New Last Glacial Maximum ice thickness constraints for the Weddell Sea Embayment, Antarctica
We describe new Last Glacial Maximum (LGM) ice thickness constraints for three locations spanning the Weddell Sea Embayment (WSE) of Antarctica. Samples collected from the Shackleton Range, Pensacola Mountains, and the Lassiter Coast constrain the LGM thickness of the Slessor Glacier, Foundation Ice...
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ftdoajarticles:oai:doaj.org/article:880996a06713462ea2b30f256658634a 2023-05-15T13:59:15+02:00 New Last Glacial Maximum ice thickness constraints for the Weddell Sea Embayment, Antarctica K. A. Nichols B. M. Goehring G. Balco J. S. Johnson A. S. Hein C. Todd 2019-11-01T00:00:00Z https://doi.org/10.5194/tc-13-2935-2019 https://doaj.org/article/880996a06713462ea2b30f256658634a EN eng Copernicus Publications https://www.the-cryosphere.net/13/2935/2019/tc-13-2935-2019.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 doi:10.5194/tc-13-2935-2019 1994-0416 1994-0424 https://doaj.org/article/880996a06713462ea2b30f256658634a The Cryosphere, Vol 13, Pp 2935-2951 (2019) Environmental sciences GE1-350 Geology QE1-996.5 article 2019 ftdoajarticles https://doi.org/10.5194/tc-13-2935-2019 2022-12-31T16:29:46Z We describe new Last Glacial Maximum (LGM) ice thickness constraints for three locations spanning the Weddell Sea Embayment (WSE) of Antarctica. Samples collected from the Shackleton Range, Pensacola Mountains, and the Lassiter Coast constrain the LGM thickness of the Slessor Glacier, Foundation Ice Stream, and grounded ice proximal to the modern Ronne Ice Shelf edge on the Antarctic Peninsula, respectively. Previous attempts to reconstruct LGM-to-present ice thickness changes around the WSE used measurements of long-lived cosmogenic nuclides, primarily 10 Be . An absence of post-LGM apparent exposure ages at many sites led to LGM thickness reconstructions that were spatially highly variable and inconsistent with flow line modelling. Estimates for the contribution of the ice sheet occupying the WSE at the LGM to global sea level since deglaciation vary by an order of magnitude, from 1.4 to 14.1 m of sea level equivalent. Here we use a short-lived cosmogenic nuclide, in situ-produced 14 C , which is less susceptible to inheritance problems than 10 Be and other long-lived nuclides. We use in situ 14 C to evaluate the possibility that sites with no post-LGM exposure ages are biased by cosmogenic nuclide inheritance due to surface preservation by cold-based ice and non-deposition of LGM-aged drift. Our measurements show that the Slessor Glacier was between 310 and up to 655 m thicker than present at the LGM. The Foundation Ice Stream was at least 800 m thicker, and ice on the Lassiter Coast was at least 385 m thicker than present at the LGM. With evidence for LGM thickening at all of our study sites, our in situ 14 C measurements indicate that the long-lived nuclide measurements of previous studies were influenced by cosmogenic nuclide inheritance. Our inferred LGM configuration, which is primarily based on minimum ice thickness constraints and thus does not constrain an upper limit, indicates a relatively modest contribution to sea level rise since the LGM of < 4.6 m, and possibly as little as < 1.5 m. Article in Journal/Newspaper Antarc* Antarctic Antarctic Peninsula Antarctica Foundation Ice Stream Ice Sheet Ice Shelf Ronne Ice Shelf Slessor Glacier The Cryosphere Weddell Sea Directory of Open Access Journals: DOAJ Articles Antarctic The Antarctic Antarctic Peninsula Weddell Sea Shackleton Weddell Ronne Ice Shelf ENVELOPE(-61.000,-61.000,-78.500,-78.500) Shackleton Range ENVELOPE(-26.000,-26.000,-80.833,-80.833) Pensacola Mountains ENVELOPE(-58.000,-58.000,-83.500,-83.500) Foundation Ice Stream ENVELOPE(-60.000,-60.000,-83.250,-83.250) Lassiter ENVELOPE(-62.000,-62.000,-73.750,-73.750) Slessor ENVELOPE(-64.967,-64.967,-66.517,-66.517) Lassiter Coast ENVELOPE(-62.000,-62.000,-74.000,-74.000) Slessor Glacier ENVELOPE(-26.000,-26.000,-79.833,-79.833) The Cryosphere 13 11 2935 2951 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Environmental sciences GE1-350 Geology QE1-996.5 |
spellingShingle |
Environmental sciences GE1-350 Geology QE1-996.5 K. A. Nichols B. M. Goehring G. Balco J. S. Johnson A. S. Hein C. Todd New Last Glacial Maximum ice thickness constraints for the Weddell Sea Embayment, Antarctica |
topic_facet |
Environmental sciences GE1-350 Geology QE1-996.5 |
description |
We describe new Last Glacial Maximum (LGM) ice thickness constraints for three locations spanning the Weddell Sea Embayment (WSE) of Antarctica. Samples collected from the Shackleton Range, Pensacola Mountains, and the Lassiter Coast constrain the LGM thickness of the Slessor Glacier, Foundation Ice Stream, and grounded ice proximal to the modern Ronne Ice Shelf edge on the Antarctic Peninsula, respectively. Previous attempts to reconstruct LGM-to-present ice thickness changes around the WSE used measurements of long-lived cosmogenic nuclides, primarily 10 Be . An absence of post-LGM apparent exposure ages at many sites led to LGM thickness reconstructions that were spatially highly variable and inconsistent with flow line modelling. Estimates for the contribution of the ice sheet occupying the WSE at the LGM to global sea level since deglaciation vary by an order of magnitude, from 1.4 to 14.1 m of sea level equivalent. Here we use a short-lived cosmogenic nuclide, in situ-produced 14 C , which is less susceptible to inheritance problems than 10 Be and other long-lived nuclides. We use in situ 14 C to evaluate the possibility that sites with no post-LGM exposure ages are biased by cosmogenic nuclide inheritance due to surface preservation by cold-based ice and non-deposition of LGM-aged drift. Our measurements show that the Slessor Glacier was between 310 and up to 655 m thicker than present at the LGM. The Foundation Ice Stream was at least 800 m thicker, and ice on the Lassiter Coast was at least 385 m thicker than present at the LGM. With evidence for LGM thickening at all of our study sites, our in situ 14 C measurements indicate that the long-lived nuclide measurements of previous studies were influenced by cosmogenic nuclide inheritance. Our inferred LGM configuration, which is primarily based on minimum ice thickness constraints and thus does not constrain an upper limit, indicates a relatively modest contribution to sea level rise since the LGM of < 4.6 m, and possibly as little as < 1.5 m. |
format |
Article in Journal/Newspaper |
author |
K. A. Nichols B. M. Goehring G. Balco J. S. Johnson A. S. Hein C. Todd |
author_facet |
K. A. Nichols B. M. Goehring G. Balco J. S. Johnson A. S. Hein C. Todd |
author_sort |
K. A. Nichols |
title |
New Last Glacial Maximum ice thickness constraints for the Weddell Sea Embayment, Antarctica |
title_short |
New Last Glacial Maximum ice thickness constraints for the Weddell Sea Embayment, Antarctica |
title_full |
New Last Glacial Maximum ice thickness constraints for the Weddell Sea Embayment, Antarctica |
title_fullStr |
New Last Glacial Maximum ice thickness constraints for the Weddell Sea Embayment, Antarctica |
title_full_unstemmed |
New Last Glacial Maximum ice thickness constraints for the Weddell Sea Embayment, Antarctica |
title_sort |
new last glacial maximum ice thickness constraints for the weddell sea embayment, antarctica |
publisher |
Copernicus Publications |
publishDate |
2019 |
url |
https://doi.org/10.5194/tc-13-2935-2019 https://doaj.org/article/880996a06713462ea2b30f256658634a |
long_lat |
ENVELOPE(-61.000,-61.000,-78.500,-78.500) ENVELOPE(-26.000,-26.000,-80.833,-80.833) ENVELOPE(-58.000,-58.000,-83.500,-83.500) ENVELOPE(-60.000,-60.000,-83.250,-83.250) ENVELOPE(-62.000,-62.000,-73.750,-73.750) ENVELOPE(-64.967,-64.967,-66.517,-66.517) ENVELOPE(-62.000,-62.000,-74.000,-74.000) ENVELOPE(-26.000,-26.000,-79.833,-79.833) |
geographic |
Antarctic The Antarctic Antarctic Peninsula Weddell Sea Shackleton Weddell Ronne Ice Shelf Shackleton Range Pensacola Mountains Foundation Ice Stream Lassiter Slessor Lassiter Coast Slessor Glacier |
geographic_facet |
Antarctic The Antarctic Antarctic Peninsula Weddell Sea Shackleton Weddell Ronne Ice Shelf Shackleton Range Pensacola Mountains Foundation Ice Stream Lassiter Slessor Lassiter Coast Slessor Glacier |
genre |
Antarc* Antarctic Antarctic Peninsula Antarctica Foundation Ice Stream Ice Sheet Ice Shelf Ronne Ice Shelf Slessor Glacier The Cryosphere Weddell Sea |
genre_facet |
Antarc* Antarctic Antarctic Peninsula Antarctica Foundation Ice Stream Ice Sheet Ice Shelf Ronne Ice Shelf Slessor Glacier The Cryosphere Weddell Sea |
op_source |
The Cryosphere, Vol 13, Pp 2935-2951 (2019) |
op_relation |
https://www.the-cryosphere.net/13/2935/2019/tc-13-2935-2019.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 doi:10.5194/tc-13-2935-2019 1994-0416 1994-0424 https://doaj.org/article/880996a06713462ea2b30f256658634a |
op_doi |
https://doi.org/10.5194/tc-13-2935-2019 |
container_title |
The Cryosphere |
container_volume |
13 |
container_issue |
11 |
container_start_page |
2935 |
op_container_end_page |
2951 |
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1766267769905479680 |