Subglacial sediment deformation in the Ross Sea, Antarctica
Abstract:: The Ross Sea embayment is the outlet for one-third of all Antarctic ice flow, receiving input from both East and West Antarctica. Marine-based ice streams, whose stability is susceptible to global sea-level changes, expand and contract across the Ross Sea continental shelf, eroding and de...
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ftdoajarticles:oai:doaj.org/article:1fd876db358b4fdc94b507c12bdf6745 2023-05-15T13:41:22+02:00 Subglacial sediment deformation in the Ross Sea, Antarctica Delaney E. Robinson John Menzies Julia S. Wellner Rachel W. Clark 2021-10-01T00:00:00Z https://doi.org/10.1016/j.qsa.2021.100029 https://doaj.org/article/1fd876db358b4fdc94b507c12bdf6745 EN eng Elsevier http://www.sciencedirect.com/science/article/pii/S2666033421000083 https://doaj.org/toc/2666-0334 2666-0334 doi:10.1016/j.qsa.2021.100029 https://doaj.org/article/1fd876db358b4fdc94b507c12bdf6745 Quaternary Science Advances, Vol 4, Iss , Pp 100029- (2021) Last glacial maximum Antarctica Sedimentology-marine cores Subglacial deformation Microsedimentology Paleo-ice stream Geography. Anthropology. Recreation G Archaeology CC1-960 article 2021 ftdoajarticles https://doi.org/10.1016/j.qsa.2021.100029 2022-12-31T07:17:44Z Abstract:: The Ross Sea embayment is the outlet for one-third of all Antarctic ice flow, receiving input from both East and West Antarctica. Marine-based ice streams, whose stability is susceptible to global sea-level changes, expand and contract across the Ross Sea continental shelf, eroding and deforming the substrate and transporting sediment subglacially. Deposits from the Last Glacial Maximum in the western Ross Sea provide an opportunity to investigate paleo-ice stream processes using sediment cores associated with glacial landforms. This study combines micro-to macro-sedimentological analyses to characterize lithofacies that represent a glacial-interglacial succession. We observe subtle variations in sediment properties within the subglacial unit that suggest till heterogeneity. Physical characteristics that vary both laterally and vertically indicates different sediment response to glacial stress, resulting in non-pervasive deformation within the till. These observations are consistent with the interpretation that a dynamic ice sheet with variable flow regimes existed across the Ross Sea during the Last Glacial Maximum. Further microscopic evidence of dynamic subglacial conditions includes sediment aggregates preserved as discrete grains in the form of soft sediment clasts or till pellets. Till pellet-rich sediment is commonly associated with the transition from a subglacial to proximal glaciomarine environment, although here we demonstrate they are widespread in both facies. Their widespread occurrence downcore and distribution across the continental shelf provides sedimentological evidence of a deformable bed beneath an ice stream during the Last Glacial Maximum. Ultimately, better tools for discriminating between glacial deposits will allow for more detailed reconstructions of ice-sheet history, and thus determine the forcing mechanisms to which the ice is responding. Article in Journal/Newspaper Antarc* Antarctic Antarctica Ice Sheet Ross Sea West Antarctica Directory of Open Access Journals: DOAJ Articles Antarctic Ross Sea West Antarctica Quaternary Science Advances 4 100029 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Last glacial maximum Antarctica Sedimentology-marine cores Subglacial deformation Microsedimentology Paleo-ice stream Geography. Anthropology. Recreation G Archaeology CC1-960 |
spellingShingle |
Last glacial maximum Antarctica Sedimentology-marine cores Subglacial deformation Microsedimentology Paleo-ice stream Geography. Anthropology. Recreation G Archaeology CC1-960 Delaney E. Robinson John Menzies Julia S. Wellner Rachel W. Clark Subglacial sediment deformation in the Ross Sea, Antarctica |
topic_facet |
Last glacial maximum Antarctica Sedimentology-marine cores Subglacial deformation Microsedimentology Paleo-ice stream Geography. Anthropology. Recreation G Archaeology CC1-960 |
description |
Abstract:: The Ross Sea embayment is the outlet for one-third of all Antarctic ice flow, receiving input from both East and West Antarctica. Marine-based ice streams, whose stability is susceptible to global sea-level changes, expand and contract across the Ross Sea continental shelf, eroding and deforming the substrate and transporting sediment subglacially. Deposits from the Last Glacial Maximum in the western Ross Sea provide an opportunity to investigate paleo-ice stream processes using sediment cores associated with glacial landforms. This study combines micro-to macro-sedimentological analyses to characterize lithofacies that represent a glacial-interglacial succession. We observe subtle variations in sediment properties within the subglacial unit that suggest till heterogeneity. Physical characteristics that vary both laterally and vertically indicates different sediment response to glacial stress, resulting in non-pervasive deformation within the till. These observations are consistent with the interpretation that a dynamic ice sheet with variable flow regimes existed across the Ross Sea during the Last Glacial Maximum. Further microscopic evidence of dynamic subglacial conditions includes sediment aggregates preserved as discrete grains in the form of soft sediment clasts or till pellets. Till pellet-rich sediment is commonly associated with the transition from a subglacial to proximal glaciomarine environment, although here we demonstrate they are widespread in both facies. Their widespread occurrence downcore and distribution across the continental shelf provides sedimentological evidence of a deformable bed beneath an ice stream during the Last Glacial Maximum. Ultimately, better tools for discriminating between glacial deposits will allow for more detailed reconstructions of ice-sheet history, and thus determine the forcing mechanisms to which the ice is responding. |
format |
Article in Journal/Newspaper |
author |
Delaney E. Robinson John Menzies Julia S. Wellner Rachel W. Clark |
author_facet |
Delaney E. Robinson John Menzies Julia S. Wellner Rachel W. Clark |
author_sort |
Delaney E. Robinson |
title |
Subglacial sediment deformation in the Ross Sea, Antarctica |
title_short |
Subglacial sediment deformation in the Ross Sea, Antarctica |
title_full |
Subglacial sediment deformation in the Ross Sea, Antarctica |
title_fullStr |
Subglacial sediment deformation in the Ross Sea, Antarctica |
title_full_unstemmed |
Subglacial sediment deformation in the Ross Sea, Antarctica |
title_sort |
subglacial sediment deformation in the ross sea, antarctica |
publisher |
Elsevier |
publishDate |
2021 |
url |
https://doi.org/10.1016/j.qsa.2021.100029 https://doaj.org/article/1fd876db358b4fdc94b507c12bdf6745 |
geographic |
Antarctic Ross Sea West Antarctica |
geographic_facet |
Antarctic Ross Sea West Antarctica |
genre |
Antarc* Antarctic Antarctica Ice Sheet Ross Sea West Antarctica |
genre_facet |
Antarc* Antarctic Antarctica Ice Sheet Ross Sea West Antarctica |
op_source |
Quaternary Science Advances, Vol 4, Iss , Pp 100029- (2021) |
op_relation |
http://www.sciencedirect.com/science/article/pii/S2666033421000083 https://doaj.org/toc/2666-0334 2666-0334 doi:10.1016/j.qsa.2021.100029 https://doaj.org/article/1fd876db358b4fdc94b507c12bdf6745 |
op_doi |
https://doi.org/10.1016/j.qsa.2021.100029 |
container_title |
Quaternary Science Advances |
container_volume |
4 |
container_start_page |
100029 |
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1766149901098418176 |