Mid-Holocene thinning of David Glacier, Antarctica: Chronology and Controls
Quantitative satellite observations provide a comprehensive assessment of ice sheet mass loss over the last four decades, but limited insights into long-term drivers of ice sheet change. Geological records can extend the observational record and aid our understanding of ice sheet–climate interaction...
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ftcopernicus:oai:publications.copernicus.org:tcd89996 2023-05-15T13:31:39+02:00 Mid-Holocene thinning of David Glacier, Antarctica: Chronology and Controls Stutz, Jamey Mackintosh, Andrew Norton, Kevin Whitmore, Ross Baroni, Carlo Jamieson, Stewart S. R. Jones, R. Selwyn Balco, Greg Salvatore, Maria Cristina Casale, Stefano Lee, Jae Il Seong, Yeong Bae Rhee, Hyun Hee McKay, Robert Vargo, Lauren J. Lowry, Daniel Spector, Perry Cristl, Marcus Ivy Ochs, Susan Nicola, Luigia Iarossi, Maria Stuart, Finlay Woodruff, Tom 2020-10-17 application/pdf https://doi.org/10.5194/tc-2020-284 https://tc.copernicus.org/preprints/tc-2020-284/ eng eng doi:10.5194/tc-2020-284 https://tc.copernicus.org/preprints/tc-2020-284/ eISSN: 1994-0424 Text 2020 ftcopernicus https://doi.org/10.5194/tc-2020-284 2020-10-19T16:22:13Z Quantitative satellite observations provide a comprehensive assessment of ice sheet mass loss over the last four decades, but limited insights into long-term drivers of ice sheet change. Geological records can extend the observational record and aid our understanding of ice sheet–climate interactions. Here we present the first millennial-scale reconstruction of David Glacier, the largest East Antarctic outlet glacier in Victoria Land. We use surface exposure dating of glacial erratics deposited on nunataks to reconstruct changes in ice surface elevation through time. We then use numerical modelling experiments to determine the drivers of glacial thinning. Thinning profiles derived from 45 10 Be and 3 He surface exposure ages show that David Glacier experienced rapid thinning up to 2 m/yr during the mid-Holocene (~ 6,500 years ago). Thinning stabilised at 6 kyr, suggesting initial formation of the Drygalski Ice Tongue at this time. Our work, along with terrestrial cosmogenic nuclide records from adjacent glaciers, shows simultaneous glacier thinning in this sector of the Transantarctic Mountains occurred ~ 3 kyr after the retreat of marine-based grounded ice in the western Ross Embayment. The timing and rapidity of the reconstructed thinning at David Glacier is similar to reconstructions in the Amundsen and Weddell embayments. In order to identify the potential causes of these rapid changes along the David Glacier, we use a glacier flow line model designed for calving glaciers and compare modelled results against our geological data. We show that glacier thinning and marine-based grounding line retreat is initiated by interactions between enhanced sub-ice shelf melting and reduced lateral buttressing, leading to Marine Ice Sheet Instability. Such rapid glacier thinning events are not captured in continental or sector-scale numerical modelling reconstructions for this period. Together, our chronology and modelling suggest a ~ 2,000-year period of dynamic thinning in the recent geological past. Text Antarc* Antarctic Antarctica David Glacier Ice Sheet Ice Shelf Victoria Land Copernicus Publications: E-Journals Antarctic David Glacier ENVELOPE(160.000,160.000,-75.333,-75.333) Drygalski ENVELOPE(-61.000,-61.000,-64.717,-64.717) Drygalski Ice Tongue ENVELOPE(163.500,163.500,-75.400,-75.400) Transantarctic Mountains Victoria Land Weddell |
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Open Polar |
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Copernicus Publications: E-Journals |
op_collection_id |
ftcopernicus |
language |
English |
description |
Quantitative satellite observations provide a comprehensive assessment of ice sheet mass loss over the last four decades, but limited insights into long-term drivers of ice sheet change. Geological records can extend the observational record and aid our understanding of ice sheet–climate interactions. Here we present the first millennial-scale reconstruction of David Glacier, the largest East Antarctic outlet glacier in Victoria Land. We use surface exposure dating of glacial erratics deposited on nunataks to reconstruct changes in ice surface elevation through time. We then use numerical modelling experiments to determine the drivers of glacial thinning. Thinning profiles derived from 45 10 Be and 3 He surface exposure ages show that David Glacier experienced rapid thinning up to 2 m/yr during the mid-Holocene (~ 6,500 years ago). Thinning stabilised at 6 kyr, suggesting initial formation of the Drygalski Ice Tongue at this time. Our work, along with terrestrial cosmogenic nuclide records from adjacent glaciers, shows simultaneous glacier thinning in this sector of the Transantarctic Mountains occurred ~ 3 kyr after the retreat of marine-based grounded ice in the western Ross Embayment. The timing and rapidity of the reconstructed thinning at David Glacier is similar to reconstructions in the Amundsen and Weddell embayments. In order to identify the potential causes of these rapid changes along the David Glacier, we use a glacier flow line model designed for calving glaciers and compare modelled results against our geological data. We show that glacier thinning and marine-based grounding line retreat is initiated by interactions between enhanced sub-ice shelf melting and reduced lateral buttressing, leading to Marine Ice Sheet Instability. Such rapid glacier thinning events are not captured in continental or sector-scale numerical modelling reconstructions for this period. Together, our chronology and modelling suggest a ~ 2,000-year period of dynamic thinning in the recent geological past. |
format |
Text |
author |
Stutz, Jamey Mackintosh, Andrew Norton, Kevin Whitmore, Ross Baroni, Carlo Jamieson, Stewart S. R. Jones, R. Selwyn Balco, Greg Salvatore, Maria Cristina Casale, Stefano Lee, Jae Il Seong, Yeong Bae Rhee, Hyun Hee McKay, Robert Vargo, Lauren J. Lowry, Daniel Spector, Perry Cristl, Marcus Ivy Ochs, Susan Nicola, Luigia Iarossi, Maria Stuart, Finlay Woodruff, Tom |
spellingShingle |
Stutz, Jamey Mackintosh, Andrew Norton, Kevin Whitmore, Ross Baroni, Carlo Jamieson, Stewart S. R. Jones, R. Selwyn Balco, Greg Salvatore, Maria Cristina Casale, Stefano Lee, Jae Il Seong, Yeong Bae Rhee, Hyun Hee McKay, Robert Vargo, Lauren J. Lowry, Daniel Spector, Perry Cristl, Marcus Ivy Ochs, Susan Nicola, Luigia Iarossi, Maria Stuart, Finlay Woodruff, Tom Mid-Holocene thinning of David Glacier, Antarctica: Chronology and Controls |
author_facet |
Stutz, Jamey Mackintosh, Andrew Norton, Kevin Whitmore, Ross Baroni, Carlo Jamieson, Stewart S. R. Jones, R. Selwyn Balco, Greg Salvatore, Maria Cristina Casale, Stefano Lee, Jae Il Seong, Yeong Bae Rhee, Hyun Hee McKay, Robert Vargo, Lauren J. Lowry, Daniel Spector, Perry Cristl, Marcus Ivy Ochs, Susan Nicola, Luigia Iarossi, Maria Stuart, Finlay Woodruff, Tom |
author_sort |
Stutz, Jamey |
title |
Mid-Holocene thinning of David Glacier, Antarctica: Chronology and Controls |
title_short |
Mid-Holocene thinning of David Glacier, Antarctica: Chronology and Controls |
title_full |
Mid-Holocene thinning of David Glacier, Antarctica: Chronology and Controls |
title_fullStr |
Mid-Holocene thinning of David Glacier, Antarctica: Chronology and Controls |
title_full_unstemmed |
Mid-Holocene thinning of David Glacier, Antarctica: Chronology and Controls |
title_sort |
mid-holocene thinning of david glacier, antarctica: chronology and controls |
publishDate |
2020 |
url |
https://doi.org/10.5194/tc-2020-284 https://tc.copernicus.org/preprints/tc-2020-284/ |
long_lat |
ENVELOPE(160.000,160.000,-75.333,-75.333) ENVELOPE(-61.000,-61.000,-64.717,-64.717) ENVELOPE(163.500,163.500,-75.400,-75.400) |
geographic |
Antarctic David Glacier Drygalski Drygalski Ice Tongue Transantarctic Mountains Victoria Land Weddell |
geographic_facet |
Antarctic David Glacier Drygalski Drygalski Ice Tongue Transantarctic Mountains Victoria Land Weddell |
genre |
Antarc* Antarctic Antarctica David Glacier Ice Sheet Ice Shelf Victoria Land |
genre_facet |
Antarc* Antarctic Antarctica David Glacier Ice Sheet Ice Shelf Victoria Land |
op_source |
eISSN: 1994-0424 |
op_relation |
doi:10.5194/tc-2020-284 https://tc.copernicus.org/preprints/tc-2020-284/ |
op_doi |
https://doi.org/10.5194/tc-2020-284 |
_version_ |
1766019754726785024 |