The last glaciation of Bear Peninsula, central Amundsen Sea Embayment of Antarctica: Constraints on timing and duration revealed by in situ cosmogenic 14C and 10Be dating
Ice streams in the Pine Island-Thwaites region of West Antarctica currently dominate contributions to sea level rise from the Antarctic ice sheet. Predictions of future ice-mass loss from this area rely on physical models that are validated with geological constraints on past extent, thickness and t...
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ftnerc:oai:nora.nerc.ac.uk:516943 2023-05-15T13:23:47+02:00 The last glaciation of Bear Peninsula, central Amundsen Sea Embayment of Antarctica: Constraints on timing and duration revealed by in situ cosmogenic 14C and 10Be dating Johnson, Joanne S. Smith, James A. Schaefer, Joerg M. Young, Nicolas E. Goehring, Brent M. Hillenbrand, Claus-Dieter Lamp, Jennifer L. Finkel, Robert C. Gohl, Karsten 2017-12-15 text http://nora.nerc.ac.uk/id/eprint/516943/ https://nora.nerc.ac.uk/id/eprint/516943/1/Johnson.pdf https://www.sciencedirect.com/science/article/pii/S0277379116305364 en eng Elsevier https://nora.nerc.ac.uk/id/eprint/516943/1/Johnson.pdf Johnson, Joanne S. orcid:0000-0003-4537-4447 Smith, James A. orcid:0000-0002-1333-2544 Schaefer, Joerg M.; Young, Nicolas E.; Goehring, Brent M.; Hillenbrand, Claus-Dieter orcid:0000-0003-0240-7317 Lamp, Jennifer L.; Finkel, Robert C.; Gohl, Karsten. 2017 The last glaciation of Bear Peninsula, central Amundsen Sea Embayment of Antarctica: Constraints on timing and duration revealed by in situ cosmogenic 14C and 10Be dating. Quaternary Science Reviews, 178. 77-88. https://doi.org/10.1016/j.quascirev.2017.11.003 <https://doi.org/10.1016/j.quascirev.2017.11.003> cc_by_4 CC-BY Publication - Article PeerReviewed 2017 ftnerc https://doi.org/10.1016/j.quascirev.2017.11.003 2023-02-04T19:44:54Z Ice streams in the Pine Island-Thwaites region of West Antarctica currently dominate contributions to sea level rise from the Antarctic ice sheet. Predictions of future ice-mass loss from this area rely on physical models that are validated with geological constraints on past extent, thickness and timing of ice cover. However, terrestrial records of ice sheet history from the region remain sparse, resulting in significant model uncertainties. We report glacial-geological evidence for the duration and timing of the last glaciation of Hunt Bluff, in the central Amundsen Sea Embayment. A multi-nuclide approach was used, measuring cosmogenic 10Be and in situ14C in bedrock surfaces and a perched erratic cobble. Bedrock 10Be ages (118–144 ka) reflect multiple periods of exposure and ice-cover, not continuous exposure since the last interglacial as had previously been hypothesized. In situ14C dating suggests that the last glaciation of Hunt Bluff did not start until 21.1 ± 5.8 ka – probably during the Last Glacial Maximum – and finished by 9.6 ± 0.9 ka, at the same time as ice sheet retreat from the continental shelf was complete. Thickening of ice at Hunt Bluff most likely post-dated the maximum extent of grounded ice on the outer continental shelf. Flow re-organisation provides a possible explanation for this, with the date for onset of ice-cover at Hunt Bluff providing a minimum age for the timing of convergence of the Dotson and Getz tributaries to form a single palaeo-ice stream. This is the first time that timing of onset of ice cover has been constrained in the Amundsen Sea Embayment. Article in Journal/Newspaper Amundsen Sea Antarc* Antarctic Antarctica Ice Sheet Pine Island West Antarctica Natural Environment Research Council: NERC Open Research Archive Antarctic The Antarctic West Antarctica Amundsen Sea Getz ENVELOPE(-145.217,-145.217,-76.550,-76.550) Bear Peninsula ENVELOPE(-110.500,-110.500,-74.333,-74.333) Hunt Bluff ENVELOPE(-111.867,-111.867,-74.600,-74.600) Quaternary Science Reviews 178 77 88 |
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Open Polar |
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Natural Environment Research Council: NERC Open Research Archive |
op_collection_id |
ftnerc |
language |
English |
description |
Ice streams in the Pine Island-Thwaites region of West Antarctica currently dominate contributions to sea level rise from the Antarctic ice sheet. Predictions of future ice-mass loss from this area rely on physical models that are validated with geological constraints on past extent, thickness and timing of ice cover. However, terrestrial records of ice sheet history from the region remain sparse, resulting in significant model uncertainties. We report glacial-geological evidence for the duration and timing of the last glaciation of Hunt Bluff, in the central Amundsen Sea Embayment. A multi-nuclide approach was used, measuring cosmogenic 10Be and in situ14C in bedrock surfaces and a perched erratic cobble. Bedrock 10Be ages (118–144 ka) reflect multiple periods of exposure and ice-cover, not continuous exposure since the last interglacial as had previously been hypothesized. In situ14C dating suggests that the last glaciation of Hunt Bluff did not start until 21.1 ± 5.8 ka – probably during the Last Glacial Maximum – and finished by 9.6 ± 0.9 ka, at the same time as ice sheet retreat from the continental shelf was complete. Thickening of ice at Hunt Bluff most likely post-dated the maximum extent of grounded ice on the outer continental shelf. Flow re-organisation provides a possible explanation for this, with the date for onset of ice-cover at Hunt Bluff providing a minimum age for the timing of convergence of the Dotson and Getz tributaries to form a single palaeo-ice stream. This is the first time that timing of onset of ice cover has been constrained in the Amundsen Sea Embayment. |
format |
Article in Journal/Newspaper |
author |
Johnson, Joanne S. Smith, James A. Schaefer, Joerg M. Young, Nicolas E. Goehring, Brent M. Hillenbrand, Claus-Dieter Lamp, Jennifer L. Finkel, Robert C. Gohl, Karsten |
spellingShingle |
Johnson, Joanne S. Smith, James A. Schaefer, Joerg M. Young, Nicolas E. Goehring, Brent M. Hillenbrand, Claus-Dieter Lamp, Jennifer L. Finkel, Robert C. Gohl, Karsten The last glaciation of Bear Peninsula, central Amundsen Sea Embayment of Antarctica: Constraints on timing and duration revealed by in situ cosmogenic 14C and 10Be dating |
author_facet |
Johnson, Joanne S. Smith, James A. Schaefer, Joerg M. Young, Nicolas E. Goehring, Brent M. Hillenbrand, Claus-Dieter Lamp, Jennifer L. Finkel, Robert C. Gohl, Karsten |
author_sort |
Johnson, Joanne S. |
title |
The last glaciation of Bear Peninsula, central Amundsen Sea Embayment of Antarctica: Constraints on timing and duration revealed by in situ cosmogenic 14C and 10Be dating |
title_short |
The last glaciation of Bear Peninsula, central Amundsen Sea Embayment of Antarctica: Constraints on timing and duration revealed by in situ cosmogenic 14C and 10Be dating |
title_full |
The last glaciation of Bear Peninsula, central Amundsen Sea Embayment of Antarctica: Constraints on timing and duration revealed by in situ cosmogenic 14C and 10Be dating |
title_fullStr |
The last glaciation of Bear Peninsula, central Amundsen Sea Embayment of Antarctica: Constraints on timing and duration revealed by in situ cosmogenic 14C and 10Be dating |
title_full_unstemmed |
The last glaciation of Bear Peninsula, central Amundsen Sea Embayment of Antarctica: Constraints on timing and duration revealed by in situ cosmogenic 14C and 10Be dating |
title_sort |
last glaciation of bear peninsula, central amundsen sea embayment of antarctica: constraints on timing and duration revealed by in situ cosmogenic 14c and 10be dating |
publisher |
Elsevier |
publishDate |
2017 |
url |
http://nora.nerc.ac.uk/id/eprint/516943/ https://nora.nerc.ac.uk/id/eprint/516943/1/Johnson.pdf https://www.sciencedirect.com/science/article/pii/S0277379116305364 |
long_lat |
ENVELOPE(-145.217,-145.217,-76.550,-76.550) ENVELOPE(-110.500,-110.500,-74.333,-74.333) ENVELOPE(-111.867,-111.867,-74.600,-74.600) |
geographic |
Antarctic The Antarctic West Antarctica Amundsen Sea Getz Bear Peninsula Hunt Bluff |
geographic_facet |
Antarctic The Antarctic West Antarctica Amundsen Sea Getz Bear Peninsula Hunt Bluff |
genre |
Amundsen Sea Antarc* Antarctic Antarctica Ice Sheet Pine Island West Antarctica |
genre_facet |
Amundsen Sea Antarc* Antarctic Antarctica Ice Sheet Pine Island West Antarctica |
op_relation |
https://nora.nerc.ac.uk/id/eprint/516943/1/Johnson.pdf Johnson, Joanne S. orcid:0000-0003-4537-4447 Smith, James A. orcid:0000-0002-1333-2544 Schaefer, Joerg M.; Young, Nicolas E.; Goehring, Brent M.; Hillenbrand, Claus-Dieter orcid:0000-0003-0240-7317 Lamp, Jennifer L.; Finkel, Robert C.; Gohl, Karsten. 2017 The last glaciation of Bear Peninsula, central Amundsen Sea Embayment of Antarctica: Constraints on timing and duration revealed by in situ cosmogenic 14C and 10Be dating. Quaternary Science Reviews, 178. 77-88. https://doi.org/10.1016/j.quascirev.2017.11.003 <https://doi.org/10.1016/j.quascirev.2017.11.003> |
op_rights |
cc_by_4 |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.1016/j.quascirev.2017.11.003 |
container_title |
Quaternary Science Reviews |
container_volume |
178 |
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77 |
op_container_end_page |
88 |
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1766375253880078336 |