Neodymium and hafnium boundary contributions to seawater along the West Antarctic continental margin
Neodymium and hafnium isotopes and elemental concentrations (Sm, Nd, Hf, Zr) have been measured in three water column profiles south of the Antarctic Circumpolar Current in, and to the east of the Ross Sea, in conjunction with five bottom water samples from the Amundsen Sea Embayment. Neodymium and ha...
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Online Access: | https://epic.awi.de/id/eprint/35892/ http://www.sciencedirect.com/science/article/pii/S0012821X14001526 https://hdl.handle.net/10013/epic.43809 |
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ftawi:oai:epic.awi.de:35892 2024-09-15T17:39:12+00:00 Neodymium and hafnium boundary contributions to seawater along the West Antarctic continental margin Rickli, Jörg Gutjahr, Marcus Vance, Derek Fischer-Gödde, Mario Hillenbrand, Claus-Dieter Kuhn, Gerhard 2014-05-15 https://epic.awi.de/id/eprint/35892/ http://www.sciencedirect.com/science/article/pii/S0012821X14001526 https://hdl.handle.net/10013/epic.43809 unknown Elsevier Rickli, J. , Gutjahr, M. , Vance, D. , Fischer-Gödde, M. , Hillenbrand, C. D. and Kuhn, G. orcid:0000-0001-6069-7485 (2014) Neodymium and hafnium boundary contributions to seawater along the West Antarctic continental margin , Earth and Planetary Science Letters, 394 , pp. 99-110 . doi:10.1016/j.epsl.2014.03.008 <https://doi.org/10.1016/j.epsl.2014.03.008> , hdl:10013/epic.43809 EPIC3Earth and Planetary Science Letters, Elsevier, 394, pp. 99-110, ISSN: 0012-821X Article isiRev 2014 ftawi https://doi.org/10.1016/j.epsl.2014.03.008 2024-06-24T04:09:53Z Neodymium and hafnium isotopes and elemental concentrations (Sm, Nd, Hf, Zr) have been measured in three water column profiles south of the Antarctic Circumpolar Current in, and to the east of the Ross Sea, in conjunction with five bottom water samples from the Amundsen Sea Embayment. Neodymium and hafnium both appear to be released from sediments in the Embayment. In the case of Nd, this is reflected in radiogenic isotope compositions (εNd up to −5.4) and highly elevated concentrations (up to 41 pmol/kg). Hafnium isotopes, on the other hand, are only very slightly altered relative to the open ocean sites, and boundary release is most prominently indicated by elevated concentrations (>1 pmol/kg versus ∼0.7 pmol/kg). There is also a local input of both Hf and Nd at the Marie Byrd Seamounts, which leads to Nd isotope compositions as radiogenic as −3.1, and hafnium shifted to less radiogenic compositions in local bottom water. A compilation of the new data with literature data reveals a consistent view of the influence of Antarctica on the Nd isotope composition in Lower Circumpolar Deep Water (LCDW) and Antarctic Bottom Water (AABW). Sector specific Nd addition shifts AABW formed in the Atlantic sector to less radiogenic isotope compositions (average εNd = −9) relative to LCDW (average εNd = −8.4), whereas AABW in the Pacific sector is shifted to more radiogenic values (average εNd = −7). The evolution towards more radiogenic εNd with depth in LCDW in the Pacific sector is likely to reflect admixture of AABW but, in addition, is also controlled by boundary exchange with the slope as observed at the Marie Byrd Seamounts. Hafnium isotopes are relatively homogeneous in the data set, ranging between εHf = +2 and +3.8 for most samples, excluding less radiogenic compositions in deep waters close to the Marie Byrd Seamounts. The Hf isotope composition in the Pacific sector is, however, slightly less radiogenic than in the Atlantic, corresponding to an average of +3 relative to an average of +3.8. This probably reflects ... Article in Journal/Newspaper Amundsen Sea Antarc* Antarctic Antarctica Ross Sea Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center) Earth and Planetary Science Letters 394 99 110 |
institution |
Open Polar |
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Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center) |
op_collection_id |
ftawi |
language |
unknown |
description |
Neodymium and hafnium isotopes and elemental concentrations (Sm, Nd, Hf, Zr) have been measured in three water column profiles south of the Antarctic Circumpolar Current in, and to the east of the Ross Sea, in conjunction with five bottom water samples from the Amundsen Sea Embayment. Neodymium and hafnium both appear to be released from sediments in the Embayment. In the case of Nd, this is reflected in radiogenic isotope compositions (εNd up to −5.4) and highly elevated concentrations (up to 41 pmol/kg). Hafnium isotopes, on the other hand, are only very slightly altered relative to the open ocean sites, and boundary release is most prominently indicated by elevated concentrations (>1 pmol/kg versus ∼0.7 pmol/kg). There is also a local input of both Hf and Nd at the Marie Byrd Seamounts, which leads to Nd isotope compositions as radiogenic as −3.1, and hafnium shifted to less radiogenic compositions in local bottom water. A compilation of the new data with literature data reveals a consistent view of the influence of Antarctica on the Nd isotope composition in Lower Circumpolar Deep Water (LCDW) and Antarctic Bottom Water (AABW). Sector specific Nd addition shifts AABW formed in the Atlantic sector to less radiogenic isotope compositions (average εNd = −9) relative to LCDW (average εNd = −8.4), whereas AABW in the Pacific sector is shifted to more radiogenic values (average εNd = −7). The evolution towards more radiogenic εNd with depth in LCDW in the Pacific sector is likely to reflect admixture of AABW but, in addition, is also controlled by boundary exchange with the slope as observed at the Marie Byrd Seamounts. Hafnium isotopes are relatively homogeneous in the data set, ranging between εHf = +2 and +3.8 for most samples, excluding less radiogenic compositions in deep waters close to the Marie Byrd Seamounts. The Hf isotope composition in the Pacific sector is, however, slightly less radiogenic than in the Atlantic, corresponding to an average of +3 relative to an average of +3.8. This probably reflects ... |
format |
Article in Journal/Newspaper |
author |
Rickli, Jörg Gutjahr, Marcus Vance, Derek Fischer-Gödde, Mario Hillenbrand, Claus-Dieter Kuhn, Gerhard |
spellingShingle |
Rickli, Jörg Gutjahr, Marcus Vance, Derek Fischer-Gödde, Mario Hillenbrand, Claus-Dieter Kuhn, Gerhard Neodymium and hafnium boundary contributions to seawater along the West Antarctic continental margin |
author_facet |
Rickli, Jörg Gutjahr, Marcus Vance, Derek Fischer-Gödde, Mario Hillenbrand, Claus-Dieter Kuhn, Gerhard |
author_sort |
Rickli, Jörg |
title |
Neodymium and hafnium boundary contributions to seawater along the West Antarctic continental margin |
title_short |
Neodymium and hafnium boundary contributions to seawater along the West Antarctic continental margin |
title_full |
Neodymium and hafnium boundary contributions to seawater along the West Antarctic continental margin |
title_fullStr |
Neodymium and hafnium boundary contributions to seawater along the West Antarctic continental margin |
title_full_unstemmed |
Neodymium and hafnium boundary contributions to seawater along the West Antarctic continental margin |
title_sort |
neodymium and hafnium boundary contributions to seawater along the west antarctic continental margin |
publisher |
Elsevier |
publishDate |
2014 |
url |
https://epic.awi.de/id/eprint/35892/ http://www.sciencedirect.com/science/article/pii/S0012821X14001526 https://hdl.handle.net/10013/epic.43809 |
genre |
Amundsen Sea Antarc* Antarctic Antarctica Ross Sea |
genre_facet |
Amundsen Sea Antarc* Antarctic Antarctica Ross Sea |
op_source |
EPIC3Earth and Planetary Science Letters, Elsevier, 394, pp. 99-110, ISSN: 0012-821X |
op_relation |
Rickli, J. , Gutjahr, M. , Vance, D. , Fischer-Gödde, M. , Hillenbrand, C. D. and Kuhn, G. orcid:0000-0001-6069-7485 (2014) Neodymium and hafnium boundary contributions to seawater along the West Antarctic continental margin , Earth and Planetary Science Letters, 394 , pp. 99-110 . doi:10.1016/j.epsl.2014.03.008 <https://doi.org/10.1016/j.epsl.2014.03.008> , hdl:10013/epic.43809 |
op_doi |
https://doi.org/10.1016/j.epsl.2014.03.008 |
container_title |
Earth and Planetary Science Letters |
container_volume |
394 |
container_start_page |
99 |
op_container_end_page |
110 |
_version_ |
1810478107580170240 |