 |
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ftdoajarticles:oai:doaj.org/article:fe4ff82228f945a7a800c7fe33df29b8 2023-05-15T13:29:33+02:00 A subglacial hydrologic drainage hypothesis for silt sorting and deposition during retreat in Pine Island Bay Dustin M. Schroeder Emma J. MacKie Timothy T. Creyts John B. Anderson 2019-12-01T00:00:00Z https://doi.org/10.1017/aog.2019.44 https://doaj.org/article/fe4ff82228f945a7a800c7fe33df29b8 EN eng Cambridge University Press https://www.cambridge.org/core/product/identifier/S0260305519000442/type/journal_article https://doaj.org/toc/0260-3055 https://doaj.org/toc/1727-5644 doi:10.1017/aog.2019.44 0260-3055 1727-5644 https://doaj.org/article/fe4ff82228f945a7a800c7fe33df29b8 Annals of Glaciology, Vol 60, Pp 14-20 (2019) Antarctic glaciology glacier hydrology subglacial lakes subglacial sediments Meteorology. Climatology QC851-999 article 2019 ftdoajarticles https://doi.org/10.1017/aog.2019.44 2023-03-12T01:31:55Z Late Holocene sediment deposits in Pine Island Bay, West Antarctica, are hypothesized to be linked to intensive meltwater drainage during the retreat of the paleo-Pine Island Ice Stream after the Last Glacial Maximum. The uppermost sediment units show an abrupt transition from ice-proximal debris to a draped silt during the late Holocene, which is interpreted to coincide with rapid deglaciation. The small scale and fine sorting of the upper unit could be attributed to origins in subglacial meltwater; however the thickness and deposition rate for this unit imply punctuated- rather than continuous-deposition. This, combined with the deposit's location seaward of large, bedrock basins, has led to the interpretation of this unit as the result of subglacial lake outbursts in these basins. However, the fine-scale sorting of the silt unit is problematic for this energetic interpretation, which should mobilize and deposit a wider range of sediment sizes. To resolve this discrepancy, we present an alternative mechanism in which the silt was sorted by a distributed subglacial water system, stored in bedrock basins far inland of the grounding line, and subsequently eroded at higher flow speeds during retreat. We demonstrate that this mechanism is physically plausible given the subglacial conditions during the late Holocene. We hypothesize that similar silt units observed elsewhere in Antarctica downstream of bedrock basins could be the result of the same mechanism. Article in Journal/Newspaper Annals of Glaciology Antarc* Antarctic Antarctica Pine Island Pine Island Bay West Antarctica Directory of Open Access Journals: DOAJ Articles Antarctic Island Bay ENVELOPE(-109.085,-109.085,59.534,59.534) Pine Island Bay ENVELOPE(-102.000,-102.000,-74.750,-74.750) West Antarctica Annals of Glaciology 60 80 14 20 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Antarctic glaciology glacier hydrology subglacial lakes subglacial sediments Meteorology. Climatology QC851-999 |
spellingShingle |
Antarctic glaciology glacier hydrology subglacial lakes subglacial sediments Meteorology. Climatology QC851-999 Dustin M. Schroeder Emma J. MacKie Timothy T. Creyts John B. Anderson A subglacial hydrologic drainage hypothesis for silt sorting and deposition during retreat in Pine Island Bay |
topic_facet |
Antarctic glaciology glacier hydrology subglacial lakes subglacial sediments Meteorology. Climatology QC851-999 |
description |
Late Holocene sediment deposits in Pine Island Bay, West Antarctica, are hypothesized to be linked to intensive meltwater drainage during the retreat of the paleo-Pine Island Ice Stream after the Last Glacial Maximum. The uppermost sediment units show an abrupt transition from ice-proximal debris to a draped silt during the late Holocene, which is interpreted to coincide with rapid deglaciation. The small scale and fine sorting of the upper unit could be attributed to origins in subglacial meltwater; however the thickness and deposition rate for this unit imply punctuated- rather than continuous-deposition. This, combined with the deposit's location seaward of large, bedrock basins, has led to the interpretation of this unit as the result of subglacial lake outbursts in these basins. However, the fine-scale sorting of the silt unit is problematic for this energetic interpretation, which should mobilize and deposit a wider range of sediment sizes. To resolve this discrepancy, we present an alternative mechanism in which the silt was sorted by a distributed subglacial water system, stored in bedrock basins far inland of the grounding line, and subsequently eroded at higher flow speeds during retreat. We demonstrate that this mechanism is physically plausible given the subglacial conditions during the late Holocene. We hypothesize that similar silt units observed elsewhere in Antarctica downstream of bedrock basins could be the result of the same mechanism. |
format |
Article in Journal/Newspaper |
author |
Dustin M. Schroeder Emma J. MacKie Timothy T. Creyts John B. Anderson |
author_facet |
Dustin M. Schroeder Emma J. MacKie Timothy T. Creyts John B. Anderson |
author_sort |
Dustin M. Schroeder |
title |
A subglacial hydrologic drainage hypothesis for silt sorting and deposition during retreat in Pine Island Bay |
title_short |
A subglacial hydrologic drainage hypothesis for silt sorting and deposition during retreat in Pine Island Bay |
title_full |
A subglacial hydrologic drainage hypothesis for silt sorting and deposition during retreat in Pine Island Bay |
title_fullStr |
A subglacial hydrologic drainage hypothesis for silt sorting and deposition during retreat in Pine Island Bay |
title_full_unstemmed |
A subglacial hydrologic drainage hypothesis for silt sorting and deposition during retreat in Pine Island Bay |
title_sort |
subglacial hydrologic drainage hypothesis for silt sorting and deposition during retreat in pine island bay |
publisher |
Cambridge University Press |
publishDate |
2019 |
url |
https://doi.org/10.1017/aog.2019.44 https://doaj.org/article/fe4ff82228f945a7a800c7fe33df29b8 |
long_lat |
ENVELOPE(-109.085,-109.085,59.534,59.534) ENVELOPE(-102.000,-102.000,-74.750,-74.750) |
geographic |
Antarctic Island Bay Pine Island Bay West Antarctica |
geographic_facet |
Antarctic Island Bay Pine Island Bay West Antarctica |
genre |
Annals of Glaciology Antarc* Antarctic Antarctica Pine Island Pine Island Bay West Antarctica |
genre_facet |
Annals of Glaciology Antarc* Antarctic Antarctica Pine Island Pine Island Bay West Antarctica |
op_source |
Annals of Glaciology, Vol 60, Pp 14-20 (2019) |
op_relation |
https://www.cambridge.org/core/product/identifier/S0260305519000442/type/journal_article https://doaj.org/toc/0260-3055 https://doaj.org/toc/1727-5644 doi:10.1017/aog.2019.44 0260-3055 1727-5644 https://doaj.org/article/fe4ff82228f945a7a800c7fe33df29b8 |
op_doi |
https://doi.org/10.1017/aog.2019.44 |
container_title |
Annals of Glaciology |
container_volume |
60 |
container_issue |
80 |
container_start_page |
14 |
op_container_end_page |
20 |
_version_ |
1766001180395175936 |