An Empirical Estimate of Post-LGM Grounding-Event Duration in Eastern Ross Sea: Implications from a Comparison with Constraints from New Radiocarbon Dates
The West Antarctic Ice Sheet (WAIS) advanced to the outer shelf during the Last Glacial Maximum (LGM) before beginning a rapid retreat to the inner shelf. In the Whales Deep paleo-ice-stream trough, subsurface and geomorphologic evidence shows that grounding-line retreat was interrupted by at least...
Main Author: | |
---|---|
Format: | Text |
Language: | unknown |
Published: |
LSU Scholarly Repository
2016
|
Subjects: | |
Online Access: | https://repository.lsu.edu/gradschool_theses/2275 https://doi.org/10.31390/gradschool_theses.2275 https://repository.lsu.edu/context/gradschool_theses/article/3274/viewcontent/uc.pdf |
id |
ftlouisianastuir:oai:repository.lsu.edu:gradschool_theses-3274 |
---|---|
record_format |
openpolar |
spelling |
ftlouisianastuir:oai:repository.lsu.edu:gradschool_theses-3274 2024-09-15T17:45:00+00:00 An Empirical Estimate of Post-LGM Grounding-Event Duration in Eastern Ross Sea: Implications from a Comparison with Constraints from New Radiocarbon Dates Krogmeier, Benjamin 2016-01-01T08:00:00Z application/pdf https://repository.lsu.edu/gradschool_theses/2275 https://doi.org/10.31390/gradschool_theses.2275 https://repository.lsu.edu/context/gradschool_theses/article/3274/viewcontent/uc.pdf unknown LSU Scholarly Repository https://repository.lsu.edu/gradschool_theses/2275 doi:10.31390/gradschool_theses.2275 https://repository.lsu.edu/context/gradschool_theses/article/3274/viewcontent/uc.pdf LSU Master's Theses Antarctic Ice Sheet Ross Sea Retreat Sediment Flux Earth Sciences text 2016 ftlouisianastuir https://doi.org/10.31390/gradschool_theses.2275 2024-08-08T04:27:17Z The West Antarctic Ice Sheet (WAIS) advanced to the outer shelf during the Last Glacial Maximum (LGM) before beginning a rapid retreat to the inner shelf. In the Whales Deep paleo-ice-stream trough, subsurface and geomorphologic evidence shows that grounding-line retreat was interrupted by at least five pauses in the area between the shelf edge and the middle shelf. During the pauses, an overlapping cluster of backstepped grounding zone wedges (GZWs) was deposited. Each GZW represents a grounding event, i.e., a time interval during which the grounding-line position was relatively stable. Seismic correlation and isopach mapping show that the cluster has a total volume of 5.34 x 1011 m3. Based on our estimate of modern deformation-till flux at Bindschadler Ice Stream, we infer that when the WAIS was grounded at the middle shelf, the paleo-sediment flux would have been as high as ~5.36 x 108 m3a-1. Using this paleo flux, the middle-shelf grounding events would have had a duration of ~995 ± 493 years. In contrasts, radiocarbon dates show that the middle-shelf grounding events had a duration of at least 3200 years. The comparison shows that in the absence of radiocarbon control, our empirical approach provides a reasonable first-order estimate of grounding event duration. Text Antarc* Antarctic Bindschadler Ice Stream Ice Sheet Ross Sea LSU Digital Commons (Louisiana State University) |
institution |
Open Polar |
collection |
LSU Digital Commons (Louisiana State University) |
op_collection_id |
ftlouisianastuir |
language |
unknown |
topic |
Antarctic Ice Sheet Ross Sea Retreat Sediment Flux Earth Sciences |
spellingShingle |
Antarctic Ice Sheet Ross Sea Retreat Sediment Flux Earth Sciences Krogmeier, Benjamin An Empirical Estimate of Post-LGM Grounding-Event Duration in Eastern Ross Sea: Implications from a Comparison with Constraints from New Radiocarbon Dates |
topic_facet |
Antarctic Ice Sheet Ross Sea Retreat Sediment Flux Earth Sciences |
description |
The West Antarctic Ice Sheet (WAIS) advanced to the outer shelf during the Last Glacial Maximum (LGM) before beginning a rapid retreat to the inner shelf. In the Whales Deep paleo-ice-stream trough, subsurface and geomorphologic evidence shows that grounding-line retreat was interrupted by at least five pauses in the area between the shelf edge and the middle shelf. During the pauses, an overlapping cluster of backstepped grounding zone wedges (GZWs) was deposited. Each GZW represents a grounding event, i.e., a time interval during which the grounding-line position was relatively stable. Seismic correlation and isopach mapping show that the cluster has a total volume of 5.34 x 1011 m3. Based on our estimate of modern deformation-till flux at Bindschadler Ice Stream, we infer that when the WAIS was grounded at the middle shelf, the paleo-sediment flux would have been as high as ~5.36 x 108 m3a-1. Using this paleo flux, the middle-shelf grounding events would have had a duration of ~995 ± 493 years. In contrasts, radiocarbon dates show that the middle-shelf grounding events had a duration of at least 3200 years. The comparison shows that in the absence of radiocarbon control, our empirical approach provides a reasonable first-order estimate of grounding event duration. |
format |
Text |
author |
Krogmeier, Benjamin |
author_facet |
Krogmeier, Benjamin |
author_sort |
Krogmeier, Benjamin |
title |
An Empirical Estimate of Post-LGM Grounding-Event Duration in Eastern Ross Sea: Implications from a Comparison with Constraints from New Radiocarbon Dates |
title_short |
An Empirical Estimate of Post-LGM Grounding-Event Duration in Eastern Ross Sea: Implications from a Comparison with Constraints from New Radiocarbon Dates |
title_full |
An Empirical Estimate of Post-LGM Grounding-Event Duration in Eastern Ross Sea: Implications from a Comparison with Constraints from New Radiocarbon Dates |
title_fullStr |
An Empirical Estimate of Post-LGM Grounding-Event Duration in Eastern Ross Sea: Implications from a Comparison with Constraints from New Radiocarbon Dates |
title_full_unstemmed |
An Empirical Estimate of Post-LGM Grounding-Event Duration in Eastern Ross Sea: Implications from a Comparison with Constraints from New Radiocarbon Dates |
title_sort |
empirical estimate of post-lgm grounding-event duration in eastern ross sea: implications from a comparison with constraints from new radiocarbon dates |
publisher |
LSU Scholarly Repository |
publishDate |
2016 |
url |
https://repository.lsu.edu/gradschool_theses/2275 https://doi.org/10.31390/gradschool_theses.2275 https://repository.lsu.edu/context/gradschool_theses/article/3274/viewcontent/uc.pdf |
genre |
Antarc* Antarctic Bindschadler Ice Stream Ice Sheet Ross Sea |
genre_facet |
Antarc* Antarctic Bindschadler Ice Stream Ice Sheet Ross Sea |
op_source |
LSU Master's Theses |
op_relation |
https://repository.lsu.edu/gradschool_theses/2275 doi:10.31390/gradschool_theses.2275 https://repository.lsu.edu/context/gradschool_theses/article/3274/viewcontent/uc.pdf |
op_doi |
https://doi.org/10.31390/gradschool_theses.2275 |
_version_ |
1810492703808421888 |