Water mass mixing versus local weathering inputs along the Bay of Biscay: Evidence from dissolved hafnium and neodymium isotopes
Highlights • Nd isotope data reflect advection and dilution of Mediterranean Outflow Water on its way north in the Bay of Biscay. • Combined Hf and Nd isotopes are a sensitive indicator of inputs from land as well as long distance advection and mixing. • Nd isotope results of this and earlier studie...
Published in: | Marine Chemistry |
---|---|
Main Authors: | , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Elsevier
2020
|
Subjects: | |
Online Access: | https://oceanrep.geomar.de/id/eprint/49956/ https://oceanrep.geomar.de/id/eprint/49956/1/Dausmann%20et%20al%202020.pdf https://doi.org/10.1016/j.marchem.2020.103844 |
id |
ftoceanrep:oai:oceanrep.geomar.de:49956 |
---|---|
record_format |
openpolar |
spelling |
ftoceanrep:oai:oceanrep.geomar.de:49956 2023-05-15T17:36:29+02:00 Water mass mixing versus local weathering inputs along the Bay of Biscay: Evidence from dissolved hafnium and neodymium isotopes Dausmann, Veit Frank, Martin Zieringer, Moritz 2020-08-20 text https://oceanrep.geomar.de/id/eprint/49956/ https://oceanrep.geomar.de/id/eprint/49956/1/Dausmann%20et%20al%202020.pdf https://doi.org/10.1016/j.marchem.2020.103844 en eng Elsevier https://oceanrep.geomar.de/id/eprint/49956/1/Dausmann%20et%20al%202020.pdf Dausmann, V. , Frank, M. and Zieringer, M. (2020) Water mass mixing versus local weathering inputs along the Bay of Biscay: Evidence from dissolved hafnium and neodymium isotopes. Marine Chemistry, 224 (Article number 103844). DOI 10.1016/j.marchem.2020.103844 <https://doi.org/10.1016/j.marchem.2020.103844>. doi:10.1016/j.marchem.2020.103844 info:eu-repo/semantics/restrictedAccess Article PeerReviewed 2020 ftoceanrep https://doi.org/10.1016/j.marchem.2020.103844 2023-04-07T15:50:56Z Highlights • Nd isotope data reflect advection and dilution of Mediterranean Outflow Water on its way north in the Bay of Biscay. • Combined Hf and Nd isotopes are a sensitive indicator of inputs from land as well as long distance advection and mixing. • Nd isotope results of this and earlier studies demonstrate the temporally variable flow path of Mediterranean Sea Water. We present dissolved neodymium and hafnium concentrations and isotope compositions of surface and deep-water masses from the Bay of Biscay. Neodymium isotope signatures in surface waters of the Bay of Biscay are mostly dominated by local weathering inputs from the surrounding continental margin. Subsurface Eastern North Atlantic Central Water (ENACW) shows a distinct Nd isotope signature (εNd ≅ −12) at the southwestern-most station and is significantly diluted by mixing with more radiogenic waters or shifted by inputs of relatively radiogenic particulate Nd on its way north along the European margin. Furthermore, the Nd isotope data clearly show a declining fraction of Mediterranean Sea Water (MSW) at intermediate depths on its way north indicating that only 40% to 60% of MSW still present in the mixture at the Galician margin arrive at the stations further north in the Bay of Biscay. An interannual variability of the flow path of MSW is identified when comparing the results of the Nd isotope compositions and salinity data of this study with those of earlier studies from the area. In agreement with Nd isotope and concentration analyses the Hf isotope composition of MSW is set by large-scale inputs of terrigenous material into the Mediterranean as can be deduced from elevated Hf concentrations still observable at the Galician margin. Hf isotope signatures of all water masses of the Bay of Biscay, moreover, are overprinted by local weathering inputs and do not reflect water mass mixing. However, combined dissolved Nd and Hf isotopes serve as indicators of local weathering influences on signatures expected from long distance water mass mixing. Article in Journal/Newspaper North Atlantic OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) Marine Chemistry 224 103844 |
institution |
Open Polar |
collection |
OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) |
op_collection_id |
ftoceanrep |
language |
English |
description |
Highlights • Nd isotope data reflect advection and dilution of Mediterranean Outflow Water on its way north in the Bay of Biscay. • Combined Hf and Nd isotopes are a sensitive indicator of inputs from land as well as long distance advection and mixing. • Nd isotope results of this and earlier studies demonstrate the temporally variable flow path of Mediterranean Sea Water. We present dissolved neodymium and hafnium concentrations and isotope compositions of surface and deep-water masses from the Bay of Biscay. Neodymium isotope signatures in surface waters of the Bay of Biscay are mostly dominated by local weathering inputs from the surrounding continental margin. Subsurface Eastern North Atlantic Central Water (ENACW) shows a distinct Nd isotope signature (εNd ≅ −12) at the southwestern-most station and is significantly diluted by mixing with more radiogenic waters or shifted by inputs of relatively radiogenic particulate Nd on its way north along the European margin. Furthermore, the Nd isotope data clearly show a declining fraction of Mediterranean Sea Water (MSW) at intermediate depths on its way north indicating that only 40% to 60% of MSW still present in the mixture at the Galician margin arrive at the stations further north in the Bay of Biscay. An interannual variability of the flow path of MSW is identified when comparing the results of the Nd isotope compositions and salinity data of this study with those of earlier studies from the area. In agreement with Nd isotope and concentration analyses the Hf isotope composition of MSW is set by large-scale inputs of terrigenous material into the Mediterranean as can be deduced from elevated Hf concentrations still observable at the Galician margin. Hf isotope signatures of all water masses of the Bay of Biscay, moreover, are overprinted by local weathering inputs and do not reflect water mass mixing. However, combined dissolved Nd and Hf isotopes serve as indicators of local weathering influences on signatures expected from long distance water mass mixing. |
format |
Article in Journal/Newspaper |
author |
Dausmann, Veit Frank, Martin Zieringer, Moritz |
spellingShingle |
Dausmann, Veit Frank, Martin Zieringer, Moritz Water mass mixing versus local weathering inputs along the Bay of Biscay: Evidence from dissolved hafnium and neodymium isotopes |
author_facet |
Dausmann, Veit Frank, Martin Zieringer, Moritz |
author_sort |
Dausmann, Veit |
title |
Water mass mixing versus local weathering inputs along the Bay of Biscay: Evidence from dissolved hafnium and neodymium isotopes |
title_short |
Water mass mixing versus local weathering inputs along the Bay of Biscay: Evidence from dissolved hafnium and neodymium isotopes |
title_full |
Water mass mixing versus local weathering inputs along the Bay of Biscay: Evidence from dissolved hafnium and neodymium isotopes |
title_fullStr |
Water mass mixing versus local weathering inputs along the Bay of Biscay: Evidence from dissolved hafnium and neodymium isotopes |
title_full_unstemmed |
Water mass mixing versus local weathering inputs along the Bay of Biscay: Evidence from dissolved hafnium and neodymium isotopes |
title_sort |
water mass mixing versus local weathering inputs along the bay of biscay: evidence from dissolved hafnium and neodymium isotopes |
publisher |
Elsevier |
publishDate |
2020 |
url |
https://oceanrep.geomar.de/id/eprint/49956/ https://oceanrep.geomar.de/id/eprint/49956/1/Dausmann%20et%20al%202020.pdf https://doi.org/10.1016/j.marchem.2020.103844 |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_relation |
https://oceanrep.geomar.de/id/eprint/49956/1/Dausmann%20et%20al%202020.pdf Dausmann, V. , Frank, M. and Zieringer, M. (2020) Water mass mixing versus local weathering inputs along the Bay of Biscay: Evidence from dissolved hafnium and neodymium isotopes. Marine Chemistry, 224 (Article number 103844). DOI 10.1016/j.marchem.2020.103844 <https://doi.org/10.1016/j.marchem.2020.103844>. doi:10.1016/j.marchem.2020.103844 |
op_rights |
info:eu-repo/semantics/restrictedAccess |
op_doi |
https://doi.org/10.1016/j.marchem.2020.103844 |
container_title |
Marine Chemistry |
container_volume |
224 |
container_start_page |
103844 |
_version_ |
1766135982733656064 |