Sea ice and productivity changes over the last glacial cycle in the Adélie Land region, East Antarctica, based on diatom assemblage variability
Diatoms can provide important paleoenvironmental information about seasonal sea ice extent, productivity, sea surface temperature and ocean circulation variability, yet there are relatively few studies analysing the last glacial cycle near the Antarctic continent. This study examines diatom assembla...
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Copernicus Publications
2022
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ftnonlinearchiv:oai:noa.gwlb.de:cop_mods_00062757 2023-05-15T13:49:21+02:00 Sea ice and productivity changes over the last glacial cycle in the Adélie Land region, East Antarctica, based on diatom assemblage variability Pesjak, Lea McMinn, Andrew Chase, Zanna Bostock, Helen 2022-10 electronic https://doi.org/10.5194/egusphere-2022-1009 https://noa.gwlb.de/receive/cop_mods_00062757 https://egusphere.copernicus.org/preprints/egusphere-2022-1009/egusphere-2022-1009.pdf eng eng Copernicus Publications https://doi.org/10.5194/egusphere-2022-1009 https://noa.gwlb.de/receive/cop_mods_00062757 https://egusphere.copernicus.org/preprints/egusphere-2022-1009/egusphere-2022-1009.pdf https://creativecommons.org/licenses/by/4.0/ uneingeschränkt info:eu-repo/semantics/restrictedAccess CC-BY article Verlagsveröffentlichung article Text doc-type:article 2022 ftnonlinearchiv https://doi.org/10.5194/egusphere-2022-1009 2022-10-09T23:12:06Z Diatoms can provide important paleoenvironmental information about seasonal sea ice extent, productivity, sea surface temperature and ocean circulation variability, yet there are relatively few studies analysing the last glacial cycle near the Antarctic continent. This study examines diatom assemblages over the last glacial cycle from core TAN1302-44, from off Adélie Land, East Antarctica. Four distinct diatom assemblages were identified using principal components analyses. The PC 1 assemblage is associated with the interglacial, sedimentary facies, Facies 1, and comprises Thalassiosira lentiginosa, Actinocyclus actinochilus, Eucampia antarctica, Azpeitia tabularis and Asteromphalus hyalinus, suggesting that MIS 5e and Holocene interglacial time periods were characterised by seasonal sea ice environments with similar ocean temperature and circulation. The PC 2 assemblage is associated with the glacial, Facies 2, and comprises Fragilariopsis obliquecostata, Asteromphalus parvulus, Rhizosolenia styliformis, Thalassiosira tumida, Chaetoceros dichaeta, and a Eucampia antarctica terminal/intercalary ratio. This indicates that, during the MIS 4-2 glacial there was an increase in the length of the sea ice season compared with the interglacial period, yet still no permanent sea ice cover. The PC 2 assemblage is also associated with the glaciation and deglacial facies. There is an initial increase of PC 2 at the start of MIS 5d-a glaciation stage and then a gradual increase throughout late MIS 4-2, suggests that sea ice cover steadily increased reaching a maximum at the end of MIS 2. The PC 3 assemblage is associated with all four facies and comprises Actinocyclus ingens, Actinocyclus actinochilus, Thalassiosira oliverana and Fragilariopsis kerguelensis, suggesting that reworking of sediments and an influx of older sediments occurred throughout the last glacial cycle. Finally, the PC 4 assemblage is associated with the deglacial, glaciation, and glacial facies and comprises Fragilariopsis kerguelensis, Thalassiothrix ... Article in Journal/Newspaper Antarc* Antarctic Antarctica East Antarctica Sea ice Niedersächsisches Online-Archiv NOA Antarctic The Antarctic East Antarctica |
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collection |
Niedersächsisches Online-Archiv NOA |
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ftnonlinearchiv |
language |
English |
topic |
article Verlagsveröffentlichung |
spellingShingle |
article Verlagsveröffentlichung Pesjak, Lea McMinn, Andrew Chase, Zanna Bostock, Helen Sea ice and productivity changes over the last glacial cycle in the Adélie Land region, East Antarctica, based on diatom assemblage variability |
topic_facet |
article Verlagsveröffentlichung |
description |
Diatoms can provide important paleoenvironmental information about seasonal sea ice extent, productivity, sea surface temperature and ocean circulation variability, yet there are relatively few studies analysing the last glacial cycle near the Antarctic continent. This study examines diatom assemblages over the last glacial cycle from core TAN1302-44, from off Adélie Land, East Antarctica. Four distinct diatom assemblages were identified using principal components analyses. The PC 1 assemblage is associated with the interglacial, sedimentary facies, Facies 1, and comprises Thalassiosira lentiginosa, Actinocyclus actinochilus, Eucampia antarctica, Azpeitia tabularis and Asteromphalus hyalinus, suggesting that MIS 5e and Holocene interglacial time periods were characterised by seasonal sea ice environments with similar ocean temperature and circulation. The PC 2 assemblage is associated with the glacial, Facies 2, and comprises Fragilariopsis obliquecostata, Asteromphalus parvulus, Rhizosolenia styliformis, Thalassiosira tumida, Chaetoceros dichaeta, and a Eucampia antarctica terminal/intercalary ratio. This indicates that, during the MIS 4-2 glacial there was an increase in the length of the sea ice season compared with the interglacial period, yet still no permanent sea ice cover. The PC 2 assemblage is also associated with the glaciation and deglacial facies. There is an initial increase of PC 2 at the start of MIS 5d-a glaciation stage and then a gradual increase throughout late MIS 4-2, suggests that sea ice cover steadily increased reaching a maximum at the end of MIS 2. The PC 3 assemblage is associated with all four facies and comprises Actinocyclus ingens, Actinocyclus actinochilus, Thalassiosira oliverana and Fragilariopsis kerguelensis, suggesting that reworking of sediments and an influx of older sediments occurred throughout the last glacial cycle. Finally, the PC 4 assemblage is associated with the deglacial, glaciation, and glacial facies and comprises Fragilariopsis kerguelensis, Thalassiothrix ... |
format |
Article in Journal/Newspaper |
author |
Pesjak, Lea McMinn, Andrew Chase, Zanna Bostock, Helen |
author_facet |
Pesjak, Lea McMinn, Andrew Chase, Zanna Bostock, Helen |
author_sort |
Pesjak, Lea |
title |
Sea ice and productivity changes over the last glacial cycle in the Adélie Land region, East Antarctica, based on diatom assemblage variability |
title_short |
Sea ice and productivity changes over the last glacial cycle in the Adélie Land region, East Antarctica, based on diatom assemblage variability |
title_full |
Sea ice and productivity changes over the last glacial cycle in the Adélie Land region, East Antarctica, based on diatom assemblage variability |
title_fullStr |
Sea ice and productivity changes over the last glacial cycle in the Adélie Land region, East Antarctica, based on diatom assemblage variability |
title_full_unstemmed |
Sea ice and productivity changes over the last glacial cycle in the Adélie Land region, East Antarctica, based on diatom assemblage variability |
title_sort |
sea ice and productivity changes over the last glacial cycle in the adélie land region, east antarctica, based on diatom assemblage variability |
publisher |
Copernicus Publications |
publishDate |
2022 |
url |
https://doi.org/10.5194/egusphere-2022-1009 https://noa.gwlb.de/receive/cop_mods_00062757 https://egusphere.copernicus.org/preprints/egusphere-2022-1009/egusphere-2022-1009.pdf |
geographic |
Antarctic The Antarctic East Antarctica |
geographic_facet |
Antarctic The Antarctic East Antarctica |
genre |
Antarc* Antarctic Antarctica East Antarctica Sea ice |
genre_facet |
Antarc* Antarctic Antarctica East Antarctica Sea ice |
op_relation |
https://doi.org/10.5194/egusphere-2022-1009 https://noa.gwlb.de/receive/cop_mods_00062757 https://egusphere.copernicus.org/preprints/egusphere-2022-1009/egusphere-2022-1009.pdf |
op_rights |
https://creativecommons.org/licenses/by/4.0/ uneingeschränkt info:eu-repo/semantics/restrictedAccess |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.5194/egusphere-2022-1009 |
_version_ |
1766251239917486080 |