Variations of biogenic particle flux in the southern Atlantic section of the Subantarctic Front during the late Quaternary: Evidence from sedimentary 231Paex and 230Thex
Variations of intensity and composition of biogenic particle flux at the northern boundary of the present PolarFrontal Zone in the Atlantic sector of the Southern Ocean are indicators of major changes of paleoenvironmentalconditions on glacial/interglacial time scales during the Late Quaternary. In...
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1999
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Online Access: | https://oceanrep.geomar.de/id/eprint/1848/ https://oceanrep.geomar.de/id/eprint/1848/1/Asmus.pdf https://doi.org/10.1016/S0025-3227(98)00199-6 |
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ftoceanrep:oai:oceanrep.geomar.de:1848 2023-05-15T13:37:52+02:00 Variations of biogenic particle flux in the southern Atlantic section of the Subantarctic Front during the late Quaternary: Evidence from sedimentary 231Paex and 230Thex Asmus, T. Frank, Martin Koschmieder, C. Frank, N. Gersonde, R. Kuhn, G. Mangini, A. 1999 text https://oceanrep.geomar.de/id/eprint/1848/ https://oceanrep.geomar.de/id/eprint/1848/1/Asmus.pdf https://doi.org/10.1016/S0025-3227(98)00199-6 en eng Elsevier https://oceanrep.geomar.de/id/eprint/1848/1/Asmus.pdf Asmus, T., Frank, M. , Koschmieder, C., Frank, N., Gersonde, R., Kuhn, G. and Mangini, A. (1999) Variations of biogenic particle flux in the southern Atlantic section of the Subantarctic Front during the late Quaternary: Evidence from sedimentary 231Paex and 230Thex. Marine Geology, 159 . pp. 63-78. DOI 10.1016/S0025-3227(98)00199-6 <https://doi.org/10.1016/S0025-3227%2898%2900199-6>. doi:10.1016/S0025-3227(98)00199-6 info:eu-repo/semantics/restrictedAccess Article PeerReviewed 1999 ftoceanrep https://doi.org/10.1016/S0025-3227(98)00199-6 2023-04-07T14:44:40Z Variations of intensity and composition of biogenic particle flux at the northern boundary of the present PolarFrontal Zone in the Atlantic sector of the Southern Ocean are indicators of major changes of paleoenvironmentalconditions on glacial/interglacial time scales during the Late Quaternary. In order to estimate those pastchanges, sediment accumulation patterns of two piston cores, one from just north and one just south of thepresent day position of the Subantarctic Front were reconstructed. Using the 230Thex method large contributionsof laterally supplied material were quantified and used to correct sediment accumulation rates. During the lastglacial focussing of biogenic opal-dominated material exceeded the original contribution from the surfacewater above by a maximum factor of 8.7. The initial activity ratio of 231Paex/230Thex was used as tracer forbiogenic particle flux and composition and indicates that during the glacial stages 2 and 4 the area of high opalproductivity was situated above the location of the southern core whereas the northern core has not beenreached by this northward shift during the last 130 kyr as shown by the pattern of focussing-corrected bulkaccumulation rates. If the position of the Antarctic Polar Front has remained at the northern boundary of thehigh opal productivity area during the last 130 kyr, the results suggest that was located exactly between thetwo core sites during glacial stages 2 and 4. A two-box modeling approach involving particle flux and boundaryscavenging intensity of 231Pa was applied to estimate the possible range of the 231Paex/230Thex ratio recordedin Southern Ocean sediments. Previous estimates on the export of 231Pa from the Atlantic into the SouthernOcean are corroborated but the model suggests a low sensitivity of the 231Paex/230Thex ratio in Southern Oceansediments to variations of the residence time of North Atlantic Deep Water in the Atlantic Ocean. Article in Journal/Newspaper Antarc* Antarctic North Atlantic Deep Water North Atlantic Southern Ocean OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) Antarctic Southern Ocean The Antarctic Marine Geology 159 1-4 63 78 |
institution |
Open Polar |
collection |
OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) |
op_collection_id |
ftoceanrep |
language |
English |
description |
Variations of intensity and composition of biogenic particle flux at the northern boundary of the present PolarFrontal Zone in the Atlantic sector of the Southern Ocean are indicators of major changes of paleoenvironmentalconditions on glacial/interglacial time scales during the Late Quaternary. In order to estimate those pastchanges, sediment accumulation patterns of two piston cores, one from just north and one just south of thepresent day position of the Subantarctic Front were reconstructed. Using the 230Thex method large contributionsof laterally supplied material were quantified and used to correct sediment accumulation rates. During the lastglacial focussing of biogenic opal-dominated material exceeded the original contribution from the surfacewater above by a maximum factor of 8.7. The initial activity ratio of 231Paex/230Thex was used as tracer forbiogenic particle flux and composition and indicates that during the glacial stages 2 and 4 the area of high opalproductivity was situated above the location of the southern core whereas the northern core has not beenreached by this northward shift during the last 130 kyr as shown by the pattern of focussing-corrected bulkaccumulation rates. If the position of the Antarctic Polar Front has remained at the northern boundary of thehigh opal productivity area during the last 130 kyr, the results suggest that was located exactly between thetwo core sites during glacial stages 2 and 4. A two-box modeling approach involving particle flux and boundaryscavenging intensity of 231Pa was applied to estimate the possible range of the 231Paex/230Thex ratio recordedin Southern Ocean sediments. Previous estimates on the export of 231Pa from the Atlantic into the SouthernOcean are corroborated but the model suggests a low sensitivity of the 231Paex/230Thex ratio in Southern Oceansediments to variations of the residence time of North Atlantic Deep Water in the Atlantic Ocean. |
format |
Article in Journal/Newspaper |
author |
Asmus, T. Frank, Martin Koschmieder, C. Frank, N. Gersonde, R. Kuhn, G. Mangini, A. |
spellingShingle |
Asmus, T. Frank, Martin Koschmieder, C. Frank, N. Gersonde, R. Kuhn, G. Mangini, A. Variations of biogenic particle flux in the southern Atlantic section of the Subantarctic Front during the late Quaternary: Evidence from sedimentary 231Paex and 230Thex |
author_facet |
Asmus, T. Frank, Martin Koschmieder, C. Frank, N. Gersonde, R. Kuhn, G. Mangini, A. |
author_sort |
Asmus, T. |
title |
Variations of biogenic particle flux in the southern Atlantic section of the Subantarctic Front during the late Quaternary: Evidence from sedimentary 231Paex and 230Thex |
title_short |
Variations of biogenic particle flux in the southern Atlantic section of the Subantarctic Front during the late Quaternary: Evidence from sedimentary 231Paex and 230Thex |
title_full |
Variations of biogenic particle flux in the southern Atlantic section of the Subantarctic Front during the late Quaternary: Evidence from sedimentary 231Paex and 230Thex |
title_fullStr |
Variations of biogenic particle flux in the southern Atlantic section of the Subantarctic Front during the late Quaternary: Evidence from sedimentary 231Paex and 230Thex |
title_full_unstemmed |
Variations of biogenic particle flux in the southern Atlantic section of the Subantarctic Front during the late Quaternary: Evidence from sedimentary 231Paex and 230Thex |
title_sort |
variations of biogenic particle flux in the southern atlantic section of the subantarctic front during the late quaternary: evidence from sedimentary 231paex and 230thex |
publisher |
Elsevier |
publishDate |
1999 |
url |
https://oceanrep.geomar.de/id/eprint/1848/ https://oceanrep.geomar.de/id/eprint/1848/1/Asmus.pdf https://doi.org/10.1016/S0025-3227(98)00199-6 |
geographic |
Antarctic Southern Ocean The Antarctic |
geographic_facet |
Antarctic Southern Ocean The Antarctic |
genre |
Antarc* Antarctic North Atlantic Deep Water North Atlantic Southern Ocean |
genre_facet |
Antarc* Antarctic North Atlantic Deep Water North Atlantic Southern Ocean |
op_relation |
https://oceanrep.geomar.de/id/eprint/1848/1/Asmus.pdf Asmus, T., Frank, M. , Koschmieder, C., Frank, N., Gersonde, R., Kuhn, G. and Mangini, A. (1999) Variations of biogenic particle flux in the southern Atlantic section of the Subantarctic Front during the late Quaternary: Evidence from sedimentary 231Paex and 230Thex. Marine Geology, 159 . pp. 63-78. DOI 10.1016/S0025-3227(98)00199-6 <https://doi.org/10.1016/S0025-3227%2898%2900199-6>. doi:10.1016/S0025-3227(98)00199-6 |
op_rights |
info:eu-repo/semantics/restrictedAccess |
op_doi |
https://doi.org/10.1016/S0025-3227(98)00199-6 |
container_title |
Marine Geology |
container_volume |
159 |
container_issue |
1-4 |
container_start_page |
63 |
op_container_end_page |
78 |
_version_ |
1766098475094638592 |