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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ftriceuniv:oai:scholarship.rice.edu:1911/111478 2023-05-15T13:29:45+02:00 A subglacial hydrologic drainage hypothesis for silt sorting and deposition during retreat in Pine Island Bay Schroeder, Dustin M. MacKie, Emma J. Creyts, Timothy T. Anderson, John B. 2019 application/pdf https://hdl.handle.net/1911/111478 https://doi.org/10.1017/aog.2019.44 eng eng Cambridge University Press Schroeder, Dustin M., MacKie, Emma J., Creyts, Timothy T., et al. "A subglacial hydrologic drainage hypothesis for silt sorting and deposition during retreat in Pine Island Bay." Annals of Glaciology, 60, no. 80 (2019) Cambridge University Press: 14-20. https://doi.org/10.1017/aog.2019.44. https://hdl.handle.net/1911/111478 a-subglacial-hydrologic-drainage-hypothesis https://doi.org/10.1017/aog.2019.44 This is an Open Access article, distributed under the terms of the Creative Commons Attribution licence (http:// creativecommons.org/licenses/by/4.0/), which permits unrestricted re-use, distribution, and reproduction in any medium, provided the original work is properly cited. https://creativecommons.org/licenses/by/4.0/ CC-BY Journal article Text publisher version 2019 ftriceuniv https://doi.org/10.1017/aog.2019.44 2022-08-09T20:49:32Z 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* Antarctica Pine Island Pine Island Bay West Antarctica Rice University: Digital Scholarship Archive 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 |
Rice University: Digital Scholarship Archive |
op_collection_id |
ftriceuniv |
language |
English |
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 |
Schroeder, Dustin M. MacKie, Emma J. Creyts, Timothy T. Anderson, John B. |
spellingShingle |
Schroeder, Dustin M. MacKie, Emma J. Creyts, Timothy T. Anderson, John B. A subglacial hydrologic drainage hypothesis for silt sorting and deposition during retreat in Pine Island Bay |
author_facet |
Schroeder, Dustin M. MacKie, Emma J. Creyts, Timothy T. Anderson, John B. |
author_sort |
Schroeder, Dustin M. |
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://hdl.handle.net/1911/111478 https://doi.org/10.1017/aog.2019.44 |
long_lat |
ENVELOPE(-109.085,-109.085,59.534,59.534) ENVELOPE(-102.000,-102.000,-74.750,-74.750) |
geographic |
Island Bay Pine Island Bay West Antarctica |
geographic_facet |
Island Bay Pine Island Bay West Antarctica |
genre |
Annals of Glaciology Antarc* Antarctica Pine Island Pine Island Bay West Antarctica |
genre_facet |
Annals of Glaciology Antarc* Antarctica Pine Island Pine Island Bay West Antarctica |
op_relation |
Schroeder, Dustin M., MacKie, Emma J., Creyts, Timothy T., et al. "A subglacial hydrologic drainage hypothesis for silt sorting and deposition during retreat in Pine Island Bay." Annals of Glaciology, 60, no. 80 (2019) Cambridge University Press: 14-20. https://doi.org/10.1017/aog.2019.44. https://hdl.handle.net/1911/111478 a-subglacial-hydrologic-drainage-hypothesis https://doi.org/10.1017/aog.2019.44 |
op_rights |
This is an Open Access article, distributed under the terms of the Creative Commons Attribution licence (http:// creativecommons.org/licenses/by/4.0/), which permits unrestricted re-use, distribution, and reproduction in any medium, provided the original work is properly cited. https://creativecommons.org/licenses/by/4.0/ |
op_rightsnorm |
CC-BY |
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_ |
1766002581592604672 |