Temperate Oligocene surface ocean conditions offshore of Cape Adare, Ross Sea, Antarctica
Antarctic continental ice masses fluctuated considerably during the Oligocene “coolhouse”, at elevated atmospheric CO 2 concentrations of ∼600 –800 ppm. To assess the role of the ocean in the Oligocene ice sheet variability, reconstruction of past ocean conditions in the proximity of the Antarctic m...
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ftdoajarticles:oai:doaj.org/article:54baa68ec1be408f9660bf9611fc14c1 2023-05-15T13:40:08+02:00 Temperate Oligocene surface ocean conditions offshore of Cape Adare, Ross Sea, Antarctica F. S. Hoem L. Valero D. Evangelinos C. Escutia B. Duncan R. M. McKay H. Brinkhuis F. Sangiorgi P. K. Bijl 2021-07-01T00:00:00Z https://doi.org/10.5194/cp-17-1423-2021 https://doaj.org/article/54baa68ec1be408f9660bf9611fc14c1 EN eng Copernicus Publications https://cp.copernicus.org/articles/17/1423/2021/cp-17-1423-2021.pdf https://doaj.org/toc/1814-9324 https://doaj.org/toc/1814-9332 doi:10.5194/cp-17-1423-2021 1814-9324 1814-9332 https://doaj.org/article/54baa68ec1be408f9660bf9611fc14c1 Climate of the Past, Vol 17, Pp 1423-1442 (2021) Environmental pollution TD172-193.5 Environmental protection TD169-171.8 Environmental sciences GE1-350 article 2021 ftdoajarticles https://doi.org/10.5194/cp-17-1423-2021 2022-12-31T13:24:14Z Antarctic continental ice masses fluctuated considerably during the Oligocene “coolhouse”, at elevated atmospheric CO 2 concentrations of ∼600 –800 ppm. To assess the role of the ocean in the Oligocene ice sheet variability, reconstruction of past ocean conditions in the proximity of the Antarctic margin is needed. While relatively warm ocean conditions have been reconstructed for the Oligocene offshore of Wilkes Land, the geographical extent of that warmth is unknown. In this study, we reconstruct past surface ocean conditions from glaciomarine sediments recovered from Deep Sea Drilling Project (DSDP) Site 274 offshore of the Ross Sea continental margin. This site, located offshore of Cape Adare is ideally situated to characterise Oligocene regional surface ocean conditions, as it is situated between the colder, higher-latitude Ross Sea continental shelf and the warm-temperate Wilkes Land margin in the Oligocene. We first improve the age model of DSDP Site 274 using integrated bio- and magnetostratigraphy. Subsequently, we analyse organic walled dinoflagellate cyst assemblages and lipid biomarkers (TEX 86 , TetraEther indeX of 86 carbon atoms) to reconstruct surface palaeoceanographic conditions during the Oligocene (33.7–24.4 Ma). Both TEX 86 -based sea surface temperature (SST) and microplankton results show temperate (10–17 ∘ C ± 5.2 ∘ C) surface ocean conditions at Site 274 throughout the Oligocene. Oceanographic conditions between the offshore Wilkes Land margin and Cape Adare became increasingly similar towards the late Oligocene (26.5–24.4 Ma); this is inferred to be the consequence of the widening of the Tasmanian Gateway, which resulted in more interconnected ocean basins and frontal systems. Maintaining marine terminations of terrestrial ice sheets in a proto-Ross Sea with offshore SSTs that are as warm as those suggested by our data requires a strong ice flux fed by intensive precipitation in the Antarctic hinterland during colder orbital states but with extensive surface melt of terrestrial ice ... Article in Journal/Newspaper Antarc* Antarctic Antarctica Ice Sheet Ross Sea Wilkes Land Directory of Open Access Journals: DOAJ Articles Antarctic The Antarctic Ross Sea Wilkes Land ENVELOPE(120.000,120.000,-69.000,-69.000) Adare ENVELOPE(170.233,170.233,-71.283,-71.283) Cape Adare ENVELOPE(175.000,175.000,-71.000,-71.000) Climate of the Past 17 4 1423 1442 |
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Open Polar |
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Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Environmental pollution TD172-193.5 Environmental protection TD169-171.8 Environmental sciences GE1-350 |
spellingShingle |
Environmental pollution TD172-193.5 Environmental protection TD169-171.8 Environmental sciences GE1-350 F. S. Hoem L. Valero D. Evangelinos C. Escutia B. Duncan R. M. McKay H. Brinkhuis F. Sangiorgi P. K. Bijl Temperate Oligocene surface ocean conditions offshore of Cape Adare, Ross Sea, Antarctica |
topic_facet |
Environmental pollution TD172-193.5 Environmental protection TD169-171.8 Environmental sciences GE1-350 |
description |
Antarctic continental ice masses fluctuated considerably during the Oligocene “coolhouse”, at elevated atmospheric CO 2 concentrations of ∼600 –800 ppm. To assess the role of the ocean in the Oligocene ice sheet variability, reconstruction of past ocean conditions in the proximity of the Antarctic margin is needed. While relatively warm ocean conditions have been reconstructed for the Oligocene offshore of Wilkes Land, the geographical extent of that warmth is unknown. In this study, we reconstruct past surface ocean conditions from glaciomarine sediments recovered from Deep Sea Drilling Project (DSDP) Site 274 offshore of the Ross Sea continental margin. This site, located offshore of Cape Adare is ideally situated to characterise Oligocene regional surface ocean conditions, as it is situated between the colder, higher-latitude Ross Sea continental shelf and the warm-temperate Wilkes Land margin in the Oligocene. We first improve the age model of DSDP Site 274 using integrated bio- and magnetostratigraphy. Subsequently, we analyse organic walled dinoflagellate cyst assemblages and lipid biomarkers (TEX 86 , TetraEther indeX of 86 carbon atoms) to reconstruct surface palaeoceanographic conditions during the Oligocene (33.7–24.4 Ma). Both TEX 86 -based sea surface temperature (SST) and microplankton results show temperate (10–17 ∘ C ± 5.2 ∘ C) surface ocean conditions at Site 274 throughout the Oligocene. Oceanographic conditions between the offshore Wilkes Land margin and Cape Adare became increasingly similar towards the late Oligocene (26.5–24.4 Ma); this is inferred to be the consequence of the widening of the Tasmanian Gateway, which resulted in more interconnected ocean basins and frontal systems. Maintaining marine terminations of terrestrial ice sheets in a proto-Ross Sea with offshore SSTs that are as warm as those suggested by our data requires a strong ice flux fed by intensive precipitation in the Antarctic hinterland during colder orbital states but with extensive surface melt of terrestrial ice ... |
format |
Article in Journal/Newspaper |
author |
F. S. Hoem L. Valero D. Evangelinos C. Escutia B. Duncan R. M. McKay H. Brinkhuis F. Sangiorgi P. K. Bijl |
author_facet |
F. S. Hoem L. Valero D. Evangelinos C. Escutia B. Duncan R. M. McKay H. Brinkhuis F. Sangiorgi P. K. Bijl |
author_sort |
F. S. Hoem |
title |
Temperate Oligocene surface ocean conditions offshore of Cape Adare, Ross Sea, Antarctica |
title_short |
Temperate Oligocene surface ocean conditions offshore of Cape Adare, Ross Sea, Antarctica |
title_full |
Temperate Oligocene surface ocean conditions offshore of Cape Adare, Ross Sea, Antarctica |
title_fullStr |
Temperate Oligocene surface ocean conditions offshore of Cape Adare, Ross Sea, Antarctica |
title_full_unstemmed |
Temperate Oligocene surface ocean conditions offshore of Cape Adare, Ross Sea, Antarctica |
title_sort |
temperate oligocene surface ocean conditions offshore of cape adare, ross sea, antarctica |
publisher |
Copernicus Publications |
publishDate |
2021 |
url |
https://doi.org/10.5194/cp-17-1423-2021 https://doaj.org/article/54baa68ec1be408f9660bf9611fc14c1 |
long_lat |
ENVELOPE(120.000,120.000,-69.000,-69.000) ENVELOPE(170.233,170.233,-71.283,-71.283) ENVELOPE(175.000,175.000,-71.000,-71.000) |
geographic |
Antarctic The Antarctic Ross Sea Wilkes Land Adare Cape Adare |
geographic_facet |
Antarctic The Antarctic Ross Sea Wilkes Land Adare Cape Adare |
genre |
Antarc* Antarctic Antarctica Ice Sheet Ross Sea Wilkes Land |
genre_facet |
Antarc* Antarctic Antarctica Ice Sheet Ross Sea Wilkes Land |
op_source |
Climate of the Past, Vol 17, Pp 1423-1442 (2021) |
op_relation |
https://cp.copernicus.org/articles/17/1423/2021/cp-17-1423-2021.pdf https://doaj.org/toc/1814-9324 https://doaj.org/toc/1814-9332 doi:10.5194/cp-17-1423-2021 1814-9324 1814-9332 https://doaj.org/article/54baa68ec1be408f9660bf9611fc14c1 |
op_doi |
https://doi.org/10.5194/cp-17-1423-2021 |
container_title |
Climate of the Past |
container_volume |
17 |
container_issue |
4 |
container_start_page |
1423 |
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1442 |
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